Biology subjects

Martin-Vazquez, E.

Publications and source records attributed to Martin-Vazquez, E..

3 recordsLinked to original sources

bioRxiv2026

From bats to humans: uncovering ISG15 as a new resistance factor in type 1 diabetes

Viral infections are one of the main environmental factors triggering type 1 diabetes (T1D). Pancreatic alpha cells are more resistant than beta cells to diabetogenic viruses, partially explaining their survival in T1D. Similarly, bats have enhanced viral resistance, suggesting putative convergent evolution in antiviral mechanisms. Herein, we compared global gene expression in bat fibroblasts under basal conditions or exposed to double-stranded RNA to human alpha and beta cells and found that alpha cells exhibit greater similarity than beta cells to the antiviral responses of bat cells, as well as stronger intrinsic resistance to viral infection. Interferon-stimulated gene 15 (ISG15), a key regulator of antiviral responses in humans and bats, has higher expression in alpha compared to beta cells in five single-cell RNASeq datasets from human islet cells and in human induced pluripotent stem cell (hiPSC)-derived alpha-like cells. ISG15 knockdown in human insulin-producing EndoC-{beta}H1 cells and human islets increases apoptosis under basal conditions and after IFN exposure, exacerbates IFN responses and increases cell death and viral production after infection with the diabetogenic virus coxsackievirus B1, while its overexpression protects EndoC-{beta}H1 cells from the virus. Collectively, the present results demonstrate that alpha cells but not beta cells have similarities with the virus resistance gene program present in bats and identify ISG15 as an important factor for islet cells to cope with viral and diabetogenic stresses.

immunology↗

bioRxiv2025

Differential immune- and apoptosis-related gene signatures in pancreatic alpha and beta cells contribute to their fate in type 1 diabetes

Both alpha and beta cells are dysfunctional in type 1 diabetes (T1D), but beta cells die while alpha cells survive the immune attack. Understanding the mechanisms underlying alpha-cell resistance could identify new approaches to protect beta cells. Herein, we analysed single-cell datasets from human alpha and beta cells under basal/unstimulated conditions and under immune-mediated stress. Alpha cells exhibit enhanced immune-like gene expression compared to beta cells. We also found that the tumour suppressor Maternally Expressed Gene 3 (MEG3), a T1D risk gene, is highly expressed in beta cells while almost undetectable in alpha cells. These observations were confirmed by analysing bulk RNA-sequencing data from fluorescence-activated cell-sorted alpha and beta cells isolated from primary human islets from non-diabetic donors. Additionally, MEG3 knockdown in human insulin-producing EndoC-{beta}H1 cells and human islets microtissues decreased cytokine-induced damage and apoptosis, preserving beta-cell function under inflammatory conditions. The fact that alpha cells exhibit increased immune-like and anti-apoptotic activity as compared to beta cells suggests that they are better equipped to endure the autoimmune assault in T1D. In addition, the marked difference in the expression of the pro-apoptotic factor MEG3 in beta cells compared to alpha cells may explain, at least in part, why beta cells are more susceptible to damage and cell death in a diabetogenic environment than neighbour alpha cells within the same islet.

cell biology↗

bioRxiv2023

Immunometabolic reprogramming by LRH-1/NR5A2 pharmacological activation resolves inflammation in immune cells of type 1 diabetes mellitus individuals and improves human islet engraftment and function

The intricate etiology of type 1 diabetes mellitus (T1D), marked by a detrimental cross-talk between the immune system and insulin-producing {beta}-cells, has impeded effective disease-modifying therapies. The discovery that pharmacological activation of the nuclear receptor LRH-1/NR5A2 can reverse hyperglycemia in mouse models of T1D by attenuating the autoimmune attack coupled to {beta}-cell survival/regeneration, prompted us to investigate whether immune tolerization could be achieved in individuals with T1D by LRH-1/NR5A2 activation as well as improving islet function/survival after xenotransplantation in mice. Pharmacological activation of LRH-1/NR5A2 induced a coordinated genetic and metabolic reprogramming of T1D macrophages and dendritic cells, shifting them from a pro-to an anti-inflammatory/tolerogenic phenotype. Regulatory T-cells were also expanded resulting in the impediment of cytotoxic T-cell proliferation. LRH-1/NR5A2 activation enhanced human islet engraftment and function in hyperglycemic immunocompetent mice. In summary our findings demonstrate the feasibility of re-establishing immune tolerance within a pro-inflammatory environment, opening a new therapeutic venue for T1D.

cell biology↗