Carnitine Palmitoyl Transferase II (CPTII) is a very important enzyme that helps with the oxidation of long-chain fatty acid to produce energy. Deficiency in CPTII will lead to energy deficiency in the case of fasting...Carnitine Palmitoyl Transferase II (CPTII) is a very important enzyme that helps with the oxidation of long-chain fatty acid to produce energy. Deficiency in CPTII will lead to energy deficiency in the case of fasting and the accumulation of the long chain fatty in the body. There are three types of CPT II deficiency, the myopathic form, the severe infantile hepatocardiomuscular form and the lethal neonatal form. They are all inherited as an autosomal recessive. Diagnosis of the CPTII are 1) tandem mass spectrometry (MS/MS) in adult form and 2) CPTII polymorphism (F352C), which is linked to reducing the activity of CPTII in infantile form [1]. Glucose is the primary management and medium-chain fatty acid is an alternative due to the bypass of the CPTII enzyme in the pathway. For the prevention of CPTII deficiency are to avoid long chain fatty acid (C12-fatty acid), fasting, prolonged exercise, known triggers, and certain medications such as anti-epileptics and general anesthesia. During the rhabdomyolysis and myoglobinuria attack, it is very important to maintain hydration to avoid acute renal failure. If, however, renal failure occurs, dialysis is recommended. We present a case of a 27-year-old African American woman with the significant past medical history of CPT II deficiency leading to recurrent rhabdomyolysis and myoglobinuria. Together with all the research studies from diagnosis to treatment of CPTII deficiency will help in clinical management of patients. And this case report will add to the existing case reports of patients who have CPTII deficiency in terms of how we diagnose, how we treat, and how we prevent symptoms from re-occurring.展开更多
AIM To investigate the dynamic alteration of mitochondrial carnitine palmitoyl transferase Ⅱ(CPT-Ⅱ) expression during malignant transformation of rat hepatocytes.METHODS Sprague-Dawley male rats were fed with normal...AIM To investigate the dynamic alteration of mitochondrial carnitine palmitoyl transferase Ⅱ(CPT-Ⅱ) expression during malignant transformation of rat hepatocytes.METHODS Sprague-Dawley male rats were fed with normal, high fat(HF), and HF containing 2-fluorenylacetamide(2-FAA) diet, respectively. According to the Hematoxylin and Eosin staining of livers, rats were divided into control, fatty liver, degeneration, pre-cancerous, and cancerous groups. Liver lipids were dyed with Oil Red O, CPT-Ⅱ alterations were analyzed by immunohistochemistry, and compared with CPT-Ⅱ specific concentration(μg/mg protein). Levels of total cholesterol(Tch), triglyceride(TG), and aminotransferases [alanine aminotransferase(ALT), aspartate aminotransferase(AST)] were determined by the routine methods.RESULTS After intake of HF and/or HF+2-FAA diets, the rat livers showed mass lipid accumulation. The lipid level in the control group was significantly lower than that in other groups. The changes of serum TG and Tch levels were abnormally increasing, 2-3 times more than those in the controls(P < 0.05). During the rat liver morphological changes from normal to cancer development process with hepatocyte injury, serum AST and ALT levels were significantly higher(4-8 times, P < 0.05) than those in the control group. The specific concentration of CPT-Ⅱ in liver tissues progressively decreased during hepatocyte malignant transformation, with the lowest CPT-Ⅱ levels in the cancer group than in any of the other groups(P < 0.05).CONCLUSION Low CPT-Ⅱ expression might lead to abnormal hepatic lipid accumulation, which should promote the malignant transformation of hepatocytes.展开更多
BACKGROUND Liver cancer is a common cancer and the main cause of cancer-related deaths worldwide.Liver cancer is the sixth most common cancer in the world.Although miR-34a and palmitoyl membrane palmitoylated protein(...BACKGROUND Liver cancer is a common cancer and the main cause of cancer-related deaths worldwide.Liver cancer is the sixth most common cancer in the world.Although miR-34a and palmitoyl membrane palmitoylated protein(MPP2)are reportedly involved in various cell processes,their precise roles in liver cancer are still unclear.AIM To investigate the expression of micro RNA 34a(miR-34a),methylation of the miR-34a promoter and the expression of MPP2 in liver cancer cells and their related mechanisms.METHODS Together,78 cases of liver cancer tissues and 78 cases of adjacent tissues were collected.The methylation degree of miR-34a promoter in liver cancer/paracancerous tissue and liver cancer cells/normal liver cells,and the expression levels of miR-34a and MPP2 in the above samples were detected.Demethylation of liver cancer cells or transfection of liver cancer cells with miR-34a mimetic was performed.The MPP2 overexpression vector was used to transfect liver cancer cells,and the changes in proliferation,invasion,apoptosis,migration,and other biological functions of liver cancer cells after the above interventions were observed.Double luciferase reporter genes were used to detect the targeting relationship between miR-34a and MPP2.RESULTS Clinical samples showed that the expression levels of miR-34a and MPP2 in liver cancer tissues were lower than those in the normal tissues.The methylation degree of miR-34a promoter region in liver cancer cells was higher than that in normal liver cells.After miR-34a demethylation/mimetic transfection/MPP2 overexpression,the apoptosis of liver cancer cells was increased;the proliferation,invasion and migration capabilities were decreased;the expression levels of caspase 3,caspase 9,E-cadherin,and B-cell lymphoma 2(Bcl-2)-associated X protein were increased;and the expression levels of Bcl-2,N-cadherin,andβ-catenin were decreased.Double luciferase reporter genes confirmed that MPP2 is targeted by miR-34a.Rescue experiments showed that small interfering MPP2 could counteract the promoting effect of miR-34a demethylation on apoptosis and the inhibitory effect on cell proliferation,invasion,and migration.CONCLUSION miR-34a demethylation upregulates the expression level of MPP2 in liver cancer cells and promotes the apoptosis of liver cancer cells.miR-34a demethylation is a potential method for liver cancer treatment.展开更多
Various degrees of palmitoylated konjac glucomannan (PKGM) are prepared by heterogeneous method. Differential thermal analysis (DTA) thermographs show PKGM having certain degree of substitution (DS) gave a new crystal...Various degrees of palmitoylated konjac glucomannan (PKGM) are prepared by heterogeneous method. Differential thermal analysis (DTA) thermographs show PKGM having certain degree of substitution (DS) gave a new crystalline peak at higher temperature. And PKGM having higher DS only shows the new crystalline state. Furthermore, the effect of the DS of PKGM on its emulsifying ability has been investigated in the water in oil(w/o) and oil in water(o/w) systems. It is demonstrated that it is a kind of good w/o emulsifier with the DS ranged between 1.00 and 1.70; Whereas for DS<0.50, It is a kind of good o/w emulsifier and an interesting phenomenon appears in o/w system. And the half time of emulsion turbidity is more than 1.5 h with PKGM having 2.72 of DS used as the emulsifier.展开更多
Konjac glucomannan(KGM) has been generally used in food,film-former and biomedical applications,especially in the edible packing films due to its excellent film-forming ability,good biocompatibility and biodegrade-abi...Konjac glucomannan(KGM) has been generally used in food,film-former and biomedical applications,especially in the edible packing films due to its excellent film-forming ability,good biocompatibility and biodegrade-ability.It has the common flaws of natural polymers,such as low mechanical properties and poor antimicrobial activity,which severely limit their applications.In this paper,novel biodegradable films(NBF) of KGM with palmitoylated KGM(PKGM) were prepared by using the solventcasting technique.The structure,thermal and mechanical properties of the NBF were investigated.The results suggested that a strong hydrogen bonding was formed in NBF,which resulted in good miscibility between KGM and PKGM.The tensile strength and elongation at break of the NBF were enhanced significantly with the increase of PKGM in a certain range.With the addition of 0.75%PKGM by weight,tensile strength and elongation at break of NBF were improved largely to 117.12 MPa and 14.39%.From this work,we hope to provide one of the promising ways to design new edible food films and coatings materials with good mechanical properties.展开更多
Multicellular organisms use chemical messengers to transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids are excellent candidates for this signaling purpose. In mo...Multicellular organisms use chemical messengers to transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids are excellent candidates for this signaling purpose. In most proteins, palmitic acid and other saturated and some unsaturated fatty acids are esterified to the free thiol of cysteines and to the N-amide terminal. This palmitoylation process enhances the surface hydrophobicity and membrane affinity of protein substrates and plays important roles in modulating proteins’ trafficking, stability, and sorting etc. Protein palmitoylation has been involved in numerous cellular processes, including signaling, apoptosis, and neuronal transmission. The palmitoylation process is involved in multiple diseases such as Huntington’s disease, various cardiovascular and T-cell mediated immune disorders, as well as cancer. Protein palmitoylation through the thioester (S-acylation) is unique in that it is the only reversible lipid modification. Our study on lipopolysaccharide (LPS) and deoxynivalenol (DON) treatment to rats provides some insights to the complex role of protein palmitoylation in chemical and microbial toxicity. In contrast, myrisoylated proteins contain the 14-carbon fatty acid myristate attached via amide linkage to the N-terminal glycine residue of protein, and occur cotranslationally. The bacterial outer membrane enzyme lipid A palmitoyltransferase (PagP) confers resistance to host immune defenses by transferring a palmitate chain from a phospholipid to the lipid A component of LPS. PagP is sensitive to cationic antimicrobial peptides (CAMP) which are included among the products of the Toll-like receptor 4 (TLR4) signal transduction pathway. This modification of lipid A with a palmitate appears to both and protects the pathogenic bacteria from host immune defenses and attenuates the activation of those same defenses through the TLR4 signal transduction pathway.展开更多
Nonalcoholic fatty liver disease(NAFLD)or metabolic-associated fatty liver disease has been characterized by the lipid accumulation with injury of hepatocytes and has become one of the most common chronic liver diseas...Nonalcoholic fatty liver disease(NAFLD)or metabolic-associated fatty liver disease has been characterized by the lipid accumulation with injury of hepatocytes and has become one of the most common chronic liver diseases in the world.The complex mechanisms of NAFLD formation are still under identification.Carnitine palmitoyltransferase-Ⅱ(CPT-Ⅱ)on inner mitochondrial membrane(IMM)regulates long chain fatty acidβ-oxidation,and its abnormality has had more and more attention paid to it by basic and clinical research in NAFLD.The sequences of its peptide chain and DNA nucleotides have been identified,and the catalytic activity of CPT-Ⅱ is affected on its gene mutations,deficiency,enzymatic thermal instability,circulating carnitine level and so on.Recently,the CPT-Ⅱ dysfunction has been discovered in models of liver lipid accumulation.Meanwhile,the malignant transformation of hepatocyte-related CD44^(+) stem T cell activation,high levels of tumor-related biomarkers(AFP,GPC3)and abnormal activation of Wnt3a expression as a key signal molecule of the Wnt/β-catenin pathway run parallel to the alterations of hepatocyte pathology.This review focuses on some of the progress of CPT-Ⅱ inactivity on IMM with liver fatty accumulation as a possible novel pathogenesis for NAFLD in hepatocarcinogenesis.展开更多
A face serum composed of a combination of biologically active compounds was evaluated for safety and efficacy <em>in vitro</em>, in a repeat insult patch test and in a human clinical efficacy trial. The se...A face serum composed of a combination of biologically active compounds was evaluated for safety and efficacy <em>in vitro</em>, in a repeat insult patch test and in a human clinical efficacy trial. The serum inhibited tyrosinase activity modestly, decreased collagenase activity and exhibited notable free radical scavenging activity <em>in vitro</em>. It is gentle to the skin, as the serum did not irritate the skin or produce symptoms of allergic contact dermatitis in the 55 healthy adults that participated in the repeat insult patch test. In the efficacy trial, daily application of the face serum for 30 days significantly increased skin hydration, with all 35 volunteers experiencing improvement. Substantial improvements in skin elasticity, roughness (fine lines and wrinkles), and brightness also occurred during the trial. Dermatological examination also revealed a trend for reduced comedone count with use of the serum. Self-assessment responses revealed that all volunteers experienced improvements in multiple skin quality parameters and that participant perceptions are consistent with the results of the instrumental analyses. These findings indicated that the measured improvements in skin quality are not only statistically significant but are also clinically relevant as they were great enough for users of the face serum to feel and recognize.展开更多
Protein palmitoylation is a widespread lipid modification in which one or more cysteine thiols on a substrate protein are modified to form a thioester with a palmitoyl group.This lipid modification is readily reversib...Protein palmitoylation is a widespread lipid modification in which one or more cysteine thiols on a substrate protein are modified to form a thioester with a palmitoyl group.This lipid modification is readily reversible;a feature of protein palmitoylation that allows for rapid regulation of the function of many cellular proteins.Mutations in palmitoyltransferases(PATs),the enzymes that catalyze the formation of this modification,are associated with a number of neurological diseases and cancer progression.This review summarizes the crucial role of palmitoylation in biological systems,the discovery of the DHHC protein family that catalyzes protein palmitoylation,and the development of methods for investigating the catalytic mechanism of PATs.展开更多
Glutamate acting on AMPA-type ionotropic glutamate receptor(AMPAR) mediates the majority of fast excitatory synaptic transmission in the mammalian central nervous system. Dynamic regulation of AMPAR by post-translatio...Glutamate acting on AMPA-type ionotropic glutamate receptor(AMPAR) mediates the majority of fast excitatory synaptic transmission in the mammalian central nervous system. Dynamic regulation of AMPAR by post-translational modifications is one of the key elements that allow the nervous system to adapt to environment stimulations. S-palmitoylation, an important lipid modification by post-translational addition of a long-chain fatty acid to a cysteine residue, regulates AMPA receptor trafficking, which dynamically affects multiple fundamental brain functions, such as learning and memory. In vivo, S-palmitoylation is controlled by palmitoyl acyl transferases and palmitoyl thioesterases.In this review, we highlight advances in the mechanisms for dynamic AMPA receptors palmitoylation,and discuss how palmitoylation affects AMPA receptors function at synapses in recent years.Pharmacological regulation of S-palmitoylation may serve as a novel therapeutic strategy for neurobiological diseases.展开更多
Epithelial ovarian cancer(EOC) exhibits strong dependency on the tricarboxylic acid(TCA) cycle and oxidative phosphorylation to fuel anabolic process.Here,we show that malate dehydrogenase 2(MDH2),a key enzyme of the ...Epithelial ovarian cancer(EOC) exhibits strong dependency on the tricarboxylic acid(TCA) cycle and oxidative phosphorylation to fuel anabolic process.Here,we show that malate dehydrogenase 2(MDH2),a key enzyme of the TCA cycle,is palmitoylated at cysteine 138(C138) residue,resulting in increased activity of MDH2.We next identify that ZDHHC18 acts as a palmitoyltransferase of MDH2.Glutamine deprivation enhances MDH2 palmitoylation by increasing the binding between ZDHHC18 and MDH2.MDH2 silencing represses mitochondrial respiration as well as ovarian cancer cell proliferation both in vitro and in vivo.Intriguingly,re-expression of wild-type MDH2,but not its palmitoylation-deficient C138 S mutant,sustains mitochondrial respiration and restores the growth as well as clonogenic capability of ovarian cancer cells.Notably,MDH2 palmitoylation level is elevated in clinical cancer samples from patients with high-grade serous ovarian cancer.These observations suggest that MDH2 palmitoylation catalyzed by ZDHHC18 sustains mitochondrial respiration and promotes the malignancy of ovarian cancer,yielding possibilities of targeting ZDHHC18-mediated MDH2 palmitoylation in the treatment of EOC.展开更多
Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy(SAVI).Furthermore,excessive activity of t...Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy(SAVI).Furthermore,excessive activity of the STING signaling pathway is associated with autoinflammatory diseases,including systemic lupus erythematosus and Aicardi–Goutières syndrome(AGS).Two independent studies recently identified pharmacological inhibitors of STING.Strikingly,both types of compounds are reactive nitrocontaining electrophiles that target STING palmitoylation,a posttranslational modification necessary for STING signaling.As a consequence,the activation of downstream signaling molecules and the induction of type I interferons were inhibited.The compounds were effective at ameliorating inflammation in a mouse model of AGS and in blocking the production of type I interferons in primary fibroblasts from SAVI patients.This mini-review focuses on the roles of palmitoylation in STING activation and signaling and as a pharmaceutical target for drug development.展开更多
The TEA domain(TEAD)family proteins(TEAD1-4)are essential transcription factors that control cell differentiation and organ size in the Hippo pathway.Although the sequences and structures of TEAD family proteins are h...The TEA domain(TEAD)family proteins(TEAD1-4)are essential transcription factors that control cell differentiation and organ size in the Hippo pathway.Although the sequences and structures of TEAD family proteins are highly conserved,each TEAD isoform has unique physiological and pathological functions.Therefore,the development and discovery of subtype selective inhibitors for TEAD protein will provide important chemical probes for the TEAD-related function studies in development and diseases.Here,we identified a novel TEAD 1/3 covalent inhibitor(DC-TEADin1072)with biochemical IC50 values of 0.61±0.02 and 0.58±0.12μmol/L against TEAD1 and TEAD3,respectively.Further chemical optimization based on DC-TEAD in 1072 yielded a selective TEAD3 inhibitor DCTEAD3 in03 with the IC_(50) value of 0.16±0.03μmol/L,which shows 100-fold selectivity over other TEAD isoforms in activity-based protein profiling(ABPP)assays.In cells,DC-TEAD3 in03 showed selective inhibitory effect on TEAD3 in GAL4-TEAD(1-4)reporter assays with the IC50 value of1.15μmol/L.When administered to zebrafish juveniles,experiments showed that DC-TEAD3 in03 reduced the growth rate of zebrafish caudal fins,indicating the importance of TEAD3 activity in controlling proportional growth of vertebrate appendages.展开更多
The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be larg...The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be largely maintained. The apparent palmitoylation ratio was significantly increased after the Goα was treated with DTT. The GTPγS binding characteristic of Goα was not influenced by palmitoylation, however, the affinity for LUVs was increased dramatically. The in vitro palmitoylation model of Goα provides a better basis for studying the functional role of G protein palmitoylation in signal transduction.展开更多
Acyl-CoA synthetase long chain family member 5(ACSL5),is a member of the acyl-CoA synthetases(ACSs)family that activates long chain fatty acids by catalyzing the synthesis of fatty acyl-CoAs.The dysregulation of ACSL5...Acyl-CoA synthetase long chain family member 5(ACSL5),is a member of the acyl-CoA synthetases(ACSs)family that activates long chain fatty acids by catalyzing the synthesis of fatty acyl-CoAs.The dysregulation of ACSL5 has been reported in some cancers,such as glioma and colon cancers.However,little is known about the role of ACSL5 in acute myeloid leukemia(AML).We found that the expression of ACSL5 was higher in bone marrow cells from AML patients compared with that from healthy donors.ACSL5 level could serve as an independent prognostic predictor of the overall survival of AML patients.In AML cells,the ACSL5 knockdown inhibited cell growth both in vitro and in vivo.Mechanistically,the knockdown of ACSL5 suppressed the activation of the Wnt/β-catenin pathway by suppressing the palmitoylation modification of Wnt3a.Additionally,triacsin c,a pan-ACS family inhibitor,inhibited cell growth and robustly induced cell apoptosis when combined with ABT-199,the FDA approved BCL-2 inhibitor for AML therapy.Our results indicate that ACSL5 is a potential prognosis marker for AML and a promising pharmacological target for the treatment of molecularly stratified AML.展开更多
More than 85%of patients with uveal melanoma(UM)carry a GNAQ or GNA11 mutation at a hotspot codon(Q209)that encodes G proteinαsubunit q/11 polypeptides(Gα_(q/11)).GNAQ/11 relies on palmitoylation for membrane associ...More than 85%of patients with uveal melanoma(UM)carry a GNAQ or GNA11 mutation at a hotspot codon(Q209)that encodes G proteinαsubunit q/11 polypeptides(Gα_(q/11)).GNAQ/11 relies on palmitoylation for membrane association and signal transduction.Despite the palmitoylation of GNAQ/11 was discovered long before,its implication in UM remains unclear.Here,results of palmitoylation-targeted mutagenesis and chemical interference approaches revealed that the loss of GNAQ/11 palmitoylation substantially affected tumor cell proliferation and survival in UM cells.Palmitoylation inhibition through the mutation of palmitoylation sites suppressed GNAQ/11^(Q209L)-induced malignant transformation in NIH3T3 cells.Importantly,the palmitoylation-deficient oncogenic GNAQ/11 failed to rescue the cell death initiated by the knock down of endogenous GNAQ/11 oncogenes in UM cells,which are much more dependent on Gα_(q/11) signaling for cell survival and proliferation than other melanoma cells without GNAQ/11 mutations.Furthermore,the palmitoylation inhibitor,2-bromopalmitate,also specifically disrupted Gα_(q/11) downstream signaling by interfering with the MAPK pathway and BCL2 survival pathway in GNAQ/11-mutant UM cells and showed a notable synergistic effect when applied in combination with the BCL2 inhibitor,ABT-199,in vitro.The findings validate that GNAQ/11 palmitoylation plays a critical role in UM and may serve as a promising therapeutic target for GNAQ/11-driven UM.展开更多
Currently,there is a lack of effective medicines capable of halting or reve rsing the progression of neurodegenerative disorde rs,including amyotrophic lateral sclerosis,Parkinson s disease,multiple sclerosis,or Alzhe...Currently,there is a lack of effective medicines capable of halting or reve rsing the progression of neurodegenerative disorde rs,including amyotrophic lateral sclerosis,Parkinson s disease,multiple sclerosis,or Alzheimer s disease.Given the unmet medical need,it is necessary to reevaluate the existing para digms of how to to rget these diseases.When considering neurodegenerative diseases from a systemic neurometabolic perspective,it becomes possible to explain the shared pathological features.This innovative approach presented in this paper draws upon exte nsive research conducted by the authors and researchers worldwide.In this review,we highlight the importance of metabolic mitochondrial dysfunction in the context of neurodegenerative diseases.We provide an overview of the risk factors associated with developing neurodegenerative disorders,including genetic,epigenetic,and environmental fa ctors.Additionally,we examine pathological mechanisms implicated in these diseases such as oxidative stress,accumulation of misfolded proteins,inflammation,demyelination,death of neurons,insulin resistance,dysbiosis,and neurotransmitter disturbances.Finally,we outline a proposal for the restoration of mitochondrial metabolism,a crucial aspect that may hold the key to facilitating curative therapeutic interventions for neurodegenerative disorders in forthcoming advancements.展开更多
文摘Carnitine Palmitoyl Transferase II (CPTII) is a very important enzyme that helps with the oxidation of long-chain fatty acid to produce energy. Deficiency in CPTII will lead to energy deficiency in the case of fasting and the accumulation of the long chain fatty in the body. There are three types of CPT II deficiency, the myopathic form, the severe infantile hepatocardiomuscular form and the lethal neonatal form. They are all inherited as an autosomal recessive. Diagnosis of the CPTII are 1) tandem mass spectrometry (MS/MS) in adult form and 2) CPTII polymorphism (F352C), which is linked to reducing the activity of CPTII in infantile form [1]. Glucose is the primary management and medium-chain fatty acid is an alternative due to the bypass of the CPTII enzyme in the pathway. For the prevention of CPTII deficiency are to avoid long chain fatty acid (C12-fatty acid), fasting, prolonged exercise, known triggers, and certain medications such as anti-epileptics and general anesthesia. During the rhabdomyolysis and myoglobinuria attack, it is very important to maintain hydration to avoid acute renal failure. If, however, renal failure occurs, dialysis is recommended. We present a case of a 27-year-old African American woman with the significant past medical history of CPT II deficiency leading to recurrent rhabdomyolysis and myoglobinuria. Together with all the research studies from diagnosis to treatment of CPTII deficiency will help in clinical management of patients. And this case report will add to the existing case reports of patients who have CPTII deficiency in terms of how we diagnose, how we treat, and how we prevent symptoms from re-occurring.
基金Supported by the National Natural Science Foundation,No.81673241,No.81200634,No.81370982the program of Jiangsu Key Research Plan,No.BE2016698the International Science and Technology Cooperation Program of China,No.2013DFA32150
文摘AIM To investigate the dynamic alteration of mitochondrial carnitine palmitoyl transferase Ⅱ(CPT-Ⅱ) expression during malignant transformation of rat hepatocytes.METHODS Sprague-Dawley male rats were fed with normal, high fat(HF), and HF containing 2-fluorenylacetamide(2-FAA) diet, respectively. According to the Hematoxylin and Eosin staining of livers, rats were divided into control, fatty liver, degeneration, pre-cancerous, and cancerous groups. Liver lipids were dyed with Oil Red O, CPT-Ⅱ alterations were analyzed by immunohistochemistry, and compared with CPT-Ⅱ specific concentration(μg/mg protein). Levels of total cholesterol(Tch), triglyceride(TG), and aminotransferases [alanine aminotransferase(ALT), aspartate aminotransferase(AST)] were determined by the routine methods.RESULTS After intake of HF and/or HF+2-FAA diets, the rat livers showed mass lipid accumulation. The lipid level in the control group was significantly lower than that in other groups. The changes of serum TG and Tch levels were abnormally increasing, 2-3 times more than those in the controls(P < 0.05). During the rat liver morphological changes from normal to cancer development process with hepatocyte injury, serum AST and ALT levels were significantly higher(4-8 times, P < 0.05) than those in the control group. The specific concentration of CPT-Ⅱ in liver tissues progressively decreased during hepatocyte malignant transformation, with the lowest CPT-Ⅱ levels in the cancer group than in any of the other groups(P < 0.05).CONCLUSION Low CPT-Ⅱ expression might lead to abnormal hepatic lipid accumulation, which should promote the malignant transformation of hepatocytes.
文摘BACKGROUND Liver cancer is a common cancer and the main cause of cancer-related deaths worldwide.Liver cancer is the sixth most common cancer in the world.Although miR-34a and palmitoyl membrane palmitoylated protein(MPP2)are reportedly involved in various cell processes,their precise roles in liver cancer are still unclear.AIM To investigate the expression of micro RNA 34a(miR-34a),methylation of the miR-34a promoter and the expression of MPP2 in liver cancer cells and their related mechanisms.METHODS Together,78 cases of liver cancer tissues and 78 cases of adjacent tissues were collected.The methylation degree of miR-34a promoter in liver cancer/paracancerous tissue and liver cancer cells/normal liver cells,and the expression levels of miR-34a and MPP2 in the above samples were detected.Demethylation of liver cancer cells or transfection of liver cancer cells with miR-34a mimetic was performed.The MPP2 overexpression vector was used to transfect liver cancer cells,and the changes in proliferation,invasion,apoptosis,migration,and other biological functions of liver cancer cells after the above interventions were observed.Double luciferase reporter genes were used to detect the targeting relationship between miR-34a and MPP2.RESULTS Clinical samples showed that the expression levels of miR-34a and MPP2 in liver cancer tissues were lower than those in the normal tissues.The methylation degree of miR-34a promoter region in liver cancer cells was higher than that in normal liver cells.After miR-34a demethylation/mimetic transfection/MPP2 overexpression,the apoptosis of liver cancer cells was increased;the proliferation,invasion and migration capabilities were decreased;the expression levels of caspase 3,caspase 9,E-cadherin,and B-cell lymphoma 2(Bcl-2)-associated X protein were increased;and the expression levels of Bcl-2,N-cadherin,andβ-catenin were decreased.Double luciferase reporter genes confirmed that MPP2 is targeted by miR-34a.Rescue experiments showed that small interfering MPP2 could counteract the promoting effect of miR-34a demethylation on apoptosis and the inhibitory effect on cell proliferation,invasion,and migration.CONCLUSION miR-34a demethylation upregulates the expression level of MPP2 in liver cancer cells and promotes the apoptosis of liver cancer cells.miR-34a demethylation is a potential method for liver cancer treatment.
文摘Various degrees of palmitoylated konjac glucomannan (PKGM) are prepared by heterogeneous method. Differential thermal analysis (DTA) thermographs show PKGM having certain degree of substitution (DS) gave a new crystalline peak at higher temperature. And PKGM having higher DS only shows the new crystalline state. Furthermore, the effect of the DS of PKGM on its emulsifying ability has been investigated in the water in oil(w/o) and oil in water(o/w) systems. It is demonstrated that it is a kind of good w/o emulsifier with the DS ranged between 1.00 and 1.70; Whereas for DS<0.50, It is a kind of good o/w emulsifier and an interesting phenomenon appears in o/w system. And the half time of emulsion turbidity is more than 1.5 h with PKGM having 2.72 of DS used as the emulsifier.
文摘Konjac glucomannan(KGM) has been generally used in food,film-former and biomedical applications,especially in the edible packing films due to its excellent film-forming ability,good biocompatibility and biodegrade-ability.It has the common flaws of natural polymers,such as low mechanical properties and poor antimicrobial activity,which severely limit their applications.In this paper,novel biodegradable films(NBF) of KGM with palmitoylated KGM(PKGM) were prepared by using the solventcasting technique.The structure,thermal and mechanical properties of the NBF were investigated.The results suggested that a strong hydrogen bonding was formed in NBF,which resulted in good miscibility between KGM and PKGM.The tensile strength and elongation at break of the NBF were enhanced significantly with the increase of PKGM in a certain range.With the addition of 0.75%PKGM by weight,tensile strength and elongation at break of NBF were improved largely to 117.12 MPa and 14.39%.From this work,we hope to provide one of the promising ways to design new edible food films and coatings materials with good mechanical properties.
文摘Multicellular organisms use chemical messengers to transmit signals among organelles and to other cells. Relatively small hydrophobic molecules such as lipids are excellent candidates for this signaling purpose. In most proteins, palmitic acid and other saturated and some unsaturated fatty acids are esterified to the free thiol of cysteines and to the N-amide terminal. This palmitoylation process enhances the surface hydrophobicity and membrane affinity of protein substrates and plays important roles in modulating proteins’ trafficking, stability, and sorting etc. Protein palmitoylation has been involved in numerous cellular processes, including signaling, apoptosis, and neuronal transmission. The palmitoylation process is involved in multiple diseases such as Huntington’s disease, various cardiovascular and T-cell mediated immune disorders, as well as cancer. Protein palmitoylation through the thioester (S-acylation) is unique in that it is the only reversible lipid modification. Our study on lipopolysaccharide (LPS) and deoxynivalenol (DON) treatment to rats provides some insights to the complex role of protein palmitoylation in chemical and microbial toxicity. In contrast, myrisoylated proteins contain the 14-carbon fatty acid myristate attached via amide linkage to the N-terminal glycine residue of protein, and occur cotranslationally. The bacterial outer membrane enzyme lipid A palmitoyltransferase (PagP) confers resistance to host immune defenses by transferring a palmitate chain from a phospholipid to the lipid A component of LPS. PagP is sensitive to cationic antimicrobial peptides (CAMP) which are included among the products of the Toll-like receptor 4 (TLR4) signal transduction pathway. This modification of lipid A with a palmitate appears to both and protects the pathogenic bacteria from host immune defenses and attenuates the activation of those same defenses through the TLR4 signal transduction pathway.
基金Supported by the National Natural Science Foundation of China,No.81873915 and No.31872738the Key Plan of Nantong S&T Development,No.MS12020021the S&T Program of Medical School of Nantong University,No.TDYX2021010.
文摘Nonalcoholic fatty liver disease(NAFLD)or metabolic-associated fatty liver disease has been characterized by the lipid accumulation with injury of hepatocytes and has become one of the most common chronic liver diseases in the world.The complex mechanisms of NAFLD formation are still under identification.Carnitine palmitoyltransferase-Ⅱ(CPT-Ⅱ)on inner mitochondrial membrane(IMM)regulates long chain fatty acidβ-oxidation,and its abnormality has had more and more attention paid to it by basic and clinical research in NAFLD.The sequences of its peptide chain and DNA nucleotides have been identified,and the catalytic activity of CPT-Ⅱ is affected on its gene mutations,deficiency,enzymatic thermal instability,circulating carnitine level and so on.Recently,the CPT-Ⅱ dysfunction has been discovered in models of liver lipid accumulation.Meanwhile,the malignant transformation of hepatocyte-related CD44^(+) stem T cell activation,high levels of tumor-related biomarkers(AFP,GPC3)and abnormal activation of Wnt3a expression as a key signal molecule of the Wnt/β-catenin pathway run parallel to the alterations of hepatocyte pathology.This review focuses on some of the progress of CPT-Ⅱ inactivity on IMM with liver fatty accumulation as a possible novel pathogenesis for NAFLD in hepatocarcinogenesis.
文摘A face serum composed of a combination of biologically active compounds was evaluated for safety and efficacy <em>in vitro</em>, in a repeat insult patch test and in a human clinical efficacy trial. The serum inhibited tyrosinase activity modestly, decreased collagenase activity and exhibited notable free radical scavenging activity <em>in vitro</em>. It is gentle to the skin, as the serum did not irritate the skin or produce symptoms of allergic contact dermatitis in the 55 healthy adults that participated in the repeat insult patch test. In the efficacy trial, daily application of the face serum for 30 days significantly increased skin hydration, with all 35 volunteers experiencing improvement. Substantial improvements in skin elasticity, roughness (fine lines and wrinkles), and brightness also occurred during the trial. Dermatological examination also revealed a trend for reduced comedone count with use of the serum. Self-assessment responses revealed that all volunteers experienced improvements in multiple skin quality parameters and that participant perceptions are consistent with the results of the instrumental analyses. These findings indicated that the measured improvements in skin quality are not only statistically significant but are also clinically relevant as they were great enough for users of the face serum to feel and recognize.
基金financially supported by the NIH R01 grant GM040602 (CAF)
文摘Protein palmitoylation is a widespread lipid modification in which one or more cysteine thiols on a substrate protein are modified to form a thioester with a palmitoyl group.This lipid modification is readily reversible;a feature of protein palmitoylation that allows for rapid regulation of the function of many cellular proteins.Mutations in palmitoyltransferases(PATs),the enzymes that catalyze the formation of this modification,are associated with a number of neurological diseases and cancer progression.This review summarizes the crucial role of palmitoylation in biological systems,the discovery of the DHHC protein family that catalyzes protein palmitoylation,and the development of methods for investigating the catalytic mechanism of PATs.
基金supported by grants from the National Basic Research Program of China (the 973 Program, No. 2013CB531303 to Dr. Jianguo Chen No. 2014CB744601 to Fang Wang)+3 种基金the National Natural Scientific Foundation of China (NSFC, No. 81222048 to Fang Wang No. 81302754 to Peng Fei Wu)supported by the International Science & Technology Cooperation Program of China (No. 2011DFA32670 to Jianguo Chen)PCSIRT (No. IRT13016)
文摘Glutamate acting on AMPA-type ionotropic glutamate receptor(AMPAR) mediates the majority of fast excitatory synaptic transmission in the mammalian central nervous system. Dynamic regulation of AMPAR by post-translational modifications is one of the key elements that allow the nervous system to adapt to environment stimulations. S-palmitoylation, an important lipid modification by post-translational addition of a long-chain fatty acid to a cysteine residue, regulates AMPA receptor trafficking, which dynamically affects multiple fundamental brain functions, such as learning and memory. In vivo, S-palmitoylation is controlled by palmitoyl acyl transferases and palmitoyl thioesterases.In this review, we highlight advances in the mechanisms for dynamic AMPA receptors palmitoylation,and discuss how palmitoylation affects AMPA receptors function at synapses in recent years.Pharmacological regulation of S-palmitoylation may serve as a novel therapeutic strategy for neurobiological diseases.
基金supported by the National Key Research and Development Program of China (2020YFA0803402 and2019YFA0801703)the National Natural Science Foundation of China(81872240,81802745,81790250/81790253 and 91959202)Innovation Program of Shanghai Municipal Education Commission (N173606)。
文摘Epithelial ovarian cancer(EOC) exhibits strong dependency on the tricarboxylic acid(TCA) cycle and oxidative phosphorylation to fuel anabolic process.Here,we show that malate dehydrogenase 2(MDH2),a key enzyme of the TCA cycle,is palmitoylated at cysteine 138(C138) residue,resulting in increased activity of MDH2.We next identify that ZDHHC18 acts as a palmitoyltransferase of MDH2.Glutamine deprivation enhances MDH2 palmitoylation by increasing the binding between ZDHHC18 and MDH2.MDH2 silencing represses mitochondrial respiration as well as ovarian cancer cell proliferation both in vitro and in vivo.Intriguingly,re-expression of wild-type MDH2,but not its palmitoylation-deficient C138 S mutant,sustains mitochondrial respiration and restores the growth as well as clonogenic capability of ovarian cancer cells.Notably,MDH2 palmitoylation level is elevated in clinical cancer samples from patients with high-grade serous ovarian cancer.These observations suggest that MDH2 palmitoylation catalyzed by ZDHHC18 sustains mitochondrial respiration and promotes the malignancy of ovarian cancer,yielding possibilities of targeting ZDHHC18-mediated MDH2 palmitoylation in the treatment of EOC.
文摘Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy(SAVI).Furthermore,excessive activity of the STING signaling pathway is associated with autoinflammatory diseases,including systemic lupus erythematosus and Aicardi–Goutières syndrome(AGS).Two independent studies recently identified pharmacological inhibitors of STING.Strikingly,both types of compounds are reactive nitrocontaining electrophiles that target STING palmitoylation,a posttranslational modification necessary for STING signaling.As a consequence,the activation of downstream signaling molecules and the induction of type I interferons were inhibited.The compounds were effective at ameliorating inflammation in a mouse model of AGS and in blocking the production of type I interferons in primary fibroblasts from SAVI patients.This mini-review focuses on the roles of palmitoylation in STING activation and signaling and as a pharmaceutical target for drug development.
基金the financial supports from the National Natural Science Foundation of China(91853205,81625022,81821005 to Cheng Luo81973166,21702218,91753207 to Bing Zhou),Wong Education to Cheng Luo and Bing Zhou+2 种基金the Department of Science and Technology of Fujian Province(2019T3029 to Cheng Luo,China)the Science and Technology Commission of Shanghai Municipality(19XD1404700 and 18431907100 to Cheng Luo,China)National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”(2018ZX09711002-008 to Cheng Luo,2018ZX09711002-008-005 to Huijin Feng,2018ZX09711002-006 to Bing Zhou,China)。
文摘The TEA domain(TEAD)family proteins(TEAD1-4)are essential transcription factors that control cell differentiation and organ size in the Hippo pathway.Although the sequences and structures of TEAD family proteins are highly conserved,each TEAD isoform has unique physiological and pathological functions.Therefore,the development and discovery of subtype selective inhibitors for TEAD protein will provide important chemical probes for the TEAD-related function studies in development and diseases.Here,we identified a novel TEAD 1/3 covalent inhibitor(DC-TEADin1072)with biochemical IC50 values of 0.61±0.02 and 0.58±0.12μmol/L against TEAD1 and TEAD3,respectively.Further chemical optimization based on DC-TEAD in 1072 yielded a selective TEAD3 inhibitor DCTEAD3 in03 with the IC_(50) value of 0.16±0.03μmol/L,which shows 100-fold selectivity over other TEAD isoforms in activity-based protein profiling(ABPP)assays.In cells,DC-TEAD3 in03 showed selective inhibitory effect on TEAD3 in GAL4-TEAD(1-4)reporter assays with the IC50 value of1.15μmol/L.When administered to zebrafish juveniles,experiments showed that DC-TEAD3 in03 reduced the growth rate of zebrafish caudal fins,indicating the importance of TEAD3 activity in controlling proportional growth of vertebrate appendages.
文摘The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be largely maintained. The apparent palmitoylation ratio was significantly increased after the Goα was treated with DTT. The GTPγS binding characteristic of Goα was not influenced by palmitoylation, however, the affinity for LUVs was increased dramatically. The in vitro palmitoylation model of Goα provides a better basis for studying the functional role of G protein palmitoylation in signal transduction.
基金supported by the key international cooperation projects of the National Natural Science Foundation of China(No.81820108004)the major projects of the Zhejiang Provincial Department of Science and Technology(No.2021C03123)the Pediatric Leukemia Diagnosis and Therapeutic Technology Research Center of Zhejiang Province(No.JBZX-201904).
文摘Acyl-CoA synthetase long chain family member 5(ACSL5),is a member of the acyl-CoA synthetases(ACSs)family that activates long chain fatty acids by catalyzing the synthesis of fatty acyl-CoAs.The dysregulation of ACSL5 has been reported in some cancers,such as glioma and colon cancers.However,little is known about the role of ACSL5 in acute myeloid leukemia(AML).We found that the expression of ACSL5 was higher in bone marrow cells from AML patients compared with that from healthy donors.ACSL5 level could serve as an independent prognostic predictor of the overall survival of AML patients.In AML cells,the ACSL5 knockdown inhibited cell growth both in vitro and in vivo.Mechanistically,the knockdown of ACSL5 suppressed the activation of the Wnt/β-catenin pathway by suppressing the palmitoylation modification of Wnt3a.Additionally,triacsin c,a pan-ACS family inhibitor,inhibited cell growth and robustly induced cell apoptosis when combined with ABT-199,the FDA approved BCL-2 inhibitor for AML therapy.Our results indicate that ACSL5 is a potential prognosis marker for AML and a promising pharmacological target for the treatment of molecularly stratified AML.
基金This work was supported by the Key Project of National Natural Science Foundation of China(No.81530006 to Ruibao Ren)Shanghai Collaborative Innovation Program on Regenerative Medicine and Stem Cell Research(No.2019CXJQ01 to Ruibao Ren)+2 种基金National Natural ScienceFoundation of China(No.81870112 to Ruibao Ren,No.81770171 to Bo Jiao,and No.81970134 to Ping Liu)Samuel Waxman Cancer Research Foundation(to Ruibao Ren)the Innovative Research Team of High-level Local Universities in Shanghai.
文摘More than 85%of patients with uveal melanoma(UM)carry a GNAQ or GNA11 mutation at a hotspot codon(Q209)that encodes G proteinαsubunit q/11 polypeptides(Gα_(q/11)).GNAQ/11 relies on palmitoylation for membrane association and signal transduction.Despite the palmitoylation of GNAQ/11 was discovered long before,its implication in UM remains unclear.Here,results of palmitoylation-targeted mutagenesis and chemical interference approaches revealed that the loss of GNAQ/11 palmitoylation substantially affected tumor cell proliferation and survival in UM cells.Palmitoylation inhibition through the mutation of palmitoylation sites suppressed GNAQ/11^(Q209L)-induced malignant transformation in NIH3T3 cells.Importantly,the palmitoylation-deficient oncogenic GNAQ/11 failed to rescue the cell death initiated by the knock down of endogenous GNAQ/11 oncogenes in UM cells,which are much more dependent on Gα_(q/11) signaling for cell survival and proliferation than other melanoma cells without GNAQ/11 mutations.Furthermore,the palmitoylation inhibitor,2-bromopalmitate,also specifically disrupted Gα_(q/11) downstream signaling by interfering with the MAPK pathway and BCL2 survival pathway in GNAQ/11-mutant UM cells and showed a notable synergistic effect when applied in combination with the BCL2 inhibitor,ABT-199,in vitro.The findings validate that GNAQ/11 palmitoylation plays a critical role in UM and may serve as a promising therapeutic target for GNAQ/11-driven UM.
文摘Currently,there is a lack of effective medicines capable of halting or reve rsing the progression of neurodegenerative disorde rs,including amyotrophic lateral sclerosis,Parkinson s disease,multiple sclerosis,or Alzheimer s disease.Given the unmet medical need,it is necessary to reevaluate the existing para digms of how to to rget these diseases.When considering neurodegenerative diseases from a systemic neurometabolic perspective,it becomes possible to explain the shared pathological features.This innovative approach presented in this paper draws upon exte nsive research conducted by the authors and researchers worldwide.In this review,we highlight the importance of metabolic mitochondrial dysfunction in the context of neurodegenerative diseases.We provide an overview of the risk factors associated with developing neurodegenerative disorders,including genetic,epigenetic,and environmental fa ctors.Additionally,we examine pathological mechanisms implicated in these diseases such as oxidative stress,accumulation of misfolded proteins,inflammation,demyelination,death of neurons,insulin resistance,dysbiosis,and neurotransmitter disturbances.Finally,we outline a proposal for the restoration of mitochondrial metabolism,a crucial aspect that may hold the key to facilitating curative therapeutic interventions for neurodegenerative disorders in forthcoming advancements.