Search Results (65)

Background/Objectives: 5-Aminolevulinic acid (5-ALA) is a biosynthetic precursor of heme that induces heme oxygenase-1 (HO-1). Therapeutic induction of HO-1 has shown effectiveness in various autoimmune disease models, including type 1 diabetes (T1D). However, the efficacy of 5-ALA as an HO-1 inducer in T1D models remains unexplored. This study aimed to investigate the therapeutic efficacy of oral 5-ALA administration in preventing autoimmune diabetes development in nonobese diabetic (NOD) mice. Methods: We evaluated diabetes incidence, levels of insulin autoantibody, and severity of insulitis in 5-ALA-treated and control NOD mice. HO-1 expression of dendritic cells in the pancreatic islets and spleen of 5-ALA-treated NOD mice was measured. The IFN-γ/IL-17 of islet-infiltrating T cells and IL-10/IL-12 productions of dendritic cells in the spleen of 5-ALA-treated NOD mice were assessed. We stimulated islet antigen-specific CD4⁺ T cells with islet antigen-pulsed dendritic cells in the presence of 5-ALA and examined the proliferation of the T cells. Finally, we adoptively transferred islet antigen-specific CD4⁺ T cells into 5-ALA-treated, immunodeficient NOD-Rag1 knockout mice, and diabetes incidence in recipients was determined. Results: Oral 5-ALA treatment did not significantly impact diabetes incidence, levels of insulin autoantibody, and insulitis. No significant difference was observed in HO-1 expression in dendritic cells and cytokine production of T cells and dendritic cells. Similarly, there was no significant difference in the proliferation of islet antigen-specific CD4⁺ T cells in vitro and diabetes induction in transfer experiments. Conclusions: Oral administration of 5-ALA has a limited effect on suppressing the development of autoimmune diabetes in NOD mice. Full article

Background: Diabetic foot ulcers present a significant clinical challenge because of their high prevalence and severe complications. The need for innovative and accessible treatment options is critical. Owing to their medicinal properties, natural products, such as geopropolis, hold promise. However, the wound healing potential of the geopropolis of Melipona fasciculata, particularly in accelerating the healing of diabetic ulcers, remains unexplored. In this study, we evaluated the ability of the geopropolis of M. fasciculata to promote wound healing in diabetic mice. Methods: Geopropolis was collected, prepared as a hydroalcoholic extract, and formulated into a topical cream. Non-obese diabetic (NOD) mice with induced chronic wounds were treated with this cream daily, and wound healing was assessed through macroscopic measurements, histological analysis, cytokine quantification, and in silico molecular docking studies. Results: The results demonstrated that, compared with the control treatment, the geopropolis cream accelerated wound closure at all the analyzed time points (days 3, 7, and 14), reduced inflammatory infiltrates, and enhanced fibroblast proliferation and collagen deposition. These alterations were particularly pronounced in the final phase of healing, indicating an improvement in wound repair processes. These effects occurred without altering systemic cytokine levels, suggesting a localized treatment action. These results may be partially associated with the theoretical ability of beta-amyrin and cycloartenol to interact with human myeloperoxidase (MPO), as suggested by in silico docking analysis. Conclusions: Overall, the findings indicate that geopropolis cream could represent a viable alternative for managing diabetic ulcers, providing an effective means to enhance wound healing while remaining accessible to low-income populations. Full article

Background: Sjögren’s syndrome (SS) is an autoimmune disorder characterized by sicca syndrome and/or systemic manifestations. In this study, non-obese diabetic (NOD) mice were used as an animal model for studying SS, to evaluate the optimal administration route and dose range of dental pulp stem cells (DPSCs) in the treatment of sialadenitis caused by SS. Methods: Different doses of DPSCs were transplanted into the submandibular glands (SMGs) of 14-week-old NOD mice through two different methods: injection or retrograde perfusion through the catheter orifice into the SMG. At 21 weeks of age, the saliva flow rate (SFR), ectopic lymphocytes, and CD4⁺ T-cell infiltration were measured. Tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) in the glandular tissues were also quantitatively detected. Results: Compared with untreated and PBS-injected controls, different-dose groups of the two administration methods showed an increased saliva flow rate of NOD mice to varying degrees, reduced infiltration of lymphocytes and CD4⁺ T cells in the SMG, and decreased IFN-γ/TNF-α levels. Finally, we compared these two administration routes and found that the perfusion of 2 × 10⁵ DPSCs presents good therapeutic effects. Conclusions: DPSC perfusion through the catheter orifice is a simple and effective treatment method, which is worthy of further investigation through clinical trials. Full article

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the progressive destruction of insulin-producing β-cells in the pancreas. Currently, no therapy exists to halt or cure T1D. Vaccination with diabetic autoantigens may offer protection against T1D development. Genetically modified, attenuated Salmonella utilizing the Salmonella-Pathogenicity Island 2 (SPI2)-encoded Type Three Secretion System (T3SS) can elicit robust immune responses, making it an attractive vaccine platform. Using SPI2-T3SS to deliver an autoantigen alongside immunomodulators and anti-CD3 antibodies induces antigen-specific regulatory T-cells. Our preclinical studies demonstrated the efficacy of a Salmonella-based vaccine in both preventing and reversing autoimmune diabetes in non-obese diabetic (NOD) mice while also exploring its genetic modifications, underlying mechanisms, and delivery strategies. This review evaluates the advantages of an oral T1D vaccine employing live, attenuated Salmonella for autoantigen delivery. We also discuss future directions for advancing this strategy in the treatment of other autoimmune diseases. Full article

Diabetes Mellitus Type 1 (DM1) is an autoimmune disease characterized by the destruction of beta cells in the pancreas. Although amyloid formation has been well-studied in Diabetes Mellitus Type 2 (DM2), its role in DM1 remains unclear. Understanding how islet amyloid polypeptide (IAPP) contributes to beta cell dysfunction and death in DM1 could provide critical insights into disease mechanisms and pave the way for novel diagnostic and therapeutic strategies. A systematic review and epistemic meta-analysis was conducted using a modified PICO framework, focusing on studies related to DM1 and the IAPP aggregation process. Searches in PubMed, BIREME, and Web of Science yielded 37 relevant articles, which were analyzed and individually evaluated based on specific quality criteria. Studies that experimentally identified the formation of IAPP oligomers in DM1 were selected, along with relevant review articles. Experimental studies from human and animal models detected the presence of IAPP oligomers in DM1 patients, as well as in nonobese diabetic (NOD) and homozygous mice. Techniques like Western Blot (WB), Transmission Electron Microscopy (TEM) and Congo red staining detected various oligomers sizes, with smaller ones showing higher cytotoxicity. IAPP oligomers have been detected in the pancreatic islets of DM1 patients, contributing to beta cell damage and disease progression. Full article

Type 1 diabetes (T1D) is caused by the immune-mediated loss of pancreatic β-cells. Hypoxia-inducible factor 1α (HIF-1α) is a transcription factor which is crucial for cellular responses to low oxygen. Here, we investigate the role of β-cell HIF-1α in β-cell death and diabetes after exposure to multiple low-dose streptozotocin (MLDS). MDLS triggers auto-immunity in susceptible animal models, such as non-obese diabetic (NOD) mice. These experiments used a novel mouse model with β-cell-specific deletion of HIF-1α on a NOD background (BIN mice). Mice were given 20 mg/kg MLDS for 5 consecutive days. Following MLDS, 100% of BIN mice developed frank diabetes versus 33% of floxed-control (FC) littermates and 17% of NOD controls (p < 0.001). BIN mice had obvious loss of β-cell mass (p < 0.0001) and increased necrotic areas within islets (p < 0.001). To confirm that diabetes was T1D, adoptive transfers of splenocytes from diabetic BIN and FC mice were performed on NOD-SCID (Severe Combined ImmunoDeficiency) recipients. All mice receiving BIN-splenocytes developed frank diabetes, confirming that MLDS induced true T1D. Interestingly, diabetes developed significantly faster in BIN-adoptive transfer mice compared to mice which developed diabetes after receiving an FC-adoptive transfer. These studies demonstrate the importance of β-cell HIF-1α in the preservation of β-cell mass and avoidance of auto-immunity. Full article

The potential of RNA-based liquid biopsy is increasingly being recognized in diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin’s lymphoma. This study explores the cell-free transcriptome in a humanized DLBCL patient-derived tumor xenograft (PDTX) model. Blood plasma samples (n = 171) derived from a DLBCL PDTX model, including 27 humanized (HIS) PDTX, 8 HIS non-PDTX, and 21 non-HIS PDTX non-obese diabetic (NOD)-scid IL2Rgnull (NSG) mice were collected during humanization, xenografting, treatment, and sacrifice. The mice were treated with either rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), CD20-targeted human IFNα2-based AcTaferon combined with CHOP (huCD20-Fc-AFN-CHOP), or phosphate-buffered saline (PBS). RNA was extracted using the miRNeasy serum/plasma kit and sequenced on the NovaSeq 6000 platform. RNA sequencing data of the formalin-fixed paraffin-embedded (FFPE) tissue and blood plasma samples of the original patient were included. Flow cytometry was performed on immune cells isolated from whole blood, spleen, and bone marrow. Bulk deconvolution was performed using the Tabula Sapiens v1 basis matrix. Both R-CHOP and huCD20-Fc-AFN-CHOP were able to control tumor growth in most mice. Xenograft tumor volume was strongly associated with circulating tumor RNA (ctRNA) concentration (p < 0.001, R = 0.89), as well as with the number of detected human genes (p < 0.001, R = 0.79). Abundance analysis identified tumor-specific biomarkers that were dynamically tracked during tumor growth or treatment. An 8-gene signature demonstrated high accuracy for assessing therapy response (AUC 0.92). The tumoral gene detectability in the ctRNA of the PDTX-derived plasma was associated with RNA abundance levels in the patient’s tumor tissue and blood plasma (p < 0.001), confirming that tumoral gene abundance contributes to the cell-free RNA (cfRNA) profile. Decomposing the transcriptome, however, revealed high inter- and intra-mouse variability, which was lower in the HIS PDTX mice, indicating an impact of human engraftment on the stability and profile of cfRNA. Immunochemotherapy resulted in B cell depletion, and tumor clearance was reflected by a decrease in the fraction of human CD45+ cells. Lastly, bulk deconvolution provided complementary biological insights into the composition of the tumor and circulating immune system. In conclusion, the blood plasma-derived transcriptome serves as a biomarker source in a preclinical PDTX model, enables the assessment of biological pathways, and enhances the understanding of cfRNA dynamics. Full article

Background: Intracerebral hemorrhage (ICH) is a severe type of stroke with high mortality. Persistent hyperglycemia following ICH is linked to deteriorated neurological functions and death. However, the exacerbating effect of hyperglycemia on ICH injury at the molecular level is still unclear. Therefore, this study explores the impact of diabetes on ICH injury using a non-obese diabetic (NOD) mouse model of type I diabetes mellitus. Methods: NOD and non-diabetic (non-obese resistant) mice subjected to ICH by intrastriatal injection of collagenase were sacrificed three days following the ICH. Brains were collected for hematoma volume measurement and immunohistochemistry. Neurobehavioral assays were conducted 24 h before ICH and then repeated at 24, 48 and 72 h following ICH. Results: NOD mice showed increased hematoma volume and impairment in neurological function, as revealed by rotarod and grip strength analyses. Immunohistochemical staining showed reduced glial cell activation, as indicated by decreased GFAP and Iba1 staining. Furthermore, the expression of oxidative/nitrosative stress markers represented by 3-nitrotyrosine and inducible nitric oxide synthase was reduced in the diabetic group. Conclusions: Overall, our findings support the notion that hyperglycemia exacerbates ICH injury and worsens neurological function and that the mechanism of injury varies depending on the type of diabetes model used. Full article

Cytokine-induced β-cell apoptosis is a major pathogenic mechanism in type 1 diabetes (T1D). Despite significant advances in understanding its underlying mechanisms, few drugs have been translated to protect β-cells in T1D. Epigenetic modulators such as bromodomain-containing BET (bromo- and extra-terminal) proteins are important regulators of immune responses. Pre-clinical studies have demonstrated a protective effect of BET inhibitors in an NOD (non-obese diabetes) mouse model of T1D. However, the effect of BET protein inhibition on β-cell function in response to cytokines is unknown. Here, we demonstrate that I-BET, a BET protein inhibitor, protected β-cells from cytokine-induced dysfunction and death. In vivo administration of I-BET to mice exposed to low-dose STZ (streptozotocin), a model of T1D, significantly reduced β-cell apoptosis, suggesting a cytoprotective function. Mechanistically, I-BET treatment inhibited cytokine-induced NF-kB signaling and enhanced FOXO1-mediated anti-oxidant response in β-cells. RNA-Seq analysis revealed that I-BET treatment also suppressed pathways involved in apoptosis while maintaining the expression of genes critical for β-cell function, such as Pdx1 and Ins1. Taken together, this study demonstrates that I-BET is effective in protecting β-cells from cytokine-induced dysfunction and apoptosis, and targeting BET proteins could have potential therapeutic value in preserving β-cell functional mass in T1D. Full article

Type 1 diabetes (T1D) affects gastrointestinal (GI) motility, favoring gastroparesis, constipation, and fecal incontinence, which are more prevalent in women. The mechanisms are unknown. Given the G-protein-coupled estrogen receptor’s (GPER) role in GI motility, we investigated sex-related diabetes-induced epigenetic changes in GPER. We assessed GPER mRNA and protein expression levels using qPCR and Western blot analyses, and quantified the changes in nuclear DNA methyltransferases and histone modifications (H3K4me3, H3Ac, and H3K27Ac) by ELISA kits. Targeted bisulfite and chromatin immunoprecipitation assays were used to evaluate DNA methylation and histone modifications around the GPER promoter by chromatin immunoprecipitation assays in gastric and colonic smooth muscle tissues of male and female control (CTR) and non-obese diabetic (NOD) mice. GPER expression was downregulated in NOD, with sex-dependent variations. In the gastric smooth muscle, not in colonic smooth muscle, downregulation coincided with differences in methylation ratios between regions 1 and 2 of the GPER promoter of NOD. DNA methylation was higher in NOD male colonic smooth muscle than in NOD females. H3K4me3 and H3ac enrichment decreased in NOD gastric smooth muscle. H3K4me3 levels diminished in the colonic smooth muscle of NOD. H3K27ac levels were unaffected, but enrichment decreased in NOD male gastric smooth muscle; however, it increased in the NOD male colonic smooth muscle and decreased in the female NOD colonic smooth muscle. Male NOD colonic smooth muscle exhibited decreased H3K27ac levels, not female, whereas female NOD colonic smooth muscle demonstrated diminished enrichment of H3ac at the GPER promoter, contrary to male NOD. Sex-specific epigenetic mechanisms contribute to T1D-mediated suppression of GPER expression in the GI tract. These insights advance our understanding of T1D complications and suggest promising avenues for targeted therapeutic interventions. Full article

Type 1 diabetes (T1D) is a metabolic disease resulting from progressive autoimmune destruction of insulin-producing pancreatic beta cells. Although the majority of beta cells are lost in T1D, a small subset undergoes senescence, a stress response involving growth arrest, DNA damage response, and activation of a senescence-associated secretory phenotype (SASP). SASP in beta cells of the nonobese diabetic (NOD) mouse model of T1D and primary human islets is regulated at the level of transcription by bromodomain extra-terminal (BET) proteins, but the mechanisms remain unclear. To explore how SASP is transcriptionally regulated in beta cells, we used the NOD beta cell line NIT-1 to model beta cell SASP and identified binding partners of BET protein Brd4 and explored the role of the cyclin-dependent kinase inhibitor p21. Brd4 interacted with a variety of proteins in senescent NIT-1 cells including subunits of the Ino80 chromatin remodeling complex, which was expressed in beta cells during T1D progression in NOD mice and in human beta cells of control, autoantibody-positive, and T1D donors as determined from single-cell RNA-seq data. RNAi knockdown of p21 during senescence in NIT-1 cells did not significantly impact viability or SASP. Taken together, these results suggest that Brd4 interacts with several protein partners during senescence in NIT-1 cells, some of which may play roles in SASP gene activation and that p21 is dispensable for the SASP in this beta cell model. Full article

Type 1 Diabetes (T1D) is a chronic metabolic disorder for which current treatments are unable to prevent the onset of complications. Previously, we used an adeno-associated viral vector (AAV8) to deliver furin-cleavable human insulin (INS-FUR) to the livers of diabetic non-obese diabetic (NOD) mice to reverse T1D. The use of the traditional AAV8-INS-FUR vector could not bring about normoglycemia. However, this vector, coupled with a transposon system in the AAV8/piggyBac-INS-FUR vector, was able to do so. This study aimed to investigate the transcriptomic profiles of the livers of diabetic, AAV8-INS-FUR-transduced, and AAV8/piggyBac-INS-FUR-transduced NOD mice and compare these to the normal liver to identify genetic differences resulting from delivery of the AAV8/piggyBac-INS-FUR vector which produced normoglycemia. Differential gene expression was determined by RNA-Seq analysis and differentially expressed genes from each treatment were mapped onto cellular pathways to determine the treatments’ cell signaling and downstream effects. We observed distinct differences between the piggyBac-transduced and diabetic models, particularly in terms of metabolic function and the upregulation of key pancreatic markers in the liver of piggyBac-transduced animals. The success of the AAV8/piggyBac-INS-FUR vector in achieving normoglycemia through stable transduction was evident. However, further engineering is necessary to achieve complete pancreatic transdifferentiation of liver cells. Full article

Recently, tissue engineering, including 3D bioprinting of the pancreas, has acquired clinical significance and has become an outstanding potential method of customized treatment for type 1 diabetes mellitus. The study aimed to evaluate the function of 3D-bioprinted pancreatic petals with pancreatic islets in the murine model. A total of 60 NOD-SCID (Nonobese diabetic/severe combined immunodeficiency) mice were used in the study and divided into three groups: control group; IsletTx (porcine islets transplanted under the renal capsule); and 3D bioprint (3D-bioprinted pancreatic petals with islets transplanted under the skin, on dorsal muscles). Glucose, C-peptide concentrations, and histological analyses were performed. In the obtained results, significantly lower mean fasting glucose levels (mg/dL) were observed both in a 3D-bioprint group and in a group with islets transplanted under the renal capsule when compared with untreated animals. Differences were observed in all control points: 7th, 14th, and 28th days post-transplantation (129, 119, 118 vs. 140, 139, 140; p < 0.001). Glucose levels were lower on the 14th and 28th days in a group with bioprinted petals compared to the group with islets transplanted under the renal capsule. Immunohistochemical staining indicated the presence of secreted insulin-living pancreatic islets and neovascularization within 3D-bioprinted pancreatic petals after transplantation. In conclusion, bioprinted bionic petals significantly lowered plasma glucose concentration in studied model species. Full article

Oil-Gan, also known as emblica, is the fruit of the genus Phyllanthus emblica L. The fruits are high in nutrients and display excellent health care functions and development values. The primary aim of this study was to investigate the activities of ethyl acetate extract from Phyllanthus emblica L. (EPE) on type 1 diabetes mellitus (T1D) and immunoregulatory activities in non-obese diabetes (NOD) mice with spontaneous and cyclophosphamide (Cyp)-accelerated diabetes. EPE was vehicle-administered to spontaneous NOD (S-NOD) mice or Cyp-accelerated NOD (Cyp-NOD) mice once daily at a dose of 400 mg/kg body weight for 15 or 4 weeks, respectively. At the end, blood samples were collected for biological analyses, organ tissues were dissected for analyses of histology and immunofluorescence (IF) staining (including expressions of Bcl and Bax), the expression levels of targeted genes by Western blotting and forkhead box P3 (Foxp3), and helper T lymphocyte 1 (Th1)/Th2/Th17/Treg regulatory T cell (Treg) cell distribution by flow cytometry. Our results showed that EPE-treated NOD mice or Cyp-accelerated NOD mice display a decrease in levels of blood glucose and HbA1c, but an increase in blood insulin levels. EPE treatment decreased blood levels of IFN-γ and tumor necrosis α (TNF-α) by Th1 cells, and reduced interleukin (IL)-1β and IL-6 by Th17 cells, but increased IL-4, IL-10, and transforming growth factor-β1 (TGF-β1) by Th2 cells in both of the two mice models by enzyme-linked immunosorbent assay (ELISA) analysis. Flow cytometric data showed that EPE-treated Cyp-NOD mice had decreased the CD4⁺ subsets T cell distribution of CD4⁺IL-17 and CD4⁺ interferon gamma (IFN-γ), but increased the CD4⁺ subsets T cell distribution of CD4⁺IL-4 and CD4⁺Foxp3. Furthermore, EPE-treated Cyp-NOD mice had decreased the percentage per 10,000 cells of CD4⁺IL-17 and CD4⁺IFNγ, and increased CD4⁺IL-4 and CD4⁺Foxp3 compared with the Cyp-NOD Con group (p < 0.001, p < 0.05, p < 0.05, and p < 0.05, respectively). For target gene expression levels in the pancreas, EPE-treated mice had reduced expression levels of inflammatory cytokines, including IFN-γ and TNF-α by Th1 cells, but increased expression levels of IL-4, IL-10, and TGF-1β by Th2 cells in both two mice models. Histological examination of the pancreas revealed that EPE-treated mice had not only increased pancreatic insulin-expressing β cells (brown), and but also enhanced the percentage of Bcl-2 (green)/Bax (red) by IF staining analyses of islets compared with the S-NOD Con and the Cyp-NOD Con mice, implying that EPE displayed the protective effects of pancreas β cells. EPE-treated mice showed an increase in the average immunoreactive system (IRS) score on insulin within the pancreas, and an enhancement in the numbers of the pancreatic islets. EPE displayed an improvement in the pancreas IRS scores and a decrease in proinflammatory cytokines. Moreover, EPE exerted blood-glucose-lowering effects by regulating IL-17 expressions. Collectively, these results implied that EPE inhibits the development of autoimmune diabetes by regulating cytokine expression. Our results demonstrated that EPE has a therapeutic potential in the preventive effects of T1D and immunoregulation as a supplementary. Full article

The incidence of the autoimmune disease type 1 diabetes is increasing, likely caused by environmental factors. A gluten-free diet has previously been shown to ameliorate autoimmune diabetes in non-obese diabetic (NOD) mice and humans. Although the exact mechanisms are not understood, interventions influencing the intestinal microbiota early in life affect the risk of type 1 diabetes. Here, we characterize how NOD mice that are fed a gluten-free (GF) diet differ from NOD mice that are fed a gluten-containing standard (STD) diet in terms of their microbiota composition by 16S rRNA gene amplicon sequencing and pancreatic immune environment by real-time quantitative PCR at the prediabetic stage at 6 and 13 weeks of age. Gut microbiota analysis revealed highly distinct microbiota compositions in both the cecum and the colon of GF-fed mice compared with STD-fed mice. The microbiotas of the GF-fed mice were characterized by an increased Firmicutes/Bacteroidetes ratio, an increased abundance of short chain fatty acid (particularly butyrate)-producing bacteria, and a reduced abundance of Lactobacilli compared with STD mice. We found that the insulitis score in the GF mice was significantly reduced compared with the STD mice and that the markers for regulatory T cells and T helper 2 cells were upregulated in the pancreas of the GF mice. In conclusion, a GF diet during pre- and early post-natal life induces shifts in the cecal and colonic microbiota compatible with a less inflammatory environment, providing a likely mechanism for the protective effect of a GF diet in humans. Full article