Type 2 Diabetes Therapy Research Articles

Comparative Ability of Various Immunosuppressants as Adjuvants on the Activity of T1D Vaccine

Background: Type 1 diabetes (T1D) is an autoimmune disorder characterised by the destruction of insulin-producing beta cells in the pancreatic islets, resulting from a breakdown in immunological tolerance. Currently, T1D treatment primarily relies on insulin replacement or immunosuppressive therapies. However, these approaches often have significant drawbacks, including adverse effects, high costs, and limited long-term efficacy. Consequently, there is a pressing need for innovative immunotherapeutic strategies capable of inducing antigen-specific tolerance and protecting beta cells from autoimmune destruction. Among the various antigens, β-cell antigens like 65 kDa glutamic acid decarboxylase (GAD65) have been explored as vaccine candidates for T1D. Despite their potential, their effectiveness in humans remains modest, necessitating the use of appropriate adjuvants to enhance the vaccine’s protective effects. Methods: In this study, we evaluated the therapeutic potential of kynurenine (KYN), dexamethasone (DXMS), tacrolimus (FK506), and aluminium hydroxide (Alum) in combination with the GAD65 phage vaccine as adjuvants. Results: Our findings demonstrate that KYN, when used in conjunction with the GAD65 vaccine, significantly enhances the vaccine’s immunosuppressive effects. Compared to dexamethasone, FK506, and Alum adjuvants, KYN more effectively reduced the incidence and delayed the onset of T1D, preserved β-cell function, and promoted the induction of regulatory T cells and antigen-specific tolerance. These results suggest that KYN combined with vaccines could offer superior preventive and therapeutic benefits for T1D compared to existing treatments. Additionally, we investigated the dose-dependent effects of the GAD65 vaccine by including a low-dose group in our study. The results indicated that reducing the vaccine dose below 1010 plaque-forming units (pfu) did not confer any protective advantage or therapeutic benefit in combination with KYN. This finding underscores that 1010 pfu is the minimum effective dose for the GAD65 vaccine in achieving a protective response. In conclusion, KYN shows considerable promise as an adjuvant for the GAD65 vaccine in T1D therapy, potentially offering a more effective and durable treatment option than current immunosuppressive strategies.

Combination blood pressure lowering therapy in patients with type 2 diabetes: messages from the ADVANCE trial.

The Action in Diabetes and Vascular disease: preterAx and diamicroN Controlled Evaluation (ADVANCE) trial investigated the effects of intensive blood pressure (BP) lowering using a fixed combination of perindopril-indapamide versus placebo in type 2 diabetes (T2D). The study showed that combination perindopril-indapamide had significant benefits in reducing cardiovascular, renal, and mortality events, with consistent relative risk reductions across different patient subgroups. Secondary analyses of ADVANCE have identified novel risk markers in T2D including cessation of BP lowering therapy, absent peripheral pulses and cardiac biomarkers to name a few. ADVANCE also shed light on practical aspects of hypertension management, including the limitations of office BP, tolerability of combination BP lowering therapy across the range of BP levels and the interpretation of changes in serum creatinine after treatment initiation. This review article summarizes the findings of ADVANCE and its subsequent substudies, which have been foundational in our understanding of BP management and the use of combination BP lowering therapy in T2D.

Drug therapy of type-2-diabetes-is metformin dispensable now?

Metformin has been recommended as first-line pharmacological therapy in type‑2 diabetes (T2D) since 1998. It was the first medication that demonstrated cardiovascular benefits in obese subjects with T2D. Efficacy and safety of metformin have since been demonstrated in further studies and in real-world data on its use in practice. The recommendation of metformin as baseline therapy has reached wide acceptance internationally. During the period 2015-2021, large cardiovascular safety trials showed superiority for cardiovascular morbidity and partly also mortality outcomes for most substances of the novel antidiabetic substance classes of GLP‑1 receptor agonists and SGLT‑2 inhibitors in people with T2D and very high cardiovascular risk or preexisting cardiovascular disease. The evidence for these two substance classes is now broader than for metformin. Therefore, the question arises as to whether it is still justified to recommend metformin generally as first-line therapy in T2D. This article provides an overview of the study data as well as an overview of the evidence-based guidelines. The status and position of metformin in the treatment of T2D are discussed.

Real-world impact of adding a glucagon-like peptide-1 receptor agonist compared with basal insulin on metabolic targets in adults living with type 2 diabetes and chronic kidney disease already treated with a sodium-glucose co-transporter-2 inhibitor: The Impact GLP-1 CKD study.

To compare the effectiveness of adding a glucagon-like peptide-1 receptor agonist (GLP-1 RA) with adding basal insulin among adults with type 2 diabetes (T2D) and chronic kidney disease (CKD) already treated with a sodium-glucose co-transporter-2 inhibitor (SGLT2i) and not reaching their glycaemic control targets. A retrospective analysis of the Canadian LMC Diabetes Registry was conducted. Adults who initiated a GLP-1 RA were matched 1:1 to adults who initiated basal insulin in a T2D and CKD population. Changes in metabolic outcomes were evaluated at 26-52 weeks following the therapy start date. Propensity score matching was used to match participants who initiated a GLP-1 RA to participants who initiated basal insulin (n = 153/cohort). A significantly greater reduction in HbA1c at 26-52 weeks of follow-up was observed in the GLP-1 RA cohort compared with the basal insulin cohort (-1.3% ± 1.4% vs. -1.1% ± 1.4%, P = .03). Weight was significantly reduced (-3.4 ± 3.7 vs. 2.6 ± 4.5 kg, P < .001), and the estimated glomerular filtration rate decline slowed significantly (-0.3 ± 8.2 vs. -2.4 ± 10.4 mL/min/1.73m2, P = .02), but the change in albuminuria was not significantly different (-5.7 ± 38.1 vs. -0.5 ± 38.3 mg/mmol, P = .47) at follow-up in the GLP-1 RA group compared with the basal insulin group. No differences in self-reported hypoglycaemic events per week and therapy discontinuations were reported between the cohorts. The study shows the real-world effectiveness of GLP-1 RA therapy for T2D and CKD. GLP-1 RAs provided superior reductions in HbA1c and weight, and greater kidney protection, compared with basal insulin among adults with T2D and CKD already treated with an SGLT2i.

Brown Adipose Tissue as a Unique Niche for Islet Organoid Transplantation: Insights From In Vivo Imaging.

Transplantation of human-induced pluripotent stem cell (hiPSC)-derived islet organoids is a promising cell replacement therapy for type 1 diabetes (T1D). It is important to improve the efficacy of islet organoids transplantation by identifying new transplantation sites with high vascularization and sufficient accommodation to support graft survival with a high capacity for oxygen delivery. A human-induced pluripotent stem cell line (hiPSCs-L1) was generated constitutively expressing luciferase. Luciferase-expressing hiPSCs were differentiated into islet organoids. The islet organoids were transplanted into the scapular brown adipose tissue (BAT) of nonobese diabetic/severe combined immunodeficiency disease (NOD/SCID) mice as the BAT group and under the left kidney capsule (KC) of NOD/SCID mice as a control group, respectively. Bioluminescence imaging (BLI) of the organoid grafts was performed on days 1, 7, 14, 28, 35, 42, 49, 56, and 63 posttransplantation. BLI signals were detected in all recipients, including both the BAT and control groups. The BLI signal gradually decreased in both BAT and KC groups. However, the graft BLI signal intensity under the left KC decreased substantially faster than that of the BAT. Furthermore, our data show that islet organoids transplanted into streptozotocin-induced diabetic mice restored normoglycemia. Positron emission tomography/MRI verified that the islet organoids were transplanted at the intended location in these diabetic mice. Immunofluorescence staining revealed the presence of functional organoid grafts, as confirmed by insulin and glucagon staining. Our results demonstrate that BAT is a potentially desirable site for islet organoid transplantation for T1D therapy.

Novel Protein Biomarkers and Therapeutic Targets for Type 1 Diabetes and Its Complications: Insights from Summary-Data-Based Mendelian Randomization and Colocalization Analysis.

Millions of patients suffer from type 1 diabetes (T1D) and its associated complications. Nevertheless, the pursuit of a cure for T1D has encountered significant challenges, with a crucial impediment being the lack of biomarkers that can accurately predict the progression of T1D and reliable therapeutic targets for T1D. Hence, there is an urgent need to discover novel protein biomarkers and therapeutic targets, which holds promise for targeted therapy for T1D. In this study, we extracted summary-level data on 4907 plasma proteins from 35,559 Icelanders and 2923 plasma proteins from 54,219 UK participants as exposures. The genome-wide association study (GWAS) summary statistics on T1D and T1D with complications were obtained from the R9 release results from the FinnGen consortium. Summary-data-based Mendelian randomization (SMR) analysis was employed to evaluate the causal associations between the genetically predicted levels of plasma proteins and T1D-associated outcomes. Colocalization analysis was utilized to investigate the shared genetic variants between the exposure and outcome. Moreover, transcriptome analysis and a protein-protein interaction (PPI) network further illustrated the expression patterns of the identified protein targets and their interactions with the established targets of T1D. Finally, a Mendelian randomization phenome-wide association study evaluated the potential side effects of the identified core protein targets. In the primary SMR analysis, we identified 72 potential protein targets for T1D and its complications, and nine of them were considered crucial protein targets. Within the group were five risk targets and four protective targets. Backed by evidence from the colocalization analysis, the protein targets were classified into four tiers, with MANSC4, CTRB1, SIGLEC5 and MST1 being categorized as tier 1 targets. Delving into the DrugBank database, we retrieved 11 existing medications for T1D along with their therapeutic targets. The PPI network clarified the interactions among the identified potential protein targets and established ones. Finally, the Mendelian randomization phenome-wide association study corroborated MANSC4 as a reliable target capable of mitigating the risk of various forms of diabetes, and it revealed the absence of adverse effects linked to CTRB1, SIGLEC5 and MST1. This study unveiled many protein biomarkers and therapeutic targets for T1D and its complications. Such advancements hold great promise for the progression of drug development and targeted therapy for T1D.

Gαz-independent and -dependent Improvements With EPA Supplementation on the Early Type 1 Diabetes Phenotype of NOD Mice.

Prostaglandin E2 (PGE2) is a key mediator of inflammation and is derived from the omega-6 polyunsaturated fatty acid, arachidonic acid (AA). In the β-cell, the PGE2 receptor, Prostaglandin EP3 receptor (EP3), is coupled to the unique heterotrimeric G protein alpha subunit, Gɑz to reduce the production of cyclic adenosine monophosphate (cAMP), a key signaling molecule that activates β-cell function, proliferation, and survival pathways. Nonobese diabetic (NOD) mice are a strong model of type 1 diabetes (T1D), and NOD mice lacking Gɑz are protected from hyperglycemia. Therefore, limiting systemic PGE2 production could potentially improve both the inflammatory and β-cell dysfunction phenotype of T1D. Here, we sought to evaluate the effect of eicosapentaenoic acid (EPA) feeding, which limits PGE2 production, on the early T1D phenotype of NOD mice in the presence and absence of Gαz. Wild-type and Gαz knockout NOD mice were fed a control or EPA-enriched diet for 12 weeks, beginning at age 4 to 5 weeks. Oral glucose tolerance, splenic T-cell populations, islet cytokine/chemokine gene expression, islet insulitis, measurements of β-cell mass, and measurements of β-cell function were quantified. EPA diet feeding and Gɑz loss independently improved different aspects of the early NOD T1D phenotype and coordinated to alter the expression of certain cytokine/chemokine genes and enhance incretin-potentiated insulin secretion. Our results shed critical light on the Gαz-dependent and -independent effects of dietary EPA enrichment and provide a rationale for future research into novel pharmacological and dietary adjuvant therapies for T1D.

Can fecal microbiota transplantations modulate autoimmune responses in type 1 diabetes?

Type 1 diabetes (T1D) is a chronic autoimmune disease targeting insulin-producing pancreatic beta cells. T1D is a multifactorial disease incorporating genetic and environmental factors. In recent years, the advances in high-throughput sequencing have allowed researchers to elucidate the changes in the gut microbiota taxonomy and functional capacity that accompany T1D development. An increasing number of studies have shown a role of the gut microbiota in mediating immune responses in health and disease, including autoimmunity. Fecal microbiota transplantations (FMT) have been largely used in murine models to prove a causal role of the gut microbiome in disease progression and have been shown to be a safe and effective treatment in inflammatory human diseases. In this review, we summarize and discuss recent research regarding the gut microbiota-host interactions in T1D, the current advancement in therapies for T1D, and the usefulness of FMT studies to explore microbiota-host immunity encounters in murine models and to shape the course of human type 1 diabetes.

Steroid therapy in patients with inflammatory bowel disease complicating diabetes diagnosis

Inflammatory bowel diseases (IBDs), such as Crohn's disease (CD), ulcerative colitis (UC) or type 1 diabetes (T1D) are autoimmune diseases that may have common susceptibility pathways. In the etiology of these diseases, scientists are seeking not only genetic, but also environmental factors, infections, nutritional deficiencies, and iatrogenic causes, especially in T1D. The relationship between T1D and steroid therapy, used in the treatment of the inflammatory bowel disease, has been well established for years. Steroids are most commonly known for causing drug-induced diabetes. We present a 35-year-old man, in whom a drug-induced diabetes was suggested due to a 4-week steroid therapy used as a treatment for his newly diagnosed ulcerative colitis and a literature review describing a similar problem. To confirm the association between diabetes and steroid therapy, it was necessary to rule out an autoimmune background of the disease. However, the presence of autoantibodies to GAD and anti-α tyrosine phosphatase (IA-2) confirmed the diagnosis of T1D. Aim of the study This review aims to present the issue of type 1 diabetes in patients treated with steroid therapy for inflammatory bowel disease, and to summarize the current state of knowledge, so that in the future it will result in an accurate diagnosis and implementation of appropriate treatment. Methods and materials A literature review was conducted based on the PubMed database, using keywords: ”diabetes mellitus”, ”inflammatory bowel diseases”, ”ulcerative colitis”, „steroids”, ”insulin”. Conclusion We should suspect T1D in patients, especially in the young population suffering from autoimmune diseases in order to prevent serious complications including dysfunction and failure of various organs, such as eyes, kidneys, nerves, heart and blood vessels.

GLP-1 Analogue-Loaded Glucose-Responsive Nanoparticles as Allies of Stem Cell Therapies for the Treatment of Type I Diabetes.

Type 1 diabetes (T1D) is characterized by insufficient insulin secretion due to β-cell loss. Despite exogenous insulin administration being a lifesaving treatment, many patients still experience severe glycemic lability. For these patients, a β-cell replacement strategy through pancreas or pancreatic islet transplantation is the most physiological approach. However, donors' scarcity and the need for lifelong immunosuppressive therapy pose some challenges. This study proposes an innovative biomimetic pancreas, comprising β- and α-cells differentiated from human induced pluripotent stem cells (hiPSCs) embedded in a biofunctional matrix with glucose-responsive nanoparticles (NPs) encapsulating a glucagon-like peptide 1 (GLP-1) analogue, which aims to enhance the glucose responsiveness of differentiated β-cells. Herein, glucose-sensitive pH-responsive NPs encapsulating exenatide or semaglutide showed an average size of 145 nm, with 40% association efficiency for exenatide-loaded NPs and 55% for semaglutide-loaded NPs. Both peptides maintained their secondary structure after in vitro release and showed a similar effect on INS-1E cells' insulin secretion. hiPSCs were differentiated into β- and α-cells, and insulin-positive cells were obtained (82%), despite low glucose responsiveness, as well as glucagon-positive cells (17.5%). The transplantation of the developed system in diabetic mice showed promising outcomes since there was an increase in the survival rate of those animals. Moreover, diabetic mice transplanted with cells and exenatide showed a decrease in their glucose levels. Overall, the biomimetic pancreas developed in this work showed improvements in diabetic mice survival rate, paving the way for new cellular therapies for T1D that explore the synergy of nanomedicines and stem cell-based approaches.

Geographic variation in sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide-1 receptor agonist use in people with type 2 diabetes in New South Wales, Australia.

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) improve glycaemic control and cardio-renal outcomes for people with type 2 diabetes (T2D). However, geographic and socio-economic variation in use is not well understood. We identified 367 829 New South Wales residents aged ≥40 years who dispensed metformin in 2020 as a proxy for T2D. We estimated the prevalence of use of other glucose-lowering medicines among people with T2D and the prevalence of SGLT2i and GLP-1RA use among people using concomitant T2D therapy (i.e. metformin + another glucose-lowering medicine). We measured the prevalence by small-level geography, stratified by age group, and characterized by remoteness and socio-economic status. The prevalence of SGLT2i (29.7%) and GLP-1RA (8.3%) use in people with T2D aged 40-64 increased with geographic remoteness and in areas of greater socio-economic disadvantage, similar to other glucose-lowering medicines. The prevalence of SGLT2i (55.4%) and GLP-1RA (15.4%) among people using concomitant T2D therapy varied across geographic areas, with lower SGLT2i use in more disadvantaged areas and localized areas of high GLP-1RA use (2.5 times the median). Compared with people aged 40-64 years, the prevalence of SGLT2i and GLP-1RA use was lower in older age groups, but with similar patterns of variation across geographic areas. The prevalence of SGLT2i and GLP-1RA use varied by geography, probably reflecting a combination of system- and prescriber-level factors. Socio-economic variation in GLP-1RA use was overshadowed by localized patterns of prescribing. Continued monitoring of variation can help shape interventions to optimize use among people who would benefit the most.

The Reasons for the Low Uptake of New Antidiabetic Drugs with Cardiovascular Effects-A Family Doctor Perspective.

Chronic diseases, such as type 2 diabetes (T2D), are difficult to manage because they demand continuous therapeutic review and monitoring. Beyond achieving the target HbA1c, new guidelines for the therapy of T2D have been introduced with the new groups of antidiabetics, glucagon-like peptide-1 receptor agonists (GLP-1ra) and sodium-glucose cotransporter-2 inhibitors (SGLT2-in). Despite new guidelines, clinical inertia, which can be caused by physicians, patients or the healthcare system, results in T2D not being effectively managed. This opinion paper explores the shift in T2D treatment, challenging assumptions and evidence-based recommendations, particularly for family physicians, considering the patient's overall situation in decision-making. We looked for the possible reasons for clinical inertia and the poor application of guidelines in the management of T2D. Guidelines for antidiabetic drugs should be more precise, providing case studies and clinical examples to define clinical contexts and contraindications. Knowledge communication can improve confidence and should include clear statements on areas of decision-making not supported by evidence. Precision medicine initiatives in diabetes aim to identify subcategories of T2D patients (including frail patients) using clustering techniques from data science applications, focusing on CV and poor treatment outcomes. Clear, unconditional recommendations for personalized T2D management may encourage drug prescription, especially for family physicians dealing with diverse patient contexts and clinical settings.

Functional maturation and longitudinal imaging of intraportal neonatal porcine islet grafts in genetically diabetic pigs

Allogeneic intraportal islet transplantation (ITx) has become an established treatment for patients with poorly controlled type 1 diabetes. However, the loss of viable beta-cell mass after transplantation remains a major challenge. Therefore, noninvasive imaging methods for long-term monitoring of the transplant fate are required. In this study, [68Ga]Ga-DOTA-exendin-4 positron emission tomography/computed tomography (PET/CT) was used for repeated monitoring of allogeneic neonatal porcine islets (NPI) after intraportal transplantation into immunosuppressed genetically diabetic pigs. NPI transplantation (3320-15,000 islet equivalents per kg body weight) led to a reduced need for exogenous insulin therapy and finally normalization of blood glucose levels in 3 out of 4 animals after 5 to 10 weeks. Longitudinal PET/CT measurements revealed a significant increase in standard uptake values in graft-bearing livers. Histologic analysis confirmed the presence of well-engrafted, mature islet clusters in the transplanted livers. Our study presents a novel large animal model for allogeneic intraportal ITx. A relatively small dose of NPIs was sufficient to normalize blood glucose levels in a clinically relevant diabetic pig model. [68Ga]Ga-DOTA-exendin-4 PET/CT proved to be efficacious for longitudinal monitoring of islet transplants. Thus, it could play a crucial role in optimizing ITx as a curative therapy for type 1 diabetes.

Assessing the effectiveness of Interleukin-2 therapy in experimental type 1 diabetes

AimMuch focus of immunotherapy for type 1 diabetes (T1D) has been devoted on selectively boosting regulatory T (Treg) cells using low dose IL-2 due to their constitutive expression of IL-2Rα, CD25. However, several clinical trials using a low dose of IL-2 only showed a limited improvement of metabolic control. It can therefore be hypothesized that further decreasing IL-2 dosage may increase the selective responsiveness of Treg cells.MethodsWe induced experimental T1D using multiple low dose streptozotocin (STZ) injections and treated the mice with an ultra-low dose IL-2 (uIL-2, approximately 7-fold lower than low dose). Immune response was studied using multicolor flow cytometry.ResultsWe found that uIL-2 did not protect STZ mice from developing hyperglycemia. It did neither increase Treg cell proportions, nor did it correct the phenotypic shift of Treg cells seen in T1D. It only partially decreased the proportion of IFN-γ+ T cells. Likewise, uIL-2 also did not protect the dysfunction of regulatory B (Breg) cells. Strikingly, when administered in combination with an anti-inflammatory cytokine IL-35, uIL-2 abrogated IL-35’s protective effect. Low dose IL-2, on the other hand, protected half of the STZ mice from developing hyperglycemia. No difference was found in the Treg and Breg response, and it only tended to decrease CD80 expression in macrophages and dendritic cells.ConclusionIn conclusion, further decreasing IL-2 dosage may not be a suitable approach for T1D therapy, and the limited success suggests that an alternative low dose IL-2 therapy strategy or other immunotherapies should be considered.

Short- and Long-Term Effects on Glucose Control of Nonadherence to Insulin Therapy in People With Type 2 Diabetes An In Silico Study.

Strict adherence to multiple daily insulin (MDI) therapy is a cornerstone for the achievement of good glucose control in people with advanced type 2 diabetes (T2D). Here, we aim to in silico assess glucose control in T2D subjects with poor adherence to MDI therapy. We tuned the Padova T2D Simulator, originally describing early-stage T2D physiology, around advanced T2D people. One hundred in silico advanced T2D subjects were generated and equipped with optimal MDI therapy: specifically, basal and bolus insulin amounts and injection times were individualized for each subject by applying titration algorithms that iteratively update insulin dose based on glucose deviation from its target. Then, the effect of nonadhering to MDI therapy was assessed using standard glucose control metrics calculated in two 6-month 3-meal/day in silico scenarios: in Scenario 1, subjects received the optimal basal and prandial insulin bolus at each meal; in Scenario 2, subjects received optimal basal insulin and randomly delayed or skipped the prandial insulin bolus in 3 lunches during working days and 1 dinner during weekends. A statistically significant degradation was found in all glucose control outcome metrics in Scenario 2 versus Scenario 1: e.g., percent time above 180 mg/dL increased by 22.2% and glucose management index by 0.2%. Impaired adherence to MDI therapy in T2D leads to glucose control deteriorations in both short and long terms. Interestingly, short-term hyperglycemia seems being contrasted by residual endogenous insulin secretion, which statistically increased by 3-fold after delayed/skipped insulin boluses compared with optimal ones.

Treatment for type 2 diabetes and diabetic nephropathy by targeting Smad3 signaling.

TGF-β/Smad3 signaling plays a critical role in type 2 diabetes (T2D) and type 2 diabetic nephropathy (T2DN), but treatment by specifically targeting Smad3 remains unexplored. To develop a new Smad3-targeted therapy for T2D and T2DN, we treated db/db mice at the pre-diabetic or established diabetic stage with a pharmacological Smad3 inhibitor SIS3. The therapeutic effect and mechanisms of anti-Smad3 treatment on T2D and T2DN were investigated. We found that anti-Smad3 treatment on pre-diabetic db/db mice largely attenuated both T2D and T2DN by markedly reducing blood glucose levels, and inhibiting the elevated serum creatinine, microalbuminuria, and renal fibrosis and inflammation. Unexpectedly, although SIS3 treatment on the established diabetic db/db mice inhibited T2DN but did not significantly improve T2D. Mechanistically, we uncovered that inhibition of T2DN in SIS3-treated db/db mice was associated with effectively restoring the balance of TGF-β/Smad signaling by inhibiting Smad3 while increasing Smad7, thereby suppressing Smad3-mediated renal fibrosis and NF-κB-driven renal inflammation via lncRNA Erbb4-IR and LRN9884-dependent mechanisms. We also revealed that inhibition of islet β cell injury by preventing the loss of islet Pax 6 could be the mechanism through which the pre-diabetic treatment, rather than the late SIS3 treatment on db/db mice significantly improved the T2D phenotype.

Phage cocktail alleviated type 2 diabetes by reshaping gut microbiota and decreasing proinflammatory cytokines.

Type 2 diabetes (T2D), a global health concern, is closely associated with the gut microbiota. Restoration of a balanced microbiota and intestinal homeostasis benefit therapy of T2D. Some special phages may selectively alter the gut microbiota without causing dysbiosis, such as MS2 and P22. However, scarcely systematic analysis of cascading effects triggered by MS2 and P22 phages on the microbiota, as well as interactions between specific gut bacteria and systemic metabolism, seriously inhibit the development of positive interventions of phages. Based on multi-omic analysis, we analyzed the intrinsic correlations among specific microbiota, their bioactive metabolites, and key indicators of T2D. We found that gavage of the MS2-P22 phage cocktail could significantly alter the gut microbiome to attenuate dysbiosis of diabetic C57BL/6 mice caused by high-fat diets (HFDs) and streptozotocin (STZ), by affecting microbial compositions as well as their metabolic pathways and metabolites, especially increasing amounts of short-chain fatty acid-producing (SCFA-producing) bacteria (e.g., Blautia and Romboutsia) and short-chain fatty acids (SCFAs). Correspondingly, a noteworthy reduction in the number of several opportunistic pathogens occurred, e.g., Candidatus Saccharimonas, Aerococcus, Oscillibacter, Desulfovibrio, and Clostridium sensu stricto 1. Synchronously, the levels of proinflammatory cytokines and lipopolysaccharide (LPS) were reduced to recover gut barrier function in T2D mice. These findings might benefit the development of a new dietary intervention for T2D based on phage cocktails. KEY POINTS: • Intestinal barrier integrity of T2D mice is improved by a phage cocktail • Negative relationship between Muribaculaceae and Corynebacterium reshaped gut microbiota • Acetate, propionate, and butyrate decreased the level of proinflammatory factors.

Colonic L-cell impairment in aged subjects with type 2 diabetes leads to diminished GLP-1 production

AimsGlucagon-like peptide 1 (GLP-1) is produced by the L subtype of enteroendocrine cells (EECs). Patients with type 2 diabetes (T2D) exhibit reduced incretin effect, but the pathophysiology and functional change of the L-cells remain unclear. Deciphering the mechanisms of the biological changes in L-cells under T2D conditions may assist in the research of gut-based strategies for T2D therapy. MethodsWe investigated the fasting serum GLP-1 levels and the distribution of colonic L-cells in young and aged participants with and without T2D. Additionally, we established an aged male T2D Wistar rat model subjected to a long-term high-fat and high-fructose (HFHF) diet. Histological investigations and single-cell RNA sequencing (scRNA-seq) analyses were performed to explore the mechanisms underlying functional changes in the colonic EECs. ResultsWe observed a decline in circulating GLP-1 levels and a reduced number of colonic L-cells in elderly patients with T2D. The mechanisms underlying impaired L-cell formation and disturbed GLP-1 production were revealed using aged T2D rats induced by a long-term HFHF diet. The scRNA-seq results showed that the transcription factors that regulate L-cell commitment, such as Foxa1, were downregulated, and the expression of genes that participate in encoding GLP-1, GLP-1 posttranslational processing, hormone secretion, and nutrient sensing was disturbed. ConclusionsTaken together, the reduced L-cell lineage commitment and disturbed L-cell functions might be the major cause of the reduced GLP-1 production in aged populations with T2D. Our study provides new insights for identifying novel targets in colonic L-cells for improving endogenous GLP-1 production.

Glucagon-related advancements in diabetes therapy

Abstract Traditionally, treatment for type 2 diabetes (T2D) centered on the failure of insulin secretion from the beta cells of the pancreas and insulin resistance. Though effective in certain respects, these treatments are marred by multiple undesirable side effects. The discovery of the incretin defect and the role of glucagon in T2D shifted the focus to therapies that addressed not only the beta cell defect but also the alpha cell defect in the pancreas. Therapies addressing these defects, simultaneously, have switched the entire focus of T2D therapy by not only improving glycemic control but also reducing the risk of hypoglycemia and weight gain and improving outcomes. These newer modalities of treatment started off with dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists (GLP1-RAs), and now further treatments in the form of twincretins (GLP1/GIP dual agonists) and triple agonists (GLP1/GIP/glucagon agonists) are unraveling. This article provides a summary of the evidence available with these newer antidiabetics, which address the glucagon defect in T2D.

Association of GLP-1 Receptor Agonists with Chronic Obstructive Pulmonary Disease Exacerbations among Patients with Type 2 Diabetes.

Rationale: Patients with chronic obstructive pulmonary disease (COPD) and type 2 diabetes (T2D) have worse clinical outcomes compared with patients without metabolic dysregulation. GLP-1 (glucagon-like peptide 1) receptor agonists (GLP-1RAs) reduce asthma exacerbation risk and improve FVC in patients with COPD. Objectives: To determine whether GLP-1RA use is associated with reduced COPD exacerbation rates, and severe and moderate exacerbation risk, compared with other T2D therapies. Methods: A retrospective, observational, electronic health records-based study was conducted using an active comparator, new-user design of 1,642 patients with COPD in a U.S. health system from 2012 to 2022. The COPD cohort was identified using a previously validated machine learning algorithm that includes a natural language processing tool. Exposures were defined as prescriptions for GLP-1RAs (reference group), DPP-4 (dipeptidyl peptidase 4) inhibitors (DPP-4is), SGLT2 (sodium-glucose cotransporter 2) inhibitors, or sulfonylureas. Measurements and Main Results: Unadjusted COPD exacerbation counts were lower in GLP-1RA users. Adjusted exacerbation rates were significantly higher in DPP-4i (incidence rate ratio, 1.48 [95% confidence interval, 1.08-2.04]; P = 0.02) and sulfonylurea (incidence rate ratio, 2.09 [95% confidence interval, 1.62-2.69]; P < 0.0001) users compared with GLP-1RA users. GLP-1RA use was also associated with significantly reduced risk of severe exacerbations compared with DPP-4i and sulfonylurea use, and of moderate exacerbations compared with sulfonylurea use. After adjustment for clinical covariates, moderate exacerbation risk was also lower in GLP-1RA users compared with DPP-4i users. No statistically significant difference in exacerbation outcomes was seen between GLP-1RA and SGLT2 inhibitor users. Conclusions: Prospective studies of COPD exacerbations in patients with comorbid T2D are warranted. Additional research may elucidate the mechanisms underlying these observed associations with T2D medications.