Glucokinase regulatory protein rs780094 polymorphism is associated with type 2 diabetes mellitus, dyslipidemia, non-alcoholic fatty liver disease, and nephropathy

In this editorial,we comment on the article by Liu et al published in the recent issue of the World Journal of Diabetes(Relationship between GCKR gene rs780094 polymorphism and type 2 diabetes with albuminuria).Type 2 diabetes mellitus(T2DM)is a chronic disorder characterized by dysregulated glucose homeostasis.The persistent elevated blood glucose level in T2DM significantly increases the risk of developing severe complications,including cardiovascular disease,re-tinopathy,neuropathy,and nephropathy.T2DM arises from a complex interplay between genetic,epigenetic,and environmental factors.Global genomic studies have identified numerous genetic variations associated with an increased risk of T2DM.Specifically,variations within the glucokinase regulatory protein(GCKR)gene have been linked to heightened susceptibility to T2DM and its associated complications.The clinical trial by Liu et al further elucidates the role of the GCKR rs780094 polymorphism in T2DM and nephropathy development.Their findings demonstrate that individuals carrying the CT or TT genotype at the GCKR rs780094 locus are at a higher risk of developing T2DM with albuminuria compared to those with the CC genotype.These findings highlight the importance of genetic testing and risk assessment in T2DM to develop effective preventive strategies and personalized treatment plans.

Establishment of Hypoglycemic Agent Screening Method Based on Human Glucokinase

Objective To establish a reliable platform for screening glucokinase activators （GKAs） in vitro. Methods Pancreatic glucokinase （PGK） protein expressed in a prokaryotic expression system as a histidine-tagged fusion protein from Homo sapiens was produced. Then, response surface methodology （RSM） was used to optimize the microplate-based GKA screening platform. In the f＇trst step of optimization with Plackett-Burman design （PBD）, initial pH, reaction time and MgC12 were found to be important factors affecting the activity ratio of GKA （RO-28-1675） significantly. In the second step, a 23 full factorial central composite design （CCD） and RSM were applied to the optimal condition determination of each significant variable. A second-order polynomial was determined by a multiple regression analysis of the experimental data. Results The following optimal values for the critical factors were obtained： initial pH 0 （7.0）, reaction time-0.63 （13.7 min） and MgC12 0.11 （2.11 mmol/L） with a predicted value of the maximum activity ratio of 34.1%. Conclusion Under the optimal conditions, the practical activity ratio is 34.8%. The determination coefficient （R2） is 0.9442, ensuring adequate credibility of the model. LLAE3, extracted from Folium nelumbinis in our laboratory, has prominently activated effects on PGK.

Facilitating effects of berberine on rat pancreatic islets through modulating hepatic nuclear factor 4 alpha expression and glucokinase activity

AIM： To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS： Pdmary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations （1, 3, 10 and 30 μmol/L） of berberine or 1 μmol/L Glibenclamide （GB） for 24 h. Glucose-stimulated insulin secretion （GSIS） assay was conducted and insulin was determined by radioimmunoassay. 3-（4,5-Dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT） assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha （HAIF4α） was determined by reverse transcription polymerase chain reaction （RT-PCR）. Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase （GK） activity was measured by spectrophotometric method. RESULTS： Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner, and GK activity was also increased accordingly. However, GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION： Berberine can enhance GSIS in rat islets, and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK, which is distinct from sulphonylureas （SUs）.

Effects of vanadate on the activities of mice glucokinase and hexokinase

This study aimed at acquiring knowledge on the hypoglycemic mechanisms of sodium metavanadate (SMV) showed that the liver glucokinase and muscle hexokinase activities increased rapidly after oral SMV was given, and that the blood glucose level was correlated closely with the activities of the two enzymes but not with the insulin level; which indicated that SMV could improve the altered glucose phosphorylation in diabetic mice independently of stimulating insulin secretion. This was probably one of the mechanisms of hypoglycemic effects of SMV.

Sapium ellipticum(Hochst) Pax ethanol leaf extract modulates glucokinase and glucose-6-phosphatase activities in streptozotocin induced diabetic rats

Objective:To examine the effects of Sapium ellipticum(SE) leaf extract on the hepatic activities of glucokinase and glucose-6-phosphatase in streptozotocin-induced diabetic Wistar rats.Methods:STZ-induced diabetic Wistar rats(four groups,n = 8) were used in this study.SE was assessed at two different doses,400 and 800 mg/kg BW,in comparison with metformin(METF)(12 mg/kg BW) as a reference antidiabetic drug.All treatments were done orally(p.o),twice daily at 8 h interval for a period of 21 days.Glucokinase and glucose-6-phosphatase activities were respectively determined using standard protocols.Hepatic and muscle glycogen contents were estimated as well.Results:STZ caused significant decrease in glucose-6-phosphatase activity and concomitant increase in glucokinase activity.SE extract especially at 400 mg dosage significantly reversed the alterations by increasing glucokinase activity by 40.31% and inhibiting glucose-6-phosphatase activity by 37.29% compared to diabetic control animals.However,the effects were significantly lower than that of METF which enhanced glucokinase activity by94.76% and simultaneously inhibited glucose-6-phosphatase activity by 49.15%.The extract also improved hepatic glycogen level by 32.37 and 27.06% at 400 and 800 mg dosage respectively.HPLC-MS analysis of some SE fractions in dynamic MRM mode(using the optimized compound-specific parameters) revealed among other active compounds,the presence of amentoflavone,which has been associated with antidiabetic function.Conclusions:The ability of SE extract to concurrently inhibit glucose-6-phosphatase and activate glucokinase in this study suggests that it may be a treatment option for type 2 diabetes patients,and the presence of amentoflavone in the plant extract may account for its anti-diabetic potential.

Persian Shallot (<i>Allium hirtifolium</i>Boiss) Extract Elevates Glucokinase (GCK) Activity and Gene Expression in Diabetic Rats

Hepatic GCK is a key enzyme in glucose homeostasis and, as such, is a potential target for treatment strategies of diabetes. We investigated the effect of Persian shallot (Allium hirtifolium Boiss) hydroalchoholic extract on blood glucose level, plasma insulin level, GCK activity and its gene expression. Thirty two male rats were divided into 4 groups of 8, diabetic groups received 100 and 200 mg/kg Persian shallot extract, diabetic control and normal control received 0.9% saline for 30 days. Investigations of gene expression by Real-Time PCR showed that Persian shallot had led to gently increased GCK gene expression in diabetic rats. GCK activity increased significantly in Persian shallot treated group in dose dependent manner (P < 0.05). These results indicated that Persian shallot exhibited a significant potential as a hypoglycemic agent perhaps via its ability to enhance insulin secretion, GCK gene expression and its activity.

Analysis of the glucokinase gene in Iranian families with maturity onset diabetes of the young

Non insulin dependent diabetes mellitus (NIDDM) as a most common form of diabetes is a major public health problem;there is a subgroup of NIDDM patients who develop the disease at an early age and show a dominant mode of inheritance. This type is nominates Maturity onset diabetes of the young (MODY). The prevalence of MODY is difficult to access, and patients with MODY genes mutations are often identified during routine screening for other purposes. MODY2 was linked to glucokinase gene (GCK) mutations, and accounted for 8% to 56% of MODY, with the highest prevalence found in the southern Europe. The aim of this study was to examine the prevalence and nature of mutations in GCK gene in Iranian paients. We have screened GCK mutations by polymerase chain reaction (PCR);single stranded conformation polymorphism (SSCP) technique in 12 Iranian families with clinical diagnosis of MODY, included 30 patients (8 males and 22 females) and their 21 family members. PCR products with abnormal mobility in denaturing gradient gel electrophoresis (DGGE) were directly sequenced. We identified 6 novel mutations in GCK gene in Iranian families (corresponding to 36.6% prevalence). Our findings and the last study on MODY1 highlight that in addition to GCK, other MODY genes such as MODY3 and MODYX may play a significant role in diabetes characterized by monogenic autosomal dominant transmission. There is an important point that the genetic recognation can be used to pre-symptomatically identify family members at risk for developing MODY.

Allosteric process of human glucokinase conducive to fight against diabetes

More than 200 million people worldwide have diabetes. In China alone, about 60 million people

ADP-dependent glucokinase controls metabolic fitness in prostate cancer progression

Background Cell metabolism plays a pivotal role in tumor progression,and targeting cancer metabolism might effectively kill cancer cells.We aimed to investigate the role of hexokinases in prostate cancer(PCa)and identify a crucial target for PCa treatment.Methods The Cancer Genome Atlas(TCGA)database,online tools and clinical samples were used to assess the expression and prognostic role of ADP-dependent glucokinase(ADPGK)in PCa.The effect of ADPGK expression on PCa cell malignant phenotypes was validated in vitro and in vivo.Quantitative proteomics,metabolomics,and extracellular acidification rate(ECAR)and oxygen consumption rate(OCR)tests were performed to evaluate the impact of ADPGK on PCa metabolism.The underlying mechanisms were explored through ADPGK overexpression and knockdown,co-immunoprecipitation(Co-IP),ECAR analysis and cell counting kit-8(CCK-8)assays.Results ADPGK was the only glucokinase that was both upregulated and predicted worse overall survival(OS)in prostate adenocarcinoma(PRAD).Clinical sample analysis demonstrated that ADPGK was markedly upregulated in PCa tissues vs.non-PCa tissues.High ADPGK expression indicates worse survival outcomes,and ADPGK serves as an independent factor of biochemical recurrence.In vitro and in vivo experiments showed that ADPGK overexpression promoted PCa cell proliferation and migration,and ADPGK inhibition suppressed malignant phenotypes.Metabolomics,proteomics,and ECAR and OCR tests revealed that ADPGK significantly accelerated glycolysis in PCa.Mechanistically,ADPGK binds aldolase C(ALDOC)to promote glycolysis via AMP-activated protein kinase(AMPK)phosphorylation.ALDOC was positively correlated with ADPGK,and high ALDOC expression was associated with worse survival outcomes in PCa.Conclusions In summary,ADPGK is a driving factor in PCa progression,and its high expression contributes to a poor prognosis in PCa patients.ADPGK accelerates PCa glycolysis and progression by activating ALDOC-AMPK signaling,suggesting that ADPGK might be an effective target and marker for PCa treatment and prognosis evaluation.

Glucokinase and glucokinase activator

Glucokinase (GK) plays a pivotal role in glucose homeostasis as the glucose sensor in the pancreas and liver. Loss of function of GK results in hyperglycemia, and gain of function causes congenital hyperinsulinemic hypoglycemia. We speculate that the progressive loss of GK at both messenger RNA (mRNA) and protein levels in the islets and liver would be the key mechanism for Type 2 diabetes (T2D) pathogenesis. The development of GK activator (GKA) as an anti-diabetic drug has been endeavored for several decades. The failure of the early development of GKAs is due to the limitation of understanding the mode of GKA action. The success of dorzagliatin in the treatment of T2D has brought new hope for GK in setting a good model for repairing the underlying defects in the pancreatic islets and liver of T2D patients.

Glucokinase activator improves glucose tolerance and induces hepatic lipid accumulation in mice with diet-induced obesity

Background and aims:Type 2 diabetes mellitus remains a substantial medical problem with increasing global prevalence.Pharmacological research is becoming increasingly focused on personalized treatment strategies.Drug development based on glucokinase(GK)activation is an important strategy for lowering blood glucose.This study aimed to investigate the effect of GK activation on glucose and lipid metabolism in diet-induced obese mice.Materials and methods:Mice were fed with a high-fat diet(HFD)for 16 weeks to induce obesity,followed by a GK activator(GKA,AZD1656)or vehicle treatment by gavage for 4 weeks.The effect of GKA treatment on glucose metabolism was evaluated using glucose and insulin tolerance tests.Hepatic lipid accumulation was assessed by hematoxylin and eosin staining,Oil Red O staining,and transmission electron microscopy.The underlying mechanism of GK activation in glucose and lipid metabolism in the liver was studied using transcriptomic analysis,with a mechanistic study in mouse livers in vivo and AML12 cells in vitro.Results:GK activation by GKA treatment improved glucose tolerance in HFD-fed mice while increasing hepatic lipid accumulation.Transcriptomic analysis of liver tissues indicated the lipogenesis and protein kinase RNA-like endoplasmic reticulum kinase(PERK)-unfolded protein response(UPR)pathway activations in GKA-treated HFD-fed mice.Inhibition of the ACC activity,which is an important protein in lipogenesis,attenuated GKA treatment-induced lipid accumulation and PERK-UPR activation in vitro.Conclusions:GK activation improved glucose tolerance and insulin sensitivity while inducing hepatic lipid accumulation by increasing the lipogenic gene expression,which subsequently activated the hepatic PERK-UPR signaling pathway.

Management of monogenic diabetes in pregnancy:A narrative review

Pregnancy in women with monogenic diabetes is potentially complex,with significant implications for both maternal and fetal health.Among these,maturity-onset diabetes of the young(MODY)stands out as a prevalent monogenic diabetes subtype frequently encountered in clinical practice.Each subtype of MODY requires a distinct approach tailored to the pregnancy,diverging from management strategies in non-pregnant individuals.Glucokinase MODY(GCK-MODY)typically does not require treatment outside of pregnancy,but special considerations arise when a woman with GCK-MODY becomes pregnant.The glycemic targets in GCK-MODY pregnancies are not exclusively dictated by the maternal/paternal MODY genotype but are also influenced by the genotype of the developing fetus.During pregnancy,the choice between sulfonylurea or insulin for treating hepatocyte nuclear factor 1-alpha(HNF1A)-MODY and HNF4A-MODY depends on the mother’s specific circumstances and the available expertise.Management of other rarer MODY subtypes is individu-alized,with decisions made on a case-by-case basis.Therefore,a collaborative approach involving expert diabetes and obstetric teams is crucial for the compre-hensive management of MODY pregnancies.

A Family of GCK-MODY, About 02 Cases and Review of the Literature

Positive diagnosis of diabetes is currently easy, but typing diagnosis of diabetes still remains a challenge for every clinician. It is currently accepted that types of diabetes apart from T1D and T2D can expand and include several forms of diabetes mellitus;From gestational diabetes, to all forms of secondary diabetes mellitus due to medications, intercurrent disease but also infections, and finally monogenic diabetes, whose diagnosis is not always easy to establish. The aim is to reveal the difficulties that clinicians may face in the process of etiological diagnosis regarding the suspicion of this type of monogenic diabetes, through the study of 2 cases, in which MODY type diabetes was suspected. Today we recognize 17 different genetic mutations that can all lead to MODY diabetes, the most common mutation of which is GCK coding for the glucokinase, the real sensor of pancreatic Beta-cell. The truly stable glycemic profile, with an A1C ranging between 7% and 7.5%, confirmed with a TIR always above 70% and a good MAGE, but also the rarity of degenerative complications and pharmacological therapeutic abstention which can last for years, these would be the most striking clinical characteristics of a GCK MODY.

THE POPULATION ASSOCIATION OF GLUCOKINASE GENE WITH TYPE 2 (NONINSULIN-DEPENDENT) DIABETES MELLITUS IN CHINESE

The association of gluckinase (GCK) gene with type 2 (non-insulin-dependent) diabetes mellitus was investigated in 168 Chinese subjects (85 unrelated type 2 diabetics and 83 non-diabetic controls), The microsatellite polymorphism marker, GCK-5', was amplified with polymerase chain reaction. Four alleles were observed in Chinese population with length varying from 137bp to 143bp and the most common one being the 139bp allele 3. In comparison with non-diabetics, allele 4 was significantly increased in type 2 diabetes (10% versus 38, respectively; X(2)=6.773, P=0.009); genotype 44 and 4X (X denotes any allele other than allele 4) were significantly increased in type 2 diabetes (16% versus 6% respectively; X(2)=6.439, P=0.011), The frequency difference was also shown in overweight / obese subgroup comparison (X(2)=7.718, P=0.021), but not in lean / normal-weight subgroup comparison, No differences of age of onset and frequency of positive family history were observed between type 2 diabetic patients with genotype 44 or 4X and those with XX. The risk for type 2 diabetes in Chinese with genotype 44 or 4X was about 3.5 times higher than in Chinese with genotype XX. Therefore, GCK gene was associated with Chinese type 2 diabetes.

Relationship between GCKR gene rs780094 polymorphism and type 2 diabetes with albuminuria

BACKGROUND Diabetic kidney disease is one of the common complications of type 2 diabetes(T2D).There are no typical symptoms in the early stage,and the disease will progress to moderate and late stage when albuminuria reaches a high level.Treatment is difficult and the prognosis is poor.At present,the pathogenesis of diabetic kidney disease is still unclear,and it is believed that it is associated with genetic and environmental factors.AIM To explore the relationship between the glucokinase regulatory protein(GCKR)gene rs780094 polymorphism and T2D with albuminuria.METHODS We selected 252 patients(126 males and 126 females)with T2D admitted to our hospital from January 2020 to October 2020,and 66 healthy people(44 females and 22 males).According to the urinary albumin/creatinine ratio,the subjects were divided into group I(control),group II(T2D with normoalbuminuria),group III(T2D with microalbuminuria),and group IV(T2D with macroalbuminuria).Additionly,the subjects were divided into group M(normal group)or group N(albuminuria group)according to whether they developed albuminuria.We detected the GCKR gene rs780094 polymorphism(C/T)of all subjects,and measured the correlation between GCKR gene rs780094 polymorphism(C/T)and T2D with albuminuria.RESULTS Gene distribution and genotype distribution among groups I-IV accorded with the Hardy-Weinberg equilibrium.Genotype frequency was significantly different among the four groups (P = 0.048, χ^(2)= 7.906). T allele frequency in groups II, III, and IV was significantly higherthan that in group I. Logistic regression analysis of the risk factors for T2D with albuminuria showed that the CT +TT genotype (odds ratio = 1.710, 95% confidence interval: 1.172-2.493) was a risk factor.CONCLUSION CT + TT genotype is a risk factor for T2D with albuminuria. In the future, we can assess the risk of individualscarrying susceptible genes to delay the onset of T2D.

Pediatric fatty liver disease:Role of ethnicity and genetics

Non-alcoholic fatty liver disease (NAFLD) comprehends a wide range of conditions, encompassing from fatty liver or steatohepatitis with or without fibrosis, to cirrhosis and its complications. NAFLD has become the most common form of liver disease in childhood as its prevalence has more than doubled over the past 20 years, paralleling the increased prevalence of childhood obesity. It currently affects between 3% and 11% of the pediatric population reaching the rate of 46% among overweight and obese children and adolescents. The prevalence of hepatic steatosis varies among different ethnic groups. The ethnic group with the highest prevalence is the Hispanic one followed by the Caucasian and the African-American. This evidence suggests that there is a strong genetic background in the predisposition to fatty liver. In fact, since 2008 several common gene variants have been implicated in the pathogenesis of fatty liver disease. The most important is probably the patatin like phospholipase containing domain 3 gene (PNPLA3) discovered by the Hobbs&#x02019; group in 2008. This article reviews the current knowledge regarding the role of ethnicity and genetics in pathogenesis of pediatric fatty liver.

Pediatric non-alcoholic fatty liver disease:New insights and future directions

One of the most common complications of childhood obesity is the non-alcoholic fatty liver disease(NAFLD),which is the most common form of liver disease in children.NAFLD is defined by hepatic fat infiltration > 5% hepatocytes,as assessed by liver biopsy,in the absence of excessive alcohol intake,viral,autoimmune and drug-induced liver disease.It encompasses a wide spectrum of liver diseases ranging from simple steatosis to non-alcoholic steatohepatitis,which,in turn,can evolve into cirrhosis and end stage liver disease.Obesity and insulin resistance are the main risk factors for pediatric NAFLD.In fact,NAFLD is strongly associated with the clinical features of insulin resistance especially the metabolic syndrome,prediabetes and type 2 diabetes mellitus(T2D).In particular,it has been clearly shown in obese youth that the prevalence of metabolic syndrome,pre-diabetes and type 2 diabetes increaseswith NAFLD severity progression.Evidence that not all of the obese patients develop NAFLD suggests that the disease progression is likely to depend on complex interplay between environmental factors and genetic predisposition.Recently,a non-synonymous SNP(rs738409),characterized by a C to G substitution encoding an isoleucine to methionine substitution at the amino acid position 148 in the patatin like phospholipase containing domain 3 gene(PNPLA3),has been associated with hepatic steatosis in a multiethnic cohort of adults as well as in children.Another important polymorphisms that acts with PNPLA3 to convey susceptibility to fatty liver in obese youths is the rs1260326 polymorphism in the glucokinase regulatory protein.The pharmacological approach in NAFLD children poorly adherent to or being unresponsive/partially responsive to lifestyle changes,is aimed at acting upon specific targets involved in the pathogenesis.There are some therapeutic approaches that are being studied in children.This article reviews the current knowledge regarding the pediatric fatty liver disease,the new insights and the future directions.

Novel and emerging diabetes mellitus drug therapies for the type 2 diabetes patient

Type 2 diabetes mellitus is a metabolic disorder of deranged fat, protein and carbohydrate metabolism resulting in hyperglycemia as a result of insulin resistance and inadequate insulin secretion. Although a wide variety of diabetes therapies is available, yet limited efficacy, adverse effects, cost, contraindications, renal dosage adjustments, inflexible dosing schedules and weight gain significantly limit their use. In addition, many patients in the United States fail to meet the therapeutic HbA1c goal of 【 7% set by the American Diabetes Association. As such new and emerging diabetes therapies with different mechanisms of action hope to address some of these drawbacks to improve the patient with type 2 diabetes. This article reviews new and emerging classes, including the sodium-glucosecotransporter-2 inhibitors, 11β-Hydroxysteroid dehydrogenase type 1 inhibitors, glycogen phosphorylase inhibitors; protein tyrosine phosphatase 1B inhibitors, G Protein-Coupled receptor agonists and glucokinase activators. These emerging diabetes agents hold the promise of providing benefit of glucose lowering, weight reduction, low hypoglycemia risk, improve insulin sensitivity, pancreatic β cell preservation, and oral formulation availability. However, further studies are needed to evaluate their safety profile, cardiovascular effects, and efficacy durability in order to determine their role in type 2 diabetes management.

Promoting genetics in non-alcoholic fatty liver disease: Combined risk score through polymorphisms and clinical variables

Non-alcoholic fatty liver disease(NAFLD) has a prevalence of approximately 30% in western countries, and is emerging as the first cause of liver cirrhosis and hepatocellular carcinoma(HCC). Therefore, risk stratification emerges as fundamental in order to optimize human and economic resources, and genetics displays intrinsic characteristics suitable to fulfill this task. According to the available data, heritability estimates for hepatic fat content range from 20% to 70%, and an almost 80% of shared heritability has been found between hepatic fat content and fibrosis. The rs738409 single nucleotide polymorphism(SNP) in patatin-like phospholipase domain-containing protein 3 gene and the rs58542926 SNP in transmembrane 6 superfamily member 2 gene have been robustly associated with NAFLD and with its progression, but promising results have been obtained with many other SNPs. Moreover, there has been proof of the additive role of the different SNPs in determining liver damage, and there have been preliminary experiences in which risk scores created through a few genetic variants, alone or in combination with clinical variables, were associated with a strongly potentiated risk of NAFLD, non-alcoholic steatohepatitis(NASH), NASH fibrosis or NAFLD-HCC. However, to date, clinical translation of genetics in the field of NAFLD has been poor or absent. Fortunately, the research we have done seems to have placed us on the right path: We should rely on longitudinal rather than on cross-sectional studies; we should focus on relevant outcomes rather than on simple liver fat accumulation; and we should put together the genetic and clinical information. The hope is that combined genetic/clinical scores, derived from longitudinal studies and built on a few strong genetic variants and relevant clinical variables, will reach a significant predictive power, such as to have clinical utility for risk stratification at the single patient level and even to esteem the impact of intervention on the risk of disease-related outcomes. Well-structured future studies would demonstrate if this vision can become a reality.

Chronic alcohol consumption potentiates the development of diabetes through pancreatic β-cell dysfunction

Chronic ethanol consumption is well established as a major risk factor for type-2 diabetes(T2D), which is evidenced by impaired glucose metabolism and insulin resistance. However, the relationships between alcoholconsumption and the development of T2 D remain controversial. In particular, the direct effects of ethanol consumption on proliferation of pancreatic β-cell and the exact mechanisms associated with ethanolmediated β-cell dysfunction and apoptosis remain elusive. Although alcoholism and alcohol consumption are prevalent and represent crucial public health problems worldwide, many people believe that low-tomoderate ethanol consumption may protect against T2 D and cardiovascular diseases. However, the J- or U-shaped curves obtained from cross-sectional and large prospective studies have not fully explained the relationship between alcohol consumption and T2 D. This review provides evidence for the harmful effects of chronic ethanol consumption on the progressive development of T2 D, particularly with respect to pancreatic β-cell mass and function in association with insulin synthesis and secretion. This review also discusses a conceptual framework for how ethanolproduced peroxynitrite contributes to pancreatic β-cell dysfunction and metabolic syndrome.