Search bioRxiv⌕ Search

Biology subjects

Mezghani, I.

Publications and source records attributed to Mezghani, I..

4 recordsLinked to original sources

Cholinergic modulation engages a CHRM1-IL-17 neuroimmune axis to promote diabetic wound repair

Chronic non-healing wounds are a major complication of diabetes, where persistent inflammation fails to transition into effective tissue repair (1-3). Here we identify cholinergic modulation as a mechanism that promotes productive inflammation and diabetic wound healing. Using a healing-associated fibroblast signature derived from single-cell profiling of human diabetic foot ulcers (3), we identified the acetylcholinesterase (AChE) inhibitor metrifonate as a candidate inducer of reparative wound programs. Topical delivery accelerated healing in diabetic mice and increased acetylcholine availability within the wound. Complementary receptor pharmacology identified muscarinic acetylcholine receptor 1 (CHRM1) as the principal receptor mediating the reparative response. Transcriptomic and cellular analyses revealed early induction of IL-17-associated inflammatory programs and enrichment of CHRM1NK1.1 innate lymphocytes. Depletion of NK1.1 cells or neutralization of IL-17A abolished the pro-healing effect, whereas spatial transcriptomics revealed treatment-associated organization of NK cells within vascular niches. Localized treatment further promoted repair in diabetic porcine wounds and human skin models. Together, these findings identify a CHRM1-IL-17 neuroimmune axis linking cholinergic modulation to diabetic wound repair and establish local AChE inhibition as a potential therapeutic strategy for chronic wounds.

immunology↗

Bedaquiline inhibits the ATP synthase leak channel and prevents glutamate-induced neuronal death

FOF1-ATP synthase is one of the most abundant proteins of the mitochondrial inner membrane and the primary enzyme responsible for ATP production in eukaryotic cells. Nevertheless, it was recently reported to play a prominent role in cell death by forming a large-conductance leak channel in the mitochondrial permeability transition pore (mPTP), making it a promising therapeutic target. Bedaquiline (BDQ), a member of the diarylquinoline class of drugs, was shown to selectively inhibit the catalytic activity of Mycobacterium tuberculosis ATP synthase with no effect on the mammalian enzyme. Here, we report a new role for BDQ as a potent inhibitor of the ATP synthase c-subunit leak channel in mammals. BDQ inhibited the single-channel activity of porcine heart ATP synthase in planar lipid bilayer recordings and prevented glutamate-induced cell death in primary hippocampal neurons. These findings reveal the potential new application of BDQ for treating mPTP-related diseases by targeting the ATP synthase c-subunit leak channel. Why it mattersBedaquiline (BDQ) is the only FDA-approved drug to treat pulmonary multidrug-resistant tuberculosis (TB), caused by the Mycobacterium tuberculosis. BDQ cures TB by specifically targeting mycobacterial ATP synthase and inhibiting ATP production. Recently, BDQ was also reported to bind to mammalian ATP synthase at the interface between the a and c-subunits and to inhibit its catalytic activity. However, the effect of BDQ on ATP synthase leak channel activity has not been explored. Here, we report that BDQ inhibits the ATP synthase c-subunit leak channel (ACLC) activity with an IC50 of [~]24 nM and prevents glutamate-induced neuronal death, suggesting a new therapeutic repurposing of BDQ for treating ACLC-related diseases.

biophysics↗

Strain-Programmable Patch for Diabetic Wound Healing

Chronic wounds with impaired healing capability such as diabetic foot ulcers (DFU) are devastating complications in diabetic patients, inflicting rapidly growing clinical and economic burdens in aging societies. Despite recent advances in therapeutic approaches, limited benefits of the existing solutions highlight the critical need for novel therapeutic solutions for diabetic wound healing. Here we propose a strain-programmable patch capable of rapid robust adhesion on and programmable mechanical contraction of wet wounded tissues over days to offer a new therapeutic platform for diabetic wounds. The strain-programmable patch, consisting of a dried bioadhesive layer and a pre-stretched elastomer backing, implements a hydration-based shape-memory mechanism to achieve both uniaxial and biaxial contractions and stress remodeling of wet wounds in a programmable manner. We develop theoretical and numerical models to rationally guide the strain-programming and mechanical modulation of wounds. In vivo rodent and ex vivo human skin culture models validate the programmability and efficacy of the proposed platform and identify mechanisms of action for accelerated diabetic wound healing. One Sentence SummaryA strain-programmable bioadhesive patch is developed for accelerated closure and healing of wounds in diabetic mice and human skin.

bioengineering↗

Single Cell Transcriptomic Landscape of Diabetic Foot Ulcers

To understand the diabetic wound healing microenvironment, we profiled 174,962 single cells from foot, forearm, and PBMCs using single-cell RNA sequencing (scRNASeq) approach. Our analysis shows enrichment of a unique population of fibroblasts overexpressing MMP1, MMP3, MMP11, HIF1A, CHI3L1, and TNFAIP6 genes and M1 macrophage polarization in the DFU patients with healing wounds. Further, scRNASeq of spatially separated samples from same patient and spatial transcriptomics (ST) revealed preferential localization of these healing associated fibroblasts toward deep wound/ulcer bed as compared to wound edge or non-wounded skin. ST also validated our findings of higher enrichment of M1 macrophages in healers and M2 macrophages in non-healers. Our analysis provides deep insights into the wound healing microenvironment, identifying cell types that could be critical in promoting DFU healing, and may inform novel therapeutic approaches for DFU treatment.

genomics↗