Islet Β-cells Research Articles

Exercise-Diet Therapy Combined with Insulin Aspart Injection for the Treatment of Gestational Diabetes Mellitus: A Study on Clinical Effect and Its Impact.

Objective To explore the clinical effect and impact of exercise-diet therapy combined with Insulin Aspart Injection on gestational diabetes mellitus (GDM). Methods The objects of study were patients with pregestational diabetes mellitus (PGDM) and 62 patients with GDM who were diagnosed by oral glucose tolerance test (OGTT) and insulin release test from February 2017 to February 2019. According to the severity of the disease, enrolled patients were informed to have appropriate exercise and diet control or Insulin Aspart Injection on this basis until the completion of delivery. By using 50 pregnant women with normal glucose as the control, the fasting plasma glucose (FPG), 1-hour postprandial glucose (1hPG), 2-hour postprandial glucose (2hPG), nocturnal glucose, and glycosylated hemoglobin (HbA1c) levels were compared between the PGDM group and the GDM group before and after treatment; besides, further comparison was made in terms of glucose compliance rate, islet B-cell secretory function, and insulin resistance after treatment. The pregnant women were examined by B-ultrasound at 24 and 26 weeks of gestation to check if the fetus had abnormalities in the central nervous system and the heart. Further B-ultrasound examination was performed at 32 and 37 weeks of gestation to check the problems such as polyhydramnios and stillbirth. In addition, a comparative analysis was carried out in terms of the adverse pregnancy outcomes and complications, associated with the comparison of the results after treatment with control group. Results After treatment, the levels of FPG, 1hPG, 2hPG, nocturnal glucose, and HbA1c were decreased in the PGDM group and GDM group than those before treatment, especially in the GDM group, with significant difference still when compared with the control group (P < 0.05). Statistical analysis revealed that the blood glucose compliance rate in the GDM group was higher than that in the PGDM group, showing a better therapeutic effect. Fasting insulin (FINS) and homeostasis model assessment index for insulin resistance (HOMA-IR) in the GDM group were significantly higher than those in control group, but lower than those in the PGDM group (P < 0.01), while the level of HOMA-β was lower in the GDM group than that in the control group and higher than that in PGDM (P < 0.01). Further ultrasound examination revealed the presence of fetal cardiac abnormality, polyhydramnios, stillbirth, and problems, showing a higher incidence in the PGDM group but almost nonexistence in the control group. In addition, the incidence of hypertension, macrosomia, premature rupture of membranes, postpartum hemorrhage, and infection were obviously higher in the PGDM group than those in the GDM group and control group (P < 0.05). Conclusion Exercise-diet therapy combined with Insulin Aspart Injection can effectively control the blood glucose level of pregnant patients with GDM, improve the pregnancy outcome to a certain extent, and ensure the health of pregnant women and fetus, which is worthy of clinical application.

Detection of Antiviral Tissue Responses and Increased Cell Stress in the Pancreatic Islets of Newly Diagnosed Type 1 Diabetes Patients: Results From the DiViD Study.

Aims/hypothesisThe Diabetes Virus Detection (DiViD) study has suggested the presence of low-grade enteroviral infection in pancreatic tissue collected from six of six live adult patients newly diagnosed with type 1 diabetes. The present study aimed to compare the gene and protein expression of selected virally induced pathogen recognition receptors and interferon stimulated genes in islets from these newly diagnosed type 1 diabetes (DiViD) subjects vs age-matched non-diabetic (ND) controls.MethodsRNA was extracted from laser-captured islets and Affymetrix Human Gene 2.0 ST arrays used to obtain gene expression profiles. Lists of differentially expressed genes were subjected to a data-mining pipeline searching for enrichment of canonical pathways, KEGG pathways, Gene Ontologies, transcription factor binding sites and other upstream regulators. In addition, the presence and localisation of specific viral response proteins (PKR, MxA and MDA5) were examined by combined immunofluorescent labelling in sections of pancreatic tissue.ResultsThe data analysis and data mining process revealed a significant enrichment of gene ontologies covering viral reproduction and infectious cycles; peptide translation, elongation and initiation, as well as oxidoreductase activity. Enrichment was identified in the KEGG pathways for oxidative phosphorylation; ribosomal and metabolic activity; antigen processing and presentation and in canonical pathways for mitochondrial dysfunction, oxidative phosphorylation and EIF2 signaling. Protein Kinase R (PKR) expression did not differ between newly diagnosed type 1 diabetes and ND islets at the level of total RNA, but a small subset of β-cells displayed markedly increased PKR protein levels. These PKR+ β-cells correspond to those previously shown to contain the viral protein, VP1. RNA encoding MDA5 was increased significantly in newly diagnosed type 1 diabetes islets, and immunostaining of MDA5 protein was seen in α- and certain β-cells in both newly diagnosed type 1 diabetes and ND islets, but the expression was increased in β-cells in type 1 diabetes. In addition, an uncharacterised subset of synaptophysin positive, but islet hormone negative, cells expressed intense MDA5 staining and these were more prevalent in DiViD cases. MxA RNA was upregulated in newly diagnosed type 1 diabetes vs ND islets and MxA protein was detected exclusively in newly diagnosed type 1 diabetes β-cells.Conclusion/interpretationThe gene expression signatures reveal that pathways associated with cellular stress and increased immunological activity are enhanced in islets from newly diagnosed type 1 diabetes patients compared to controls. The increases in viral response proteins seen in β-cells in newly diagnosed type 1 diabetes provide clear evidence for the activation of IFN signalling pathways. As such, these data strengthen the hypothesis that an enteroviral infection of islet β-cells contributes to the pathogenesis of type 1 diabetes.

Metformin and Gegen Qinlian Decoction boost islet α-cell proliferation of the STZ induced diabetic rats

BackgroundThe traditional Chinese medicine Gegen Qinlian Decoction (GQD), as well as metformin, had been reported with anti-diabetic effects in clinical practice.ObjectiveTo verify whether these two medicines effectively ameliorate hyperglycemia caused by deficiency of islet β-cell mass which occurs in both type 1 and type 2 diabetes.MethodsSD rats were injected with a single dose of STZ (55 mg/kg) to induce β-cell destruction. The rats were then divided into control, diabetes, GQD and metformin group. GQD and metformin groups were administered with GQD extract or metformin for 6 weeks. The islet α-cell or β-cell mass changes were tested by immunohistochemical and immunofluorescent staining. The potential targets and mechanisms of GQD and metformin on cell proliferation were tested using in silico network pharmacology. Real-time PCR was performed to test the expression of islet cells related genes and targets related genes.ResultsBoth GQD and metformin did not significantly reduce the FBG level caused by β-cell mass reduction, but alleviated liver and pancreas histopathology. Both GQD and metformin did not change the insulin positive cell mass but increased α-cell proliferation of the diabetic rats. Gene expression analysis showed that GQD and metformin significantly increased the targets gene cyclin-dependent kinase 4 (Cdk4) and insulin receptor substrate (Irs1) level.ConclusionThis research indicates that GQD and metformin significantly increased the α-cell proliferation of β-cell deficiency induced diabetic rats by restoring Cdk4 and Irs1 gene expression.

Time in range assessed by capillary blood glucose in relation to insulin sensitivity and β-cell function in patients with type 2 diabetes mellitus: A cross-sectional study in China.

This study investigated the association of capillary blood glucose (CBG)-assessed time in range (TIR) (3.9-10.0 mmol/L) with insulin sensitivity and islet β-cell function. We recruited 455 patients with type 2 diabetes mellitus. Seven-point glucose-profile data (pre- and 120 min post-main meals, bedtime) were collected over three consecutive days. Plasma glucose and serum insulin concentrations were measured at 0, 60, and 120 min after a 100 g standard steamed bread meal test. The homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index were computed to evaluate insulin resistance. The HOMA of β-cell function (HOMA-β) and the area under the curve between insulin and blood glucose (IAUC0-120 /GAUC0-120 ) were used to estimate β-cell function. TIR was positively correlated with the 60 and 120 min insulin values, IAUC0-120 , the Matsuda index, HOMA-β, and IAUC0-120 /GAUC0-120 (rs : 0.154, 0.129, 0.137, 0.194, 0.341, and 0.334, respectively; P < 0.05) but inversely correlated with HOMA-IR (rs : -0.239, P < 0.001). After adjusting for confounders, multinomial multiple logistic regression analysis revealed that the odds ratios (ORs) of achieving the target time in range (>70%) increased by 12% (95% confidence interval [CI]: 3-21%), 7% (95% CI: 1-14%), 10% (95% CI: 5-16%), and 45% (95% CI: 25-68%) for each 10 mIU/L increase in the 60 and 120 min insulin values, 10 unit increase in HOMA-β, and unit increase in IAUC0-120 /GAUC0-120 , respectively (P < 0.05). Nevertheless, the OR decreased by 10% (95% CI: 1-18%) for each unit increase in HOMA-IR (P < 0.05). Insulin resistance and islet β-cell function are related to capillary blood glucose-assessed TIR.

The m6A Methyltransferase METTL3 Ameliorates Methylglyoxal-Induced Impairment of Insulin Secretion in Pancreatic β Cells by Regulating MafA Expression.

Methylglyoxal, a major precursor of advanced glycation end products, is elevated in the plasma of patients with type 2 diabetes mellitus. Islet β-cell function was recently shown to be regulated by N6-methyladenosine (m6A), an RNA modification consisting of methylation at the N6 position of adenosine. However, the role of m6A methylation modification in methylglyoxal-induced impairment of insulin secretion in pancreatic β cells has not been clarified. In this study, we showed that treatment of two β-cell lines, NIT-1 and β-TC-6, with methylglyoxal reduced m6A RNA content and methyltransferase-like 3 (METTL3) expression levels. We also showed that silencing of METTL3 inhibited glucose-stimulated insulin secretion (GSIS) from NIT-1 cells, whereas upregulation of METTL3 significantly reversed the methylglyoxal-induced decrease in GSIS. The methylglyoxal-induced decreases in m6A RNA levels and METTL3 expression were not altered by knockdown of the receptor for the advanced glycation end product but were further decreased by silencing of glyoxalase 1. Mechanistic investigations revealed that silencing of METTL3 reduced m6A levels, mRNA stability, and the mRNA and protein expression levels of musculoaponeurotic fibrosarcoma oncogene family A (MafA). Overexpression of MafA greatly improved the decrease in GSIS induced by METTL3 silencing; silencing of MafA blocked the reversal of the MG-induced decrease in GSIS caused by METTL3 overexpression. The current study demonstrated that METTL3 ameliorates MG-induced impairment of insulin secretion in pancreatic β cells by regulating MafA.

Curcuma longa modulates Islet β-cell function and insulin resistance in diabetic rat.

Objective: To analyze modulating effect of Curcuma longa on Pancreatic Islet β-cell function and insulin resistance in alloxan induced diabetic rat model. Study Design: Experimental study. Setting: Department of Anatomy, Pharmacology and Pathology, SRMCH, T. Adam. Period: February 2019 to January 2020. Material &amp; Methods: One hundred adult male rats were selected according to criteria and grouped A to E. Group A and B was negative and positive control rats, and C –E were diabetic experimental rats. Alloxan (120 mg/Kg body weight) was injected intraperitoneally (i.p) to induce diabetes mellitus. Curcuma longa was used in doses of 200, 300 and 500 mg/d for 28 days. Body weight, blood glucose, HbA1c, insulin and C-peptide were estimated. Insulin resistance (HOMA-IR) and β- cell function (HOMA-β) were calculated by formulae. Data was analyzed on SPSS package ver. 21.0 (IBM, incorporation, USA) (p≤ 0.05). Results: Twenty eight days therapy of Curcuma longa extract ameliorates blood glucose, A1C, serum Insulin levels and C-peptide levels. Insulin resistance (HOMA-IR) was found improved and β- cell function (HOMA-β) was augmented in in Curcuma longa treated experimental rats (P=0.0001). Conclusion: Administration of Curcuma longa positively modulates the Islet β-cell function and insulin resistance in alloxan induced diabetic rats.

Impact of biotin supplemented diet on mouse pancreatic islet β-cell mass expansion and glucose induced electrical activity

ABSTRACT Biotin supplemented diet (BSD) is known to enhance β-cell replication and insulin secretion in mice. Here, we first describe BSD impact on the islet β-cell membrane potential (Vm) and glucose-induced electrical activity. BALB/c female mice (n ≥ 20) were fed for nine weeks after weaning with a control diet (CD) or a BSD (100X). In both groups, islet area was compared in pancreatic sections incubated with anti-insulin and anti-glucagon antibodies; Vm was recorded in micro dissected islet β-cells during perfusion with saline solutions containing 2.8, 5.0, 7.5-, or 11.0 mM glucose. BSD increased the islet and β-cell area compared with CD. In islet β-cells of the BSD group, a larger ΔVm/Δ[glucose] was found at sub-stimulatory glucose concentrations and the threshold glucose concentration for generation of action potentials (APs) was increased by 1.23 mM. Moreover, at 11.0 mM glucose, a significant decrease was found in AP amplitude, frequency, ascending and descending slopes as well as in the calculated net charge influx and efflux of islet β-cells from BSD compared to the CD group, without changes in slow Vm oscillation parameters. A pharmacological dose of biotin in mice increases islet insulin cell mass, shifts islet β-cell intracellular electrical activity dose response curve toward higher glucose concentrations, very likely by increasing KATP conductance, and decreases voltage gated Ca2+ and K+ conductance at stimulatory glucose concentrations.

Polysaccharide from Hovenia dulcis (Guaizao) improves pancreatic injury and regulates liver glycometabolism to alleviate STZ-induced type 1 diabetes mellitus in rats

Hovenia dulcis is a traditional medicinal and edible plant and has a major geographical presence in China. In this study, a polysaccharide purified from H. dulcis (HDPs-2A) was found to ameliorate type 1 diabetes mellitus (T1DM) in streptozotocin-induced diabetic rat. HDPs-2A treatment resulted in significantly lower fasting blood glucose levels, but higher body weight, plasma insulin, and liver glycogen levels. Moreover, HDPs-2A improved dyslipidemia, pancreatic oxidative stress, and reduced serum pro-inflammatory factors. In addition, HDPs-2A up-regulated PDX-1, activated and up-regulated IRS2 expression, and regulated apoptosis and regeneration of islet β cells to recover islet β-cell function injury in TIDM rats. HDPs-2A also up-regulated the expression of pancreatic GK and GLUT2 to improve insulin secretion ability of islet β-cells, ultimately improving the glucose metabolism disorder of T1DM rats. Moreover, HDPs-2A significantly up-regulated the expression of GK and down-regulated the expression of G6Pase in liver to improve liver glycogen synthesis, inhibit liver gluconiogenesis, and improve liver glucose metabolism disorder of T1DM rats. In summary, the hypoglycemic mechanisms of HDPs-2A may include regulating the regeneration and apoptosis of islet β-cells and activating liver glycometabolism-related signaling pathways in T1DM rats.

Relationship between the Level of Amylinemia and Albuminuria Categories in Patients with Latent Autoimmune Diabetes in Adults

BACKGROUND: β-cells of islets of Langerhans produce not only insulin but another hormone – amylin, whose role in the development and progression of chronic kidney disease (CKD) in patients with diabetes mellitus (DM) is not known for certain. AIM: The aim of the study was to determine the relationship between amylinemia and albuminuria categories in patients with latent autoimmune diabetes in adults (LADA) and CKD. METHODS: 89 patients with DM and CKD were examined, as well as 15 representatives of the control group. The patients were divided into three groups by the types of DM: 36 patients with LADA, 25 patients with classical type 1 diabetes mellitus (T1D), and 28 patients with type 2 diabetes (T2D). Serum amylin levels were measured using the enzyme-linked immunosorbent assay (ELISA) method. RESULTS: In the group of patients with LADA, the amylin content was 9.0 times higher than in control (p &lt; 0.01) and 6.8 times higher compared to classical T1D (p &lt; 0.01); at the same time, it was 17.3% lower than in T2D group (p &lt; 0.05). In patients with T1D, the level of amylinemia did not change, whereas in T2D group it was 10.8 times significantly higher compared to the control and 8.3 times higher than in the group of patients with classical T1D. The highest indicator was registered in patients with LADA2 phenotype. The level of amylin was increasing in proportion to the categories of albuminuria. Positive correlations were found between the content of amylin and insulin, C-peptide, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) index and creatinine. CONCLUSION: Serum amylin level significantly increases progrediently to the albuminuria categories in patients with LADA (especially in LADA2 phenotype) and T2D.

315-OR: The Membrane Protease Prostasin Promotes Insulin Secretion by Regulating the Epidermal Growth Factor Receptor Pathway

Prostasin (PRSS8) is a serine protease that cleaves and regulates the activity of specific substrates. Epidermal growth factor receptor (EGFR) , which regulates insulin secretion and pancreatic β-cell proliferation, is activated via proteolytic shedding by PRSS8. In this study, we first found that PRSS8 is expressed in β-cells of mouse pancreatic islets. To clarify the molecular mechanisms of PRSS8-associated insulin secretion, we generated pancreatic β-cell-specific PRSS8 knockout (βKO) and PRSS8-overexpressing (βTG) mice. Overall, we observed glucose intolerance and decreased glucose-stimulated insulin secretion in the βKO mice compared to controls, whereas an increased response to glucose was observed in isolated islets from βTG mice. In vitro studies using MIN6 cells, we demonstrated that erlotinib, a specific inhibitor of EGFR, inhibits both EGF- and glucose-stimulated insulin secretion, and that glucose increases EGF secretion from β-cells. Following silencing of PRSS8, MIN6 cells showed lower levels of insulin secretion upon glucose stimulation, impaired EGFR signaling and lower expression levels of SNARE proteins. On the other hand, MIN6 cells overexpressing PRSS8 showed higher levels of insulin secretion at both the basal and glucose-stimulated insulin secretion, and higher phospho-EGFR levels. Furthermore, short-term exposure to glucose increased the expression level of endogenous PRSS8 protein in MIN6 cells, by blocking intracellular degradation. Our findings suggested that PRSS8 might be a blood glucose-dependent physiological modulator of insulin secretion via EGF-EGFR signaling in pancreatic β-cells. Disclosure T. Ishii: None. K. Uchimura: None. F. Furuya: None. Funding KAKENHI (19K17958 and 21K16367)

258-LB: ICAM-1 Abundance Is Increased in Pancreatic Islets of Hyperglycemic NOD Mice and Is Rapidly Upregulated by NF-kB in Pancreatic Beta Cells

Type 1 diabetes (T1D) is an autoimmune disease strongly associated with immune cell targeting of pancreatic β-cells, which ultimately produces insulin insufficiency. We identified the Icam1 gene and ICAM-1 protein, which facilitate interaction with immune cells, as elevated in female NOD mice relative to male mice. This observation is consistent with a greater frequency of diabetes onset in female mice in this well-established model of T1D. In addition, ICAM-1 protein abundance was greater in hyperglycemic female NOD compared with age-matched normoglycemic female NOD mice. Upon examining islet β-cell responses to immune cell-derived cytokines, we discovered that the Icam1 gene was rapidly (within 3h) and strongly (&amp;gt; 20-fold) upregulated in mouse, rat, and human islets as well as 832/13 rat insulinoma cells in response to IL-1β (p &amp;lt; 0.01) . Using chromatin immunoprecipitation (ChIP) assays, we identified rapid recruitment (within 30 minutes) of the p65 transcriptional subunit of NF-κB to κB genomic elements within the Icam1 gene promoter (3-fold; p &amp;lt; 0.05 relative to isotype control) . ChIP assays also revealed elevated RNA polymerase II recruitment to the Icam1 gene promoter (within 30 min) in response to IL-1β (7-fold, p &amp;lt; 0.05) . Finally, using single-cell RNA-Sequencing, we discovered that only a few clusters of β-cells expressed Icam1 at very low abundance in the basal (unstimulated) condition, while the majority of β-cell clusters in the IL-1β (3 h) stimulated condition presented with strong Icam1 positive (mRNA expressing) cells. Thus, we conclude that most, if not all, β-cells undergo rapid genetic reprogramming by IL-1β to enhance expression of the Icam1 gene and promote accumulation of the ICAM-1 protein. These findings illustrate the importance of pancreatic β-cell communication with the immune system and reveal inducible events at the β-cell level that are linked with onset and progression of T1D. Disclosure T. Martin: None. S. Burke: None. S. Ghosh: None. M. D. Karlstad: None. J. Collier: None. Funding National Institutes of Health (R03 AI151920-02)

Effect of Fatty Acids and Uremic Toxins on the Binding of Nateglinide, an Insulin Secretagogue, to Site II on Human Serum Albumin.

Nateglinide (NAT) is used to treat diabetes, stimulating pancreatic islet β-cells with residual insulin secretory capacity to increase insulin secretion. NAT has been reported to bind to human serum albumin (HSA), but the detail is still unclear. In the current study, we investigated the location and the affinity for the binding of NAT to HSA. Quantitative analysis data from the ultrafiltration experiment indicated that NAT binds strongly to a primary site on HSA with a high affinity. The presence of diazepam (DZP) or ibuprofen (IB), the specific site II ligands of HSA, decreased the binding constants of NAT respectively, without the significant changes in the number of binding sites. Whereas warfarin (WF), a site I specific ligand, did not affect the binding of NAT. Fluorescent replacement experiment showed that NAT replaced dansylsarcosine (DNSS), a site II probe of HSA, but not WF. An increasing level of myristate and uremic toxins, indoxyl sulphate (IS), indoxyl acetate (IA) and p-cresyl sulphate (PCS), during renal disease significantly increased the concentration of unbound NAT. These findings suggest that NAT specifically binds to site II of HSA and the binding capacity and pharmacokinetics of NAT change in renal diseases.

74-OR: Adoptively Transferred T Lymphocytes with Reduced iPLA2b Expression Delays Type 1 Diabetes Development in NOD Mice

Type 1 diabetes (T1D) is a T-cell mediated autoimmune disease characterized by the destruction of insulin-producing pancreatic islet β-cells. An understudied area is the role lipid signaling plays in this process. We find that the Ca2+-independent phospholipase A2β (iPLA2β) is induced under a diabetic milieu and mitigation of iPLA2β activity attenuates β-cell death. iPLA2β, a member of the PLA2 family, hydrolyzes the sn-2 substituent from glycerophospholipid substrates to yield a free fatty acid. When the fatty acid is arachidonic acid, it can be metabolized to eicosanoids, many of which are pro-inflammatory. To address our overarching hypothesis that iPLA2β-derived lipids (iDLs) contribute to T1D development, we investigated the role of immune cell-iDLs by utilizing a T-cell adoptive transfer. We isolated CD4+/8+ T-cells from splenocytes prepared from 11-week-old donor female NOD and NOD.iPLA2 β +/- (HET) . These were transferred i.p. to 4-week-old NOD.scid recipient mice. We find that NOD4/8-recipient mice develop T1D between 14-16 weeks of age. In contrast, T1D onset in HET4/8-recipient mice is delayed by 12 weeks and this was associated with better glucose tolerance, compared to NOD4/8 T-cell recipients. This finding is also supported by histology analysis of the pancreatic islet, which revealed less islet infiltration, more islet abundance, and the frequency of CD4 T cells were increased in the pancreas of HET4/8-recipient mice compared to NOD4/8 recipients. Further, lipidomics analyses revealed that HET donor T-cell production of proinflammatory lipids (i.e., PGE2 and DHETs) is decreased, relative to NOD T-cells. These findings suggest that pro-inflammatory iDLs generated by CD4 T-cells are critical contributors T1D development and can be targeted to counter T1D onset. Disclosure T.White: None. C.Chalfant: None. T.P.Dilorenzo: None. S.Ramanadham: None. D.Stephenson: None. Funding Training Program in Cell, Molecular, and Developmental Biology (5T32GM008111-34) NIH/NIDDK (R01DK110292) NIH/NIAID R21 (AI 146743) Cell, Developmental, &amp; Integrative Biology (CDIB) , the University of Alabama at Birmingham

Identification of autophagy-related genes as potential biomarkers for type 1 diabetes mellitus.

BackgroundType 1 diabetes mellitus (T1DM) is a metabolic disease in which the autoimmune destruction of pancreatic islet β-cells occurs. This study sought to investigate the role of autophagy-related genes and immune cells in the development of T1DM.MethodsWe acquired the raw gene expression profiles of 302 T1DM and 422 normal control peripheral blood samples from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified using the Limma package, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. The Search Tool for the Retrieval of Interacting Genes/Proteins (https://string-db.org/) and Cytoscape autophagy genes were intersected with the DEGs for the immune cell analysis and the correlation analysis.ResultsA total of 568 DEGs were identified in the T1DM and normal samples, of which 301 were upregulated and 267 were downregulated. The results of the functional and pathway enrichment analyses showed that the DEGs were closely associated with autophagy and immunity. Member RAS oncogene family (RAB11A), protein tyrosine phosphatase non-receptor type 11, lamin A/C, heat shock protein70, heat shock protein family A member 4, cluster of differentiation 8A, caspase 3 (CASP3), exportin 1, proto-oncogene, non-receptor tyrosine kinase, SMAD family member 4, and sirtuin 1 (SIRT1) were located at the center of the protein-protein interaction network as the core genes. The peripheral blood T cells were more elevated in the T1DM subjects than the normal subjects. RAB11A, CASP3, and SIRT1 are autophagy-associated genes. RAB11A and CASP3 were positively correlated with most immune cells, while SIRT1 was negatively correlated with most immune cells.ConclusionsAutophagy-related genes (i.e., RAB11A, CASP3, and SIRT1) and immune cells (i.e., T and B cells) may play important regulatory roles in the development of T1DM. Our findings provide novel insights into and potential targets for T1DM prediction and treatment.

Islet cell replacement and transplantation immunology in a mouse strain with inducible diabetes

Improved models of experimental diabetes are needed to develop cell therapies for diabetes. Here, we introduce the B6 RIP-DTR mouse, a model of experimental diabetes in fully immunocompetent animals. These inbred mice harbor the H2b major histocompatibility complex (MHC), selectively express high affinity human diphtheria toxin receptor (DTR) in islet β-cells, and are homozygous for the Ptprca (CD45.1) allele rather than wild-type Ptprcb (CD45.2). 100% of B6 RIP-DTR mice rapidly became diabetic after a single dose of diphtheria toxin, and this was reversed indefinitely after transplantation with islets from congenic C57BL/6 mice. By contrast, MHC-mismatched islets were rapidly rejected, and this allotransplant response was readily monitored via blood glucose and graft histology. In peripheral blood of B6 RIP-DTR with mixed hematopoietic chimerism, CD45.2 BALB/c donor blood immune cells were readily distinguished from host CD45.1 cells by flow cytometry. Reliable diabetes induction and other properties in B6 RIP-DTR mice provide an important new tool to advance transplant-based studies of islet replacement and immunomodulation to treat diabetes.

Artemisia dracunculus L. Ethanolic Extract and an Isolated Component, DMC2, Ameliorate Inflammatory Signaling in Pancreatic β-Cells via Inhibition of p38 MAPK

Non-resolving pancreatic islet inflammation is widely viewed as a contributor to decreases in β-cell mass and function that occur in both Type 1 and Type 2 diabetes. Therefore, strategies aimed at reducing or eliminating pathological inflammation would be useful to protect islet β-cells. Herein, we described the use of 2′,4′-dihydroxy-4-methoxydihydrochalcone (DMC2), a bioactive molecule isolated from an ethanolic extract of Artemisia dracunculus L., as a novel anti-inflammatory agent. The ethanolic extract, termed PMI 5011, reduced IL-1β-mediated NF-κB activity. DMC2 retained this ability, indicating this compound as the likely source of anti-inflammatory activity within the overall PMI 5011 extract. We further examined NF-κB activity using promoter-luciferase reporter constructs, Western blots, mRNA abundance, and protein secretion. Specifically, we found that PMI 5011 and DMC2 each reduced the ability of IL-1β to promote increases in the expression of the Ccl2 and Ccl20 genes. These genes encode proteins that promote immune cell recruitment and are secreted by β-cells in response to IL-1β. Phosphorylation of IκBα and the p65 subunit of NF-κB were not reduced by either PMI 5011 or DMC2; however, phosphorylation of p38 MAPK was blunted in the presence of DMC2. Finally, we observed that while PMI 5011 impaired glucose-stimulated insulin secretion, insulin output was preserved in the presence of DMC2. In conclusion, PMI 5011 and DMC2 reduced inflammation, but only DMC2 did so with the preservation of glucose-stimulated insulin secretion.

Upregulating Human Cathelicidin Antimicrobial Peptide LL-37 Expression May Prevent Severe COVID-19 Inflammatory Responses and Reduce Microthrombosis.

COVID-19 is characterized by hyperactivation by inflammatory cytokines and recruitment of macrophages, neutrophils, and other immune cells, all hallmarks of a strong inflammatory response that can lead to severe complications and multi-organ damage. Mortality in COVID-19 patients is associated with a high prevalence of neutrophil extracellular trap (NET) formation and microthrombosis that are exacerbated by hyperglycemia, diabetes, and old age. SARS-CoV-2 infection in humans and non-human primates have revealed long-term neurological consequences of COVID-19, possibly concomitant with the formation of Lewy bodies in the brain and invasion of the nervous system via the olfactory bulb. In this paper, we review the relevance of the human cathelicidin LL-37 in SARS-CoV-2 infections. LL-37 is an immunomodulatory, host defense peptide with direct anti-SARS-CoV-2 activity, and pleiotropic effects on the inflammatory response, neovascularization, Lewy body formation, and pancreatic islet cell function. The bioactive form of vitamin D and a number of other compounds induce LL-37 expression and one might predict its upregulation, could reduce the prevalence of severe COVID-19. We hypothesize upregulation of LL-37 will act therapeutically, facilitating efficient NET clearance by macrophages, speeding endothelial repair after inflammatory tissue damage, preventing α-synuclein aggregation, and supporting blood-glucose level stabilization by facilitating insulin release and islet β-cell neogenesis. In addition, it has been postulated that LL-37 can directly bind the S1 domain of SARS-CoV-2, mask angiotensin converting enzyme 2 (ACE2) receptors, and limit SARS-CoV-2 infection. Purposeful upregulation of LL-37 could also serve as a preventative and therapeutic strategy for SARS-CoV-2 infections.

Pancreatic INS-1 β-Cell Response to Thapsigargin and Rotenone: A Comparative Proteomics Analysis Uncovers Key Pathways of β-Cell Dysfunction.

Insulin-secreting β-cells in the pancreatic islets are exposed to various endogenous and exogenous stressing conditions, which may lead to β-cell dysfunction or apoptosis and ultimately to diabetes mellitus. However, the detailed molecular mechanisms underlying β-cell's inability to survive under severe stresses remain to be explored. This study used two common chemical stressors, thapsigargin and rotenone, to induce endoplasmic reticulum (ER) and mitochondria stress in a rat insuloma INS-1 832/13 β-cell line, mimicking the conditions experienced by dysfunctional β-cells. Proteomic changes of cells upon treatment with stressors at IC50 were profiled with TMT-based quantitative proteomics and further verified using label-free quantitive proteomics. The differentially expressed proteins under stress conditions were selected for in-depth bioinformatic analysis. Thapsigargin treatment specifically perturbed unfolded protein response (UPR) related pathways; in addition, 58 proteins not previously linked to the UPR related pathways were identified with consistent upregulation under stress induced by thapsigargin. Conversely, rotenone treatment resulted in significant proteome changes in key mitochondria regulatory pathways such as fatty acid β-oxidation, cellular respiration, citric acid cycle, and respiratory electron transport. Our data also demonstrated that both stressors increased reactive oxygen species production and depleted adenosine triphosphate synthesis, resulting in significant dysregulation of oxidative phosphorylation signaling pathways. These novel dysregulated proteins may suggest an alternative mechanism of action in β-cell dysfunction and provide potential targets for probing ER- and mitochondria stress-induced β-cell death.

Efficacy and safety of sitagliptin and insulin forlatent autoimmune diabetes in adults: Asystematic review and meta-analysis.

ABSTRACTAims/IntroductionThe optimal therapy for latent autoimmune diabetes in adults (LADA) remains undefined. Increasing evidence has shown that sitagliptin and insulin treatment can benefit patients with LADA, but the efficacy still lacks systematic evaluation. We carried out this systematic review and meta‐analysis to summarize the current data on the efficacy and safety of sitagliptin combined with insulin on LADA, providing a reliable reference for the effective therapeutic treatment of LADA patients.Materials and MethodsWe retrieved the literature in PubMed, Cochrane Library, Embase, Web of Science and CNKI from inception to August 2021. Randomized controlled trials comparing the effects of sitagliptin plus insulin with insulin alone in LADA patients were identified. The outcome measures included parameters of glycemic control, β‐cell function, body mass index and adverse events. The Review Manager 5.2 and Stata 14.0 were utilized for data analysis.ResultsEight randomized controlled trials involving 295 participants were identified. Sitagliptin and insulin treatment lowered hemoglobin A1c (weighted mean difference −0.36, 95% confidence interval −0.61 to −0.10, I 2 = 91.6%), increased fasting C‐peptide (weighted mean difference 0.08, 95% confidence interval −0.02 to 0.17, I 2 = 88.8%) and had fewer adverse events compared with insulin alone. The inter‐study heterogeneity, potential publication bias and other factors might interpret asymmetrical presentation of funnel plots. There was no significant association between sitagliptin plus insulin treatment and levels of hemoglobin A1c or fasting C‐peptide, regardless of the duration of intervention and sample size.ConclusionsSitagliptin combined with insulin can achieve better glycemic control and improve islet β‐cell function with lower incidence of hypoglycemia compared with insulin alone, which provides an effective and tolerated therapeutic regimen for LADA patients. However, further well‐designed and rigorous randomized controlled trials are required to validate this benefit due to the limited methodology quality of included trials.

Efficacy and safety of umbilical cord-derived mesenchymal stem cells in Chinese adults with type 2 diabetes: a single-center, double-blinded, randomized, placebo-controlled phase II trial

BackgroundTo determine the efficacy and safety of umbilical cord-derived mesenchymal stem cells (UC-MSCs) in Chinese adults with type 2 diabetes mellitus (T2DM).MethodsIn this single-center, double-blinded, randomized, placebo-controlled phase II trial, 91 patients were randomly assigned to receive intravenous infusion of UC-MSCs (n = 45) or placebo (n = 46) three times with 4-week intervals and followed up for 48 weeks from October 2015 to December 2018. The primary endpoint was the percentage of patients with glycated hemoglobin (HbA1c) levels of < 7.0% and daily insulin reduction of ≥ 50% at 48 weeks. Additional endpoints were changes of metabolic control, islet β-cell function, insulin resistance, and safety.ResultsAt 48 weeks, 20% of the patients in the UC-MSCs group and 4.55% in the placebo group reached the primary endpoint (p < 0.05, 95% confidence interval (CI) 2.25–28.66%). The percentage of insulin reduction of the UC-MSCs group was significantly higher than that of the placebo group (27.78% versus 15.62%, p < 0.05). The levels of HbA1c decreased 1.31% (9.02 ± 1.27% to 7.52 ± 1.07%, p < 0.01) in the UC-MSCs group, and only 0.63% in the placebo group (8.89 ± 1.11% to 8.19 ± 1.02%, p˃0.05; p = 0.0081 between both groups). The glucose infusion rate (GIR) increased significantly in the UC-MSCs group (from 3.12 to 4.76 mg/min/kg, p < 0.01), whereas no significant change was observed in the placebo group (from 3.26 to 3.60 mg/min/kg, p ˃ 0.05; p < 0.01 between both groups). There was no improvement in islet β-cell function in both groups. No major UC-MSCs transplantation-related adverse events occurred.ConclusionsUC-MSCs transplantation could be a potential therapeutic approach for Chinese adults with T2DM.Trial registration This study was registered on ClinicalTrials.gov (identifier: NCT02302599).