Leverage biomaterials to modulate immunity for type 1 diabetes

Bioengineering Platelets Presenting PD-L1, Galectin-9 and BTLA to Ameliorate Type 1 Diabetes

Autoimmune destruction of pancreatic β-cells leads to impaired insulin production and onset of type 1 diabetes (T1D). Hence, immunomodulation of pancreas-infiltrated immune cells especially the β-cells autoreactive-T cells is a promising way to hinder and reverse the progress of T1D. Herein, megakaryocytes are primed with interferon-γ (IFN-γ) to produce platelets presenting high levels of immunosuppressive checkpoint ligands including programmed death-ligand 1 (PD-L1), Programmed Death-Ligand 2 (PD-L2), the B and T lymphocyte attenuator (BTLA) and Galectin-9 (Gal-9), termed as IFN-γ platelets. The IFN-γ platelets bound and interacted with T cells through immune checkpoint ligands and receptors, which efficaciously induced T cell exhaustion and apoptosis in vitro. Virtually, NOD diabetes mice received IFN-γ platelets treatments prominently preserved β-cell integrity and insulin production, ultimately hindering the progress to hyperglycemia. Intriguingly, both the amount and activity of the pancreas infiltrate-T cells intensively reduced, whereas the magnitude of regulatory T cells (Tregs) remarkably increased, which is attributed to IFN-γ platelets treatments. Moreover, IFN-γ platelets treatment instigated macrophage polarization toward an anti-inflammatory M2 phenotype that may stimulate pancreatic angiogenesis, and promote β-cell proliferation, consequently ameliorating the new-onset T1D.

Systematic review of peptide nanoparticles for improved diabetes outcomes: insights and opportunities

This present study carried out a systematic review and meta-analysis of peptide nanoparticles in diabetes management for improved patient outcomes from 2014 to 2024. Different electronic databases, including PubMed, Scopus, Web of Science, ResearchGate, Google Scholar, and the Cochrane Library, were searched for relevant literature using Medical Subject Headings (MeSH) and boolean operators. A total of 317 articles were obtained and include PUBMED (39), Scopus (215), ResearchGate (30), Google Scholar (25), and Cochrane Library (8). From these, 186 duplicate entries were eliminated, while 76 articles were dismissed for some reasons. After scanning the titles, abstracts, and contents of the remaining 55 articles for relevance, 22 articles were eliminated. After a full-text screening using inclusion/exclusion criteria, an additional 11 articles were discarded, while 4 were excluded during the data extraction phase. In the end, seven (7) publications were considered relevant based on the eligibility criteria, representing 2.22%. Results showed that sequential exclusion of the studies did not have a significant impact on the effects of peptide nanoparticles on glucose control, insulin delivery, bioavailability, efficacy, safety, and patient outcomes in diabetes management. Also, peptide nanoparticles had positive improvement on glycemic control, insulin levels, glycated hemoglobin (HbA1C) levels, and overall patient outcomes. The study concludes that peptide nanoparticles harbour the potential to improve diabetes management through enhanced glucose control, insulin delivery, and patient outcomes. However, there is a significant gap in knowledge. Further research is required to understand the long-term safety and efficacy of many of the enlisted nanoparticles. Additionally, future studies should explore a wider range of peptides and proteins for encapsulation, develop delivery systems for larger and conformationally diverse molecules, and improve the oral bioavailability of encapsulated therapeutics. Long-term clinical trials are needed to validate this approach in humans and elucidate the underlying mechanisms for optimal treatment design. If these knowledge gaps are addressed, peptide nanoparticles will unavoidably become a powerful tool for effective management of diabetes along with traditional methods.

The Role of Dietary Anthocyanins for Managing Diabetes Mellitus-Associated Complications

Diabetes mellitus (DM) is an intricate metabolic disorder marked by persistent hyperglycemia, arising from disruptions in glucose metabolism, with two main forms, type 1 and type 2, involving distinct etiologies affecting β-cell destruction or insulin levels and sensitivity. The islets of Langerhans, particularly β-cells and α-cells, play a pivotal role in glucose regulation, and both DM types lead to severe complications, including retinopathy, nephropathy, and neuropathy. Plant-derived anthocyanins, rich in anti-inflammatory and antioxidant properties, show promise in mitigating DM-related complications, providing a potential avenue for prevention and treatment. Medicinal herbs, fruits, and vegetables, abundant in bioactive compounds like phenolics, offer diverse benefits, including glucose regulation and anti-inflammatory, antioxidant, anticancer, anti-mutagenic, and neuroprotective properties. Anthocyanins, a subgroup of polyphenols, exhibit diverse isoforms and biosynthesis involving glycosylation, making them potential natural replacements for synthetic food colorants. Clinical trials demonstrate the efficacy and safety of anthocyanins in controlling glucose, reducing oxidative stress, and enhancing insulin sensitivity in diabetic patients, emphasizing their therapeutic potential. Preclinical studies revealed their multifaceted mechanisms, positioning anthocyanins as promising bioactive compounds for managing diabetes and its associated complications, including retinopathy, nephropathy, and neuropathy.

Engineered extracellular vesicles as "supply vehicles" to alleviate type 1 diabetes

Recent findings have indicated that the deficiency of inhibitory programmed cell death ligand 1 (PD-L1) and galectin-9 (Gal-9) in pancreatic β-cells is associated with the progression of type 1 diabetes (T1D). This suggests that exogenous PD-L1 and Gal-9 may have promising potential as therapeutics for the treatment of T1D. In light of these reports, a recent work investigated the potential of artificial extracellular vesicles (aEVs) with the presentation of PD-L1 and Gal-9 ligands (PD-L1-Gal-9 aEVs) as a treatment for T1D, with the findings published in Diabetes. Notably, the PD-L1-Gal-9 aEVs demonstrated the capacity to induce apoptosis of T cells and the formation of regulatory T (Treg) cells, thereby maintaining immune tolerance. Furthermore, the in vivo administration of PD-L1-Gal-9 aEVs resulted in a reduction in T cell infiltration in the pancreas, an increase in β-cell integrity protection, a significant decrease in blood glucose levels, and a delay in the progression of T1D. In conclusion, this study proposed an innovative approach to the treatment of T1D progression through the use of immunosuppressive EVs. This highlight provides a comprehensive analysis and discussion of the pivotal findings of this study.

Therapeutic effect of oral insulin-chitosan nanobeads pectin-dextrin shell on streptozotocin-diabetic male albino rats

The current study inspects the therapeutic effects of orally ingested insulin-loaded chitosan nanobeads (INS-CsNBs) with a pectin-dextrin (PD) coating on streptozotocin (STZ)-induced diabetes in Wistar rats. The study also assessed antioxidant effects in pancreatic tissue homogenate, insulin, C-peptide, and inflammatory markers interleukin-1 beta and interleukin-6 (IL-1β and IL-6) in serum. Additionally, histopathological and immunohistochemical examination of insulin granules, oxidative stress, nuclear factor kappa B (NF-κB P65), and sirtuin-1 (SIRT-1) protein detection, as well as gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), B-cell lymphoma 2 (Bcl2), and Bcl-2-associated X protein (Bax) in pancreatic tissue were investigated. After induction of diabetes with STZ, rats were allocated into 6 groups: the normal control (C), the diabetic control (D), and the diabetic groups treated with INS-CsNBs coated with PD shell (50 IU/kg) (NF), free oral insulin (10 IU/kg) (FO), CsNBs-PD shell (50 IU/kg) (NB), and subcutaneous insulin (10 IU/kg) (Sc). The rats were treated daily for four weeks. Treatment of diabetic rats with INS-CsNBs coated with PD shell resulted in a significant improvement in blood glucose levels, elevated antioxidant activities, decreased NF-κB P65, IL-1β, and IL-6 levels, upregulated Nrf-2 and HO-1, in addition to a marked improvement in the histological architecture and integrity compared to the diabetic group. The effects of oral INS-CsNBs administration were comparable to those of subcutaneous insulin. In conclusion, oral administration of INS-loaded Cs-NBs with a pectin-dextrin shell demonstrated an ameliorative effect on STZ-induced diabetes, avoiding the drawbacks of subcutaneous insulin.

Kynurenines as a Novel Target for the Treatment of Inflammatory Disorders

This review discusses the potential of targeting the kynurenine pathway (KP) in the treatment of inflammatory diseases. The KP, responsible for the catabolism of the amino acid tryptophan (TRP), produces metabolites that regulate various physiological processes, including inflammation, cell cycle, and neurotransmission. These metabolites, although necessary to maintain immune balance, may accumulate excessively during inflammation, leading to systemic disorders. Key KP enzymes such as indoleamine 2,3-dioxygenase 1 (IDO1), indoleamine 2,3-dioxygenase 2 (IDO2), tryptophan 2,3-dioxygenase (TDO), and kynurenine 3-monooxygenase (KMO) have been considered promising therapeutic targets. It was highlighted that both inhibition and activation of these enzymes may be beneficial, depending on the specific inflammatory disorder. Several inflammatory conditions, including autoimmune diseases, for which modulation of KP activity holds therapeutic promise, have been described in detail. Preclinical studies suggest that this modulation may be an effective treatment strategy for diseases for which treatment options are currently limited. Taken together, this review highlights the importance of further research on the clinical application of KP enzyme modulation in the development of new therapeutic strategies for inflammatory diseases.

T follicular helper cells and T follicular regulatory cells in autoimmune diseases

T follicular helper (Tfh) cells are heterogeneous and mainly characterized by expressing surface markers CXCR5, ICOS, and PD-1; cytokine IL-21; and transcription factor Bcl6. They are crucial for B-cell differentiation into long-lived plasma cells and high-affinity antibody production. T follicular regulatory (Tfr) cells were described to express markers of conventional T regulatory (Treg) cells and Tfh cells and were able to suppress Tfh-cell and B-cell responses. Evidence has revealed that the dysregulation of Tfh and Tfr cells is positively associated with the pathogenic processes of autoimmune diseases. Herein, we briefly introduce the phenotype, differentiation, and function of Tfh and Tfr cells, and review their potential roles in autoimmune diseases. In addition, we discuss perspectives to develop novel therapies targeting Tfh/Tfr balance.