Monogenic Diabetes: A Comprehensive Overview and Therapeutic Management of Subtypes of Mody.

BACKGROUND: Monogenic diabetes often occurs as a result of single-gene mutations. The illness is minimally affected by environmental and behavioral factors, and it constitutes around one to five percent of all cases of diabetes. METHODS: Newborn diabetes mellitus (NDM) and maturity-onset diabetes of the young (MODY) are the predominant causes of monogenic diabetes, accounting for a larger proportion of cases, while syndromic diabetes represents a smaller percentage. MODY, a group of inherited non-autoimmune diabetes mellitus disorders, is quite common. However, it remains frequently misdiagnosed despite increasing public awareness. The condition is characterized by insulin resistance, the development of diabetes at a young age (before 25 years), mild high blood sugar levels, inheritance in an autosomal dominant pattern, and the preservation of natural insulin production. RESULTS: Currently, there are 14 distinct subtypes of MODY that have been identified. Each subtype possesses distinct characteristics in terms of their frequency, clinical symptoms, severity of diabetes, related complications, and response to medicinal interventions. Due to the clinical similarities, lack of awareness, and high expense of genetic testing, distinguishing between type I (T1D) and type II diabetes mellitus (T2D) can be challenging, resulting in misdiagnosis of this type of diabetes. As a consequence, a significant number of individuals are being deprived of adequate medical attention. Accurate diagnosis enables the utilization of novel therapeutic strategies and enhances the management of therapy in comparison to type II and type I diabetes. CONCLUSION: This article offers a concise overview of the clinical subtypes and characteristics of monogenic diabetes. Furthermore, this article discusses the various subtypes of MODY, as well as the process of diagnosing, managing, and treating the condition. It also addresses the difficulties encountered in detecting and treating MODY.

Examining the clinical and genetic spectrum of maturity-onset diabetes of the young (MODY) in Iran.

Maturity-onset diabetes of the young (MODY) is an uncommon monogenic type of diabetes mellitus. Detecting genetic variants for MODY is a necessity for precise diagnosis and treatment. The majority of MODY genetic predisposition has been documented in European populations and a lack of information is present in Iranians which leads to misdiagnosis as a consequence of defects in unknown variants. In this study, using genetic variant information of 20,002 participants from the family-based TCGS (Tehran Cardiometabolic Genetic Study) cohort, we evaluated the genetic spectrum of MODY in Iran. We concentrated on previously discovered MODY-causing genes. Genetic variants were evaluated for their pathogenicity. We discovered 6 variants that were previously reported in the ClinVar as pathogenic/likely pathogenic (P/LP) for MODY in 45 participants from 24 families (INS in 21 cases, GCK in 13, HNF1B in 8, HNF4A, HNF1A, and CEL in 1 case). One potential MODY variant with Uncertain Risk Allele in ClinVar classification was also identified, which showed complete disease penetrance (100%) in four subjects from one family. This is the first family-based study to define the genetic spectrum and estimate the prevalence of MODY in Iran. The discovered variants need to be investigated by additional studies.

A Flavonoid Concentrate from Moringa Oleifera Lam. Leaves Extends Exhaustive Swimming Time by Improving Energy Metabolism and Antioxidant Capacity in Mice.

Moringa oleifera Lam. leaves contain various nutrients and bioactive compounds. The present study aimed to assess the anti-fatigue capacity of a flavonoids concentrate purified from M. oleifera Lam. leaves. The total flavonoids in the purified extract were analyzed by ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-MS/MS). The mice were supplemented with purified M. oleifera Lam. leaf flavonoid-rich extract (MLFE) for 14 days. The weight-loaded forced swimming test was used for evaluating exercise endurance. The 90-min non-weight-bearing swimming test was carried out to assess biochemical biomarkers correlated to fatigue and energy metabolism. UPLC-MS/MS analysis identified 83 flavonoids from MLFE. MLFE significantly increased the swimming time by 60%. Serum lactate (9.9 ± 0.9 vs. 8.9 ± 0.7), blood urea nitrogen (BUN) (8.8 ± 0.8 vs. 7.2 ± 0.5), and nonesterified fatty acid (NEFA) (2.4 ± 0.2 vs. 1.7 ± 0.3) were significantly elevated; phosphoenolpyruvate carboxykinase (PEPCK), glucokinase (GCK), and nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression were significantly downregulated; and heme oxygenase 1 mRNA expression was significantly upregulated in muscle after swimming. MLFE supplement significantly decreased serum lactate (8.0 ± 1.0 vs. 9.9 ± 0.9), BUN (8.6 ± 0.4 vs. 8.9 ± 0.8), and NEFA (2.3 ± 0.4 vs. 2.4 ± 0.2) and increased the protein and mRNA expression of GCK, PEPCK, and Nrf2. The enhancement of glucose metabolism and antioxidant function by MLFE contributes partly to its anti-fatigue action.

Management of pregnancy in women with monogenic diabetes due to mutations in GCK, HNF1A and HNF4A genes.

Women with maturity-onset diabetes of the young (MODY) need tailored antenatal care and monitoring of their offspring. Each MODY subtype has different implications for glycaemic targets, treatment choices and neonatal management. Hyperglycaemia of MODY is often first diagnosed in adolescence or early adulthood and therefore is clinically relevant to pregnant women. MODY remains an under-recognised and undiagnosed condition. Pregnancy represents an opportune time to make a genetic diagnosis of MODY and provide precision treatment. This review describes the nuance of antenatal care in women with MODY and the implications for pregnancies affected by a positive paternal genotype. Mutations in hepatic nuclear factor 1-alpha (HNF1A) and 4-alpha (HNF4A) genes are associated with progressive ß-cell dysfunction resulting in early onset diabetes. Patients are largely managed with sulphonylureas outside of pregnancy. Macrosomia and persistent neonatal hypoglycaemia are reported in 54% and 15% of HNF4A genotype positive offspring respectively with a median increase in birthweight of 790 g. Close observation of foetal growth in utero allows optimal timing of delivery to minimise peri- and postpartum materno-foetal complications. Glucokinase (GCK)-MODY causes mild fasting hyperglycaemia which does not require treatment outside of pregnancy. Birthweight of offspring of maternal carriers is dependent on foetal genotype; heterozygous mutation carriers are usually normal weight while genotype negative offspring are large for gestational age (600 g heavier). Affected offspring of paternal carriers may be small for gestational age (500 g lighter). Serial growth scans with measurement of the abdominal circumference indirectly differentiate foetal genotype. Measurement of cell free foetal DNA in maternal blood from the late first trimester is superior to traditionally used ultrasound to distinguish foetal genotype. Cost and accessibility may limit its use.

Inhibition of Hmbox1 Promotes Cardiomyocyte Survival and Glucose Metabolism Through Gck Activation in Ischemia/Reperfusion Injury.

BACKGROUND: Exercise-induced physiological cardiac growth regulators may protect the heart from ischemia/reperfusion (I/R) injury. Homeobox-containing 1 (Hmbox1), a homeobox family member, has been identified as a putative transcriptional repressor and is downregulated in the exercised heart. However, its roles in exercise-induced physiological cardiac growth and its potential protective effects against cardiac I/R injury remain largely unexplored. METHODS: We studied the function of Hmbox1 in exercise-induced physiological cardiac growth in mice after 4 weeks of swimming exercise. Hmbox1 expression was then evaluated in human heart samples from deceased patients with myocardial infarction and in the animal cardiac I/R injury model. Its role in cardiac I/R injury was examined in mice with adeno-associated virus 9 (AAV9) vector-mediated Hmbox1 knockdown and in those with cardiac myocyte-specific Hmbox1 ablation. We performed RNA sequencing, promoter prediction, and binding assays and identified glucokinase (Gck) as a downstream effector of Hmbox1. The effects of Hmbox1 together with Gck were examined in cardiomyocytes to evaluate their cell size, proliferation, apoptosis, mitochondrial respiration, and glycolysis. The function of upstream regulator of Hmbox1, ETS1, was investigated through ETS1 overexpression in cardiac I/R mice in vivo. RESULTS: We demonstrated that Hmbox1 downregulation was required for exercise-induced physiological cardiac growth. Inhibition of Hmbox1 increased cardiomyocyte size in isolated neonatal rat cardiomyocytes and human embryonic stem cell-derived cardiomyocytes but did not affect cardiomyocyte proliferation. Under pathological conditions, Hmbox1 was upregulated in both human and animal postinfarct cardiac tissues. Furthermore, both cardiac myocyte-specific Hmbox1 knockout and AAV9-mediated Hmbox1 knockdown protected against cardiac I/R injury and heart failure. Therapeutic effects were observed when sh-Hmbox1 AAV9 was administered after I/R injury. Inhibition of Hmbox1 activated the Akt/mTOR/P70S6K pathway and transcriptionally upregulated Gck, leading to reduced apoptosis and improved mitochondrial respiration and glycolysis in cardiomyocytes. ETS1 functioned as an upstream negative regulator of Hmbox1 transcription, and its overexpression was protective against cardiac I/R injury. CONCLUSIONS: Our studies unravel a new role for the transcriptional repressor Hmbox1 in exercise-induced physiological cardiac growth. They also highlight the therapeutic potential of targeting Hmbox1 to improve myocardial survival and glucose metabolism after I/R injury.

Enhancing fetal outcomes in GCK-MODY pregnancies: a precision medicine approach via non-invasive prenatal GCK mutation detection.

Background: Mutations in the GCK gene cause Maturity Onset Diabetes of the Young (GCK-MODY) by impairing glucose-sensing in pancreatic beta cells. During pregnancy, managing this type of diabetes varies based on fetal genotype. Fetuses carrying a GCK mutation can derive benefit from moderate maternal hyperglycemia, stimulating insulin secretion in fetal islets, whereas this may cause macrosomia in wild-type fetuses. Modulating maternal glycemia can thus be viewed as a form of personalized prenatal therapy, highly beneficial but not justifying the risk of invasive testing. We therefore developed a monogenic non-invasive prenatal diagnostic (NIPD-M) test to reliably detect the transmission of a known maternal GCK mutation to the fetus. Methods: A small amount of fetal circulating cell-free DNA is present in maternal plasma but cannot be distinguished from maternal cell-free DNA. Determining transmission of a maternal mutation to the fetus thus implies sequencing adjacent polymorphisms to determine the balance of maternal haplotypes, the transmitted haplotype being over-represented in maternal plasma. Results: Here we present a series of such tests in which fetal genotype was successfully determined and show that it can be used to guide therapeutic decisions during pregnancy and improve the outcome for the offspring. We discuss several potential hurdles inherent to the technique, and strategies to overcome these. Conclusion: Our NIPD-M test allows reliable determination of the presence of a maternal GCK mutation in the fetus, thereby allowing personalized in utero therapy by modulating maternal glycemia, without incurring the risk of miscarriage inherent to invasive testing.

Characterizing glucokinase variant mechanisms using a multiplexed abundance assay.

BACKGROUND: Amino acid substitutions can perturb protein activity in multiple ways. Understanding their mechanistic basis may pinpoint how residues contribute to protein function. Here, we characterize the mechanisms underlying variant effects in human glucokinase (GCK) variants, building on our previous comprehensive study on GCK variant activity. RESULTS: Using a yeast growth-based assay, we score the abundance of 95% of GCK missense and nonsense variants. When combining the abundance scores with our previously determined activity scores, we find that 43% of hypoactive variants also decrease cellular protein abundance. The low-abundance variants are enriched in the large domain, while residues in the small domain are tolerant to mutations with respect to abundance. Instead, many variants in the small domain perturb GCK conformational dynamics which are essential for appropriate activity. CONCLUSIONS: In this study, we identify residues important for GCK metabolic stability and conformational dynamics. These residues could be targeted to modulate GCK activity, and thereby affect glucose homeostasis.

Evolution of chromosome-arm aberrations in breast cancer through genetic network rewiring.

The basal breast cancer subtype is enriched for triple-negative breast cancer (TNBC) and displays consistent large chromosomal deletions. Here, we characterize evolution and maintenance of chromosome 4p (chr4p) loss in basal breast cancer. Analysis of The Cancer Genome Atlas data shows recurrent deletion of chr4p in basal breast cancer. Phylogenetic analysis of a panel of 23 primary tumor/patient-derived xenograft basal breast cancers reveals early evolution of chr4p deletion. Mechanistically we show that chr4p loss is associated with enhanced proliferation. Gene function studies identify an unknown gene, C4orf19, within chr4p, which suppresses proliferation when overexpressed-a member of the PDCD10-GCKIII kinase module we name PGCKA1. Genome-wide pooled overexpression screens using a barcoded library of human open reading frames identify chromosomal regions, including chr4p, that suppress proliferation when overexpressed in a context-dependent manner, implicating network interactions. Together, these results shed light on the early emergence of complex aneuploid karyotypes involving chr4p and adaptive landscapes shaping breast cancer genomes.

An Italian MODY family with proband and son carrying variants in GCK and HFN1A: is it a true case of digenic MODY?

Maturity Onset Diabetes of the Young (MODY) is a monogenic autosomal dominant disorder affecting 1-5 % of all patients with diabetes mellitus. In Caucasians, GCK and HNF1A mutations are the most common cause of MODY. Here, we report two family members carrying a genetic variant of both GCK and HNF1A gene and their nine year clinical follow-up. Our report urges physicians to be cautious when variants in two genes are found in a single patient and suggests that collaboration with MODY genetics experts is necessary for correct diagnosis and treatment.

Partial GCK gene deletion mutations causing maturity-onset diabetes of the young.

AIMS: Maturity-onset diabetes of the young (MODY) is an autosomal dominant monogenic form of diabetes, and glucokinase-maturity-onset diabetes of the young (GCK-MODY), or MODY 2, being the most prevalent type. However, the presence of copy number variants (CNVs) may lead to misdiagnoses, as genetic testing for MODY is typically reliant on sequencing techniques. This study aimed to describe the process of diagnosis in a Chinese pedigree with an exon 8-10 deletion of the GCK gene. METHODS: This study collected clinical data and medical history through direct interviews with the patient and reviewing relevant medical records. Sanger sequencing and whole exome sequencing (WES) were conducted over years of follow up. WES-based CNV sequencing technology was used to detect CNVs and the results were validated by multiplex ligation-dependent amplification dosage assay (MLPA). Additionally, we reviewed the previously reported cases caused by heterozygous exon deletion of the GCK gene. RESULTS: WES-based CNV detection revealed a heterozygous exon 8-10 deletion in the GCK gene within this particular pedigree after Sanger sequencing and WES failed to find causal variants in single nucleotide variations (SNVs) and small indels. The deletion was considered pathogenic according to ACMG/AMP and ClinGen guidelines. Most of the previously reported cases caused by heterozygous exon deletion or whole gene deletion of the GCK gene present similarly to GCK-MODY caused by SNVs and small indels. CONCLUSIONS: This study contributed to progress in our comprehension of the mutation spectrum of the GCK gene and underscored the significance of CNV detection in the genetic testing of MODY.

Two novel GCK mutations in Chinese patients with maturity-onset diabetes of the young.

PURPOSE: Heterozygous inactivating mutations in the glucokinase (GCK) gene result in the asymptomatic fasting hyperglycemia named as GCK-MODY or MODY2. The genetic testing can effectively avoid the misdiagnosis and inappropriate treatment for GCK-MODY. METHODS: A total of 25 unrelated families with MODY were screened for mutations in coding region of GCK by using direct sequencing. Three different bioinformatics tools such as PolyPhen2, Mutation Taster and PROVEAN were performed to predict the function of mutant proteins. The glucose profile was recorded by continuous glucose monitoring system (CGMS) to evaluate the glycemic variability for the GCK-MODY patient. RESULTS: Our study identified five GCK mutations in 24% of the families (6/25): two novel mutations (I126fs and G385A) and three already described mutations (G44S, H50fs and S383L). In silico analyses predicted that these mutations altered structural conformational changes. The values of mean amplitude of glycemic excursions (MAGE), an important index of blood glucose fluctuation in CGMS system, were 0.81 in the first 24 h and 1.61 in the second 24 h record in the patient with GCK-MODY (F3), suggesting little glucose fluctuation. CONCLUSION: The genetic testing is suggested to be important to differentiate GCK-MODY from other types of diabetes. CGMS might be used to screen GCK-MODY cases prior to genetic testing.

Integration of proteomics and metabolomics reveals energy and metabolic alterations induced by glucokinase (GCK) partial inactivation in hepatocytes.

AIMS: Glucokinase (GCK) acts as the glucose sensor in maintaining glucose homeostasis. The inactivating mutation of the GCK gene leads to glucokinase-maturity onset diabetes of the young (GCK-MODY). This study aims to gain further insights into the molecular alterations triggered by GCK partial inactivation in hepatocytes, potentially underlying the favorable prognosis of GCK-MODY. MAIN METHODS: A GCK knockdown HepG2 cell model was established, and the integration of proteomics and metabolomics was used to gain a comprehensive understanding of the molecular pathway changes caused by GCK inactivation in the liver. KEY FINDINGS: Proteomic analysis identified 257 differential proteins. KEGG pathway enrichment analysis showed that protein expression changes in the GCK knockdown group were significantly enriched in central carbon metabolism, the TCA cycle, amino acid metabolism and the oxidative phosphorylation pathway. Among them, enzymes in the TCA cycle (PC, IDH2, SDH) were significantly downregulated in GCK-knockdown group. Targeted metabolomics revealed that in the GCK knockdown hepatocytes, TCA cycle intermediates were significantly decreased, including pyruvate, oxaloacetate, citrate and succinic acid, and three metabolites increased including glycine, betaine and homocysteine. These metabolic alterations in turn reduced the accumulation of reactive oxygen species in GCK knockdown hepatocytes. Correlation analysis indicated that TCA cycle metabolites were positively correlated with proteins involved in the TCA cycle, carbon metabolism, glycolysis, Ras signaling, fibrosis and inflammation. SIGNIFICANCE: In conclusion, GCK knockdown reduced TCA cycle flux and oxidative stress in hepatocytes by influencing the levels of key transcription factors and enzymes, providing a comprehensive understanding of the effects of GCK partial inactivation on liver metabolism and molecular mechanisms.

The Theranostic Optimization of PSMA-GCK01 Does Not Compromise the Imaging Characteristics of [99mTc]Tc-PSMA-GCK01 Compared to Dedicated Diagnostic [99mTc]Tc-EDDA/HYNIC-iPSMA in Prostate Cancer.

PURPOSE: Radiolabeled PSMA-ligands play a major role in today's nuclear medicine. Since approval of [177Lu]Lu-PSMA-617 for therapy of metastatic prostate cancer, availability of 177Lu became bottleneck of supply due to the high demand. Recently, a theranostic PSMA-ligand, PSMA-GCK01, was developed which can be labeled either diagnostically with 99mTc or therapeutically with 188Re with both nuclides available from well-known generator systems. This novel tracer might aid to overcome aforementioned supply limitations. In this investigation, the biodistribution and general imaging characteristics of [99mTc]Tc-PSMA-GCK01 were compared with the diagnostic reference compound [99mTc]Tc-EDDA/HYNIC-iPSMA in patients with advanced stage prostate cancer. In addition, the binding of both ligands to PSMA was analyzed at the molecular level using molecular docking. PROCEDURES: Two cohorts (n = 19 vs. n = 21) of patients with metastatic castration-resistant prostate cancer matched for age, tumor stage, and Gleason score underwent a planar gamma camera imaging with [99mTc]Tc-EDDA/HYNIC-iPSMA or [99mTc]Tc-PSMA-GCK01 prior to PSMA-ligand therapy for PSMA-phenotyping. The imaging data were retrospective analyzed for salivary gland, kidney, liver, soft tissue, and tumor uptake on a semi-automated ROI-analysis using HERMES Medical Solutions AB (HMS, Sweden). RESULTS: The data sets were semi-automated quantified on a ROI-based analysis. The tumor-to-background presented equal results of [99mTc]Tc-PSMA-GCK01 compared to [99mTc]Tc-EDDA/HYNIC-iPSMA. The physiological PSMA-positive organs like salivary gland presented also equal uptake in counts/MBq (salivary gland median 9.48 [99mTc]Tc-PSMA-GCK01 vs. median 9.11 [99mTc]Tc-EDDA/HYNIC-iPSMA), while liver-to-kidney ratio presented a slight shift to the liver parenchyma using [99mTc]Tc-PSMA-GCK01 (0.83) compared to [99mTc]Tc-EDDA/HYNIC-iPSMA (0.55) with no statistical significance. This is in agreement with the results from the docking study revealing only a minor difference in the docking scores for both ligands. CONCLUSIONS: The novel theranostic tracer [99mTc]Tc/[188Re]Re-PSMA-GCK01 demonstrates comparable general imaging characteristic with the reference compound [99mTc]Tc-EDDA/HYNIC-iPSMA. These results pave the way for the PSMA-targeting imaging and theranostic agents for a broader, rather low-cost, generator applied radio-ligand therapy utilization.

ChREBP is activated by reductive stress and mediates GCKR-associated metabolic traits.

Common genetic variants in glucokinase regulator (GCKR), which encodes GKRP, a regulator of hepatic glucokinase (GCK), influence multiple metabolic traits in genome-wide association studies (GWASs), making GCKR one of the most pleiotropic GWAS loci in the genome. It is unclear why. Prior work has demonstrated that GCKR influences the hepatic cytosolic NADH/NAD+ ratio, also referred to as reductive stress. Here, we demonstrate that reductive stress is sufficient to activate the transcription factor ChREBP and necessary for its activation by the GKRP-GCK interaction, glucose, and ethanol. We show that hepatic reductive stress induces GCKR GWAS traits such as increased hepatic fat, circulating FGF21, and circulating acylglycerol species, which are also influenced by ChREBP. We define the transcriptional signature of hepatic reductive stress and show its upregulation in fatty liver disease and downregulation after bariatric surgery in humans. These findings highlight how a GCKR-reductive stress-ChREBP axis influences multiple human metabolic traits.

Genotype-phenotype correlation in Taiwanese children with diazoxide-unresponsive congenital hyperinsulinism.

Objective: Congenital hyperinsulinism (CHI) is a group of clinically and genetically heterogeneous disorders characterized by dysregulated insulin secretion. The aim of the study was to elucidate genetic etiologies of Taiwanese children with the most severe diazoxide-unresponsive CHI and analyze their genotype-phenotype correlations. Methods: We combined Sanger with whole exome sequencing (WES) to analyze CHI-related genes. The allele frequency of the most common variant was estimated by single-nucleotide polymorphism haplotype analysis. The functional effects of the ATP-sensitive potassium (KATP) channel variants were assessed using patch clamp recording and Western blot. Results: Nine of 13 (69%) patients with ten different pathogenic variants (7 in ABCC8, 2 in KCNJ11 and 1 in GCK) were identified by the combined sequencing. The variant ABCC8 p.T1042QfsX75 identified in three probands was located in a specific haplotype. Functional study revealed the human SUR1 (hSUR1)-L366F KATP channels failed to respond to intracellular MgADP and diazoxide while hSUR1-R797Q and hSUR1-R1393C KATP channels were defective in trafficking. One patient had a de novo dominant mutation in the GCK gene (p.I211F), and WES revealed mosaicism of this variant from another patient. Conclusion: Pathogenic variants in KATP channels are the most common underlying cause of diazoxide-unresponsive CHI in the Taiwanese cohort. The p.T1042QfsX75 variant in the ABCC8 gene is highly suggestive of a founder effect. The I211F mutation in the GCK gene and three rare SUR1 variants associated with defective gating (p.L366F) or traffic (p.R797Q and p.R1393C) KATP channels are also associated with the diazoxide-unresponsive phenotype.

Nano-Stevia reduces the liver injury caused by streptozotocin (STZ)-induced diabetes in rats by targeting PEPCK/GCK genes, INSR pathway and apoptosis.

Objectives: Extensive application of stevia in the treatment of type 2 diabetes mellitus (DM) has been proven by a large number of previous studies. We prepared stevia loaded in nanoniosomes (nanostevia) to improve its bioavailability, functionality, and stability and explore its protective effects and underlying mechanisms in the liver of STZ-induced diabetic rats. Methods: Single-dose intraperitoneal injection of STZ (50 mg/kg body weight) was used to establish diabetic model. The mRNA levels of PEPCK and GCK genes and the protein level of INSR were evaluated by Real time-PCR and Western blot assays, respectively. TUNEL assay was used to detect apoptotic cell death in the liver tissue. Results: Diabetic rats exhibited significantly reduced levels of INSR (*** P < 0.001) as well as elevated levels of PEPCK (*** P < 0.001). Both stevia and nano-stevia were capable of increasing levels of GCK and INSR and reducing levels of PEPCK (## P < 0.01 and ### P < 0.001, respectively). In addition, significantly increased number of apoptotic cell death was seen in the liver tissue of diabetic rats (*** P < 0.001) which was markedly mitigated by treatment with both Stevia and nano-Stevia (#P < 0.05 and ## P < 0.01, respectively). Conclusion: Both stevia and nano-stevia demonstrates potent anti-apoptotic activity in the liver tissue of diabetic rats by targeting PEPCK/GCK genes and INSR pathway. These finding show that nano-stevia has more potential to reduce the liver injury caused by STZ-induced diabetes in rats and hence can be considered a valid agent and alternative therapy for attenuating complications of type 2 DM. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01278-2.

Glomerulocystic kidney in two red piranhas Pygocentrus nattereri.

Glomerulocystic kidney (GCK) is defined by a dilatation of the Bowman's space (greater than 2 times the normal size) of more than 5% of all glomeruli. Although GCK has been occasionally documented in dogs, cats, and humans with renal failure, in fish, reports of spontaneous GCK are rare. For the present study, 2 captive adult red piranhas Pygocentrus nattereri from a closed population were submitted for post-mortem examination. Clinical history included lethargy, inappetence, dyspnea, and altered buoyancy. Macroscopically, the fish displayed coelomic distension and ascites. The kidneys were markedly enlarged and dark yellow. Histologically, Bowman's space was noticeably dilated, occasionally with atrophic glomerular tufts. Degeneration and necrosis of the tubular epithelium, infiltration, and nephrocalcinosis were also present. To the authors' knowledge, this present study is the first report of spontaneously occurring GCK in red piranhas and freshwater fish in general. Despite being rare, GCK is a condition with the potential to impair the health of fish and mammals, and further studies are needed to shed new light on this condition.

Systematic Review of Treatment of Beta-Cell Monogenic Diabetes.

Background: Beta-cell monogenic forms of diabetes are the area of diabetes care with the strongest support for precision medicine. We reviewed treatment of hyperglycemia in GCK-related hyperglycemia, HNF1A-HNF4A- and HNF1B-diabetes, Mitochondrial diabetes (MD) due to m.3243A>G variant, 6q24-transient neonatal diabetes (TND) and SLC19A2-diabetes. Methods: Systematic reviews with data from PubMed, MEDLINE and Embase were performed for the different subtypes. Individual and group level data was extracted for glycemic outcomes in individuals with genetically confirmed monogenic diabetes. Results: 147 studies met inclusion criteria with only six experimental studies and the rest being single case reports or cohort studies. Most studies had moderate or serious risk of bias.For GCK-related hyperglycemia, six studies (N=35) showed no deterioration in HbA1c on discontinuing glucose lowering therapy. A randomized trial (n=18 per group) showed that sulfonylureas (SU) were more effective in HNF1A-diabetes than in type 2 diabetes, and cohort and case studies supported SU effectiveness in lowering HbA1c. Two crossover trials (n=15 and n=16) suggested glinides and GLP-1 receptor agonists might be used in place of SU. Evidence for HNF4A-diabetes was limited. While some patients with HNF1B-diabetes (n=301) and MD (n=250) were treated with oral agents, most were on insulin. There was some support for the use of oral agents after relapse in 6q24-TND, and for thiamine improving glycemic control and reducing insulin requirement in SLC19A2-diabetes (less than half achieved insulin-independency). Conclusion: There is limited evidence to guide the treatment in monogenic diabetes with most studies being non-randomized and small. The data supports: no treatment in GCK-related hyperglycemia; SU for HNF1A-diabetes. Further evidence is needed to examine the optimum treatment in monogenic subtypes.

GCK exonic mutations induce abnormal biochemical activities and result in GCK-MODY.

Objective: Glucokinase-maturity-onset diabetes of the young (GCK-MODY; MODY2) is a rare genetic disorder caused by mutations in the glucokinase (GCK) gene. It is often under- or misdiagnosed in clinical practice, but correct diagnosis can be facilitated by genetic testing. In this study, we examined the genes of three patients diagnosed with GCK-MODY and tested their biochemical properties, such as protein stability and half-life, to explore the function of the mutant proteins and identify the pathogenic mechanism of GCK-MODY. Methods: Three patients with increased blood glucose levels were diagnosed with MODY2 according to the diagnostic guidelines of GCK-MODY proposed by the International Society for Pediatric and Adolescent Diabetes (ISPAD) in 2018. Next-generation sequencing (whole exome detection) was performed to detect gene mutations. The GCK gene and its mutations were introduced into the pCDNA3.0 and pGEX-4T-1 vectors. Following protein purification, enzyme activity assay, and protein immunoblotting, the enzyme activity of GCK was determined, along with the ubiquitination level of the mutant GCK protein. Results: Genetic testing revealed three mutations in the GCK gene of the three patients, including c.574C>T (p.R192W), c.758G>A (p.C253Y), and c.794G>A (p.G265D). The biochemical characteristics of the protein encoded by wild-type GCK and mutant GCK were different, compared to wild-type GCK, the enzyme activity encoded by the mutant GCK was reduced, suggesting thermal instability of the mutant GST-GCK. The protein stability and expression levels of the mutant GCK were reduced, and the enzyme activity of GCK was negatively correlated with the levels of fasting blood glucose and HbA1c. In addition, ubiquitination of the mutant GCK protein was higher than that of the wild-type, suggesting a higher degradation rate of mutant GCK than WT-GCK. Conclusion: GCK mutations lead to changes in the biochemical characteristics of its encoded proteins. The enzyme activities, protein expression, and protein stability of GCK may be reduced in patients with GCK gene mutations, which further causes glucose metabolism disorders and induces MODY2.

Maternal and Infant Outcomes in GCK-MODY Complicated by Pregnancy.

CONTEXT: Challenges exist in the management of Glucokinase-maturity-onset diabetes of the young (GCK-MODY), especially during pregnancy. OBJECTIVE: This work aimed to evaluate the prevalence of congenital anomaly in newborns from GCK-MODY mothers, and the relationship between fetus genotype and the risk of congenital malformation as well as other adverse pregnancy outcomes. METHODS: Electronic databases including PubMed, EMBASE, and Cochrane database last updated July 16, 2022, were searched. We included observational studies conducted in GCK-MODY complicated by pregnancy, and reporting at least one pregnancy outcome. We extracted data in duplicate, and the risk of bias was evaluated by the Newcastle-Ottawa Quality Assessment Scale (NOS). All statistical analysis was performed by Cochrane Review Manager. RESULTS: Eight studies were selected in the meta-analysis. Five were of high quality and 3 were of medium quality evaluated by NOS. A total of 257 GCK-MODY mothers and 499 offspring were enrolled. Among them, 370 offspring were divided into 2 groups: GCK-affected offspring (GCK+, n = 238) and GCK-unaffected offspring (GCK-, n = 132). The percentage of congenital malformations in GCK pregnant women's offspring was 2.4%. The risk of congenital malformations was similar between the GCK+ and GCK- group (odds ratio = 0.56; 95% CI, 0.07-4.51; I2 = 0%; P = .59). The risk of macrosomia/large for gestational age, neonatal hypoglycemia, and combined adverse neonatal outcome was significantly lower in offspring with the GCK mutation compared with non-GCK mutation carriers. CONCLUSION: The percentage of congenital malformations was 2.4% in GCK-MODY pregnant women's offspring, and newborns with the GCK mutation have lower birth complication than non-GCK mutation carriers.