Alzheimer's disease is a multifactorial pathology, for which no cure is currently available. Nowadays, researchers are moving towards a new hypothesis of the onset of the illness, linking it to a metabolic impairment...Alzheimer's disease is a multifactorial pathology, for which no cure is currently available. Nowadays, researchers are moving towards a new hypothesis of the onset of the illness, linking it to a metabolic impairment, q-his innovative approach will lead to the identification of new targets for the preparation of new effective drugs. Peroxisome proliferator-activated receptors and their ligands are the ideal candidates to reach the necessary breakthrough to defeat this complicate disease.展开更多
Background: In dairy cows circulating non-esterified fatty acids(NEFA) increase early post-partum while liver and other tissues undergo adaptation to greater lipid metabolism, mainly regulated by peroxisome proliferat...Background: In dairy cows circulating non-esterified fatty acids(NEFA) increase early post-partum while liver and other tissues undergo adaptation to greater lipid metabolism, mainly regulated by peroxisome proliferator-activated receptors(PPAR). PPAR are activated by fatty acids(FA), but it remains to be demonstrated that circulating NEFA or dietary FA activate bovine PPAR. We hypothesized that circulating NEFA and dietary FA activate PPAR in dairy cows.Methods: The dose-response activation of PPAR by NEFA or dietary FA was assessed using HP300 e digital dispenser and luciferase reporter in several bovine cell types. Cells were treated with blood plasma isolated from Jersey cows before and after parturition, NEFA isolated from the blood plasma, FA released from lipoproteins using milk lipoprotein lipase(LPL), and palmitic acid(C16:0). Effect on each PPAR isotype was assessed using specific synthetic inhibitors.Results: NEFA isolated from blood serum activate PPAR linearly up to ~ 4-fold at 400 μmol/L in MAC-T cells but had cytotoxic effect. Addition of albumin to the culture media decreases cytotoxic effects of NEFA but also PPAR activation by ~ 2-fold. Treating cells with serum from peripartum cows reveals that much of the PPAR activation can be explained by the amount of NEFA in the serum(R~2 = 0.91) and that the response to serum NEFA follows a quadratic tendency, with peak activation around 1.4 mmol/L. Analysis of PPAR activation by serum in MAC-T, BFH-12 and BPAEC cells revealed that most of the activation is explained by the activity of PPARδ and PPARγ, but not PPARα. Palmitic acid activated PPAR when added in culture media or blood serum but the activation was limited to PPARδ and PPARα and the response was nil in serum from post-partum cows. The addition of LPL to the serum increased > 1.5-fold PPAR activation.Conclusion: Our results support dose-dependent activation of PPAR by circulating NEFA in bovine, specifically δand γ isotypes. Data also support the possibility of increasing PPAR activation by dietary FA;however, this nutrigenomics approach maybe only effective in pre-partum but not post-partum cows.展开更多
The aim of this investigation was to determine whether a PPAR72 Prol2Ala polymorphism was associated with insulin resistance, β-cellfunction and hypertension in Chinese populations. 289 unrelated Chinese subjects fir...The aim of this investigation was to determine whether a PPAR72 Prol2Ala polymorphism was associated with insulin resistance, β-cellfunction and hypertension in Chinese populations. 289 unrelated Chinese subjects first diagnosed Type 2 diabetes (HbAC1〈6.0) were investigated, including 132 hypertensive diabetic (HTD) subjects, 157 normotensive diabetic (NTD) subjects. Blood pressure and anthropometric measurements were collected from all participants, as well as several venous blood samples during oral glucose tolerance test (OGTT). Biochemical measurements (high-density lipoprotein (HDL) and low-density lipoprotein-cholesterol (LDL), triglycerides) and PPARγ2 Pro12Ala genotype were also determined. And insulin resistance and β-cells function was assessed by HOMA-IR and HOMA-β respectively. The frequency of subjects bearing the Pro12Ala was lower in the hypertension group (3. 03 %) than in the non-hypertension group (5.7 %) (P〈0.05) after adjusted for age, BMI and gender. Hypertensive diabetic Pro12Ala subjects had lower fasting plasma glucose level (P=0. 0127), and better glucose tolerance 60 min after oral glucose (P=0. 0361). Moreover, plasma insulin concentrations at 60 min was lower than those without A variant (P = 0. 0275), and both hypertensive Ala/Pro in HOMA-β (P : 0. 0455) and AUC for insulin (P=0. 0473) were higher, and HOMA-IR was lower (P=0. 0375) as compared with hypertensive Pro/Pro subjects. No association was observed between Prol2Ala genotype and BMI, total cholesterol, HDL- cholesterol or triglycerides in either group. Our findings suggested that the Ala 12 allele of the PPARγ2 gene may improve insulin resistance and ameliorate β-cell function reserves in T2DM with hypertension, and protect patients from hypertension in T2DM. As an important thrifty gene, environment factors may exerts an effect of PPARγ2 on glucose homeostasis and insulin resistance.展开更多
BACKGROUND This study presents the clinical and genetic mutation characteristics of an unusual case of adult-onset diabetes mellitus occurring in adolescence,featuring a unique mutation in the peroxisome proliferator-...BACKGROUND This study presents the clinical and genetic mutation characteristics of an unusual case of adult-onset diabetes mellitus occurring in adolescence,featuring a unique mutation in the peroxisome proliferator-activated receptor gamma(PPARG)gene.Data Access Statement:Research data supporting this publication are available from the NN repository at www.NNN.org/download/.CASE SUMMARY The methodology employed entailed meticulous collection of comprehensive clinical data from the probands and their respective family members.Additionally,high-throughput sequencing was conducted to analyze the PPARG genes of the patient,her siblings,and their offspring.The results of this investigation revealed that the patient initially exhibited elevated blood glucose levels during pregnancy,accompanied by insulin resistance and hypertriglyceridemia.Furthermore,these strains displayed increased susceptibility to diabetic kidney disease without any discernible aggregation patterns.The results from the gene detection process demonstrated a heterozygous mutation of guanine(G)at position 284 in the coding region of exon 2 of PPARG,which replaced the base adenine(A)(exon2c.284A>Gp.Tyr95Cys).This missense mutation resulted in the substitution of tyrosine with cysteine at the 95th position of the translated protein.Notably,both of her siblings harbored a nucleotide heterozygous variation at the same site,and both were diagnosed with diabetes.CONCLUSION The PPARG gene mutation,particularly the p.Tyr95Cys mutation,may represent a newly identified subtype of maturity-onset diabetes of the young.This subtype is characterized by insulin resistance and lipid metabolism disorders.展开更多
Nutrient metabolism is regulated by several factors.Social determinants of health with or without genetics are the primary regulator of metabolism,and an unhealthy lifestyle affects all modulators and mediators,leadin...Nutrient metabolism is regulated by several factors.Social determinants of health with or without genetics are the primary regulator of metabolism,and an unhealthy lifestyle affects all modulators and mediators,leading to the adaptation and finally to the exhaustion of cellular functions.Hepatic steatosis is defined by presence of fat in more than 5%of hepatocytes.In hepatocytes,fat is stored as triglycerides in lipid droplet.Hepatic steatosis results from a combination of multiple intracellular processes.In a healthy individual nutrient metabolism is regulated at several steps.It ranges from the selection of nutrients in a grocery store to the last step of consumption of ATP as an energy or as a building block of a cell as structural component.Several hormones,peptides,and genes have been described that participate in nutrient metabolism.Several enzymes participate in each nutrient metabolism as described above from ingestion to generation of ATP.As of now several publications have revealed very intricate regulation of nutrient metabolism,where most of the regulatory factors are tied to each other bidirectionally,making it difficult to comprehend chronological sequence of events.Insulin hormone is the primary regulator of all nutrients’metabolism both in prandial and fasting states.Insulin exerts its effects directly and indirectly on enzymes involved in the three main cellular function processes;metabolic,inflammation and repair,and cell growth and regeneration.Final regulators that control the enzymatic functions through stimulation or suppression of a cell are nuclear receptors in especially farnesoid X receptor and peroxisome proliferator-activated receptor/RXR ligands,adiponectin,leptin,and adiponutrin.Insulin hormone has direct effect on these final modulators.Whereas blood glucose level,serum lipids,incretin hormones,bile acids in conjunction with microbiota are intermediary modulators which are controlled by lifestyle.The purpose of this review is to overview the key players in the pathogenesis of metabolic dysfunction-associated steatotic liver disease(MASLD)that help us understand the disease natural course,risk stratification,role of lifestyle and pharmacotherapy in each individual patient with MASLD to achieve personalized care and target the practice of precision medicine.PubMed and Google Scholar databases were used to identify publication related to metabolism of carbohydrate and fat in states of health and disease states;MASLD,cardiovascular disease and cancer.More than 1000 publications including original research and review papers were reviewed.展开更多
Background Some single nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor-y coactivator (PGC)-1α gene have been reported to be associated with type 2 diabetes in different populatio...Background Some single nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor-y coactivator (PGC)-1α gene have been reported to be associated with type 2 diabetes in different populations, and studies on Chinese patients yielded controversial results. The objective of this case-control study was to explore the relationship between SNPs of PGC-1α and type 2 diabetes in the southern Chinese population and to determine whether the common variants: Gly482Ser and Thr394Thr, in the PGC-1α gene have any impacts on interaction with myocyte enhancer factor (MEF) 2C. Methods The SNPs in all exons of the PGC-1α gene was investigated in 50 type 2 diabetic patients using polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and direct sequencing. Thereafter, 263 type 2 diabetic patients and 282 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A bacterial two-hybrid system and site-directed mutagenesis were used to investigate whether Gly482Ser and Thr394Thr variants in the PGC-1α gene alter the interaction with MEF2C. Results Three frequent SNPs (Thr394Thr, Gly482Ser and Thr528Thr) were found in exons of the PGC-1α gene. Only the Gly482Ser variant had a different distribution between diabetic patients and healthy subjects, with the 482Ser allele more frequent in patients than in controls (40.1% vs 29.3%, P〈0.01). Even in controls, the 482Ser(A) carriers were more likely to have higher levels of total cholesterol and low-density lipoprotein cholesterol than the 482Gly(G) carriers. The 394A-482G-528A haplotype was associated with protection from diabetes, while the 394A-482A-528A was associated with the susceptibility to diabetes. The bacterial two-hybrid system and site-directed mutagenesis revealed that the 482Ser variant was less efficient than the 482Gly variant to interact with MEF2C, whereas the 394Thr (A) had a synergic effect on the interaction between 482Ser variant and MEF2C. Conclusions The results suggested that the 482Ser variant of PGC-1α conferred the susceptibility to type 2 diabetes in the southern Chinese population. The underlying mechanism may be attributable, at least in part, to the altered interaction between the different variants (Gly482Ser, Thr394Thr) in the PGC-1α gene and MEF2C.展开更多
The purpose of this study was to examine the induction profiles (as judged by quantitative reverse tran- scription polymerase chain reaction (qRT-PCR)) of peroxisome proliferator-activated receptor (PPAR) α,β,...The purpose of this study was to examine the induction profiles (as judged by quantitative reverse tran- scription polymerase chain reaction (qRT-PCR)) of peroxisome proliferator-activated receptor (PPAR) α,β, y subtypes and major PPAR-target genes bearing a functional peroxisome proliferator responsive element (PPRE) in HepG2 cell model upon feeding with cis-9,trans-11-octadecadienoic acid (9-CLA) or trans-10,cis-12-octadecadienoic acid (10-CLA) or their precursor fatty acids (FAs). HepG2 cells were treated with 100 pmol/L 9-CLA or 10-CLA or their precursor FAs, viz., oleic, linoleic, and trans-11-vaccenic acids against bezafibrate control to evaluate the induc- tion/expression profiles of PPAR (α, β, γ subtypes and major PPAR-target genes bearing a functional PPRE, i.e., fatty acid transporter (FAT), glucose transporter-2 (GLUT-2), liver-type FA binding protein (L-FABP), acyl CoA oxidase-1 (ACOX-1), and peroxisomal bifunctional enzyme (PBE) with reference to β-actin as house keeping gene. Of the three housekeeping genes (glyceraldehyde 3-phosphate dehydrogenase (GAPDH), β-actin, and ubiquitin), β-actin was found to be stable. Dimethyl sulfoxide (DMSO), the common solubilizer of agonists, showed a significantly higher induction of genes analyzed, qRT-PCR profiles of CLAs and their precursor FAs clearly showed upregulation of FAT, GLUT-2, and L-FABP (-0.5-.0-fold). Compared to 10-CLA, 9-CLA decreased the induction of the FA metabolizing gene ACOX-1 less than did PBE, while 10-CLA decreased the induction of PBE less than did ACOX-I. Both CLAs and precursor FAs upregulated PPRE-beadng genes, but with comparatively less or marginal activation of PPAR subtypes This indicates that the binding of CLAs and their precursor FAs to PPAR subtypes results in PPAR activation, thereby induction of the target transporter genes coupled with downstream lipid metabolising genes such as ACOX-1 and PBE. To sum up, the expression profiles of these candidate genes showed that CLAs and their precursor FAs are involved in lipid signalling by modulating the PPAR a, 13, or ~ subtype for the indirect activation of the PPAR-target genes, which may in turn be responsible for the supposed health effects of CLA, and that care should be taken while calculating the actual fold induction values of candidate genes with reference to housekeeping gene and DMSO as they may impart false positive results.展开更多
Chiglitazar sodium is a new peroxisome proliferator-activated receptor(PPAR)pan-agonist with independent intellectual property rights in China.It can treat type 2 diabetes mellitus and regulate metabolism by modestly ...Chiglitazar sodium is a new peroxisome proliferator-activated receptor(PPAR)pan-agonist with independent intellectual property rights in China.It can treat type 2 diabetes mellitus and regulate metabolism by modestly activating PPARα,PPARγ,and PPARδto improve insulin sensitivity,regulate blood glucose,and promote fatty acid oxidation and utilization.Chiglitazar sodium has a significant insulin-sensitizing effect and is advantageous in reducing fasting and postprandial blood glucose levels,particularly at the 48 mg dose in patients with concomitant high triglycerides in terms of blood glucose and triglyceride level control.展开更多
Objective:To investigate the peroxisome proliferator-activated receptor-γ (peroxisome)in patients with type 2 diabetes mellitus.Proliferators-activated receptors-γ ,PPARs-γ (γ )gene.polymorphisms about serum lipof...Objective:To investigate the peroxisome proliferator-activated receptor-γ (peroxisome)in patients with type 2 diabetes mellitus.Proliferators-activated receptors-γ ,PPARs-γ (γ )gene.polymorphisms about serum lipofuscin and leptin.Methods:One humdred and twenty patients with type 2 diabetes admitted to our hospital from June 2015 to June 2018 were selected.The patients were divided into an obese group and a non-obese group of 60 patients each according to their waist circumference.A polymerase chain reaction-length polymorphism protocol was implemented in all patients to explore the PPAR-γ gene polymorphism and blood glucose,lipid,adiponectin and leptin levels were measured in both groups.Results:PPAR-γ gene polymorphisms in type 2 diabetic patients were dominated by wild-type homozygous;The levels of total cholesterol,triglyceride and LDL cholesterol in the obese group were significantly higher than those in the non-obese group,while the levels of HDL cholesterol were lower than those in the non-obese group.There is significant difference in comparison between groups(P<0.05)Those canrying the A alele had a significant lipid disorder profile and decreased adiponectin levels.Conclusions:PPAR-γ gene polymorphisms in type 2 diabetes are not significantly associated with adiponectin and leptin,and only in the obese group,the patients with the Allele A showed significant dyslipidemia and a declining trend of adiponectin levels.展开更多
Background Peroxisome proliferator activated receptor γ (PPARγ) is a ligand-activated transcription factor. Activation of PPARγ has recently been demonstrated to inhibit various tumor cells growth, progression an...Background Peroxisome proliferator activated receptor γ (PPARγ) is a ligand-activated transcription factor. Activation of PPARγ has recently been demonstrated to inhibit various tumor cells growth, progression and metastasis. E-cadherin-mediated cell adhesion system is now considered to be an “invasion suppressor system” in cancer tissues. Matrix metalloproteinases-2 (MMP-2) is a prerequisite for metastasizing tumor cells. However their correlation is still unknown in gastric carcinoma. The aim of this study was to assess the expression of PPAR7, E-cadherin, MMP-2 and their correlation in gastric carcinoma and metastases. Methods Gastric carcinoma tissues and their corresponding lymph nodes with metastases and the adjacent non-tumor tissues were obtained from 54 patients with gastric cancer who underwent gastrectomy. Expression of PPARγ, E-cadherin and MMP-2 was assessed by immunohistochemical staining. Results The nuclear expression level of PPARγ in neoplastic cells was significantly lower than that in the normal controls (P〈0.001), with the expression of PPARγ being weaker in primary tumors compared with that in metastases. In all neoplastic cells, E-cadherin was expressed with abnormal patterns (cytoplasm pattern, cytoplasm and membrane pattern or absent), compared with normal cells where E-cadherin was expressed with a normal pattern (membrane pattern). Compared with the normal tissues, the expression level of E-cadherin decreased in primary tumors and further decreased in metastases (P〈0.001). Membrane staining of MMP-2 was detected in the foveolar epithelia of normal gastric mucosa, whereas predominant cytoplasm staining of MMP-2 was found in malignant tissues. The expression of MMP-2 was stronger in metastatic tissues than in primary tumors. In neoplastic foci the expression of PPARγ was negatively correlated with MMP-2 expression (P〈0.05). However, there was no correlation between E-cadherin and PPARγ or MM P-2 expression. Conclusions Down-regulation of PPARγ and E-cadherin and up-regulation of MMP-2 in neoplastic foci might be helpful to gastric carcinogenesis and metastases. An inverse relationship between PPARγ and MMP-2 in human gastric carcinoma suggests that PPARγ might modulate MMP-2 expression and affect gastric cancer metastases.展开更多
Peroxisome proliferator-activated receptor gamma(PPARγor PPARG)is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily.It plays a master role in the differentiation and prolif...Peroxisome proliferator-activated receptor gamma(PPARγor PPARG)is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily.It plays a master role in the differentiation and proliferation of adipose tissues.It has two major isoforms,PPARγ1 and PPARγ2,encoded from a single gene using two separate promoters and alternative splicing.Among them,PPARγ2 is most abundantly expressed in adipocytes and plays major adipogenic and lipogenic roles in the tissue.Furthermore,it has been shown that PPARγ2 is also expressed in the liver,specifically in hepatocytes,and its expression level positively correlates with fat accumulation induced by pathological conditions such as obesity and diabetes.Knockout of the hepatic Pparg gene ameliorates hepatic steatosis induced by diet or genetic manipulations.Transcriptional activation of Pparg in the liver induces the adipogenic program to store fatty acids in lipid droplets as observed in adipocytes.Understanding how the hepatic Pparg gene expression is regulated will help develop preventative and therapeutic treatments for non-alcoholic fatty liver disease(NAFLD).Due to the potential adverse effect of hepatic Pparg gene deletion on peripheral tissue functions,therapeutic interventions that target PPAR g for fatty liver diseases require fine-tuning of this gene's expression and transcriptional activity。展开更多
基金supported by Intervento cofinanziato dal Fondo di Sviluppo e Coesione 2007-2013–APQ Ricerca Regione Puglia "Programma regionale a sostegno della specializzazione intelligente e della sostenibilitàsociale ed ambientale-FutureInResearch".Project ID:I2PCTF6
文摘Alzheimer's disease is a multifactorial pathology, for which no cure is currently available. Nowadays, researchers are moving towards a new hypothesis of the onset of the illness, linking it to a metabolic impairment, q-his innovative approach will lead to the identification of new targets for the preparation of new effective drugs. Peroxisome proliferator-activated receptors and their ligands are the ideal candidates to reach the necessary breakthrough to defeat this complicate disease.
基金performed with fund provided by the Oregon Beef Council。
文摘Background: In dairy cows circulating non-esterified fatty acids(NEFA) increase early post-partum while liver and other tissues undergo adaptation to greater lipid metabolism, mainly regulated by peroxisome proliferator-activated receptors(PPAR). PPAR are activated by fatty acids(FA), but it remains to be demonstrated that circulating NEFA or dietary FA activate bovine PPAR. We hypothesized that circulating NEFA and dietary FA activate PPAR in dairy cows.Methods: The dose-response activation of PPAR by NEFA or dietary FA was assessed using HP300 e digital dispenser and luciferase reporter in several bovine cell types. Cells were treated with blood plasma isolated from Jersey cows before and after parturition, NEFA isolated from the blood plasma, FA released from lipoproteins using milk lipoprotein lipase(LPL), and palmitic acid(C16:0). Effect on each PPAR isotype was assessed using specific synthetic inhibitors.Results: NEFA isolated from blood serum activate PPAR linearly up to ~ 4-fold at 400 μmol/L in MAC-T cells but had cytotoxic effect. Addition of albumin to the culture media decreases cytotoxic effects of NEFA but also PPAR activation by ~ 2-fold. Treating cells with serum from peripartum cows reveals that much of the PPAR activation can be explained by the amount of NEFA in the serum(R~2 = 0.91) and that the response to serum NEFA follows a quadratic tendency, with peak activation around 1.4 mmol/L. Analysis of PPAR activation by serum in MAC-T, BFH-12 and BPAEC cells revealed that most of the activation is explained by the activity of PPARδ and PPARγ, but not PPARα. Palmitic acid activated PPAR when added in culture media or blood serum but the activation was limited to PPARδ and PPARα and the response was nil in serum from post-partum cows. The addition of LPL to the serum increased > 1.5-fold PPAR activation.Conclusion: Our results support dose-dependent activation of PPAR by circulating NEFA in bovine, specifically δand γ isotypes. Data also support the possibility of increasing PPAR activation by dietary FA;however, this nutrigenomics approach maybe only effective in pre-partum but not post-partum cows.
文摘The aim of this investigation was to determine whether a PPAR72 Prol2Ala polymorphism was associated with insulin resistance, β-cellfunction and hypertension in Chinese populations. 289 unrelated Chinese subjects first diagnosed Type 2 diabetes (HbAC1〈6.0) were investigated, including 132 hypertensive diabetic (HTD) subjects, 157 normotensive diabetic (NTD) subjects. Blood pressure and anthropometric measurements were collected from all participants, as well as several venous blood samples during oral glucose tolerance test (OGTT). Biochemical measurements (high-density lipoprotein (HDL) and low-density lipoprotein-cholesterol (LDL), triglycerides) and PPARγ2 Pro12Ala genotype were also determined. And insulin resistance and β-cells function was assessed by HOMA-IR and HOMA-β respectively. The frequency of subjects bearing the Pro12Ala was lower in the hypertension group (3. 03 %) than in the non-hypertension group (5.7 %) (P〈0.05) after adjusted for age, BMI and gender. Hypertensive diabetic Pro12Ala subjects had lower fasting plasma glucose level (P=0. 0127), and better glucose tolerance 60 min after oral glucose (P=0. 0361). Moreover, plasma insulin concentrations at 60 min was lower than those without A variant (P = 0. 0275), and both hypertensive Ala/Pro in HOMA-β (P : 0. 0455) and AUC for insulin (P=0. 0473) were higher, and HOMA-IR was lower (P=0. 0375) as compared with hypertensive Pro/Pro subjects. No association was observed between Prol2Ala genotype and BMI, total cholesterol, HDL- cholesterol or triglycerides in either group. Our findings suggested that the Ala 12 allele of the PPARγ2 gene may improve insulin resistance and ameliorate β-cell function reserves in T2DM with hypertension, and protect patients from hypertension in T2DM. As an important thrifty gene, environment factors may exerts an effect of PPARγ2 on glucose homeostasis and insulin resistance.
文摘BACKGROUND This study presents the clinical and genetic mutation characteristics of an unusual case of adult-onset diabetes mellitus occurring in adolescence,featuring a unique mutation in the peroxisome proliferator-activated receptor gamma(PPARG)gene.Data Access Statement:Research data supporting this publication are available from the NN repository at www.NNN.org/download/.CASE SUMMARY The methodology employed entailed meticulous collection of comprehensive clinical data from the probands and their respective family members.Additionally,high-throughput sequencing was conducted to analyze the PPARG genes of the patient,her siblings,and their offspring.The results of this investigation revealed that the patient initially exhibited elevated blood glucose levels during pregnancy,accompanied by insulin resistance and hypertriglyceridemia.Furthermore,these strains displayed increased susceptibility to diabetic kidney disease without any discernible aggregation patterns.The results from the gene detection process demonstrated a heterozygous mutation of guanine(G)at position 284 in the coding region of exon 2 of PPARG,which replaced the base adenine(A)(exon2c.284A>Gp.Tyr95Cys).This missense mutation resulted in the substitution of tyrosine with cysteine at the 95th position of the translated protein.Notably,both of her siblings harbored a nucleotide heterozygous variation at the same site,and both were diagnosed with diabetes.CONCLUSION The PPARG gene mutation,particularly the p.Tyr95Cys mutation,may represent a newly identified subtype of maturity-onset diabetes of the young.This subtype is characterized by insulin resistance and lipid metabolism disorders.
文摘Nutrient metabolism is regulated by several factors.Social determinants of health with or without genetics are the primary regulator of metabolism,and an unhealthy lifestyle affects all modulators and mediators,leading to the adaptation and finally to the exhaustion of cellular functions.Hepatic steatosis is defined by presence of fat in more than 5%of hepatocytes.In hepatocytes,fat is stored as triglycerides in lipid droplet.Hepatic steatosis results from a combination of multiple intracellular processes.In a healthy individual nutrient metabolism is regulated at several steps.It ranges from the selection of nutrients in a grocery store to the last step of consumption of ATP as an energy or as a building block of a cell as structural component.Several hormones,peptides,and genes have been described that participate in nutrient metabolism.Several enzymes participate in each nutrient metabolism as described above from ingestion to generation of ATP.As of now several publications have revealed very intricate regulation of nutrient metabolism,where most of the regulatory factors are tied to each other bidirectionally,making it difficult to comprehend chronological sequence of events.Insulin hormone is the primary regulator of all nutrients’metabolism both in prandial and fasting states.Insulin exerts its effects directly and indirectly on enzymes involved in the three main cellular function processes;metabolic,inflammation and repair,and cell growth and regeneration.Final regulators that control the enzymatic functions through stimulation or suppression of a cell are nuclear receptors in especially farnesoid X receptor and peroxisome proliferator-activated receptor/RXR ligands,adiponectin,leptin,and adiponutrin.Insulin hormone has direct effect on these final modulators.Whereas blood glucose level,serum lipids,incretin hormones,bile acids in conjunction with microbiota are intermediary modulators which are controlled by lifestyle.The purpose of this review is to overview the key players in the pathogenesis of metabolic dysfunction-associated steatotic liver disease(MASLD)that help us understand the disease natural course,risk stratification,role of lifestyle and pharmacotherapy in each individual patient with MASLD to achieve personalized care and target the practice of precision medicine.PubMed and Google Scholar databases were used to identify publication related to metabolism of carbohydrate and fat in states of health and disease states;MASLD,cardiovascular disease and cancer.More than 1000 publications including original research and review papers were reviewed.
文摘Background Some single nucleotide polymorphisms (SNPs) in the peroxisome proliferator-activated receptor-y coactivator (PGC)-1α gene have been reported to be associated with type 2 diabetes in different populations, and studies on Chinese patients yielded controversial results. The objective of this case-control study was to explore the relationship between SNPs of PGC-1α and type 2 diabetes in the southern Chinese population and to determine whether the common variants: Gly482Ser and Thr394Thr, in the PGC-1α gene have any impacts on interaction with myocyte enhancer factor (MEF) 2C. Methods The SNPs in all exons of the PGC-1α gene was investigated in 50 type 2 diabetic patients using polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and direct sequencing. Thereafter, 263 type 2 diabetic patients and 282 healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A bacterial two-hybrid system and site-directed mutagenesis were used to investigate whether Gly482Ser and Thr394Thr variants in the PGC-1α gene alter the interaction with MEF2C. Results Three frequent SNPs (Thr394Thr, Gly482Ser and Thr528Thr) were found in exons of the PGC-1α gene. Only the Gly482Ser variant had a different distribution between diabetic patients and healthy subjects, with the 482Ser allele more frequent in patients than in controls (40.1% vs 29.3%, P〈0.01). Even in controls, the 482Ser(A) carriers were more likely to have higher levels of total cholesterol and low-density lipoprotein cholesterol than the 482Gly(G) carriers. The 394A-482G-528A haplotype was associated with protection from diabetes, while the 394A-482A-528A was associated with the susceptibility to diabetes. The bacterial two-hybrid system and site-directed mutagenesis revealed that the 482Ser variant was less efficient than the 482Gly variant to interact with MEF2C, whereas the 394Thr (A) had a synergic effect on the interaction between 482Ser variant and MEF2C. Conclusions The results suggested that the 482Ser variant of PGC-1α conferred the susceptibility to type 2 diabetes in the southern Chinese population. The underlying mechanism may be attributable, at least in part, to the altered interaction between the different variants (Gly482Ser, Thr394Thr) in the PGC-1α gene and MEF2C.
基金Project (No. SP 135/14-1) supported by the Deutsche Forschungs-gemeinschaft,Germany
文摘The purpose of this study was to examine the induction profiles (as judged by quantitative reverse tran- scription polymerase chain reaction (qRT-PCR)) of peroxisome proliferator-activated receptor (PPAR) α,β, y subtypes and major PPAR-target genes bearing a functional peroxisome proliferator responsive element (PPRE) in HepG2 cell model upon feeding with cis-9,trans-11-octadecadienoic acid (9-CLA) or trans-10,cis-12-octadecadienoic acid (10-CLA) or their precursor fatty acids (FAs). HepG2 cells were treated with 100 pmol/L 9-CLA or 10-CLA or their precursor FAs, viz., oleic, linoleic, and trans-11-vaccenic acids against bezafibrate control to evaluate the induc- tion/expression profiles of PPAR (α, β, γ subtypes and major PPAR-target genes bearing a functional PPRE, i.e., fatty acid transporter (FAT), glucose transporter-2 (GLUT-2), liver-type FA binding protein (L-FABP), acyl CoA oxidase-1 (ACOX-1), and peroxisomal bifunctional enzyme (PBE) with reference to β-actin as house keeping gene. Of the three housekeeping genes (glyceraldehyde 3-phosphate dehydrogenase (GAPDH), β-actin, and ubiquitin), β-actin was found to be stable. Dimethyl sulfoxide (DMSO), the common solubilizer of agonists, showed a significantly higher induction of genes analyzed, qRT-PCR profiles of CLAs and their precursor FAs clearly showed upregulation of FAT, GLUT-2, and L-FABP (-0.5-.0-fold). Compared to 10-CLA, 9-CLA decreased the induction of the FA metabolizing gene ACOX-1 less than did PBE, while 10-CLA decreased the induction of PBE less than did ACOX-I. Both CLAs and precursor FAs upregulated PPRE-beadng genes, but with comparatively less or marginal activation of PPAR subtypes This indicates that the binding of CLAs and their precursor FAs to PPAR subtypes results in PPAR activation, thereby induction of the target transporter genes coupled with downstream lipid metabolising genes such as ACOX-1 and PBE. To sum up, the expression profiles of these candidate genes showed that CLAs and their precursor FAs are involved in lipid signalling by modulating the PPAR a, 13, or ~ subtype for the indirect activation of the PPAR-target genes, which may in turn be responsible for the supposed health effects of CLA, and that care should be taken while calculating the actual fold induction values of candidate genes with reference to housekeeping gene and DMSO as they may impart false positive results.
文摘Chiglitazar sodium is a new peroxisome proliferator-activated receptor(PPAR)pan-agonist with independent intellectual property rights in China.It can treat type 2 diabetes mellitus and regulate metabolism by modestly activating PPARα,PPARγ,and PPARδto improve insulin sensitivity,regulate blood glucose,and promote fatty acid oxidation and utilization.Chiglitazar sodium has a significant insulin-sensitizing effect and is advantageous in reducing fasting and postprandial blood glucose levels,particularly at the 48 mg dose in patients with concomitant high triglycerides in terms of blood glucose and triglyceride level control.
基金Xi'an Science and Technology Plan Project(2017114SF/YX008(5))National Science Foundation Youth Science Fund Project(81800711)。
文摘Objective:To investigate the peroxisome proliferator-activated receptor-γ (peroxisome)in patients with type 2 diabetes mellitus.Proliferators-activated receptors-γ ,PPARs-γ (γ )gene.polymorphisms about serum lipofuscin and leptin.Methods:One humdred and twenty patients with type 2 diabetes admitted to our hospital from June 2015 to June 2018 were selected.The patients were divided into an obese group and a non-obese group of 60 patients each according to their waist circumference.A polymerase chain reaction-length polymorphism protocol was implemented in all patients to explore the PPAR-γ gene polymorphism and blood glucose,lipid,adiponectin and leptin levels were measured in both groups.Results:PPAR-γ gene polymorphisms in type 2 diabetic patients were dominated by wild-type homozygous;The levels of total cholesterol,triglyceride and LDL cholesterol in the obese group were significantly higher than those in the non-obese group,while the levels of HDL cholesterol were lower than those in the non-obese group.There is significant difference in comparison between groups(P<0.05)Those canrying the A alele had a significant lipid disorder profile and decreased adiponectin levels.Conclusions:PPAR-γ gene polymorphisms in type 2 diabetes are not significantly associated with adiponectin and leptin,and only in the obese group,the patients with the Allele A showed significant dyslipidemia and a declining trend of adiponectin levels.
基金the grants from the National Natural Science Foundation of China (No. 30671904 and No. 30670949)the Doctor Subjects Foundation of the Ministry of Education of the People's Republic of China (No. 20060558010).
文摘Background Peroxisome proliferator activated receptor γ (PPARγ) is a ligand-activated transcription factor. Activation of PPARγ has recently been demonstrated to inhibit various tumor cells growth, progression and metastasis. E-cadherin-mediated cell adhesion system is now considered to be an “invasion suppressor system” in cancer tissues. Matrix metalloproteinases-2 (MMP-2) is a prerequisite for metastasizing tumor cells. However their correlation is still unknown in gastric carcinoma. The aim of this study was to assess the expression of PPAR7, E-cadherin, MMP-2 and their correlation in gastric carcinoma and metastases. Methods Gastric carcinoma tissues and their corresponding lymph nodes with metastases and the adjacent non-tumor tissues were obtained from 54 patients with gastric cancer who underwent gastrectomy. Expression of PPARγ, E-cadherin and MMP-2 was assessed by immunohistochemical staining. Results The nuclear expression level of PPARγ in neoplastic cells was significantly lower than that in the normal controls (P〈0.001), with the expression of PPARγ being weaker in primary tumors compared with that in metastases. In all neoplastic cells, E-cadherin was expressed with abnormal patterns (cytoplasm pattern, cytoplasm and membrane pattern or absent), compared with normal cells where E-cadherin was expressed with a normal pattern (membrane pattern). Compared with the normal tissues, the expression level of E-cadherin decreased in primary tumors and further decreased in metastases (P〈0.001). Membrane staining of MMP-2 was detected in the foveolar epithelia of normal gastric mucosa, whereas predominant cytoplasm staining of MMP-2 was found in malignant tissues. The expression of MMP-2 was stronger in metastatic tissues than in primary tumors. In neoplastic foci the expression of PPARγ was negatively correlated with MMP-2 expression (P〈0.05). However, there was no correlation between E-cadherin and PPARγ or MM P-2 expression. Conclusions Down-regulation of PPARγ and E-cadherin and up-regulation of MMP-2 in neoplastic foci might be helpful to gastric carcinogenesis and metastases. An inverse relationship between PPARγ and MMP-2 in human gastric carcinoma suggests that PPARγ might modulate MMP-2 expression and affect gastric cancer metastases.
基金This work was supported by USA National Institutes of Health(NIH)grant,R01DK093774 to Y.K.Lee.
文摘Peroxisome proliferator-activated receptor gamma(PPARγor PPARG)is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily.It plays a master role in the differentiation and proliferation of adipose tissues.It has two major isoforms,PPARγ1 and PPARγ2,encoded from a single gene using two separate promoters and alternative splicing.Among them,PPARγ2 is most abundantly expressed in adipocytes and plays major adipogenic and lipogenic roles in the tissue.Furthermore,it has been shown that PPARγ2 is also expressed in the liver,specifically in hepatocytes,and its expression level positively correlates with fat accumulation induced by pathological conditions such as obesity and diabetes.Knockout of the hepatic Pparg gene ameliorates hepatic steatosis induced by diet or genetic manipulations.Transcriptional activation of Pparg in the liver induces the adipogenic program to store fatty acids in lipid droplets as observed in adipocytes.Understanding how the hepatic Pparg gene expression is regulated will help develop preventative and therapeutic treatments for non-alcoholic fatty liver disease(NAFLD).Due to the potential adverse effect of hepatic Pparg gene deletion on peripheral tissue functions,therapeutic interventions that target PPAR g for fatty liver diseases require fine-tuning of this gene's expression and transcriptional activity。