Impaired Insulin Secretion Research Articles

The effects of SOD Melon Gliadin as an Antioxidant on VEGF and TGF β blood serum and vitreoretina in hyperglycemia rat model a literature review

Diabetes Mellitus is a chronic metabolic disorder characterized by hyperglycemia resulting from impaired insulin secretion, action, or both. Persistent hyperglycemia can lead to organ damage, including ocular complications such as diabetic retinopathy. Diabetic retinopathy is a primary cause of preventable blindness and can become vision-threatening if complications are persistent. Over one-third of individuals with diabetes exhibit signs of diabetic retinopathy, and among them, approximately one-third experience vision-threatening diabetic retinopathy (VTDR), defined as severe non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), or the presence of diabetic macular edema (DME). Diabetic retinopathy triggers the production of reactive oxygen species (ROS). Excessive accumulation of ROS can damage tissues surrounding retinal blood vessels, leading to oxidative stress that compromises the blood-retina barrier (BRB). Vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) are two markers that indicate retinal dysfunction. Cells possess an intrinsic defense system against ROS, comprising antioxidants such as superoxide dismutase (SOD), glutathione reductase, glutathione peroxidase, and catalase. SOD melon gliadin (Glisodin®) is a potent antioxidant that elevates endogenous SOD levels, reduces ROS, and protects retinal tissues from damage and cell death. Research on SOD melon gliadin (Glisodin®) shows its potential as an antioxidant for preventing diabetic complications in the retina, specifically diabetic retinopathy.

Visceral Adipocyte-Derived Extracellular Vesicle miR-27a-5p Elicits Glucose Intolerance by Inhibiting Pancreatic β-Cell Insulin Secretion.

Pancreatic β-cell dysfunction caused by obesity can be associated with alterations in the levels of microRNAs (miRNAs). However, the role of miRNAs in such processes remains elusive. Here, we show that pancreatic islet miR-27a-5p, which is markedly increased in obese mice and impairs insulin secretion, is mainly delivered by visceral adipocyte-derived extracellular vesicles (EVs). Depleting miR-27a-5p significantly improves insulin secretion and glucose intolerance in db/db mice. Supporting the function of EVs' miR-27a-5p as a key pathogenic factor, intravenous injection of miR-27a-5p-containing EVs shows their distribution in mouse pancreatic islets. Tracing the injected AAV-miR-27a-5p (AAV-miR-27a) or AAV-FABP4-miR-27a-5p (AAV-FABP4-miR-27a) in visceral fat results in upregulating miR-27a-5p in EVs and serum, and elicits mouse pancreatic β-cell dysfunction. Mechanistically, miR-27a-5p directly targets L-type Ca2+ channel subtype CaV1.2 (Cacna1c) and reduces insulin secretion in β-cells. Overexpressing mouse CaV1.2 largely abolishes the insulin secretion injury induced by miR-27a-5p. These findings reveal a causative role of EVs' miR-27a-5p in visceral adipocyte-mediated pancreatic β-cell dysfunction in obesity-associated type 2 diabetes mellitus.

A Novel Dipterocarpol Derivative That Targets Alpha-Glucosidase and NLRP3 Inflammasome Activity for Treatment of Diabetes Mellitus.

Type 2 diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia, chronic inflammation, impaired insulin secretion, and/or peripheral insulin resistance. Current α-glucosidase inhibitors approved for clinical use exhibit limited efficacy compared to other glucose-lowering agents. In this study, a series of mono- and bis-benzylidene derivatives were synthesized via aldol condensation of 3-oxo-dammarane triterpenoids with terephthalic aldehyde. The target mono- and bis-benzylidene derivatives, based on the dammarane triterpenoids hollongdione 1, (20S)-23,24-epoxy-25,26,27-trinordammar-3,24-dione 2, and 24(R,S)-20(S)-epoxy-25-hydroxy-dammar-3-one 3, were successfully synthesized. Several of these inhibitors demonstrated significantly greater efficacy than the reference drug acarbose. Notably, compound 4 inhibited S. cerevisiae α-glucosidase with an IC50 of 2.67 μM. Furthermore, the target compounds effectively inhibited NLRP3 inflammasome activation, reducing IL-1β production in LPS+ATP-stimulated murine peritoneal macrophages without detectable cytotoxicity. Compound 8, which exhibited dual activity, was further characterized as an inhibitor of NLRP3 activation in peripheral blood mononuclear cells, leading to the prevention of pyroptosis and IL-1β release. Additionally, compound 8 was shown to promote neuronal survival in LPS+ATP-treated rat hippocampal slices, highlighting its potential as a promising antidiabetic agent that targets both postprandial hyperglycemia and metaflammation.

Clozapine impaired glucose-stimulated insulin secretion partly by increasing plasma 5-HT levels due to the inhibition of OCT1-mediated hepatic 5-HT uptake in mice.

Patients taking atypical antipsychotics (AAPs), especially clozapine, are often associated with hyperglycaemia. Here, clozapine served as a representative agent for investigating how AAPs induce hyperglycaemia. In normal mice and mice fed a high fat diet (HFD), clozapine impaired glucose tolerance and glucose-stimulated insulin secretion (GSIS) following intraperitoneal glucose administration and increased plasma 5-HT levels. Intraperitoneal 5-HT administration also impaired glucose tolerance and GSIS in mice. In INS-1 cells, high 5-HT levels impaired GSIS, which was attenuated by the 5-HTR3 antagonist tropisetron or by silencing 5-HTR3a. The 5-HTR2a agonist TCB2 attenuated clozapine-induced GSIS impairment. Silencing 5-HTR2a or the 5-HTR2a antagonist ketanserin impaired GSIS. In mice, 5-HT administration impaired GSIS, which was attenuated by tropisetron but aggravated by clozapine. Clozapine increased plasma [2H]5-HT exposure following intravenous administration to mice. In HEK293-OCT1 cells, clozapine inhibited [2H]5-HT and MPP+ uptake. Clozapine or OCT1 silencing impaired 5-HT metabolism in mouse primary hepatocytes, demonstrating that clozapine increased plasma 5-HT levels via the inhibition of OCT1-mediated hepatic 5-HT uptake. Liver-specific silencing of OCT1 increased plasma [2H]5-HT exposure and 5-HT levels and impaired GSIS and glucose tolerance in mice. In conclusion, clozapine impaired GSIS and glucose tolerance by increasing plasma 5-HT levels via the inhibition of OCT1-mediated hepatic 5-HT uptake. Increased 5-HT impaired GSIS by activating islet 5-HTR3a. The antagonistic effect of clozapine on islet 5-HTR2a also contributed to GSIS impairment. The finding that clozapine-induced GSIS impairment was attributed to increased 5-HT levels via the inhibition of OCT1-mediated hepatic 5-HT uptake may partly explain hyperglycaemia caused by other AAPs.

Cystic fibrosis-related diabetes is associated with reduced islet protein expression of GLP-1 receptor and perturbation of cell-specific transcriptional programs

Insulin secretion is impaired in individuals with cystic fibrosis (CF), contributing to high rates of CF-related diabetes (CFRD) and substantially increasing disease burden. To develop improved therapies for CFRD, better knowledge of pancreatic pathology in CF is needed. Glucagon like peptide-1 (GLP-1) from islet α cells potentiates insulin secretion by binding GLP-1 receptors (GLP-1Rs) on β cells. We determined whether expression of GLP-1 and/or its signaling components are reduced in CFRD, thereby contributing to impaired insulin secretion. Immunohistochemistry of pancreas from humans with CFRD versus no-CF/no-diabetes revealed no difference in GLP-1 immunoreactivity per islet area, whereas GLP-1R immunoreactivity per islet area or per insulin-positive islet area was reduced in CFRD. Using spatial transcriptomics, we observed several differentially expressed α- and/or β-cell genes between CFRD and control pancreas. In CFRD, we found upregulation of α-cell PCSK1 which encodes the enzyme (PC1/3) that generates GLP-1, and downregulation of α-cell PCSK1N which inhibits PC1/3. Gene set enrichment analysis also revealed α and β cell-specific pathway dysregulation in CFRD. Together, our data suggest intra-islet GLP-1 is not limiting in CFRD, but its action may be restricted due to reduced GLP-1R protein levels. Thus, restoring β-cell GLP-1R protein expression may improve β-cell function in CFRD.

Individual and combined antagonism of aryl hydrocarbon receptor (AhR) and estrogen receptors (ERs) offers distinct level of protection against Bisphenol A (BPA)-induced pancreatic islet cell toxicity in mice.

Bisphenol A (BPA), a pervasive endocrine-disrupting chemical, is known to convey harmful impact on pancreatic islets through estrogen receptors (ERs). Conversely, BPA can activate aryl hydrocarbon receptor (AhR) in certain contexts and has raised concerns about potential toxicological effects. However, BPA-AhR interaction in the context of pancreatic islet toxicity is yet to be reported. We demonstrated the specific role of AhR and its interaction with ERs to mediate BPA toxicity in pancreatic islets. In vitro, isolated islet cells treated with BPA (1 nM), with or without CH22319 (10 mM) and ICI182780 (1 mM) and insulin release, glucose-stimulated insulin secretion (GSIS), cell viability, and pERK1/2 and pAkt expression were measured. In vivo, mice were treated with BPA (10 and 100 µg/kg body weight/day for 21 days) with or without intraperitonial co-treatment of CH22319 (AhR antagonist, 10mg/kg), and ICI182780 (ER antagonist, 500 µg/kg). Glucose homeostasis, insulin resistance, oxidative stress, and inflammatory markers were measured. In vitro data revealed the involvement of AhR in the BPA-mediated alteration in insulin secretion, GSIS, and pERK1/2 and pAkt expression which were counteracted by CH223191 (AhR antagonist) alone or with ICI182780 (ER antagonist). Further, CH223191 alone or with ICI182780 modulated BPA-induced oxidative stress and pro-inflammatory cytokines and alleviated islet cell dysfunction and impaired insulin secretion. In conclusion, therapeutic targeting of AhR and ER combined might be a promising target against diabetogenic action of BPA.

Novel treatment options in patients with maturity onset diabetes of the young.

Maturity onset diabetes of the young (MODY) is the most common monogenetic form of diabetes with an autosomal dominant inheritance pattern. MODY is caused by mutations in genes that are important for the development and function of pancreatic beta cells, resulting in impaired insulin secretion capacity. To date, 14 different types have been described. While GCK-MODY (formerly MODY-2) generally requires no drug therapy, other forms of MODY such as HNF1A-MODY (formerly MODY-3) and HNF4A (formerly MODY-1) usually respond very well to sulfonylurea therapy. However, these MODY forms are characterised by a progressive course, meaning that insulin therapy is often required as the disease progresses. Both sulfonylurea therapy and insulin therapy are associated with an increased risk of hypoglycaemia and frequent weight gain. Newer blood glucose-lowering therapies, such as SGLT2 inhibitors (SGLT2i), DPP-4 inhibitors (DPP4i) and GLP-1 receptor agonists (GLP-1RA), have a much lower risk of hypoglycaemia and usually have a favourable effect on body weight. This review aims to provide an overview of the treatment of MODY patients with SGLT2i, DPP4i and GLP-1RA on the basis of previously published clinical studies, case series and case reports.

12315 Unveiling A Paraganglioma: Catecholamine-Induced Hyperglycemia Masquerading As Type 2 Diabetes Mellitus

Abstract Disclosure: S. Salman: None. M. Hussine: None. J. Tibaldi: None. Background: Excessive catecholamines have been demonstrated to exert adverse effects on insulin homeostasis and carbohydrate metabolism, potentially resulting in the onset of secondary DM. We present a case of a patient who had been previously misdiagnosed with T2DM for an extended period. Clinical Case: A 34-year-old woman with history of T2DM, HTN, and chronic tachycardia on beta blockers, presented with complaints of palpitations, headaches, and abdominal pain for two weeks. Upon admission, she was found to be in DKA, necessitating transient administration of insulin drip. Furthermore, she exhibited persistent tachycardia and intermittent episodes of hypertensive urgency. Notably, thyroid levels revealed euthyroidism. Although DKA resolved, her fasting blood sugar levels remained elevated and refractory to escalating insulin therapy. CT abdomen with contrast revealed a large enhancing mass in the RUQ. MRI abdomen confirmed an 8.1 cm heterogeneously enhancing T2 hyperintense mass located in the RUQ, abutting the right hepatic lobe, right adrenal gland, extrahepatic biliary ducts, and adjacent vessels. Given suspicions of a neuroendocrine tumor, she was transferred to the surgical service for tumor excision. Hormonal analysis revealed elevations in plasma metanephrines (620 pg/mL, n 0-88 pg/mL), plasma normetanephrines (9954 pg/mL, n 0-210.1 pg/mL), 24-hr urine normetanephrines (10,952 μg/24hr, n 110-720 μg/24hr) and 24-hr urine metanephrines (1406 μg/24hr, n 35-278 μg/24hr). Additionally, she exhibited elevated 24-hr urine epinephrine fraction (218 μg/g Cr, 0-20 μg/g Cr) and 24-hr urine norepinephrine fraction (2775 μg/g Cr, 0-45 μg/g Cr). Preoperatively, appropriate alpha and beta blockade were administered, followed by successful retroperitoneal tumor resection. Postoperatively, her glucose levels normalized without the need for further insulin therapy, and no episodes of hypoglycemia were reported. Histopathological examination of the excised mass revealed an 11 cm sympathetic paraganglioma with retention of SDHB staining. Genetic testing for SDHB, SDHD, VHL, and RET mutations is pending. Conclusion: This case underscores the potential oversight of pheochromocytomas and paragangliomas due to their nonspecific symptomatology, often mimicking more prevalent conditions, thereby presenting diagnostic challenges. The catecholamines secreted by these tumors can lead to both impaired insulin secretion and increased insulin resistance, resulting in clinically significant manifestations. The exact mechanism underlying the glycemic dysregulation remains controversial, necessitating further investigation through large-scale multicenter prospective studies to enhance understanding and inform diagnostic and therapeutic strategies for these tumors, which can manifest with severe and potentially fatal glycemic disturbances. Presentation: 6/1/2024

12615 Extremely High-dose Insulin Requirement In A Child With Covid-19 Infection

Abstract Disclosure: R. Pratibha: None. T.R. Langner: None. Background: COVID-19 infection has been associated with new diagnosis of diabetes, worsening of hyperglycemia, and increased frequency and severity of diabetic ketoacidosis (DKA) in type 1 diabetes (DM) patients. Stress- related and steroid induced hyperglycemia are also well described during COVID infection with poor glycemic control being linked to more severe SARS-CoV-2 infection outcomes. While insulin needs increase during infection, extremely high insulin requirement is uncommon and not described in the pediatric population. We present here a case of mild COVID infection with transient markedly high insulin requirements. Clinical Case A 16-year-old-African-American- female with history of fairly well controlled type 2 diabetes mellitus on closed loop system insulin pump (Omnipod) with continuous glucose monitor (CGM), was admitted with COVID-19, aspiration pneumonia and hyperglycemia. She had been diagnosed 10 months prior with Hemoglobin A1c (HbA1c) of 11.4% and mild diabetic ketoacidosis (DKA). Diabetes antibodies were negative. Four months prior to admission her HbA1c was 7.8%. Upon this hospitalization she had no hypoxemia or respiratory failure and did not need steroids. Procalcitonin level 0.09 ng/mL was normal. Developmental delay, non-ambulatory and non-verbal status, an underlying mitochondrial neurological disease with G tube and ventilator dependence added to the medical complexity. HbA1c (8.1%) and Fructosamine 316 (n 200-285 mcmol/L) were not indicative of poor control. While her pneumonia resolved promptly, blood sugar (BG) elevation prolonged her hospitalization. She was not in DKA. Despite increasing her basal rate by 50% and an additional 20% higher temporary basal rate via her insulin pump there was little response. She was switched to Insulin drip by the 7th day. Her Insulin rate had increased to 26 units per hour (at 0.64 Units/Kg/hour) by day 8. This high insulin-dose need lasted for around 36 hours, before gradually reducing over a week. She has a history of recurrent pancreatitis. Lipase 335 U/L was elevated initially but started reducing within 2 days and had normalized by day 13. She was transitioned back to her pump although at higher basal rate than the previous home regimen, by 14th day. Conclusion While a constellation of factors such as stress, steroids, underlying poor glycemic control may cause hyperglycemia in COVID-19, these do not explain the high insulin demand in our patient. COVID infection with impaired insulin secretion, mild pancreatitis may have contributed to the brief remarkably high-dose insulin requirement, but it appears to be increased insulin resistance which could possibly explain the transient derangement. To our knowledge this has previously not been described in a pediatric diabetic patient. Presentation: 6/3/2024

12394 "Sugar And Tumors: A Case Report On New-onset Diabetes In Metastatic Pheochromocytoma With Elevated Dopamine Levels"

Abstract Disclosure: B. Agrawal: None. V. mehta: None. R. naseem: None. M. Renzu: None. R. rashid: None. Introduction: Metastatic pheochromocytoma is a rare neuroendocrine tumor with potential complication of new-onset diabetes mellitus (DM). We present a case highlighting the challenges in managing a patient with metastatic pheochromocytoma and concurrent DM. Case presentation: A 66-year-old male with a history of hypertension and gout initially presented in 2010 with an adrenal mass, later identified as pheochromocytoma and resected. In 2018, he presented with bilateral leg pain, revealing metastatic disease-causing spinal cord compression along with metastatic lung nodules and metastasis in adrenalectomy bed. Despite interventions including T6,7,8 laminectomy in 2020 and radiation therapy, metastases persisted. In 2024, he presented with polyuria, polydipsia, and hyperglycemia (blood glucose >500 mg/dL). Laboratory findings showed elevated a1c of 15 in addition to elevated normetanephrines, metanephrines, and dopamine with levels of 3880, 48 and 488 respectively. He was diagnosed with new-onset DM and started on insulin therapy in addition to metformin and jardiance. Discussion: Secondary diabetes mellitus (DM) in secretory pheochromocytoma occurs in approximately 50% of cases, manifesting from mild insulin resistance to severe presentation like DKA. Epinephrine-secreting tumors contribute to glucose intolerance by activating beta receptors, thereby stimulating gluconeogenesis. Patients with higher levels of epinephrine and preoperative glucose intolerance were more prone to developing postoperative hypoglycemia, requiring close monitoring during the postoperative period. Additionally, research by DiSalvo et al. Epinephrine-secreting tumors have a more significant impact on hyperglycemia by impairing insulin secretion and stimulation GLP-1. Tumor resection has been found to be more effective effective in restoring normal glucose homeostasis in these patients. Dopamine-secreting pheochromocytomas are rare neoplasms characterized by the presence of immature catecholamine vesicles that inhibit dopamine conversio owing to localized dopamine beta hydroxylase. Typically presenting around the age of 48, these tumors often lack excess catecholamines, leading to atypical symptoms such as local discomfort or pain from tumor compression. These neoplasms are less detectable on metaiodobenzylguanidine (MIBG) scans, necessitating positron emission tomography (PET) for accurate diagnosis. Surgical resection is the treatment, with preoperative management involving metyrosine instead of alpha blockers. These tumors are frequently diagnosed late, often in a malignant stage, contributing to poor prognosis Conclusion: Overall, understanding the complex interplay between catecholamines and glucose metabolism is crucial for the comprehensive management of patients with pheochromocytoma and secondary DM. Presentation: 6/1/2024

9250 carRNA m6A methylation regulates transcription state and chromatin accessibility in human islets in normal physiology and type 2 diabetes

Abstract Disclosure: N. Shukla: None. C. Ju: None. H. Li: None. C. He: None. R. Kulkarni: Advisory Board Member; Self; Novo Nordisk, Biomea Fusion Inc, REDD Pharma. Grant Recipient; Self; Inversago. Chromatin-associated regulatory RNAs (carRNA), which include promoter- and enhancer-associated RNAs as well as several non-coding repeat elements have been established in the literature as important regulators of global gene transcription. However, the regulation of carRNAs themselves has been an enigma. Recent publications from the He Lab at UChicago have shown the role of RNA N6-methyladenosine (m6A) in regulating carRNA stability and function. m6A is among the most abundant mRNA modifications in mammals. Seminal work from our lab has reported that the “writers” of m6A (e.g. methyltransferase-like [METTL3] and METTL14) are significantly downregulated in islets of humans with type 2 diabetes (T2D). Consequently, the global m6A landscape in the islets segregates the T2D from the control group significantly better than the transcriptome (n=7 for Control and n=8 for T2D islets). Hypomethylation of key transcripts in the insulin/IGF-1-AKT-PDX1 pathway led to impaired insulin secretion and decreased β-cell proliferation. We now show this decreased m6A on RNA is not limited to the mRNA but also affects chromatin-associated regulatory RNAs (carRNA). Intriguingly, downregulation of METTL3 and METTL14 in human β-cell line EndoC-βH1 differentially regulates these regulatory versus protein-coding transcripts. We observe that while METTL14 KD causes global downregulation of transcripts belonging to pathways important for β-cell identity and function (including calcium signaling, PI3K-AKT/MAPK signaling pathway, pancreatic secretion etc.), it leads to an upregulation of pathways involved in RNA processing and global gene transcription (Transcription by RNA Pol II, metabolism and splicing of mRNA, chromatin organization and modification etc.) {false discovery rate (FDR) < 0.05}. Considering carRNAs have been previously reported to regulate global chromatin accessibility and transcription, our observations on their ability to get differentially regulated m6A writer proteins provide novel insights into the epigenetic regulation of human islet cells. These findings provide opportunities to develop therapeutic approaches to regulate β-cell identity and/or insulin secretion in T2D. Presentation: 6/3/2024

6370 New-Onset Autoimmune Diabetes Following COVID-19 Infection and its Implications for Identical Twin Siblings

Abstract Disclosure: G. Wintermyer: None. S. Gillis-Funderburk: None. COVID-19 patients face many post-recovery complications,including autoimmune disorders. Late autoimmune diabetes ofadults (LADA) is one such disorder. Studies suggest that SARS-CoV may trigger proinflammatory cytokines that damage beta cellsand impair insulin secretion. Here, we explore a case of new-onsetLADA in a patient after recovery from COVID-19. Further, asidentical twins of LADA patients have a higher risk of developingit, we discuss how we approached the patient’s identical twin.A 29-year-old female with history of obesity (BMI 32.3) presentedto our endocrinology clinic. She complained of difficulty losingweight and fatigue and reported having COVID-19 three monthsearlier. She also mentioned having polyuria. She underwent labtests, including CBC, CMP, TSH, A1C, and a lipid panel. The testresults were within normal limits, except for her A1C of 11.3%.She was started on metformin and weekly Semaglutide injections.Given her recent COVID-19 history, she was assessed for LADA.Anti-GAD-65 and ZNT8 antibodies were 120 U/mL and 150U/mL, respectively. Serum C-peptide and IA-antibodies werewithin normal ranges. The patient informed us of her twin sister’sconcurrent COVID-19 infection. Due to the risk of LADA in hertwin sister, we recommended an evaluation by our clinic. Duringthe sister’s first visit, her BMI was 37.5, and she asked for weightloss medication. Comprehensive testing, including LADAantibodies, was conducted, with results within normal ranges andA1C level of 4.9%. The sister was also started on Semaglutide forweight management.The patient had quarterly follow-up appointments at the clinic.After a year, her A1C and continuous glucose monitoring machine(CGM) readings showed improvement. Her BMI decreased to 24.She never required insulin therapy, as her diabetes was well-managed and her average monthly glucose level on GCM readings were 125, 123 and 119 mg/dL in three different periods. Antibodieswere retested. This time IA-2 antibody was also elevated.Similarly, her twin sister continued to follow-up at our clinic. Thesister achieved significant weight loss without complications. HerLADA antibodies remained negative, and her A1C remainednormal. Clinicians should be vigilant for post-COVID LADA. In this case,Semaglutide aided weight loss, which benefits diabetesmanagement. Ongoing studies explore the potential of GLP-1medications in early-stage LADA. Historically, LADA patientswere started on insulin. However, CGM has enabled close glucosemonitoring, offering management of LADA with non-insulinmedications. It is also important to remember that autoimmunedisease risk is elevated in identical twins. In this case, although thetwin sister did not develop antibodies, the risk remains. Regularevaluation of high-risk patients is crucial for early detection ofantibodies, facilitating timely treatment to prevent adverseoutcomes. Presentation: 6/3/2024

8052 carRNA m6A methylation regulates transcription state and chromatin accessibility in human islets in normal physiology and type 2 diabetes

Abstract Disclosure: N. Shukla: None. C. Ju: None. H. Li: None. C. He: None. R. Kulkarni: Advisory Board Member; Self; Novo Nordisk, Biomea Fusion Inc, REDD Pharma. Grant Recipient; Self; Inversago. Chromatin-associated regulatory RNAs (carRNA), which include promoter- and enhancer-associated RNAs as well as several non-coding repeat elements have been established in the literature as important regulators of global gene transcription. However, the regulation of carRNAs themselves has been an enigma. Recent publications from the He Lab at UChicago have shown the role of RNA N6-methyladenosine (m6A) in regulating carRNA stability and function. m6A is among the most abundant mRNA modifications in mammals. Seminal work from our lab has reported that the “writers” of m6A (e.g. methyltransferase-like [METTL3] and METTL14) are significantly downregulated in islets of humans with type 2 diabetes (T2D). Consequently, the global m6A landscape in the islets segregates the T2D from the control group significantly better than the transcriptome (n=7 for Control and n=8 for T2D islets). Hypomethylation of key transcripts in the insulin/IGF-1-AKT-PDX1 pathway led to impaired insulin secretion and decreased β-cell proliferation. We now show this decreased m6A on RNA is not limited to the mRNA but also affects chromatin-associated regulatory RNAs (carRNA). Intriguingly, downregulation of METTL3 and METTL14 in human β-cell line EndoC-βH1 differentially regulates these regulatory versus protein-coding transcripts. We observe that while METTL14 KD causes global downregulation of transcripts belonging to pathways important for β-cell identity and function (including calcium signaling, PI3K-AKT/MAPK signaling pathway, pancreatic secretion etc.), it leads to an upregulation of pathways involved in RNA processing and global gene transcription (Transcription by RNA Pol II, metabolism and splicing of mRNA, chromatin organization and modification etc.) {false discovery rate (FDR) < 0.05}. Considering carRNAs have been previously reported to regulate global chromatin accessibility and transcription, our observations on their ability to get differentially regulated m6A writer proteins provide novel insights into the epigenetic regulation of human islet cells. These findings provide opportunities to develop therapeutic approaches to regulate β-cell identity and/or insulin secretion in T2D. Presentation: 6/3/2024

Antidiabetic Potential of Nypa fruticans Fronds: Inhibition of α-Amylase, α-Glucosidase, and Glucose Absorption In Vivo

Background: Diabetes mellitus (DM) results from insulin resistance or impaired insulin secretion, leading to hyperglycemia, which, in advanced stages, causes macrovascular and microvascular complications. Effective management of postprandial hyperglycemia is critical to reducing these complications. Inhibition of carbohydrate hydrolyzing enzymes such as α-amylase and α-glucosidase offers a therapeutic approach for controlling postprandial glucose levels. While acarbose is a known inhibitor of these enzymes, its long-term use can cause gastrointestinal side effects. Therefore, alternative treatments, such as medicinal plants, are being explored. This study focuses on the antidiabetic potential of the Nipah frond (Nypa fruticans Wurmb), a traditional remedy, which is believed to inhibit glucose absorption and carbohydrate degradation. Methods; Nipah frond powder was extracted using ethanol through maceration. Phytochemical screening was conducted to detect bioactive compounds, and in vivo and in vitro assays were performed to evaluate antidiabetic properties. The inverted intestinal pouch technique assessed glucose absorption, while the Oral Glucose Tolerance Test (OGTT) was conducted on male Wistar rats. Enzyme inhibition assays for α-amylase and α-glucosidase were carried out to measure the extract's effectiveness in inhibiting carbohydrate degradation. Results: In vitro tests demonstrated that the ethanol extract exhibited inhibitory activity against both α-amylase and α-glucosidase enzymes, with IC50 values of 38.493 ± 0.900 ppm and 40.401 ± 0.558 ppm, respectively. In vivo studies using the everted sac technique showed that the extract reduced glucose absorption by 74.10% compared to the control group, similar to acarbose. In the OGTT, administration of 1000 mg/kg BW of Nipah frond extract significantly reduced postprandial glucose levels, with an area under the curve (AUC) comparable to glibenclamide. Conclusion: The ethanol extract of Nypa fruticans fronds demonstrated significant antidiabetic activity by inhibiting α-amylase and α-glucosidase, reducing glucose absorption, and suppressing postprandial hyperglycemia in vivo.

Carbohydrate Counting: A Bibliometric Analysis with a Focus on Research.

Diabetes is a metabolic disease characterized by hyperglycemia due to impaired insulin secretion, activity, or both. Carbohydrate counting, known for optimal metabolic control, plays in the therapeutic strategy in diabetes. In the last decade, an increasing amount of research has been conducted on carbohydrate counting, and the literature on this topic has been published in academic journals. This bibliometric analysis aimed to comprehensively review and analyze publications from this period, shedding light on trends, developments, and key contributors. The Expanded Science Citation Index published by the Institute for Scientific Information Web of Science, which covers English-language articles published from 1993 to 2024, was used. We selected "carbohydrate counting", "carbohydrate count", "carbohydrate counts", "carbohydrate counts", and similar words as "TOPIC" to search for related articles. All basic information about each article were collected, including authors, countries, citations, and keywords. The findings emphasized the need for continued research in this area and to learn more about studies showing the relationship between carbohydrate counting and the pathophysiology of diabetes, treatment, complications, and technologies. This analysis summarizes the general trends and key findings of research on carbohydrate counting over the past years and provides guidance for future research.

The role of magnesium in pancreatic beta-cell function and homeostasis.

Magnesium plays an essential role in glucose utilization and insulin signaling. Recent advances have revealed a greater prevalence of hypomagnesemia in general, and low intracellular magnesium levels in individuals with diabetes contribute to β-cell dysfunction and insulin resistance. This article describes the documented effects of magnesium on various aspects of β-cells and glucose homeostasis. Studies have demonstrated that magnesium deficiency is associated with reduced pancreatic β-cell activity and increased insulin resistance in patients with type 2 diabetes. Additionally, magnesium is involved in many cellular events, including energy homeostasis, protein synthesis, and DNA stability. Furthermore, magnesium is critical for proper glucose utilization and insulin signaling, and magnesium deficiency can lead to the dysregulation of ATP-sensitive potassium (KATP) channels in pancreatic β-cells, impairing insulin secretion. Therefore, maintaining adequate magnesium levels is crucial for maintaining overall health and preventing of metabolic disorders such as type 2 diabetes.

Carbohydrate response element-binding protein (ChREBP) mediates decreased SNAP25 expression in islets from diabetic Goto-Kakizaki (GK) rats.

SNAP25 plays an essential role in the glucose-stimulated insulin secretion (GSIS) of pancreatic β-cells. Carbohydrate response element-binding protein (ChREBP) is an important transcription factor in β-cells and, in this study, we aimed to explore whether ChREBP regulates SNAP25 expression in β-cells. We show that diabetic Goto-Kakizaki (GK) rats exhibited impaired insulin secretion and hyperglycemia, along with decreased SNAP25 expression and ChREBP phosphorylation in islets. SNAP25 knockdown decreased GSIS in β-cells, while SNAP25 overexpression increased GSIS in β-cells. Activation or overexpression of ChREBP led to reduced SNAP25 expression and subsequent suppression of GSIS. Conversely, ChREBP knockdown mitigated the reduction in SNAP25 expression caused by high glucose. Mechanistically, the activation of ChREBP by high glucose increased its occupancy and decreased the level of H3K4me3 at the Snap25 promoter. Our findings reveal the novel regulatory mechanisms of SNAP25 expression in β-cells and suggest that SNAP25 may be involved in the regulation of β-cell secretory function controlled by ChREBP.

Tipping-point transition from transient to persistent inflammation in pancreatic islets

Type 2 diabetes (T2D) is associated with a systemic increase in the pro-inflammatory cytokine IL-1β. While transient exposure to low IL-1β concentrations improves insulin secretion and β-cell proliferation in pancreatic islets, prolonged exposure leads to impaired insulin secretion and collective β-cell death. IL-1 is secreted locally by islet-resident macrophages and β-cells; however, it is unknown if and how the two opposing modes may emerge at single islet level. We investigated the duality of IL-1β with a quantitative in silico model of the IL-1 regulatory network in pancreatic islets. We find that the network can produce either transient or persistent IL-1 responses when induced by pro-inflammatory and metabolic cues. This suggests that the duality of IL-1 may be regulated at the single islet level. We use two core feedbacks in the IL-1 regulation to explain both modes: First, a fast positive feedback in which IL-1 induces its own production through the IL-1R/IKK/NF-κB pathway. Second, a slow negative feedback where NF-κB upregulates inhibitors acting at different levels along the IL-1R/IKK/NF-κB pathway—IL-1 receptor antagonist and A20, among others. A transient response ensues when the two feedbacks are balanced. When the positive feedback dominates over the negative, islets transit into the persistent inflammation mode. Consistent with several observations, where the size of islets was implicated in its inflammatory state, we find that large islets and islets with high density of IL-1β amplifying cells are more prone to transit into persistent IL-1β mode. Our results are likely not limited to IL-1β but are general for the combined effect of multiple pro-inflammatory cytokines and chemokines. Generalizing complex regulations in terms of two feedback mechanisms of opposing nature and acting on different time scales provides a number of testable predictions. Taking islet architecture and cellular heterogeneity into consideration, further dynamic monitoring and experimental validation in actual islet samples will be crucial to verify the model predictions and enhance its utility in clinical applications.

SRSF2 is essential for maintaining pancreatic beta-cell identity and regulating glucose homeostasis in mice

Diabetes is characterized by decreased beta-cell mass and islet dysfunction. The splicing factor SRSF2 plays a crucial role in cell survival, yet its impact on pancreatic beta cell survival and glucose homeostasis remains unclear. We observed that the deletion of Srsf2 specifically in beta cells led to time-dependent deterioration in glucose tolerance, impaired insulin secretion, decreased islet mass, an increased number of alpha cells, and the onset of diabetes by the age of 10 months in mice. Single-cell RNA sequencing (scRNA-seq) analyses revealed that, despite an increase in populations of unfolded protein response (UPR)-activated and undifferentiated beta cells within the SRSF2_KO group, there was a notable decrease in the expression of UPR-related and endoplasmic reticulum (ER)-related genes, accompanied by a loss of beta-cell identity. This suggests that beta cells have transitioned from an adaptive phase to a maladaptive phase in islets of 10-month-old SRSF2_KO mice. Further results demonstrated that deletion of SRSF2 caused decreased proliferation in beta cells within 3-month-old islets and Min6 cells. These findings underscore the essential role of SRSF2 in controlling beta-cell proliferation and preserving beta-cell function in mice.

Asuhan Keperawatan Keluarga pada Tn. A dengan Diabetes Melitus di Desa Kalibuntu RT 02 RW 02 Kecamatan Losari Kabupaten Berebes

Diabetes Mellitus (DM) is a chronic metabolic disease that often occurs in the elderly, characterized by hyperglycemia due to impaired insulin secretion or action. This research focuses on family nursing care for Mr. A, a DM sufferer, in Kalibuntu Village, Losari District, Brebes Regency. Based on data, the prevalence of diabetes in Indonesia is very high, with Indonesia ranking third in Southeast Asia. In Brebes Regency, the prevalence of DM is also significant, requiring special attention in management. The Friedman model is used in family nursing care, which emphasizes the role of the family in supporting the patient's health management. The care process includes assessment, diagnosis, planning, implementation, and evaluation. The assessment is carried out by collecting family data using clear and simple language. Nursing diagnoses are established based on data analysis, while nursing interventions are designed to meet the patient's specific needs. Implementation is carried out by carrying out the plans that have been prepared, followed by ongoing evaluation to assess the effectiveness of the intervention and make necessary adjustments. Management of DM in Mr. A involves five main pillars: education, meal planning, physical exercise, pharmacological interventions, and blood sugar checks. A positive attitude towards treatment plays an important role in achieving good glucose control and improving quality of life. These findings emphasize the importance of family involvement in DM care to ensure effective and sustainable management.