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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 -
Blood Apr 2023Human hematopoietic stem cells (HSCs), like their counterparts in mice, comprise a functionally and molecularly heterogeneous population of cells throughout life that...
Human hematopoietic stem cells (HSCs), like their counterparts in mice, comprise a functionally and molecularly heterogeneous population of cells throughout life that collectively maintain required outputs of mature blood cells under homeostatic conditions. In both species, an early developmental change in the HSC population involves a postnatal switch from a state in which most of these cells exist in a rapidly cycling state and maintain a high self-renewal potential to a state in which the majority of cells are in a quiescent state with an overall reduced self-renewal potential. However, despite the well-established growth factor dependence of HSC proliferation, whether and how this mechanism of HSC regulation might be affected by aging has remained poorly understood. To address this knowledge gap, we isolated highly HSC-enriched CD34+CD38-CD45RA-CD90+CD49f+ (CD49f+) cells from cord blood, adult bone marrow, and mobilized peripheral blood samples obtained from normal humans spanning 7 decades of age and then measured their functional and molecular responses to growth factor stimulation in vitro and their regenerative activity in vivo in mice that had undergone transplantation. Initial experiments revealed that advancing donor age was accompanied by a significant and progressively delayed proliferative response but not the altered mature cell outputs seen in normal older individuals. Importantly, subsequent dose-response analyses revealed an age-associated reduction in the growth factor-stimulated proliferation of CD49f+ cells mediated by reduced activation of AKT and altered cell cycle entry and progression. These findings identify a new intrinsic, pervasive, and progressive aging-related alteration in the biological and signaling mechanisms required to drive the proliferation of very primitive, normal human hematopoietic cells.
Topics: Adult; Humans; Animals; Mice; Integrin alpha6; Mitogens; Hematopoietic Stem Cells; Antigens, CD34; Cell Proliferation; Cell Cycle Checkpoints; Cell Cycle; Intercellular Signaling Peptides and Proteins
PubMed: 36652668
DOI: 10.1182/blood.2022017174 -
Journal of Traditional Chinese Medicine... Dec 2021To investigate the chemical characters of water-extract of Baqi Lingmao formula (BQLM formula) and its effects on anti-liver injury in model mice and live cells.
OBJECTIVE
To investigate the chemical characters of water-extract of Baqi Lingmao formula (BQLM formula) and its effects on anti-liver injury in model mice and live cells.
METHODS
BQLM formula was composed of ten herbal medicines. We determined the contents of alkaloids, saponins, phenolic acids and flavonoid in BQLM formula by UV spectrophotometry. The active components of alkaloids and phenolic acids in BQLM formula were identified by HPLC chromatography. The anti-hepatic injury effects of BQLM formula were investigated with concanavalin A (ConA)-induced hepatitis model of mice, human liver LO2 and HepG2.2.15 cells.
RESULTS
BQLM formula (2 and 10 g/kg, orally) significantly improved the damages of liver tissues and functions caused by ConA in mice, reduced the infiltration of inflammatory cells into liver and inhibited the inflammatory cytokine secretion of interferon-γ, tumor necrosis factor-α and interleukin-6. BQLM formula simultaneously decreased the levels of alanine aminotransferase and aspartate aminotransferase of liver and serum, and recovered the superoxide dismutase and catalase activities of liver to normal levels in ConA-induced hepatic-injury mice. The serum of BQLM formula group stimulated the human liver LO2 cell proliferation in vitro. Further, BQLM formula obviously promoted the proliferation of normal hepatocytes (LO2 cells) and inhibited the hepatocytes death induced by ConA. It also significantly inhibited the proliferation of HepG2.2.15 cells and decreased the secretion of HBsAg and HBeAg in vitro.
CONCLUSIONS
BQLM formula has anti-inflammation and anti-hepatitis virus Beffects, and is capable of improving liver injury in vivo and in vitro.
Topics: Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatocytes; Liver; Mice
PubMed: 34939382
DOI: 10.19852/j.cnki.jtcm.2021.06.005 -
Proceedings of the National Academy of... May 2022B and T lymphocytes of the adaptive immune system undergo proliferative bursts to generate pools of antigen-specific cells for effective immunity. Here we show that in...
B and T lymphocytes of the adaptive immune system undergo proliferative bursts to generate pools of antigen-specific cells for effective immunity. Here we show that in contrast to the canonical view that G1 progression signals are essential after mitosis to reenter S phase, B lymphocytes sustain several rounds of mitogen-independent cell division following the first mitosis. Such division appears to be driven by unique characteristics of the postmitotic G1 phase that has features of S and G2/M phases. Birc5 (survivin), a protein associated with chromosome segregation in G2/M, is expressed in the G1 phase of divided B cells and is necessary for mitogen-independent divisions. The partially active G1 phase and propensity for apoptosis inherited after each division may underlie rapid proliferation and cell death, which are hallmarks of B cell proliferative responses.
Topics: B-Lymphocytes; Cell Division; G1 Phase; Intercellular Signaling Peptides and Proteins; Mitogens; Proteomics; Survivin
PubMed: 35476510
DOI: 10.1073/pnas.2115567119 -
Frontiers in Immunology 2022The mRNA vaccines help protect from COVID-19 severity, however multiple sclerosis (MS) disease modifying therapies (DMTs) might affect the development of humoral and...
BACKGROUND
The mRNA vaccines help protect from COVID-19 severity, however multiple sclerosis (MS) disease modifying therapies (DMTs) might affect the development of humoral and T-cell specific response to vaccination.
METHODS
The aim of the study was to evaluate humoral and specific T-cell response, as well as B-cell activation and survival factors, in people with MS (pwMS) under DMTs before (T0) and after two months (T1) from the third dose of vaccine, comparing the obtained findings to healthy donors (HD). All possible combinations of intracellular IFNγ, IL2 and TNFα T-cell production were evaluated, and T-cells were labelled "responding T-cells", those cells that produced at least one of the three cytokines of interest, and "triple positive T-cells", those cells that produced simultaneously all the three cytokines.
RESULTS
The cross-sectional evaluation showed no significant differences in anti-S antibody titers between pwMS and HD at both time-points. In pwMS, lower percentages of responding T-cells at T0 (CD4: p=0.0165; CD8: p=0.0022) and triple positive T-cells at both time-points compared to HD were observed (at T0, CD4: p=0.0007 and CD8: p=0.0703; at T1, CD4: p=0.0422 and CD8: p=0.0535). At T0, pwMS showed higher plasma levels of APRIL, BAFF and CD40L compared to HD (p<0.0001, p<0.0001 and p<0.0001, respectively) and at T1, plasma levels of BAFF were still higher in pwMS compared to HD (p=0.0022).According to DMTs, at both T0 and T1, lower anti-S antibody titers in the depleting/sequestering-out compared to the enriching-in pwMS subgroup were found (p=0.0410 and p=0.0047, respectively) as well as lower percentages of responding CD4+ T-cells (CD4: p=0.0394 and p=0.0004, respectively). Moreover, the depleting/sequestering-out subgroup showed higher percentages of IFNγ-IL2-TNFα+ T-cells at both time-points, compared to the enriching-in subgroup in which a more heterogeneous cytokine profile was observed (at T0 CD4: p=0.0187; at T0 and T1 CD8: p =0.0007 and p =0.0077, respectively).
CONCLUSION
In pwMS, humoral and T-cell response to vaccination seems to be influenced by the different DMTs. pwMS under depleting/sequestering-out treatment can mount cellular responses even in the presence of a low positive humoral response, although the cellular response seems qualitatively inferior compared to HD. An understanding of T-cell quality dynamic is needed to determine the best vaccination strategy and in general the capability of immune response in pwMS under different DMT.
Topics: Humans; Multiple Sclerosis; Tumor Necrosis Factor-alpha; COVID-19 Vaccines; Cross-Sectional Studies; Interleukin-2; COVID-19; Pokeweed Mitogens; Antibodies; Cytokines; RNA, Messenger
PubMed: 36532061
DOI: 10.3389/fimmu.2022.1050183 -
Communications Biology Aug 2023Insulin-like Growth Factor-2 (IGF2) is important for the regulation of human embryonic growth and development, and for adults' physiology. Incorrect processing of the...
Insulin-like Growth Factor-2 (IGF2) is important for the regulation of human embryonic growth and development, and for adults' physiology. Incorrect processing of the IGF2 precursor, pro-IGF2(156), leads to the formation of two IGF2 proforms, big-IGF2(87) and big-IGF2(104). Unprocessed and mainly non-glycosylated IGF2 proforms are found at abnormally high levels in certain diseases, but their mode of action is still unclear. Here, we found that pro-IGF2(156) has the lowest ability to form its inactivating complexes with IGF-Binding Proteins and has higher proliferative properties in cells than IGF2 and other IGF prohormones. We also showed that big-IGF2(104) has a seven-fold higher binding affinity for the IGF2 receptor than IGF2, and that pro-IGF2(87) binds and activates specific receptors and stimulates cell growth similarly to the mature IGF2. The properties of these pro-IGF2 forms, especially of pro-IGF2(156) and big-IGF2(104), indicate them as hormones that may be associated with human diseases related to the accumulation of IGF-2 proforms in the circulation.
Topics: Adult; Humans; Insulin-Like Growth Factor II; Cell Proliferation; Cell Cycle; Intercellular Signaling Peptides and Proteins; Mitogens
PubMed: 37598269
DOI: 10.1038/s42003-023-05239-6 -
Nature Jun 2024Kainate receptors, a subclass of ionotropic glutamate receptors, are tetrameric ligand-gated ion channels that mediate excitatory neurotransmission. Kainate receptors...
Kainate receptors, a subclass of ionotropic glutamate receptors, are tetrameric ligand-gated ion channels that mediate excitatory neurotransmission. Kainate receptors modulate neuronal circuits and synaptic plasticity during the development and function of the central nervous system and are implicated in various neurological and psychiatric diseases, including epilepsy, depression, schizophrenia, anxiety and autism. Although structures of kainate receptor domains and subunit assemblies are available, the mechanism of kainate receptor gating remains poorly understood. Here we present cryo-electron microscopy structures of the kainate receptor GluK2 in the presence of the agonist glutamate and the positive allosteric modulators lectin concanavalin A and BPAM344. Concanavalin A and BPAM344 inhibit kainate receptor desensitization and prolong activation by acting as a spacer between the amino-terminal and ligand-binding domains and a stabilizer of the ligand-binding domain dimer interface, respectively. Channel opening involves the kinking of all four pore-forming M3 helices. Our structures reveal the molecular basis of kainate receptor gating, which could guide the development of drugs for treatment of neurological disorders.
Topics: Cryoelectron Microscopy; Receptors, Kainic Acid; Ion Channel Gating; Models, Molecular; Humans; GluK2 Kainate Receptor; Glutamic Acid; Animals; Concanavalin A; Protein Domains; Ligands; Allosteric Regulation; Binding Sites
PubMed: 38778115
DOI: 10.1038/s41586-024-07475-0 -
Cells Nov 2019Increased vascular smooth muscle cell (VSMC) proliferation contributes towards restenosis after angioplasty, vein graft intimal thickening and atherogenesis. The second... (Review)
Review
Increased vascular smooth muscle cell (VSMC) proliferation contributes towards restenosis after angioplasty, vein graft intimal thickening and atherogenesis. The second messenger 3' 5' cyclic adenosine monophosphate (cAMP) plays an important role in maintaining VSMC quiescence in healthy vessels and repressing VSMC proliferation during resolution of vascular injury. Although the anti-mitogenic properties of cAMP in VSMC have been recognised for many years, it is only recently that we gained a detailed understanding of the underlying signalling mechanisms. Stimuli that elevate cAMP in VSMC inhibit G-S phase cell cycle progression by inhibiting expression of cyclins and preventing S-Phase Kinase Associated Protein-2 (Skp2-mediated degradation of cyclin-dependent kinase inhibitors. Early studies implicated inhibition of MAPK signalling, although this does not fully explain the anti-mitogenic effects of cAMP. The cAMP effectors, Protein Kinase A (PKA) and Exchange Protein Activated by cAMP (EPAC) act together to inhibit VSMC proliferation by inducing Cyclic-AMP Response Element Binding protein (CREB) activity and inhibiting members of the RhoGTPases, which results in remodelling of the actin cytoskeleton. Cyclic-AMP induced actin remodelling controls proliferation by modulating the activity of Serum Response Factor (SRF) and TEA Domain Transcription Factors (TEAD), which regulate expression of genes required for proliferation. Here we review recent research characterising these mechanisms, highlighting novel drug targets that may allow the anti-mitogenic properties of cAMP to be harnessed therapeutically to limit restenosis.
Topics: Animals; Cell Proliferation; Cyclic AMP; Graft Occlusion, Vascular; Humans; Muscle, Smooth, Vascular; Signal Transduction
PubMed: 31744111
DOI: 10.3390/cells8111447 -
Scientific Reports Jun 2023Ex vivo culturing of isolated PBMCs from individuals vaccinated with the coronavirus disease 2019 (COVID-19) vaccine BNT162b1 revealed a pronounced T cell response in...
Ex vivo culturing of isolated PBMCs from individuals vaccinated with the coronavirus disease 2019 (COVID-19) vaccine BNT162b1 revealed a pronounced T cell response in the presence of the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. The latter was 10-fold more pronounced than the ex vivo response of PBMCs from the same individuals to other common pathogen T cell epitope pools, suggesting COVID-19 vaccination to induce RBD-specific T cell responses and not to facilitate T cell (re)activity in general. In the current study we investigated whether COVID-19 vaccination long-lastingly affects plasma interleukin (IL)-6 concentrations, complete blood counts, ex vivo IL-6 and IL-10 secretion of PBMCs cultured under basal conditions or in the presence of concanavalin (Con) A and lipopolysaccharide (LPS), salivary cortisol and α-amylase, mean arterial pressure (MAP), heart rate (HR) as well as mental and physical health status. The study was initially designed to investigate whether the presence vs. absence of own pets during urban upbringing has protective effects against psychosocial stress-induced immune activation during adulthood. However, as COVID-19 vaccines were approved while the study was ongoing and as, therefore, both vaccinated and non-vaccinated individuals have been recruited, we were able to stratify our data set with respect to the COVID-19 vaccination status and to assess the long-lasting effects of COVID-19 vaccination on physiological immunological, cardiovascular and psychosomatic health parameters. This data is presented in the current study. We show that isolated PBMCs from individuals vaccinated against COVID-19 show a ~ 600-fold increase in basal and a ~ 6000-fold increase in ConA-induced proinflammatory IL-6 secretion, and a ~ 2-fold increase in basal and ConA-induced antiinflammatory IL-10 secretion, both in comparison with non-vaccinated individuals. In contrast, LPS-induced ex vivo IL-6 and IL-10 secretions were not affected by vaccination status, as were plasma IL-6 concentrations, complete blood counts, salivary cortisol and α-amylase, cardiovascular measures and psychosomatic health. In summary, our findings are of relevance for many clinical studies ran before/during the pandemic, clearly indicating that consideration of participants' vaccination status is critical, at least when assessing ex vivo PBMC functionality.
Topics: Humans; Adult; COVID-19; COVID-19 Vaccines; SARS-CoV-2; Interleukin-6; BNT162 Vaccine; Hydrocortisone; Interleukin-10; Leukocytes, Mononuclear; Lipopolysaccharides; Concanavalin A
PubMed: 37308487
DOI: 10.1038/s41598-023-35731-2 -
Frontiers in Immunology 2021In mammals, Interleukin-17 cytokine family plays critical roles in both acute and chronic inflammatory responses. In fish species, three Interleukin-17A/F (IL-17A/F)...
In mammals, Interleukin-17 cytokine family plays critical roles in both acute and chronic inflammatory responses. In fish species, three Interleukin-17A/F (IL-17A/F) genes have been identified to be homologous to mammalian IL-17A and IL-17F, but little is known about their functional activity. In this study, _IL-17A/F1, 2 and 3 genes were cloned from yellow catfish () and they differed in protein structure and exon length, implying that they may have divergent bioactivity. Real-time quantitative PCR analyses revealed that three _IL-17A/F genes were highly expressed in blood and mucosal tissues (skin+mucus and gill) from healthy adult fish. The mRNA expressions of _IL-17A/F1, 2 and 3 genes were significantly up-regulated in the gill, skin+mucus, head kidney and spleen after challenge with and in the isolated peripheral blood leucocytes (PBLs) of yellow catfish after stimulation with phytohaemagglutinin (PHA), lipopolysaccharides (LPS), peptidoglycan (PGN) and polyinosinic-polycytidylic acid (Poly I:C). These results indicate that _IL-17A/F1, 2 and 3 genes may play a vital role in the regulation of immune against pathogens. Additionally, the recombinant (r) _IL-17A/F1, 2 and 3 proteins significantly induced the mRNA expressions of proinflammatory cytokines, chemokines and antibacterial peptides genes, and the r_IL-17A/F 2 and 3 proteins promoted phagocytosis of PBLs more powerfully than the r_IL-17A/F1. Furthermore, the r_IL-17A/F1, 2 and 3 proteins might activate the NF-κB and MAPK signal pathways by IL-17RA, ACT1, TRAF6, TRAF2, TRAF5 and TAK1, indicating that the three _IL-17A/F proteins may play different roles in promoting inflammatory response.
Topics: Animals; Catfishes; Fish Proteins; Head Kidney; Interleukin-17; Leukocytes; Lipopolysaccharides; Peptidoglycan; Phytohemagglutinins; Poly I-C; Spleen
PubMed: 34267744
DOI: 10.3389/fimmu.2021.626895