Role of Toll-like receptor 4 and Janus kinase and signal transducer and activator of transcription signal transduction pathway in sepsis-induced brain damage

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.

Galectin 2 regulates JAK/STAT3 signaling activity to modulate oral squamous cell carcinoma proliferation and migration in vitro

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.

Gossypol acetic acid regulates leukemia stem cells by degrading LRPPRC via inhibiting IL-6/JAK1/STAT3 signaling or resulting mitochondrial dysfunction

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.

Liuwei Dihuang Pill(六味地黄丸)Treats Postmenopausal Osteoporosis with Shen(Kidney) Yin Deficiency via Janus Kinase/Signal Transducer and Activator of Transcription Signal Pathway by Up-regulating Cardiotrophin-Like Cytokine Factor 1 Expression

Objectives： To investigate the mechanism of Liuwei Dihuang Pill （六味地黄丸, LDP） in treating postmenopausal osteoporosis （PMOP） with Shen （Kidney） yin deficiency. Methods： In this study, 205 cases of PMOP were divided into the PMOP Shen-yin deficiency group （Group A）, PMOP Shen-yang deficiency group （Group B）, PMOP without Shen deficiency group （Group C）, and control group （Group N）. Real-time polymerase chain reaction （RT-PCR） and Western blot techniques were used to observe the effects of LDP treatment on the cardiotrophin-like cytokine factor 1 （CLCF1）, ankyrin repeat and SOCS box containing 1 （ASB1）, and proldneticin 2 （PROK2） genes and the Janus kinase/signal transducer and activator of transcription （JAK/STAT） signaling pathway. Results： The mRNA （P〈0.05） and protein （P〈0.01） expression levels of the CLCF1 gone in Group A were significantly lower than the corresponding levels in Group N. After LDP treatment for 3 months, the mRNA expression levels of the CLCF1 gone were obviously up-regulated （P〈0.01）. After 6-month treatment, the expression levels of CLCF1 mRNA and protein were significantly up-regulated （both P〈0.01）, and the average bone density of the top femur had significantly increased （P〈0.05）. In vitro, CLCF1 overexpression resulted in a significant increase in the total protein and phosphorylated protein levels of JAK2 and STAT3. Conclusions： The CLCF1 gone is an important gone associated with PMOP Shen-yin deficiency and the therapeutic effects of LDP may be mediated by up-regulation of CLCF1 gone expression and activation of the JAK/STAT signaling pathway.

Hepatocellular carcinoma-derived exosomal miRNA-761 regulates the tumor microenvironment by targeting the SOCS2/JAK2/STAT3 pathway

BACKGROUND:Exosomes and exosomal microRNAs have been implicated in tumor occurrence and metastasis.Our previous study showed that microRNA-761(miR-761)is overexpressed in hepatocellular carcinoma(HCC)tissues and that its inhibition affects mitochondrial function and inhibits HCC metastasis.The mechanism by which exosomal miR-761 modulates the tumor microenvironment has not been elucidated.METHODS:Exosomal miR-761 was detected in six cell lines.Cell counting kit-8(CCK-8)and transwell migration assays were performed to determine the function of exosomal miR-761 in HCC cells.The luciferase reporter assay was used to analyze miR-761 target genes in normal fi broblasts(NFs).The inhibitors AZD1480 and C188-9 were employed to determine the role of the Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)signaling pathway in the transformation of cancer-associated fi broblasts(CAFs).RESULTS:In this study,we characterized the mechanism by which miR-761 reprogrammed the tumor microenvironment.We found that HCC-derived exosomal miR-761 was taken up by NFs.Moreover,HCC exosomes aff ected the tumor microenvironment by activating NFs via suppressor of cytokine signaling 2(SOCS2)and the JAK2/STAT3 signaling pathway.CONCLUSIONS:These results demonstrated that exosomal miR-761 modulated the tumor microenvironment via SOCS2/JAK2/STAT3 pathway-dependent activation of CAFs.Our fi ndings may inspire new strategies for HCC prevention and therapy.

Profilin-1 is involved in macroangiopathy induced by advanced glycation end products via vascular remodeling and inflammation

BACKGROUND The accumulation of advanced glycation end products(AGEs)have been implicated in the development and progression of diabetic vasculopathy.However,the role of profilin-1 as a multifunctional actin-binding protein in AGEs-induced atherosclerosis(AS)is largely unknown.AIM To explore the potential role of profilin-1 in the pathogenesis of AS induced by AGEs,particularly in relation to the Janus kinase 2(JAK2)and signal transducer and activator of transcription 3(STAT3)signaling pathway.METHODS Eighty-nine individuals undergoing coronary angiography were enrolled in the study.Plasma cytokine levels were detected using ELISA kits.Rat aortic vascular smooth muscle cells(RASMCs)were incubated with different compounds for different times.Cell proliferation was determined by performing the MTT assay and EdU staining.An AGEs-induced vascular remodeling model was established in rats and histological and immunohistochemical analyses were performed.The mRNA and protein levels were detected using real-time PCR and Western blot analysis,respectively.In vivo,shRNA transfection was performed to verify the role of profilin-1 in AGEs-induced proatherogenic mediator release and aortic remodeling.Statistical analyses were performed using SPSS 22.0 software.RESULTS Compared with the control group,plasma levels of profilin-1 and receptor for AGEs(RAGE)were significantly increased in patients with coronary artery disease,especially in those complicated with diabetes mellitus(P<0.01).The levels of profilin-1 were positively correlated with the levels of RAGE(P<0.01);additionally,the levels of both molecules were positively associated with the degree of coronary artery stenosis(P<0.01).In vivo,tail vein injections of AGEs induced the release of proatherogenic mediators,such as asymmetric dimethylarginine,intercellular adhesion molecule-1,and the N-terminus of procollagen III peptide,concomitant with apparent aortic morphological changes and significantly upregulated expression of the profilin-1 mRNA and protein in the thoracic aorta(P<0.05 or P<0.01).Downregulation of profilin-1 expression with an shRNA significantly attenuated AGEs-induced proatherogenic mediator release(P<0.05)and aortic remodeling.In vitro,incubation of vascular smooth muscle cells(VSMCs)with AGEs significantly promoted cell proliferation and upregulated the expression of the profilin-1 mRNA and protein(P<0.05).AGEs(200μg/mL,24 h)significantly upregulated the expression of the STAT3 mRNA and protein and JAK2 protein,which was blocked by a JAK2 inhibitor(T3042-1)and/or STAT3 inhibitor(T6308-1)(P<0.05).In addition,pretreatment with T3042-1 or T6308-1 significantly inhibited AGEs-induced RASMC proliferation(P<0.05).CONCLUSION AGEs induce proatherogenic events such as VSMC proliferation,proatherogenic mediator release,and vascular remodeling,changes that can be attenuated by silencing profilin-1 expression.These results suggest a crucial role for profilin-1 in AGEs-induced vasculopathy.

Electroacupuncture Alleviates Neuropathic Pain by Modulating Th2 Infiltration and Inhibiting Microglial Activation in the Spinal Cord of Rats with Spared Nerve Injury

Objective:The objective is to explore the potential mechanisms mediating the analgesic effect of electroacupuncture(EA)for neuropathic pain.Materials and Methods:Sprague-Dawley(SD)rats were used to establish a spared nerve injury(SNI)model of neuropathic pain.The intensity of neuropathic pain was measured by assessing the mechanical withdrawal threshold and thermal withdrawal latency.Immunofluorescent analysis and western blotting were performed to evaluate the activation of microglia and Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)signaling in the L4-6 spinal cord of SD rats.The infiltration of Th2 and expression of interleukin-10(IL-10)in the L4-6 spine were analyzed by flow cytometry and enzyme-linked immunosorbent assay.Results:Behavioral test results demonstrated that SNI-induced hyperalgesia was significantly ameliorated by EA stimulation at"Zusanli"(ST36)and"Yanglingquan"(GB34)points.In addition,EA therapy significantly suppressed microglia activation and phosphorylation of JAK2/STAT3 in the L4-6 spine of rats with SNI.Moreover,EA promoted the infiltration of Th2 and secretion of IL-10 in the L4-6 spine of rats with SNI.Conclusions:The study findings indicate that EA stimulation mediated the infiltration of Th2 in the spinal cord of rats with SNI.In addition,EA inhibited microglial activation in the L4-6 spine of rats with SNI.

Targeting the JAK/STAT pathway in solid tumors

Aberrant activation of signal transducer and activator of transcription(STAT)proteins is associated with the development and progression of solid tumors.However,as transcription factors,these proteins are difficult to target directly.In this review,we summarize the role of targeting Janus kinases(JAKs),upstream activators of STATs,as a strategy for decreasing STAT activation in solid tumors.Preclinical studies in solid tumor cell line models show that JAK inhibitors decrease STAT activation,cell proliferation,and cell survival;in in vivo models,they also inhibit tumor growth.JAK inhibitors,particularly the JAK1/2 inhibitor ruxolitinib,sensitize cell lines and murine models to chemotherapy,immunotherapy,and oncolytic viral therapy.Ten JAK inhibitors have been or are actively being tested in clinical trials as monotherapy or in combination with other agents in patients with solid tumors;two of these inhibitors are already Food and Drug Administration(FDA)approved for the treatment of myeloproliferative disorders and rheumatoid arthritis,making them attractive agents for use in patients with solid tumors as they are known to be well-tolerated.Four JAK inhibitors(two of which are FDA approved for other indications)have exhibited promising anti-cancer effects in preclinical studies;however,clinical studies specifically assessing their activity against the JAK/STAT pathway in solid tumors have not yet been conducted.In summary,JAK inhibition is a viable option for targeting the JAK/STAT pathway in solid tumors and merits further testing in clinical trials.

Regulatory Effect of JAK2/STAT3 on the Immune Function of Endotoxin-tolerant Dendritic Cells and its Involvement in Acute Liver Failure

Background and Aims:Acute liver failure(ALF)is a potentially fatal clinical syndrome with no effective treatment.This study aimed to explore the role of Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)pathway in modulating the phenotype and immune function of endotoxin-tolerant dendritic cells(ETDCs).In addition,we explored the use of EDTCs in an experimental model of ALF and investigated the associated mechanisms.Methods:In the in vitro experiment,ETDCs were transfected with adenovirus to induce SOCS1^(+/+)ETDCs and SOCS1^(−/−)ETDCs.Thereafter,costimulatory molecules and mixed lymphocyte reaction were assessed.Experimental mice were randomly divided into normal control,ALF,ALF+mock-ETDCs,ALF+SOCS1^(+/+)ETDCs,ALF+AG490,and ALF+AG490+SOCS1^(+/+)ETDCs groups.We examined the therapeutic effect of adoptive cellular immunotherapy by tail-vein injection of target ETDCs 12 h before ALF modeling.AG490,a JAK2/STAT3 inhibitor,was used in the in vivo experiment to further explore the protective mechanism of SOCS1^(+/+)ETDCs.Results:Compared with control ETDCs,SOCS1^(+/+)ETDCs had lower expression of costimulatory molecules,weaker allostimulatory ability,lower levels of IL-6 and TNF-αexpression and higher IL-10 secretion.SOCS1^(−/−)ETDCs showed the opposite results.In the in vivo experiments,the ALF+SOCS1^(+/+)ETDCs and ALF+AG490+SOCS1^(+/+)ETDCs groups showed less pathological damage and suppressed activation of JAK2/STAT3 pathway.The changes were more pronounced in the ALF+AG490+SOCS1^(+/+)ETDCs group.Infusion of SOCS1^(+/+)ETDCs had a protective effect against ALF possibly via inhibition of JAK2 and STAT3 phosphorylation.Conclusions:The SOCS1 gene had an important role in induction of endotoxin tolerance.SOCS1^(+/+)ETDCs alleviated lipopolysaccharide/D-galactosamine-induced ALF by downregulating the JAK2/STAT3 signaling pathway.