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Microbiology Spectrum Oct 2022Autoimmune hepatitis (AIH) is a progressive inflammation-associated liver injury. Pyroptosis is a novel inflammatory programmed cell death wherein gasdermin D (GSDMD)...
Autoimmune hepatitis (AIH) is a progressive inflammation-associated liver injury. Pyroptosis is a novel inflammatory programmed cell death wherein gasdermin D (GSDMD) serves as the executioner. Our work challenged mice with concanavalin A (ConA) to try to unveil the actual role of GSDMD in AIH. After ConA injection, mice exhibited more severe liver damage characterized by a lower survival rate, more extensive hepatocyte necrosis and apoptosis, and higher serum transaminase levels, indicating the protection of GSDMD in ConA-induced AIH. Furthermore, the mice exhibited higher hepatic expression and serum levels of inflammatory cytokines (gamma interferon [IFN-γ], tumor necrosis factor alpha [TNF-α], and interleukin-17A [IL-17A]) and more infiltration of macrophages and neutrophils after ConA treatment than did wild-type (WT) mice. mice with AIH showed increased hepatic l-glutamine levels but decreased glycerophospholipid metabolites levels. L-glutamine levels showed positive correlations while glycerophospholipid metabolites showed negative associations with liver injury indexes and inflammation markers. We further observed a destroyed intestinal barrier in mice after ConA injection as indicated by decreased transcriptional expressions of , , , and . ConA-treated mice also exhibited higher serum LPS binding protein (LBP) concentrations and hepatic and mRNA levels. Further fecal 16S rRNA gene sequencing demonstrated decreased relative abundances of and but increased relative abundances of and in mice with AIH. was negatively correlated with liver injury and inflammation indexes and positively associated with , , and levels. was positively related to liver injury and inflammatory cytokines and negatively correlated with gut barrier indexes. Our study provides the first direct clues to the protective role of gasdermin D (GSDMD) in autoimmune hepatitis (AIH). We demonstrated that knockout exacerbated concanavalin A (ConA)-induced AIH in mice. It may be due to the destroyed intestinal barrier and changes in certain intestinal microbes and hepatic metabolites resulting in increased liver injury and inflammation in ConA-treated mice. This finding suggested a nonnegligible role of GSDMD in AIH and also confirmed its physiological nonpyroptosis effects on the host. The role of GSDMD in autoimmune liver diseases or other liver diseases is complex and intriguing, deserving deep investigation.
Topics: Animals; Mice; Concanavalin A; Glutamine; Glycerophospholipids; Hepatitis, Autoimmune; Inflammation; Interferon-gamma; Interleukin-17; Lipopolysaccharides; Liver; RNA, Ribosomal, 16S; Toll-Like Receptor 4; Transaminases; Tumor Necrosis Factor-alpha
PubMed: 35972273
DOI: 10.1128/spectrum.01717-22 -
The Journal of Cell Biology Nov 2022Fibroblast growth factor (FGF2) is a potent mitogen that is secreted through an unconventional secretory pathway by crossing the plasma membrane directly. In this...
Fibroblast growth factor (FGF2) is a potent mitogen that is secreted through an unconventional secretory pathway by crossing the plasma membrane directly. In this current issue, Lolicato et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202106123) find that the secretion process is promoted by cholesterol, which enhances PI(4,5)P2 accessibility to FGF2 binding and alters membrane property to increase FGF2 translocation.
Topics: Cell Membrane; Cholesterol; Fibroblast Growth Factor 2; Mitogens; Secretory Pathway
PubMed: 36255389
DOI: 10.1083/jcb.202210007 -
Frontiers in Cell and Developmental... 2021Hypoxia-induced mitogenic factor (HIMF), also known as resistin-like molecule α (RELMα) or found in inflammatory zone 1 (FIZZ1) is a member of the RELM protein family... (Review)
Review
Hypoxia-induced mitogenic factor (HIMF), also known as resistin-like molecule α (RELMα) or found in inflammatory zone 1 (FIZZ1) is a member of the RELM protein family expressed in mice. It is involved in a plethora of physiological processes, including mitogenesis, angiogenesis, inflammation, and vasoconstriction. HIMF expression can be stimulated under pathological conditions and this plays a critical role in pulmonary, cardiovascular and metabolic disorders. The present review summarizes the molecular characteristics, and the physiological and pathological roles of HIMF in normal and diseased conditions. The potential clinical significance of these findings for human is also discussed.
PubMed: 34336840
DOI: 10.3389/fcell.2021.691774 -
International Journal of Biological... Dec 2020Bioadhesives have a potential to modulate the wound closure process with significant biological outcomes. However, none of the currently commercialized adhesives are...
Bioadhesives have a potential to modulate the wound closure process with significant biological outcomes. However, none of the currently commercialized adhesives are satisfactory in their performance. It is a challenging task to develop an adhesive system that can work on wet surface and enhances tissue repair and closure. In this study, we have fabricated a series of gelatin-dopamine (Gel-dop) conjugates and studied their adhesive properties after being chemically crosslinked using sodium periodate. The designed material was assessed for its adhesive properties including tensile, lap shear and peeling study by varying the degree of dopamine substitution. It was observed that the adhesive property has a direct correlation with increase in dopamine content until reaching a maximum and then a subsequent decrease. We tested the adhesive strength of the different formulations by varying the degree of substitution and compared against fibrin glue, which is considered as the gold standard of adhesives. The formulation with a moderate substitution degree demonstrated the optimal adhesive property than those formulations with lower and larger substitution degree. Further, the in vitro cytotoxicity study showed that this tunable Gel-dop adhesives are to non-cytotoxic, indicating a potential use in clinic applications. This study illustrates that adhesiveness can be regulated by changing the degree of dopamine substitution.
Topics: Adhesiveness; Animals; Benzoquinones; Catechols; Cell Adhesion; Cell Survival; Cross-Linking Reagents; Dopamine; Fibrin Tissue Adhesive; Gelatin; Hydrogels; Materials Testing; Oxygen; Periodic Acid; Pressure; Rheology; Shear Strength; Skin; Surface Properties; Swine; Tensile Strength; Tissue Adhesives
PubMed: 32721461
DOI: 10.1016/j.ijbiomac.2020.07.195 -
Cellular and Molecular Gastroenterology... 2021Serotonin signaling is ubiquitous in the gastrointestinal (GI) system, where it acts as a neurotransmitter in the enteric nervous system (ENS) and influences intestinal... (Review)
Review
Serotonin signaling is ubiquitous in the gastrointestinal (GI) system, where it acts as a neurotransmitter in the enteric nervous system (ENS) and influences intestinal motility and inflammation. Since its discovery, serotonin has been linked to cellular proliferation in several types of tissues, including vascular smooth muscle, neurons, and hepatocytes. Activation of serotonin receptors on distinct cell types has been shown to induce well-known intracellular proliferation pathways. In the GI tract, potentiation of serotonin signaling results in enhanced intestinal epithelial proliferation, and decreased injury from intestinal inflammation. Furthermore, activation of the type 4 serotonin receptor on enteric neurons leads to neurogenesis and neuroprotection in the setting of intestinal injury. It is not surprising that the mitogenic properties of serotonin are pronounced within the GI tract, where enterochromaffin cells in the intestinal epithelium produce 90% of the body's serotonin; however, these proliferative effects are attributed to increased serotonin signaling within the ENS compartment as opposed to the intestinal mucosa, which are functionally and chemically separate by virtue of the distinct tryptophan hydroxylase enzyme isoforms involved in serotonin synthesis. The exact mechanism by which serotonergic neurons in the ENS lead to intestinal proliferation are not known, but the activation of muscarinic receptors on intestinal crypt cells indicate that cholinergic signaling is essential to this signaling pathway. Further understanding of serotonin's role in mucosal and enteric nervous system mitogenesis may aid in harnessing serotonin signaling for therapeutic benefit in many GI diseases, including inflammatory bowel disease, malabsorptive conditions, and cancer.
Topics: Animals; Cell Proliferation; Cell Survival; Gastrointestinal Motility; Gastrointestinal Tract; Humans; Mitogens; Receptors, Serotonin; Serotonin; Signal Transduction
PubMed: 34022423
DOI: 10.1016/j.jcmgh.2021.05.008 -
Frontiers in Immunology 2022The expeditious progress of Mesenchymal Stromal Cells (MSC) for therapeutic intervention calls for means to compare differences in potency of cell products. The...
The expeditious progress of Mesenchymal Stromal Cells (MSC) for therapeutic intervention calls for means to compare differences in potency of cell products. The differences may be attributed to innumerable sources including tissue origin, production methods, or even between batches. While the immunomodulatory potential of MSC is recognized and well-documented by an expansive body of evidence, the methodologies and findings vary markedly. In this study, we utilized flowcytometric analysis of lymphocyte proliferation based on cryopreserved peripheral blood mononuclear cells for quantification of the inhibitory effect of MSC. Technical aspects of fluorescent staining and cryopreservation of peripheral blood mononuclear cells were evaluated to obtain optimal results and increase feasibility. A range of common specific and unspecific mitogens was titrated to identify the conditions, in which the effects of Adipose tissue-derived Stromal Cells (ASC; a type of MSC) were most pronounced. Specific stimulation by antibody-mediated activation of CD3 and CD28 TransAct and Dynabeads lead to substantial proliferation of lymphocytes, which was inhibited by ASC. These results were closely mirrored when applying unspecific stimulation in form of phytohemagglutinin (PHA), but not concanavalin A or pokeweed mitogen. The mixed lymphocyte reaction is a common assay which exploits alloreactivity between donors. While arguably more physiologic, the output of the assay often varies substantially, and the extent of proliferation is limited since the frequency of alloreactive cells is low, as opposed to the mitogens. To heighten the proliferative response and robustness, combinations of 2-5 donors were tested. Maximum proliferation was observed when combining 4 or more donors, which was efficiently suppressed by ASC. Several desirable and unfavorable traits can be attributed to the tested stimuli in the form of keywords. The importance of these traits should be scored on a laboratory-level to identify the ideal mitogen. In our case the ranking listed PHA as the most suited candidate. Developing robust assays is no trivial feat. By disclosing the full methodological framework in the present study, we hope to aid others in establishing functional metrics on the road to potency assays.
Topics: Leukocytes, Mononuclear; Cells, Cultured; Mesenchymal Stem Cells; Immunomodulation; Stromal Cells; Mitogens
PubMed: 36578497
DOI: 10.3389/fimmu.2022.1085312 -
Veterinary Immunology and... May 2020CellTrace Violet™ is a commonly used fluorescent dye used with flow cytometry to identify cell proliferation. Activated equine lymphocytes were examined using flow...
CellTrace Violet™ is a commonly used fluorescent dye used with flow cytometry to identify cell proliferation. Activated equine lymphocytes were examined using flow cytometry, microscopy and tritiated thymidine proliferation assays. CellTrace Violet™ was incorporated into the equine lymphocytes effectively. Equine lymphocytes proliferated when activated with pokeweed mitogen, but did not proliferate when previously stained with CellTrace Violet™. Serial dilutions of CellTrace Violet™ did not eliminate the inhibition of activated lymphocytes. Equine lymphocyte viability was greater than 90 % for both stained and unstained cells. Based on these data, CellTrace Violet™ is not recommended for the assessment of lymphocyte proliferation in equine cells. The mechanism of inhibition of equine lymphocyte proliferation by CellTrace Violet™ is unknown.
Topics: Animals; Cell Proliferation; Cell Survival; Concanavalin A; Flow Cytometry; Fluorescent Dyes; Horses; Lymphocyte Activation; Lymphocytes; Pokeweed Mitogens
PubMed: 32229340
DOI: 10.1016/j.vetimm.2020.110037 -
Genes & Genetic Systems Jun 2022Continuity of spermatogenesis in mammals is underpinned by spermatogenic (also called spermatogonial) stem cells (SSCs) that self-renew and differentiate into sperm that... (Review)
Review
Continuity of spermatogenesis in mammals is underpinned by spermatogenic (also called spermatogonial) stem cells (SSCs) that self-renew and differentiate into sperm that pass on genetic information to the next generation. Despite the fundamental role of SSCs, the mechanisms underlying SSC homeostasis are only partly understood. During homeostasis, the stem cell pool remains constant while differentiating cells are continually produced to replenish the lost differentiated cells. One of the outstanding questions here is how self-renewal and differentiation of SSCs are balanced to achieve a constant self-renewing pool. In this review, we shed light on the regulatory mechanism of SSC homeostasis, with focus on the recently proposed mitogen competition model in a facultative (or open) niche microenvironment.
Topics: Adult Germline Stem Cells; Animals; Cell Differentiation; Homeostasis; Intercellular Signaling Peptides and Proteins; Male; Mammals; Mitogens; Spermatogenesis; Spermatogonia; Stem Cells
PubMed: 35125370
DOI: 10.1266/ggs.21-00062 -
Journal of Dairy Science Apr 2023We examined whether distinct staphylococcal and mammaliicoccal species and strains trigger B- and T-lymphocyte proliferation and interleukin (IL)-17A and interferon...
We examined whether distinct staphylococcal and mammaliicoccal species and strains trigger B- and T-lymphocyte proliferation and interleukin (IL)-17A and interferon (IFN)-γ production by peripheral blood mononuclear cells in nulliparous, primiparous, and multiparous dairy cows. Flow cytometry was used to measure lymphocyte proliferation with the Ki67 antibody, and specific monoclonal antibodies were used to identify CD3, CD4, and CD8 T lymphocyte and CD21 B lymphocyte populations. The supernatant of the peripheral blood mononuclear cell culture was used to measure IL-17A and IFN-γ production. Two distinct, inactivated strains of bovine-associated Staphylococcus aureus [one causing a persistent intramammary infection (IMI) and the other from the nose], 2 inactivated Staphylococcus chromogenes strains [one causing an IMI and the other from a teat apex), as well as an inactivated Mammaliicoccus fleurettii strain originating from sawdust from a dairy farm, and the mitogens concanavalin A and phytohemagglutinin M-form (both specifically to measure lymphocyte proliferation) were studied. In contrast to the "commensal" Staph. aureus strain originating from the nose, the Staph. aureus strain causing a persistent IMI triggered proliferation of CD4 and CD8 subpopulations of T lymphocytes. The M. fleurettii strain and the 2 Staph. chromogenes strains had no effect on T- or B-cell proliferation. Furthermore, both Staph. aureus and Staph. chromogenes strains causing persistent IMI significantly increased IL-17A and IFN-γ production by peripheral blood mononuclear cells. Overall, multiparous cows tended to have a higher B-lymphocyte and a lower T-lymphocyte proliferative response than primiparous and nulliparous cows. Peripheral blood mononuclear cells of multiparous cows also produced significantly more IL-17A and IFN-γ. In contrast to concanavalin A, phytohemagglutinin M-form selectively stimulated T-cell proliferation.
Topics: Female; Cattle; Animals; Phytohemagglutinins; Interleukin-17; Concanavalin A; Leukocytes, Mononuclear; Staphylococcus aureus; Staphylococcal Infections; Antibodies, Monoclonal; Cell Proliferation; Mastitis, Bovine; Milk; Cattle Diseases
PubMed: 36870844
DOI: 10.3168/jds.2022-22529 -
Chinese Medical Journal Jun 2022Sepsis, a serious condition with high mortality, usually causes sepsis associated encephalopathy (SAE) that involves neuronal cell death. However, the cell death...
A new cell death program regulated by toll-like receptor 9 through p38 mitogen-activated protein kinase signaling pathway in a neonatal rat model with sepsis associated encephalopathy.
BACKGROUND
Sepsis, a serious condition with high mortality, usually causes sepsis associated encephalopathy (SAE) that involves neuronal cell death. However, the cell death programs involved and their underlying mechanisms are not clear. This study aimed to explore the regulatory mechanisms of different cell death programs in SAE.
METHODS
A neonatal rat model of SAE was established by cecal ligation and perforation. Survival rate and vital signs (mean arterial pressure and heart rate) were monitored, nerve reflexes were evaluated, and cortical pathological changes were observed by hematoxylin and eosin staining. The expression of pyroptosis, apoptosis, and necroptosis (PANoptosis)-related proteins, mitogen- activated protein kinase (MAPK), and its upstream regulator toll-like receptor 9 (TLR9) were detected. The expression of TLR9 in neurons was observed by immunofluorescence staining. The ultrastructure of neurons was observed by transmission electron microscope.
RESULTS
First, PANoptosis was found in cortical nerve cells of the SAE rats. Meanwhile, the subunits of MAPKs, p38 MAPK, Jun N- terminal kinase, and extracellular signal-regulated kinase (ERK) were activated. After pharmacologically inhibiting each of the subunits, only p38 MAPK was found to be associated with PANoptosis. Furthermore, blocking the p38 MAPK signaling pathway activated necroptosis but inhibited apoptosis and pyroptosis. When necroptosis was pharmacologically inhibited, apoptosis and pyroptosis were reactivated. Finally, we found that the expression of TLR9, a regulator of MAPKs, was significantly increased in this model. After down-regulation of TLR9, p38 MAPK, and ERK signaling pathways were inhibited, which led to the inhibition of PANoptosis. Further analysis found that down-regulation of TLR9 improved the survival rate and reduced the pathological changes in SAE rats.
CONCLUSIONS
Our study showed that the programs comprising PANoptosis are activated simultaneously in SAE rats. TLR9 activated PANoptosis through the p38 MAPK signaling pathway. TLR9 may work as a potential target for SAE treatment.
Topics: Animals; Animals, Newborn; Apoptosis; Eosine Yellowish-(YS); Extracellular Signal-Regulated MAP Kinases; Hematoxylin; JNK Mitogen-Activated Protein Kinases; MAP Kinase Signaling System; Mitogens; Rats; Sepsis-Associated Encephalopathy; Signal Transduction; Toll-Like Receptor 9; p38 Mitogen-Activated Protein Kinases
PubMed: 35261352
DOI: 10.1097/CM9.0000000000002010