Biology subjects

Kandeel, F.

Publications and source records attributed to Kandeel, F..

3 recordsLinked to original sources

bioRxiv2026

Harmine Plus Exendin-4 Enhances Remission of Recent-Onset Type 1 Diabetes Following Anti-CD3 Therapy

Type 1 diabetes (T1D) results from autoimmune destruction of pancreatic {beta}-cells. While anti-CD3 therapy can delay disease progression and preserve residual {beta}-cell function, disease reversal will likely require both immune modulation and {beta}-cell regeneration. We found that the combination of harmine and exendin-4 (H+E) reduced inflammation-induced human {beta}-cell apoptosis, suppressed cytokine signaling and immunogenicity pathways, and improved {beta}-cell function. Although H+E alone did not reverse diabetes in NOD mice, low-dose anti-CD3 followed by H+E normalized blood glucose, increased insulin levels, improved glucose tolerance, expanded {beta}-cell mass, and enhanced diabetes remission. These effects were associated with reduced pro-inflammatory T-cell responses, increased regulatory T cells, and greater expression of exhaustion-related T-cell markers, without broad lymphocyte depletion. Similar immunomodulatory effects were observed in activated human PBMCs. Transcriptomic analyses identified the lncRNA SNHG6 as a key mediator of H+E action; SNHG6 protected {beta}-cells from cytokine-induced stress, apoptosis, and immunogenicity. Together, these findings demonstrate that H+E promotes {beta}-cell recovery and resilience while reducing {beta}-cell immunogenicity, enabling remission of recent-onset T1D when combined with anti-CD3 therapy. SNHG6 emerges as a novel regulator of {beta}-cell protection during inflammation.

cell biology↗

bioRxiv2025

Loss of Exocytosis Protein DOC2B is an Early Event in Type 1 Diabetes Development

Abstract: Type 1 diabetes (T1D) affects millions worldwide, yet few non-invasive biomarkers detect immune-mediated {beta}-cell dysfunction during the presymptomatic phase, a critical window for therapeutic intervention. Previously, we identified reduced double C2-like domain containing beta protein (DOC2B) levels in circulating platelets as a marker of reduced {beta}-cell function in early-onset T1D cohorts and nonobese diabetic (NOD) mice. Here, we assessed whether plasma DOC2B could serve as a sensitive early biomarker of T1D progression risk in the autoantibody-positive pediatric cohort (progressors vs non-progressors) from the longitudinal Diabetes Evaluation in Washington (DEW-IT) study; T1D patients and non-diabetic cohorts from the DEW-IT study served as controls. At pre-onset, progressors showed a decline in DOC2B that preceded measurable changes in random C-peptide and HbA1c levels, while non-progressors maintained stable levels. These observations were further supported by our analysis in prediabetic NOD mice. Comparisons of plasma levels pre- and post-clinical islet transplantation in long-standing T1D patients highlights its potential utility as a reporter of {beta}-cell functional mass. Together, these findings suggest that DOC2B decline may precede C-peptide decline in early presymptomatic T1D progression. This work could have significant future implications for clinical trial stratification and assessing response outcomes to disease-modifying or cell replacement therapies.

physiology↗

bioRxiv2025

Proinflammatory circulating extracellular vesicles from type 1 diabetes patients contribute to beta cell cytotoxicity and disease pathogenicity

In Type 1 diabetes (T1D), {beta}-cell loss and autoimmunity initiate years before disease diagnosis. However, the mechanisms remain unknown. Here, we investigated the role and mechanisms of circulating extracellular vesicles (cEVs) on T1D pathogenesis and {beta}-cell cytotoxicity. We used cEVs isolated from healthy donors (HD), T1D, multiple autoantibody-positive (AAb+), pre- and post-islet transplantation T1D subjects, NOD-T1D mice, and T1D PBMCs. Patient T1D-cEVs significantly induced apoptosis in vitro in human {beta}-cells but not -cells compared to HD-cEVs. cEVs from AAb+ subjects and pre-diabetic mice were cytotoxic, demonstrating that cEV-induced {beta}-cell cytotoxicity precedes T1D onset and diagnosis. cEV reduction in prediabetic NOD-T1D mice improved {beta}-cell health implying cEV contribution to T1D development. Proteomic analysis of patient T1D-cEVs found several proinflammatory proteins, including interferon gamma, which induced {beta}-cell cytotoxicity. Our data using cEVs from pre- and post-islet transplant and PBMC-EVs from T1D patients implicated immune cells as a potential cellular source of cytotoxic cEVs in T1D. Collectively, our data using T1D patient samples coupled with studies in mice demonstrate that cEVs contribute to {beta}-cell cytotoxicity and to the progression of T1D pathogenicity. Our study is one of the first to demonstrate a functional role of the proinflammatory cEV protein cargo on glucose homeostasis, {beta}-cell health, and insulitis. Our studies on T1D-cEVs may lead to discovery of novel biomarkers and therapeutic targets for T1D.

cell biology↗