Karl Ocius

Bioact Mater. 2025 Nov 21;57:601-615. doi: 10.1016/j.bioactmat.2025.10.007. eCollection 2026 Mar.

ABSTRACT

Chronic diabetic wounds remain a major clinical challenge due to impaired angiogenesis and dysregulated immune homeostasis. While mesenchymal stem cell (MSC) therapy holds promise, poor survival and inconsistent paracrine function limit efficacy. Herein, we present a novel biohybrid strategy that synergistically combines microbe-mimetic preconditioning of MSCs with bacterial cell wall components (peptidoglycan, PGN and lipoteichoic acid, LTA) and their sustained delivery within a gelatin methacryloyl (GelMA) hydrogel (plMSC-GelMA) to overcome these limitations. We demonstrate that dual PGN/LTA priming uniquely activates MSCs via Toll-like receptor 2 (TLR2), triggering the PI3K/Akt pathway and profoundly enhancing their pro-angiogenic (e.g., VEGF) and immunomodulatory (e.g., IL-10, TGF-β) secretome, promoting endothelial cell function and M2 macrophage polarization in vitro. Encapsulation within biocompatible GelMA hydrogel ensured prolonged viability and localized release of these potent factors. In both acute and diabetic murine wound models, plMSC-GelMA significantly accelerated wound closure, surpassing unprimed MSC-GelMA or GelMA alone. This was driven by enhanced neovascularization (CD31+/α-SMA+) and a shift towards pro-healing M2 macrophages. Mechanistic studies confirmed the pivotal role of the TLR2-PI3K/Akt axis, as genetic (siRNA) or pharmacological (LY294002) inhibition abolished the enhanced therapeutic benefits of plMSCs. This study uncovers a microbiota-inspired priming strategy that reprograms MSC paracrine function and establishes a translational biohybrid platform (plMSC-GelMA). By harnessing microbial cues and biomaterial engineering, we offer a promising solution for enhancing stem cell therapy in refractory diabetic wound healing.

PMID:41362831 | PMC:PMC12681737 | DOI:10.1016/j.bioactmat.2025.10.007

Front Immunol. 2025 Nov 21;16:1657782. doi: 10.3389/fimmu.2025.1657782. eCollection 2025.

ABSTRACT

INTRODUCTION: Syndrome of Undifferentiated Recurrent Fever (SURF) is an autoinflammatory disorder with onset in childhood, marked by recurrent episodes of fever without an established molecular diagnosis. Although NOD2 gene variants that are generally considered non-pathogenic are often identified in these patients, their contribution to disease development is still not well understood.

METHODS: This study aimed to assess the clinical characteristics, long-term progression, and functional implications of NOD2 variants in a group of twelve children diagnosed with SURF, along with two Blau syndrome cases and two healthy controls. Clinical information was gathered at presentation and during follow-up. Peripheral blood mononuclear cells were examined for cytokine secretion and NF-kB pathway activation, both at baseline and following muramyl dipeptide stimulation, using multiplex cytokine analysis, Western blot, and ELISA.

RESULTS: The median follow-up period was 3.75 years, with most children developing symptoms before 10 years of age. Abdominal pain and limb pain were the most frequent complaints. All patients were treated with colchicine, and selected cases required corticosteroids or disease-modifying antirheumatic drugs. Elevated levels of proinflammatory cytokines, including IL-2, TNF-a, IL- 6, and IL-8, were observed in SURF patients. Our functional studies suggested that variants like R702W, G908R, P268S/V955I, and R702W/P268S might have triggered stronger inflammatory responses, whereas L682F, L1007fs, and R587C might have been linked to diminished cytokine production and lower NF-kB activity. Certain variants, such as A1000T and P268S, appeared to show baseline NF-kB activation with moderate inflammatory activity.

DISCUSSION: Our findings emphasize the clinical and functional diversity of NOD2 variants in SURF and may point to a possible genotype-phenotype relationship that could aid in understanding disease pathways and refining diagnostic approaches.

PMID:41357180 | PMC:PMC12678341 | DOI:10.3389/fimmu.2025.1657782

bioRxiv [Preprint]. 2026 Jan 26:2025.11.14.688347. doi: 10.1101/2025.11.14.688347.

ABSTRACT

The Mycobacteriales are an order of diverse bacteria that thrive in many environmental and host-associated niches. Because the most notorious member of this clade, Mycobacterium tuberculosis, is a major human pathogen, research on Mycobacteriales has focused on pathogenesis, and, as a consequence, many fundamental aspects of Mycobacterial biology remain understudied. Here, we address this gap by performing a genome-wide CRISPRi chemical genomics screen using a diverse set of >35 antibiotics, detergents, and other anti-microbials predominantly targeting the cell envelope of Mycobacterium smegmatis, a saprophytic model Mycobacterium. We highlight new information derived from this screen, including the identification of novel functions for previously uncharacterized conserved and essential genes (in mycolic acid and arabinogalactan synthesis), the discovery of a new drug scaffold/protein target pair, and insights into the mechanism of action of two commonly used antibiotics. These data are also a valuable resource for the mycobacterial research community, as they provide thousands of novel phenotypes for uncharacterized genes and meaningful phenotypic correlations between annotated and uncharacterized genes.

PMID:41332778 | PMC:PMC12667753 | DOI:10.1101/2025.11.14.688347

J Clin Invest. 2025 Oct 2;135(23):e190851. doi: 10.1172/JCI190851. eCollection 2025 Dec 1.

ABSTRACT

Single-cell studies have revealed that intestinal macrophages maintain gut homeostasis through the balanced actions of reactive (inflammatory) and tolerant (noninflammatory) subpopulations. How such balance is impaired in inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), remains unresolved. Here, we define colon-specific macrophage states and reveal the critical role of noninflammatory colon-associated macrophages (niColAMs) in IBD recovery. Through trans-scale analyses-integrating computational transcriptomics, proteomics, and in vivo interventional studies-we identified GIV (CCDC88A) as a key regulator of niColAMs. GIV emerged as the top-ranked gene in niColAMs that physically and functionally interacts with NOD2, an innate immune sensor implicated in CD and UC. Myeloid-specific GIV depletion exacerbates infectious colitis, prolongs disease, and abolishes the protective effects of the NOD2 ligand muramyl dipeptide in colitis and sepsis models. Mechanistically, GIV's C-terminus binds the terminal leucine-rich repeat 10 (LRR 10) of NOD2 and is required for NOD2 to dampen inflammation and clear microbes. The CD-associated 1007fs NOD2 variant, which lacks LRR 10, cannot bind GIV, which provides critical insights into how this clinically relevant variant impairs microbial sensing and clearance. These findings illuminate a critical GIV•NOD2 axis essential for gut homeostasis and highlight its disruption as a driver of dysbiosis and inflammation in IBD.

PMID:41321314 | PMC:PMC12646664 | DOI:10.1172/JCI190851

Mol Ther Nucleic Acids. 2025 Nov 5;36(4):102762. doi: 10.1016/j.omtn.2025.102762. eCollection 2025 Dec 9.

ABSTRACT

Salmonella is a significant global enteric pathogen with a high incidence of multidrug resistance (MDR), which limits therapeutic options and necessitates the development of novel treatments. Antisense peptide nucleic acids (PNAs), which target essential bacterial genes, have demonstrated potential as antibacterial agents by effectively inhibiting the growth of various pathogens. Peptidoglycan (PG) has historically been one of the central targets for antibiotics in the ongoing battle against pathogenic bacteria. In this study, PNAs conjugated to the cell-penetrating peptide (CPP) (KFF)3K were designed to target three essential genes based on the genome sequence of the MDR Salmonella Typhimurium strain SL1344: ftsI (encoding penicillin-binding protein [PBP] 3), mrcB (PBP1B), and mrdA (PBP2). These CPP-PNA conjugates showed dose-dependent antibacterial activity in vitro and in vivo, with the anti-mrdA CPP-PNA demonstrating the strongest inhibition. The results were associated with selective expression inhibition of the targeted genes. Morphological analysis confirmed that the antisense inhibition of Salmonella-targeted genes led to interference with the cell division and elongation. Consistently, treatment with these CPP-PNAs significantly improved the survival of Caenorhabditis elegans in an intestinal infection model. These findings present a viable approach for addressing MDR Salmonella infections using the antisense-based therapy.

PMID:41323793 | PMC:PMC12663837 | DOI:10.1016/j.omtn.2025.102762