Genetic information is transcribed from genomic DNA to mRNA,which is then translated into threedimensional proteins.mRNAs can undergo various post-transcriptional modifications,including RNA editing that alters mRNA s...Genetic information is transcribed from genomic DNA to mRNA,which is then translated into threedimensional proteins.mRNAs can undergo various post-transcriptional modifications,including RNA editing that alters mRNA sequences,ultimately affecting protein function.In this study,RNA editing was identified at the 499th base(c.499)of human vaccinia-related kinase 2(VRK2).This RNA editing changes the amino acid in the catalytic domain of VRK2 from isoleucine(with adenine base)to valine(with guanine base).Isoleucine-containing VRK2 has higher kinase activity than the valine-containing VRK2,which leads to an increase in tumor cell proliferation.Earlier we reported that VRK2 directly interacts with dystrobrevin-binding protein(dysbindin)and results in reducing its stability.Herein,we demonstrate that isoleucine-containing VRK2 decreases the level of dysbindin than valinecontaining VRK2.Dysbindin interacts with cyclin D and thereby regulates its expression and function.The reduction in the level of dysbindin by isoleucine-containing VRK2 further enhances the cyclin D expression,resulting in increased tumor growth and reduction in survival rates.It has also been observed that in patient samples,VRK2 level was elevated in breast cancer tissue compared to normal breast tissue.Additionally,the isoleucine form of VRK2 exhibited a greater increase in breast cancer tissue.Therefore,it is concluded that VRK2,especially dependent on the 167th variant amino acid,can be one of the indexes of tumor progression and proliferation.展开更多
The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to al...The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to alterations in neuronal tissue that occur during the aging process. The normal aging process may be conceived of as the neuronal cell’s increasing inability to maintain normal cellular function which ultimately results in a number of morphological and biochemical changes. Morphologically, there is a loss of neuronal cells with increasing age (Brizzee and展开更多
BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its d...BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its damage is an important indicator of DR.Receptor for activated C kinase 1(RACK1)activates protein kinase C-ε(PKC-ε)to promote the generation of reactive oxygen species(ROS)in RPE cells,leading to apoptosis.Therefore,we hypothesize that the activation of RACK1 under hypoxic/high-glucose conditions may promote RPE cell apoptosis by modulating PKC-ε/ROS,thereby disrupting the barrier effect of the outer blood retinal barrier and contributing to the progression of DR.AIM To investigate the role and associated underlying mechanisms of RACK1 in the development of early DR.METHODS In this study,Sprague-Dawley rats and adult RPE cell line-19(ARPE-19)cells were used as in vivo and in vitro models,respectively,to explore the role of RACK1 in mediating PKC-εin early DR.Furthermore,the impact of RACK1 on apoptosis and barrier function of RPE cells was also investigated in the former model.RESULTS Streptozotocin-induced diabetic rats showed increased apoptosis and upregulated expression of RACK1 and PKC-εproteins in RPE cells following a prolonged modeling.Similarly,ARPE-19 cells exposed to high glucose and hypoxia displayed elevated mRNA and protein levels of RACK1 and PKC-ε,accompanied by an increases in ROS production,apoptosis rate,and monolayer permeability.However,silencing RACK1 significantly downregulated the expression of PKC-εand ROS,reduced cell apoptosis and permeability,and protected barrier function.CONCLUSION RACK1 plays a significant role in the development of early DR and might serve as a potential therapeutic target for DR by regulating RPE apoptosis and barrier function.展开更多
Background:Galectin 2(LGALS2)is a protein previously reported to serve as a mediator of disease progression in a range of cancers.The function of LGALS2 in oral squamous cell carcinoma(OSCC),however,has yet to be expl...Background:Galectin 2(LGALS2)is a protein previously reported to serve as a mediator of disease progression in a range of cancers.The function of LGALS2 in oral squamous cell carcinoma(OSCC),however,has yet to be explored,prompting the present study to address this literature gap.Methods:Overall,144 paired malignant tumor tissues and paracancerous OSCC patient samples were harvested and the LGALS2 expression levels were examined through qPCR and western immunoblotting.The LGALS2 coding sequence was introduced into the pcDNA3.0 vector,to enable the overexpression of this gene,while an LGALS2-specific shRNA and corresponding controls were also obtained.The functionality of LGALS2 as a regulator of the ability of OSCC cells to grow and undergo apoptotic death in vitro was assessed through EdU uptake and CCK-8 assays,and flow cytometer,whereas a Transwell system was used to assess migratory activity and invasivity.An agonist of the Janus Kinase 2(JAK2)/Signal Transducer and Activator of Transcription 3(STAT3)pathway was also used to assess the role of this pathway in the context of LGALS2 signaling.Results:Here,we found that lower LGALS2 protein and mRNA expression were evident in OSCC tumor tissue samples,and these expression levels were associated with clinicopathological characteristics and patient survival outcomes.Silencing LGALS2 enhanced proliferation in OSCC cells while rendering these cells better able to resist apoptosis.The opposite was instead observed after LGALS2 was overexpressed.Mechanistically,the ability of LGALS2 to suppress the progression of OSCC was related to its ability to activate the JAK/STAT3 signaling axis.Conclusion:Those results suggest a role for LGALS2 as a suppressor of OSCC progression through its ability to modulate JAK/STAT3 signaling,supporting the potential utility of LGALS2 as a target for efforts aimed at treating OSCC patients.展开更多
Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has ...Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.展开更多
BACKGROUND Leukemia stem cells(LSCs)are found to be one of the main factors contributing to poor therapeutic effects in acute myeloid leukemia(AML),as they are protected by the bone marrow microenvironment(BMM)against...BACKGROUND Leukemia stem cells(LSCs)are found to be one of the main factors contributing to poor therapeutic effects in acute myeloid leukemia(AML),as they are protected by the bone marrow microenvironment(BMM)against conventional therapies.Gossypol acetic acid(GAA),which is extracted from the seeds of cotton plants,exerts anti-tumor roles in several types of cancer and has been reported to induce apoptosis of LSCs by inhibiting Bcl2.AIM To investigate the exact roles of GAA in regulating LSCs under different microenvironments and the exact mechanism.METHODS In this study,LSCs were magnetically sorted from AML cell lines and the CD34+CD38-population was obtained.The expression of leucine-rich pentatricopeptide repeat-containing protein(LRPPRC)and forkhead box M1(FOXM1)was evaluated in LSCs,and the effects of GAA on malignancies and mitochondrial RESULTS LRPPRC was found to be upregulated,and GAA inhibited cell proliferation by degrading LRPPRC.GAA induced LRPPRC degradation and inhibited the activation of interleukin 6(IL-6)/janus kinase(JAK)1/signal transducer and activator of transcription(STAT)3 signaling,enhancing chemosensitivity in LSCs against conventional chemotherapies,including L-Asparaginase,Dexamethasone,and cytarabine.GAA was also found to downregulate FOXM1 indirectly by regulating LRPPRC.Furthermore,GAA induced reactive oxygen species accumulation,disturbed mitochondrial homeostasis,and caused mitochondrial dysfunction.By inhibiting IL-6/JAK1/STAT3 signaling via degrading LRPPRC,GAA resulted in the elimination of LSCs.Meanwhile,GAA induced oxidative stress and subsequent cell damage by causing mitochondrial damage.CONCLUSION Taken together,the results indicate that GAA might overcome the BMM protective effect and be considered as a novel and effective combination therapy for AML.展开更多
Src regulates cell adhesion, invasiveness, motility and growth in cancer cells. In melanoma, accumulating data show that Src inhibition can be effective and may enhance the effects of other agents. Increased Src expre...Src regulates cell adhesion, invasiveness, motility and growth in cancer cells. In melanoma, accumulating data show that Src inhibition can be effective and may enhance the effects of other agents. Increased Src expression and activity thus has recently become a target for drug therapy. Several melanoma cell lines were exposed to inhibitors of Src activity despite their broad specificity. To examine the particular activity of Src in human melanoma cells, we used SU6656, the selective inhibitor of Src family protein kinases. The activity of Src and cell proliferation were suppressed in HBL human cells, wild type melanoma cells and in SK-MEL-5 human melanoma cells harboring mutant BRAF V600E, upon their treatment with SU6656. The suppression of Src kinase activity had not inhibitory effects on Akt/PKB activity in SK-MEL-5 cells, which we have previously found in HBL cells. This may indicate that changes of Src involvement in the control of Akt/PKB activity and its downstream signaling could be induced by BRAF V600E mutation in SK-MEL-5 cells.展开更多
Dendritic cells (DCs) are the most potent antigen-presen ting cells that play crucial roles in the regulation of immune response. Triptol ide, an active component purified from the medicinal plant Tripterygium wilfor ...Dendritic cells (DCs) are the most potent antigen-presen ting cells that play crucial roles in the regulation of immune response. Triptol ide, an active component purified from the medicinal plant Tripterygium wilfor dii Hook F., has been demonstrated to act as a potent immunosuppressive drug c apab le of inhibiting T cell activation and proliferation. However, little is known a bout the effects of triptolide on DCs. The present study shows that triptolide d oes not affect phenotypic differentiation and LPS-induced maturation of murine DCs. But triptolide can dramatically reduce cell recovery by inducing apoptosis of DCs at concentration as low as 10 ng/ml, as demonstrated by phosphatidylserin e exposure, mitochondria potential decrease, and nuclear DNA condensation. Tript olide induces activation of p38 in DCs, which precedes the activation of caspase 3. SB203580, a specific kinase inhibitor for p38, can block the activation of caspase 3 and inhibit the resultant apoptosis of DCs. Our results suggest that t he anti-inflammatory and immunosuppressive activities of triptolide may be due, in part, to its apoptosis-inducing effects on DCs.展开更多
Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase...Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase (p38 MAPK) pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin (30 mg/kg) for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.展开更多
The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury(IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for ...The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury(IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for 60 min followed by reperfusion for 24 h. Eighteen male C57BL/6 mice were randomly divided into three groups: sham-operated group(sham), IRI+saline group(IRI group), IRI+Fenofibrate(FEN) group. Normal saline or Fenofibrate(3 mg/kg) was intravenously injected 60 min before renal ischemia in IRI group and FEN group, respectively. Blood samples and renal tissues were collected at the end of reperfusion. The renal function, histopathologic changes, and the expression levels of pro-inflammatory cytokines [interleukin-8(IL-8), tumor necrosis factor alpha(TNF-α) and IL-6] in serum and renal tissue homogenate were assessed. Moreover, the effects of Fenofibrate on activating phosphoinositide 3 kinase/protein kinase B(PI3K/Akt) signaling and peroxisome proliferator-activated receptor-α(PPAR-α) were also measured in renal IRI. The results showed that plasma levels of blood urea nitrogen and creatinine, histopathologic scores and the expression levels of TNF-α, IL-8 and IL-6 were significantly lower in FEN group than in IRI group. Moreover, Fenofibrate pretreatment could further induce PI3K/Akt signal pathway and PPAR-α activation following renal IRI. These findings indicated PPAR-α activation by Fenofibrate exerts protective effects on renal IRI in mice by suppressing inflammation via PI3K/Akt activation. Thus, Fenofibrate could be a novel therapeutic alternative in renal IRI.展开更多
We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis fac...We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.展开更多
The Janus kinase and signal transducer and activator of transcription (JAK/STAT) signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs. However, th...The Janus kinase and signal transducer and activator of transcription (JAK/STAT) signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs. However, the cellular and molecular mechanisms underlying sepsis-induced brain damage remain elusive. In the present study, we found severe loss of neurons in the hippocampal CA1 region in rats with sepsis-induced brain damage following intraperitoneal injection of endotoxin, The expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 was significantly increased in brain tissues following lipopolysaccharide exposure. AG490 (JAK2 antagonist) and rapamycin (STAT3 antagonist) significantly reduced neuronal loss and suppressed the increased expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 in the hippocampal CA1 region in sepsis-induced brain damaged rats. Overall, these data suggest that blockade of the JAK/STAT signal transduction pathway is neuroprotective in sepsis-induced brain damage via the inhibition of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 exoression.展开更多
Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in ...Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in teleost.Identification,characterization,classification,and expression profiling of totally 15 mapk genes in black rockfish(Sebastes schlegelii)were conducted.Phylogenetic relationships show that these mapk genes could be divided into extracellular signal-regulated kinase(ERK),c-Jun N-terminal kinase(JNK),and p38 sub-families.In addition,gene structures,syntenic analysis,and selective pressure analysis are performed to confirm their annotations.Results of selective pressure analysis indicate that mapk1,mapk3,mapk7,mapk10,mapk11,and mapk12 underwent significantly-positive selections,while the others genes such as mapk4,mapk6,mapk15,mapk8a,mapk8b,mapk9,mapk13,mapk14a,and mapk14b were under purifying selections.Moreover,results of qRT-PCR indicate that mapk genes in 8 healthy tissues displayed different expression patterns.The expression patterns of several mapk genes including mapk12,mapk13,mapk14a,mapk14b,and mapk15 were significantly changed in mucosal tissues after Edwardsiella piscicida infection.This study demonstrates that mapk genes in black rockfish play vital prevention roles against bacterial infection,which not only helps us understand the structure and function of mapk genes in black rockfish,but also provides a reference to understand the role of mapk genes in teleost immune responses.展开更多
Red Fuji apple(Malus domestica Borkh var. Red Fuji)fruits were used to study the effect of 1-MCP on ethylene biosynthesis metabolism during storage. The results showed that 1-MCP maintained the firmness and inhibited ...Red Fuji apple(Malus domestica Borkh var. Red Fuji)fruits were used to study the effect of 1-MCP on ethylene biosynthesis metabolism during storage. The results showed that 1-MCP maintained the firmness and inhibited the respiration rate, LOX activity and ethylene production rate of fruits. Further study indicated that 1-MCP inhibited ACS(ACC synthase)activity from the 15th day, increased ACC accumulation, and delayed the appearance of ACO(ACC oxidase)activity peak. The increase of protein kinase activity was also inhibited by 1-MCP during fruit ethylene climacteric time.展开更多
Accumulating evidence indicates that early and essential events for receptor-like kinase(RLK)function involve both autophosphorylation and substrate phosphorylation.However,the structural and biochemical basis for the...Accumulating evidence indicates that early and essential events for receptor-like kinase(RLK)function involve both autophosphorylation and substrate phosphorylation.However,the structural and biochemical basis for these events is largely unclear.Here,we used RLK FERONIA(FER)as a model and crystallized its core kinase domain(FER-KD)and two FER-KD mutants(K565R,S525A)in complexes with ATP/ADP and Mg^(2+) in the unphosphorylated state.Unphosphorylated FER-KD was found to adopt an unexpected active conformation in its crystal structure.Moreover,unphosphorylated FER-KD mutants with reduced(S525A)or no catalytic activity(K565R)also adopt similar active conformations.Biochemical studies revealed that FER-KD is a dual-specificity kinase,and its autophosphorylation is accomplished via an intermolecular mechanism.Further investigations confirmed that initiating substrate phosphorylation requires autophosphorylation of the activation segment on T696,S701,and Y704.This study reveals the structural and biochemical basis for the activation and regulatory mechanism of FER,providing a paradigm for the early steps in RLK signaling initiation.展开更多
Objective:Src is a protein tyrosine kinase that plays important roles in cancer development,and Src kinase activity has been found to be elevated in several types of cancers.However,the cause of the elevation of Src ...Objective:Src is a protein tyrosine kinase that plays important roles in cancer development,and Src kinase activity has been found to be elevated in several types of cancers.However,the cause of the elevation of Src kinase activity in the majority of human colon carcinomas is still largely unknown.We aim at finding the cause of elevated Src kinase activity in human colon carcinomas.Methods:We employed normal colon epithelial FHC cells and examined Src activation in human colon carcinoma specimens from 8 patients.Protein expression levels were determined by Western blotting,and the activity of Src kinase by kinase assay.Results:Actin levels were different between tumor and normal tissues,demonstrating the complexities and inhomogeneities of the tissue samples.Src kinase activities were increased in the majority of the colon carcinomas as compared with normal colon epithelial cells (range 13-29).Src protein levels were reduced in the colon carcinomas.Src Y530 phosphorylation levels were reduced to a higher extent than protein levels in the carcinomas.Conclusion:The results suggest that Src specific activities were highly increased in human colon carcinomas;phosphorylation at Src Y530 was reduced,contributing to the highly elevated Src specific activity and Src kinase activity.展开更多
The American Heart Association and the European Resuscitation Council recently recommend- ed that vasopressin can be used for cardiopulmonary resuscitation, instead of epinephrine. However, the guidelines do not discu...The American Heart Association and the European Resuscitation Council recently recommend- ed that vasopressin can be used for cardiopulmonary resuscitation, instead of epinephrine. However, the guidelines do not discuss the effects of vasopressin during cerebral resuscitation. In this study, we intraperitoneally injected epinephrine and/or vasopressin during cardiopul- monary resuscitation in a rat model of asphyxial cardiac arrest. The results demonstrated that, compared with epinephrine alone, the pathological damage to nerve cells was lessened, and the levels of c-Iun N-terminal kinase and p38 expression were significantly decreased in the hippo- campus after treatment with vasopressin alone or the vasopressin and epinephrine combination. No significant difference in resuscitation effects was detected between vasopressin alone and the vasopressin and epinephrine combination. These results suggest that vasopressin alone or the vasopressin and epinephrine combination suppress the activation of mitogen-activated protein kinase and c-Iun N-terminal kinase signaling pathways and reduce neuronal apoptosis during cardiopulmonary resuscitation.展开更多
Curcumin, as a main pharmacological component in the traditional Chinese medicine-- tttrmeric, has shown anti-inflammatory, anti-oxidation, anti-tumor and anti-fibrotic effects. This study aimed to investigate the pos...Curcumin, as a main pharmacological component in the traditional Chinese medicine-- tttrmeric, has shown anti-inflammatory, anti-oxidation, anti-tumor and anti-fibrotic effects. This study aimed to investigate the possible underlying signaling pathway which was involved in the inhibition of LDL-induced proliferation of mesangial cells and matrix by curcumin. Rat mesangial cells in vitro were incubated with low-density lipoprotein (LDL) and different concentrations of curcumin (0, 6.25, 12.5, 25.0 9mol/L) or p38 MAPK inhibitor, SB203580 (10 μmol/L). Under LDL incubation, mesangial cells proliferated, the expression of MMP-2 mRNA and protein was decreased, the expression of COX-2 mRNA and protein was increased, reactive oxygen species (ROS) generation was increased and p38 MAPK was activated significantly (P〈0.05). When LDL-induced cells were treated with curcumin in the concentration of 12.5 or 25.0 μmol/L, LDL-induced proliferation ofmesangial cells was suppressed, the expression of MMP-2 mRNA and protein increased, the expression of COX-2 mRNA and protein downregulated, the production of ROS inhibited and p38 MAPK inactivated (P〈0.05). In conclusion, curcumin can inhibit the LDL-induced proliferation of mesangial cells and up-regulate the expression of MMP-2, which may be related with the inhibitory effect of curcumin on COX-2 expression, ROS pro- duction and p38 MAPK.展开更多
基金supported by the BK21 FOUR funded by the Ministry of Education,Republic of Korea,the National Research Foundation of Korea(NRF-2022R1F1A1066642,RS-2023-00272063)grant funded by the Korean government(MSIT),and POSTECH Basic Science Research Institute Grant(NRF-2021R1A6A1A10042944).Research was also supported by funds donated by Dr.Jae Kyu Lee and Mr.Jason Gim.Following are results of a study on the“Leaders in INdustry-University Cooperation 3.0”Project,supported by the Ministry of Education and National Research Foundation of Korea.
文摘Genetic information is transcribed from genomic DNA to mRNA,which is then translated into threedimensional proteins.mRNAs can undergo various post-transcriptional modifications,including RNA editing that alters mRNA sequences,ultimately affecting protein function.In this study,RNA editing was identified at the 499th base(c.499)of human vaccinia-related kinase 2(VRK2).This RNA editing changes the amino acid in the catalytic domain of VRK2 from isoleucine(with adenine base)to valine(with guanine base).Isoleucine-containing VRK2 has higher kinase activity than the valine-containing VRK2,which leads to an increase in tumor cell proliferation.Earlier we reported that VRK2 directly interacts with dystrobrevin-binding protein(dysbindin)and results in reducing its stability.Herein,we demonstrate that isoleucine-containing VRK2 decreases the level of dysbindin than valinecontaining VRK2.Dysbindin interacts with cyclin D and thereby regulates its expression and function.The reduction in the level of dysbindin by isoleucine-containing VRK2 further enhances the cyclin D expression,resulting in increased tumor growth and reduction in survival rates.It has also been observed that in patient samples,VRK2 level was elevated in breast cancer tissue compared to normal breast tissue.Additionally,the isoleucine form of VRK2 exhibited a greater increase in breast cancer tissue.Therefore,it is concluded that VRK2,especially dependent on the 167th variant amino acid,can be one of the indexes of tumor progression and proliferation.
文摘The aging process in mammals is correlated with changes in psychomotor performance, cognitive function, and ability to adapt to stress (Montgomery et al., 1982; Lorens et al., 1990). These changes may be related to alterations in neuronal tissue that occur during the aging process. The normal aging process may be conceived of as the neuronal cell’s increasing inability to maintain normal cellular function which ultimately results in a number of morphological and biochemical changes. Morphologically, there is a loss of neuronal cells with increasing age (Brizzee and
基金Supported by National Natural Science Foundation of China,No.82260211Key Research and Development Project in Jiangxi Province,No.20203BBG73058Chinese Medicine Science and Technology Project in Jiangxi Province,No.2020A0166.
文摘BACKGROUND Diabetic retinopathy(DR)is a major ocular complication of diabetes mellitus,leading to visual impairment.Retinal pigment epithelium(RPE)injury is a key component of the outer blood retinal barrier,and its damage is an important indicator of DR.Receptor for activated C kinase 1(RACK1)activates protein kinase C-ε(PKC-ε)to promote the generation of reactive oxygen species(ROS)in RPE cells,leading to apoptosis.Therefore,we hypothesize that the activation of RACK1 under hypoxic/high-glucose conditions may promote RPE cell apoptosis by modulating PKC-ε/ROS,thereby disrupting the barrier effect of the outer blood retinal barrier and contributing to the progression of DR.AIM To investigate the role and associated underlying mechanisms of RACK1 in the development of early DR.METHODS In this study,Sprague-Dawley rats and adult RPE cell line-19(ARPE-19)cells were used as in vivo and in vitro models,respectively,to explore the role of RACK1 in mediating PKC-εin early DR.Furthermore,the impact of RACK1 on apoptosis and barrier function of RPE cells was also investigated in the former model.RESULTS Streptozotocin-induced diabetic rats showed increased apoptosis and upregulated expression of RACK1 and PKC-εproteins in RPE cells following a prolonged modeling.Similarly,ARPE-19 cells exposed to high glucose and hypoxia displayed elevated mRNA and protein levels of RACK1 and PKC-ε,accompanied by an increases in ROS production,apoptosis rate,and monolayer permeability.However,silencing RACK1 significantly downregulated the expression of PKC-εand ROS,reduced cell apoptosis and permeability,and protected barrier function.CONCLUSION RACK1 plays a significant role in the development of early DR and might serve as a potential therapeutic target for DR by regulating RPE apoptosis and barrier function.
基金supported by grants from Key R&D Project of Science and Technology Foundation of Sichuan Province(2022YFS0290).
文摘Background:Galectin 2(LGALS2)is a protein previously reported to serve as a mediator of disease progression in a range of cancers.The function of LGALS2 in oral squamous cell carcinoma(OSCC),however,has yet to be explored,prompting the present study to address this literature gap.Methods:Overall,144 paired malignant tumor tissues and paracancerous OSCC patient samples were harvested and the LGALS2 expression levels were examined through qPCR and western immunoblotting.The LGALS2 coding sequence was introduced into the pcDNA3.0 vector,to enable the overexpression of this gene,while an LGALS2-specific shRNA and corresponding controls were also obtained.The functionality of LGALS2 as a regulator of the ability of OSCC cells to grow and undergo apoptotic death in vitro was assessed through EdU uptake and CCK-8 assays,and flow cytometer,whereas a Transwell system was used to assess migratory activity and invasivity.An agonist of the Janus Kinase 2(JAK2)/Signal Transducer and Activator of Transcription 3(STAT3)pathway was also used to assess the role of this pathway in the context of LGALS2 signaling.Results:Here,we found that lower LGALS2 protein and mRNA expression were evident in OSCC tumor tissue samples,and these expression levels were associated with clinicopathological characteristics and patient survival outcomes.Silencing LGALS2 enhanced proliferation in OSCC cells while rendering these cells better able to resist apoptosis.The opposite was instead observed after LGALS2 was overexpressed.Mechanistically,the ability of LGALS2 to suppress the progression of OSCC was related to its ability to activate the JAK/STAT3 signaling axis.Conclusion:Those results suggest a role for LGALS2 as a suppressor of OSCC progression through its ability to modulate JAK/STAT3 signaling,supporting the potential utility of LGALS2 as a target for efforts aimed at treating OSCC patients.
文摘Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.
文摘BACKGROUND Leukemia stem cells(LSCs)are found to be one of the main factors contributing to poor therapeutic effects in acute myeloid leukemia(AML),as they are protected by the bone marrow microenvironment(BMM)against conventional therapies.Gossypol acetic acid(GAA),which is extracted from the seeds of cotton plants,exerts anti-tumor roles in several types of cancer and has been reported to induce apoptosis of LSCs by inhibiting Bcl2.AIM To investigate the exact roles of GAA in regulating LSCs under different microenvironments and the exact mechanism.METHODS In this study,LSCs were magnetically sorted from AML cell lines and the CD34+CD38-population was obtained.The expression of leucine-rich pentatricopeptide repeat-containing protein(LRPPRC)and forkhead box M1(FOXM1)was evaluated in LSCs,and the effects of GAA on malignancies and mitochondrial RESULTS LRPPRC was found to be upregulated,and GAA inhibited cell proliferation by degrading LRPPRC.GAA induced LRPPRC degradation and inhibited the activation of interleukin 6(IL-6)/janus kinase(JAK)1/signal transducer and activator of transcription(STAT)3 signaling,enhancing chemosensitivity in LSCs against conventional chemotherapies,including L-Asparaginase,Dexamethasone,and cytarabine.GAA was also found to downregulate FOXM1 indirectly by regulating LRPPRC.Furthermore,GAA induced reactive oxygen species accumulation,disturbed mitochondrial homeostasis,and caused mitochondrial dysfunction.By inhibiting IL-6/JAK1/STAT3 signaling via degrading LRPPRC,GAA resulted in the elimination of LSCs.Meanwhile,GAA induced oxidative stress and subsequent cell damage by causing mitochondrial damage.CONCLUSION Taken together,the results indicate that GAA might overcome the BMM protective effect and be considered as a novel and effective combination therapy for AML.
基金supported by grant NT11231-3/2010 from the Ministry of Health of the Czech Republic
文摘Src regulates cell adhesion, invasiveness, motility and growth in cancer cells. In melanoma, accumulating data show that Src inhibition can be effective and may enhance the effects of other agents. Increased Src expression and activity thus has recently become a target for drug therapy. Several melanoma cell lines were exposed to inhibitors of Src activity despite their broad specificity. To examine the particular activity of Src in human melanoma cells, we used SU6656, the selective inhibitor of Src family protein kinases. The activity of Src and cell proliferation were suppressed in HBL human cells, wild type melanoma cells and in SK-MEL-5 human melanoma cells harboring mutant BRAF V600E, upon their treatment with SU6656. The suppression of Src kinase activity had not inhibitory effects on Akt/PKB activity in SK-MEL-5 cells, which we have previously found in HBL cells. This may indicate that changes of Src involvement in the control of Akt/PKB activity and its downstream signaling could be induced by BRAF V600E mutation in SK-MEL-5 cells.
文摘Dendritic cells (DCs) are the most potent antigen-presen ting cells that play crucial roles in the regulation of immune response. Triptol ide, an active component purified from the medicinal plant Tripterygium wilfor dii Hook F., has been demonstrated to act as a potent immunosuppressive drug c apab le of inhibiting T cell activation and proliferation. However, little is known a bout the effects of triptolide on DCs. The present study shows that triptolide d oes not affect phenotypic differentiation and LPS-induced maturation of murine DCs. But triptolide can dramatically reduce cell recovery by inducing apoptosis of DCs at concentration as low as 10 ng/ml, as demonstrated by phosphatidylserin e exposure, mitochondria potential decrease, and nuclear DNA condensation. Tript olide induces activation of p38 in DCs, which precedes the activation of caspase 3. SB203580, a specific kinase inhibitor for p38, can block the activation of caspase 3 and inhibit the resultant apoptosis of DCs. Our results suggest that t he anti-inflammatory and immunosuppressive activities of triptolide may be due, in part, to its apoptosis-inducing effects on DCs.
基金supported in part by grants from the Young Scientists Awards Foundation of Shandong Province of China,No.BS2013YY049the China Postdoctoral Science Foundation,No.2012M511036
文摘Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase (p38 MAPK) pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin (30 mg/kg) for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.
基金supported by the National Natural Science Foundation of China(No.81070557)
文摘The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury(IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for 60 min followed by reperfusion for 24 h. Eighteen male C57BL/6 mice were randomly divided into three groups: sham-operated group(sham), IRI+saline group(IRI group), IRI+Fenofibrate(FEN) group. Normal saline or Fenofibrate(3 mg/kg) was intravenously injected 60 min before renal ischemia in IRI group and FEN group, respectively. Blood samples and renal tissues were collected at the end of reperfusion. The renal function, histopathologic changes, and the expression levels of pro-inflammatory cytokines [interleukin-8(IL-8), tumor necrosis factor alpha(TNF-α) and IL-6] in serum and renal tissue homogenate were assessed. Moreover, the effects of Fenofibrate on activating phosphoinositide 3 kinase/protein kinase B(PI3K/Akt) signaling and peroxisome proliferator-activated receptor-α(PPAR-α) were also measured in renal IRI. The results showed that plasma levels of blood urea nitrogen and creatinine, histopathologic scores and the expression levels of TNF-α, IL-8 and IL-6 were significantly lower in FEN group than in IRI group. Moreover, Fenofibrate pretreatment could further induce PI3K/Akt signal pathway and PPAR-α activation following renal IRI. These findings indicated PPAR-α activation by Fenofibrate exerts protective effects on renal IRI in mice by suppressing inflammation via PI3K/Akt activation. Thus, Fenofibrate could be a novel therapeutic alternative in renal IRI.
基金a grant from the Science and Technology Department of Jilin Province,No. 200705172
文摘We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.
文摘The Janus kinase and signal transducer and activator of transcription (JAK/STAT) signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs. However, the cellular and molecular mechanisms underlying sepsis-induced brain damage remain elusive. In the present study, we found severe loss of neurons in the hippocampal CA1 region in rats with sepsis-induced brain damage following intraperitoneal injection of endotoxin, The expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 was significantly increased in brain tissues following lipopolysaccharide exposure. AG490 (JAK2 antagonist) and rapamycin (STAT3 antagonist) significantly reduced neuronal loss and suppressed the increased expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 in the hippocampal CA1 region in sepsis-induced brain damaged rats. Overall, these data suggest that blockade of the JAK/STAT signal transduction pathway is neuroprotective in sepsis-induced brain damage via the inhibition of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 exoression.
基金Supported by the National Key R&D Program of China(No.2018YFD0900101)the Young Experts of Taishan Scholars(No.tsqn201909130)+2 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities in Shandong Province(No.2019KJF003)the“First Class Fishery Discipline”Program in Shandong Provincethe Shandong Technical System of Fish Industry(No.SDAIT-12-03)。
文摘Mitogen-activated protein kinases(MAPKs)play pivotal roles in response to environmental stresses and bacterial infections.Compared with those in the higher vertebrates,studies of mapk gene family are still limited in teleost.Identification,characterization,classification,and expression profiling of totally 15 mapk genes in black rockfish(Sebastes schlegelii)were conducted.Phylogenetic relationships show that these mapk genes could be divided into extracellular signal-regulated kinase(ERK),c-Jun N-terminal kinase(JNK),and p38 sub-families.In addition,gene structures,syntenic analysis,and selective pressure analysis are performed to confirm their annotations.Results of selective pressure analysis indicate that mapk1,mapk3,mapk7,mapk10,mapk11,and mapk12 underwent significantly-positive selections,while the others genes such as mapk4,mapk6,mapk15,mapk8a,mapk8b,mapk9,mapk13,mapk14a,and mapk14b were under purifying selections.Moreover,results of qRT-PCR indicate that mapk genes in 8 healthy tissues displayed different expression patterns.The expression patterns of several mapk genes including mapk12,mapk13,mapk14a,mapk14b,and mapk15 were significantly changed in mucosal tissues after Edwardsiella piscicida infection.This study demonstrates that mapk genes in black rockfish play vital prevention roles against bacterial infection,which not only helps us understand the structure and function of mapk genes in black rockfish,but also provides a reference to understand the role of mapk genes in teleost immune responses.
文摘Red Fuji apple(Malus domestica Borkh var. Red Fuji)fruits were used to study the effect of 1-MCP on ethylene biosynthesis metabolism during storage. The results showed that 1-MCP maintained the firmness and inhibited the respiration rate, LOX activity and ethylene production rate of fruits. Further study indicated that 1-MCP inhibited ACS(ACC synthase)activity from the 15th day, increased ACC accumulation, and delayed the appearance of ACO(ACC oxidase)activity peak. The increase of protein kinase activity was also inhibited by 1-MCP during fruit ethylene climacteric time.
基金supported by grants from the National Natural Science Foundation of China(32160064,31871396,31571444,and 32000916)the State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources(SKLCUSA-a201806)+3 种基金the China Postdoctoral Science Foundation(2019M662764)the Hunan Provincial Natural Science Foundation of China(2021JJ40050)the Guangxi Natural Science Foundation(2020GXNSFFA297007)the Guangxi Key Laboratory for Sugarcane Biology(GXKLSCB-20190304).
文摘Accumulating evidence indicates that early and essential events for receptor-like kinase(RLK)function involve both autophosphorylation and substrate phosphorylation.However,the structural and biochemical basis for these events is largely unclear.Here,we used RLK FERONIA(FER)as a model and crystallized its core kinase domain(FER-KD)and two FER-KD mutants(K565R,S525A)in complexes with ATP/ADP and Mg^(2+) in the unphosphorylated state.Unphosphorylated FER-KD was found to adopt an unexpected active conformation in its crystal structure.Moreover,unphosphorylated FER-KD mutants with reduced(S525A)or no catalytic activity(K565R)also adopt similar active conformations.Biochemical studies revealed that FER-KD is a dual-specificity kinase,and its autophosphorylation is accomplished via an intermolecular mechanism.Further investigations confirmed that initiating substrate phosphorylation requires autophosphorylation of the activation segment on T696,S701,and Y704.This study reveals the structural and biochemical basis for the activation and regulatory mechanism of FER,providing a paradigm for the early steps in RLK signaling initiation.
基金supported by grants from the Alberta Cancer Board of Canada (2007-2010) to DJF
文摘Objective:Src is a protein tyrosine kinase that plays important roles in cancer development,and Src kinase activity has been found to be elevated in several types of cancers.However,the cause of the elevation of Src kinase activity in the majority of human colon carcinomas is still largely unknown.We aim at finding the cause of elevated Src kinase activity in human colon carcinomas.Methods:We employed normal colon epithelial FHC cells and examined Src activation in human colon carcinoma specimens from 8 patients.Protein expression levels were determined by Western blotting,and the activity of Src kinase by kinase assay.Results:Actin levels were different between tumor and normal tissues,demonstrating the complexities and inhomogeneities of the tissue samples.Src kinase activities were increased in the majority of the colon carcinomas as compared with normal colon epithelial cells (range 13-29).Src protein levels were reduced in the colon carcinomas.Src Y530 phosphorylation levels were reduced to a higher extent than protein levels in the carcinomas.Conclusion:The results suggest that Src specific activities were highly increased in human colon carcinomas;phosphorylation at Src Y530 was reduced,contributing to the highly elevated Src specific activity and Src kinase activity.
文摘The American Heart Association and the European Resuscitation Council recently recommend- ed that vasopressin can be used for cardiopulmonary resuscitation, instead of epinephrine. However, the guidelines do not discuss the effects of vasopressin during cerebral resuscitation. In this study, we intraperitoneally injected epinephrine and/or vasopressin during cardiopul- monary resuscitation in a rat model of asphyxial cardiac arrest. The results demonstrated that, compared with epinephrine alone, the pathological damage to nerve cells was lessened, and the levels of c-Iun N-terminal kinase and p38 expression were significantly decreased in the hippo- campus after treatment with vasopressin alone or the vasopressin and epinephrine combination. No significant difference in resuscitation effects was detected between vasopressin alone and the vasopressin and epinephrine combination. These results suggest that vasopressin alone or the vasopressin and epinephrine combination suppress the activation of mitogen-activated protein kinase and c-Iun N-terminal kinase signaling pathways and reduce neuronal apoptosis during cardiopulmonary resuscitation.
基金supported by grants from the National Natural Science Foundation of China(No.81100485)Scientific Research Foundation for Returned Scholars, Ministry of Education of China(No.[2011]1568)
文摘Curcumin, as a main pharmacological component in the traditional Chinese medicine-- tttrmeric, has shown anti-inflammatory, anti-oxidation, anti-tumor and anti-fibrotic effects. This study aimed to investigate the possible underlying signaling pathway which was involved in the inhibition of LDL-induced proliferation of mesangial cells and matrix by curcumin. Rat mesangial cells in vitro were incubated with low-density lipoprotein (LDL) and different concentrations of curcumin (0, 6.25, 12.5, 25.0 9mol/L) or p38 MAPK inhibitor, SB203580 (10 μmol/L). Under LDL incubation, mesangial cells proliferated, the expression of MMP-2 mRNA and protein was decreased, the expression of COX-2 mRNA and protein was increased, reactive oxygen species (ROS) generation was increased and p38 MAPK was activated significantly (P〈0.05). When LDL-induced cells were treated with curcumin in the concentration of 12.5 or 25.0 μmol/L, LDL-induced proliferation ofmesangial cells was suppressed, the expression of MMP-2 mRNA and protein increased, the expression of COX-2 mRNA and protein downregulated, the production of ROS inhibited and p38 MAPK inactivated (P〈0.05). In conclusion, curcumin can inhibit the LDL-induced proliferation of mesangial cells and up-regulate the expression of MMP-2, which may be related with the inhibitory effect of curcumin on COX-2 expression, ROS pro- duction and p38 MAPK.