Eldesouki, Mohamed

ABSTRACT The enteric nervous system (ENS) is a complex peripheral neural network that coordinates gastrointestinal motility through highly organized synaptic communication. Although tissue-resident muscularis macrophages (MMs) closely associate with enteric neurons, whether they regulate enteric synaptic organization remains unknown. In the central nervous system (CNS), microglia sculpt neural circuits through complement-dependent synaptic remodeling, raising the possibility that analogous neuroimmune mechanisms operate in the gut. Here, we identify a previously unrecognized role for C1qa□ MMs in regulating enteric synaptic homeostasis and gastrointestinal motility. Using macrophage-specific constitutive and inducible C1qa deletion models, single-cell RNA sequencing, enteric synaptosome proteomics, physiology, and advanced imaging, we demonstrate that loss of MMs-derived C1qa increases enteric synaptic density without altering neuronal numbers. C1qa deficiency induced broad transcriptional changes in enteric neurons and macrophages, including altered synapse-associated, lysosomal, and endocytic programs. Proteomic analysis revealed that enteric synapses share a conserved molecular architecture with brain synapses while exhibiting distinct gastrointestinal-specific complement-associated synaptic networks enriched for structural and receptor-localization pathways. Functionally, macrophage-specific C1qa deletion altered excitatory and inhibitory enteric neurotransmission, enhanced cholinergic signaling, reduced nitrergic responses, and accelerated gastrointestinal transit, while smooth muscle responsiveness remained preserved. C1qa□ MMs displayed transcriptional and functional features consistent with a phagocytic synapse-remodeling phenotype, including enrichment of complement, lysosomal, and engulfment pathways. Loss of C1qa impaired macrophage phagocytic activity both in vitro and in vivo and was associated with synapse accumulation and altered macrophage morphology. Importantly, inducible deletion of C1qa in adulthood recapitulated the synaptic and motility phenotypes, demonstrating that C1qa□ MMs continuously regulate enteric synaptic organization beyond development. Together, these findings identify a complement-dependent neuroimmune mechanism that regulates enteric circuit organization and gut motility, establishing MMs as active modulators of adult ENS synaptic homeostasis. Abstract Figure

Objective Macrophages are highly plastic immune cells that maintain tissue homeostasis through their roles in immune surveillance, repair, and remodeling. Emerging evidence reveals that macrophages, residing in tissues with widely varying stiffness, are profoundly influenced by the mechanical properties of their microenvironment. Methods Relevant publications on macrophage mechanoregulation published up to January 2026 were identified through systematic searches of PubMed, EMBASE, and Web of Science using combinations of keywords related to macrophages, mechanosensing, mechanotransduction, and mechanical stimuli (e.g., stiffness, stretch, and shear stress). Articles were screened based on relevance to macrophage biology and mechanistic insights. Results Mechanical cues are sensed through mechanosensors such as Piezo1, TRPV4, and integrins, which integrate these signals to regulate immune surveillance, inflammation, tissue repair, and remodeling. Dysregulation of these pathways contributes to the pathogenesis of multiple diseases, including fibrosis, atherosclerosis, and neurodegeneration. Conclusion Macrophage mechanobiology represents a critical regulatory axis in tissue homeostasis and disease. Targeting mechanosensing pathways offers promising therapeutic opportunities to modulate inflammation and enhance tissue regeneration.

Abstract Background Patients with moderate-to-severe inflammatory bowel disease (IBD) often require immunosuppressive therapy to achieve and maintain remission; however, the impact of these medications on influenza risk and the severity of influenza-related complications remains inadequately characterized. Methods Using the TriNetX U.S. Analytics Network, adults (≥ 18 years) with Crohn’s disease or ulcerative colitis during the 2022–2023 influenza season were identified. Patients were stratified by disease activity into two cohorts: (1) moderate-to-severe/active IBD, defined by elevated inflammatory markers, initiation of corticosteroids or a new biologic or small-molecule agent, or documented IBD-related symptoms or complications within the prior six months; and (2) mild/inactive IBD, defined by the absence of these features and no recent immunosuppressive therapy. Propensity score matching (1:1) was used to balance baseline characteristics, and Cox proportional hazards models were applied to estimate hazard ratios for influenza-related outcomes. Results After propensity score matching, each group had 22,784 patients. The incidence of influenza diagnosis was significantly higher in the moderate-to-severe/active IBD group (HR 1.41; 95% CI, 1.30–1.52). Hospitalization rates were also increased (HR 2.05; 95% CI, 1.89–2.23), as were influenza-related complications (HR 1.36; 95% CI, 1.23–1.51). ICU admissions (HR 1.51; 95% CI, 1.33–1.72) and mechanical ventilation (HR 1.68; 95% CI, 1.32–2.13) were both more frequent in the moderate-to-severe/active IBD group. Use of antiviral medications was higher among those in this cohort (HR 1.60; 95% CI, 1.22–2.10), and overall mortality was modestly increased (HR 1.17; 95% CI, 1.02–1.35). Subgroup analysis revealed the highest risk among patients on corticosteroids, followed by JAK inhibitors and anti–IL-23 agents. Conclusion Patients with moderate-to-severe/active IBD had more severe influenza-related outcomes compared with mild/inactive controls. Improving vaccine uptake and prompt evaluation of upper respiratory symptoms during influenza seasons are key to reducing influenza-related risks in immunosuppressed patients with IBD.

Background Topical timolol appears to provide a curative effect in managing chronic ulcers. However, the pooled evidence of its effect hasn’t been established yet. This is the first Meta-analysis to evaluate and assess the efficacy of topical timolol in accelerating wound healing in patients with chronic refractory ulcers. Methods We comprehensively searched different electronic databases; PubMed, Scopus, Web of Science, Cochrane library and ClinicalTrials.gov from their inception to November 2024. The search was conducted without imposing any restrictions on publication date or study design. The ROB-II tool was used to assess the quality of included RCTs. NIH tools were used to evaluate the quality of included cohort and single arm studies. Risk ratios (RR) and mean differences (MD), with 95% confidence intervals (CIs), were used as effect estimates. Results Six studies were included in this systematic review, comprising two single-arm studies and four double-arm studies (3 RCTs and 1 cohort study). Data from the four double-arm studies on venous ulcers were pooled for meta-analysis. The results showed that topical timolol significantly reduced ulcer area compared to control at 2 weeks (−23.63%; 95% CI: −29.26 to −18.00; p < 0.00001), 4 weeks (−41.40%; 95% CI: −49.57 to −33.23; p < 0.00001), and 12 weeks (−23.38%; 95% CI: −39.43 to −7.33; p = 0.004). Complete ulcer healing was observed at 4 weeks (RR: 12.00; 95% CI: 1.68 to 85.84; p = 0.01) and 12 weeks (RR: 3.79; 95% CI: 0.44 to 32.54; p = 0.22). Conclusion Topical timolol has the potential to promote healing in chronic unhealed ulcers. This meta-analysis, focusing on chronic venous ulcers, consistently showed favorable results across different time points. However, the small sample sizes, lack of blinding, and inclusion of only four studies limit the generalizability of the findings.