Molecular mechanisms of emerging inflammasome complexes and their activation and signaling in inflammation and pyroptosis.

Inflammasomes are multi-protein complexes that assemble within the cytoplasm of mammalian cells in response to pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs), driving the secretion of the pro-inflammatory cytokines IL-1β and IL-18, and pyroptosis. The best-characterized inflammasome complexes are the NLRP3, NAIP-NLRC4, NLRP1, AIM2, and Pyrin canonical caspase-1-containing inflammasomes, and the caspase-11 non-canonical inflammasome. Newer inflammasome sensor proteins have been identified, including NLRP6, NLRP7, NLRP9, NLRP10, NLRP11, NLRP12, CARD8, and MxA.

Protocol for the processing, cryopreservation, and biobanking of patient-derived cells and tissues.

Biobanking of patient-derived specimens offers unique opportunities for retrospective testing that could potentially contribute to diagnosing and evaluating clinical conditions, advancing personalized medicine and translational biomedical discovery. In this protocol, we detail the collection, processing, and cryopreservation of peripheral blood, bone marrow, and lymph nodes from patients with hematological malignancies. This protocol can be used for multiomics to gain cellular and molecular insights into blood cancers and to test the therapeutic potential of compounds for translational biomedical research.

Profiling the colonic mucosal response to fecal microbiota transplantation identifies a role for GBP5 in colitis in humans and mice.

Host molecular responses to fecal microbiota transplantation (FMT) in ulcerative colitis are not well understood. Here, we profile the human colonic mucosal transcriptome prior to and following FMT or placebo to identify molecules regulated during disease remission. FMT alters the transcriptome above the effect of placebo (n = 75 vs 3 genes, q < 0.

Ku70 senses cytosolic DNA and assembles a tumor-suppressive signalosome.

The innate immune response contributes to the development or attenuation of acute and chronic diseases, including cancer. Microbial DNA and mislocalized DNA from damaged host cells can activate different host responses that shape disease outcomes. Here, we show that mice and humans lacking a single allele of the DNA repair protein Ku70 had increased susceptibility to the development of intestinal cancer.

Primary Intestinal Fibroblasts: Isolation, Cultivation, and Maintenance.

Intestinal fibroblasts maintain homeostasis and contribute to inflammatory responses and the development of cancer. Intestinal fibroblasts express pattern recognition receptors which can mount an immune response. Since intestinal fibroblasts interact with diverse immune and nonimmune cells, further insights into the biology of intestinal fibroblasts could expand our knowledge of the development, homeostasis, and pathophysiology of the intestine.

Clostridium perfringens virulence factors are nonredundant activators of the NLRP3 inflammasome.

Inflammasome signaling is a central pillar of innate immunity triggering inflammation and cell death in response to microbes and danger signals. Here, we show that two virulence factors from the human bacterial pathogen Clostridium perfringens are nonredundant activators of the NLRP3 inflammasome in mice and humans. C.

Immunity against Moraxella catarrhalis requires guanylate-binding proteins and caspase-11-NLRP3 inflammasomes.

Moraxella catarrhalis is an important human respiratory pathogen and a major causative agent of otitis media and chronic obstructive pulmonary disease. Toll-like receptors contribute to, but cannot fully account for, the complexity of the immune response seen in M. catarrhalis infection.

Plasma cells arise from differentiation of clonal lymphocytes and secrete IgM in Waldenström macroglobulinemia.

Waldenström macroglobulinemia (WM) is characterized by bone marrow infiltration with malignant lymphoplasmacytic cells (LPCs), a smaller population of plasma cells (PCs), and hypersecretion of IgM monoclonal protein. Here, we show that CD45, CD38, and CD138 PCs and CD45, CD38, CD138, CD19, and CD20 LPCs carry a heterozygous L265P mutation in the Toll-like receptor signaling adaptor MYD88. Both PCs and LPCs express the same auto-reactive IgHV sequences, suggesting a similar clonal origin and role for auto-antigens in WM cell survival.

Pathogen-selective killing by guanylate-binding proteins as a molecular mechanism leading to inflammasome signaling.

Inflammasomes are cytosolic signaling complexes capable of sensing microbial ligands to trigger inflammation and cell death responses. Here, we show that guanylate-binding proteins (GBPs) mediate pathogen-selective inflammasome activation. We show that mouse GBP1 and GBP3 are specifically required for inflammasome activation during infection with the cytosolic bacterium Francisella novicida.

Cell biology of inflammasome activation.

Organelles are critical structures in mediating the assembly and activation of inflammasomes in mammalian cells, resulting in inflammation and cell death. Assembly of inflammasomes can occur at the mitochondria, endoplasmic reticulum, nucleus, trans-Golgi network, or pathogen surface, facilitated by the overarching architecture of the cytoskeleton. NLRP3 and Pyrin inflammasome sensors may form smaller speckles and converge on a single larger speck at the microtubule-organizing center (MTOC).

Effect of roxithromycin on contractile activity of gastrointestinal smooth muscles in colitic rats.

Objectives: Roxithromycin, a macrolide antibiotic, has been shown to ameliorate acetic acid induced colitis in rats by suppressing inflammation and oxidative stress. The aim of this study was to evaluate the effect of roxithromycin on small intestinal transit and cholinergic responsiveness of the colonic smooth muscles of colitic rats.

Methods: Colitis was induced in rats by acetic acid and the small intestinal transit was determined by measuring the distance traversed by charcoal meal from the gastro-duodenal junction in 1 h.

Bacillus cereus non-haemolytic enterotoxin activates the NLRP3 inflammasome.

Inflammasomes are important for host defence against pathogens and homeostasis with commensal microbes. Here, we show non-haemolytic enterotoxin (NHE) from the neglected human foodborne pathogen Bacillus cereus is an activator of the NLRP3 inflammasome and pyroptosis. NHE is a non-redundant toxin to haemolysin BL (HBL) despite having a similar mechanism of action.

Inflammasomes in Colitis and Colorectal Cancer: Mechanism of Action and Therapies.

Colorectal cancer is a multifactorial disease and a leading cause of cancer-related deaths worldwide. Inflammation is a driver across multiple stages in the development of colorectal cancer. The inflammasome is a cytosolic multiprotein complex of the innate immune system central to the regulation of inflammation, pyroptosis, and other cellular processes important for maintaining gut homeostasis.

Protection afforded by methanol extract of Calotropis procera latex in experimental model of colitis is mediated through inhibition of oxidative stress and pro-inflammatory signaling.

Calotropis procera, a latex producing plant is known to possess medicinal properties including its beneficial effect in gastrointestinal disorders. The anti-inflammatory effect of its latex in various experimental models is noteworthy and in light of this the present study was carried out with an objective to evaluate its efficacy in ulcerative colitis, an inflammatory condition of the colon. Colitis was induced in rats by acetic acid and the rats were divided into four groups where one group served as experimental control and the other groups were treated with two doses of methanol extract of dried latex of C.

Metformin maintains mucosal integrity in experimental model of colitis by inhibiting oxidative stress and pro-inflammatory signaling.

Metformin, an antidiabetic drug, is well known for its multifarious properties and its ability to modulate inflammatory cascade. Ulcerative colitis (UC) is an inflammatory condition of the colon where drugs exhibiting anti-inflammatory property have been shown to induce and maintain remission. The objective of the present study was to evaluate the efficacy of metformin against acetic-acid induced colitis in rat.

Protective Effect of Metformin against Acute Inflammation and Oxidative Stress in Rat.

Preclinical Research The antidiabetic drug, metformin, can inhibit the release of inflammatory mediators in several disease conditions. The present study was carried out to evaluate the efficacy of metformin in ameliorating edema formation, oxidative stress, mediator release and vascular changes associated with acute inflammation in the rat carrageenan model. Metformin dose-dependently inhibited paw swelling induced by carrageenan and normalized the tissue levels of the inflammatory markers myeloperoxidase and nitrite.