Project description:Renal fibrosis is the final common pathway of various renal injuries and it leads to chronic kidney disease. Autophagy is a cellular process of degradation of damaged cytoplasmic components and regulates cell death and proliferation. Cellular response during unilateral ureteral obstruction (UUO) is tubular segment specific. Thus the role of autophagy on renal tubulointerstitial fibrosis (TIF) after UUO may be different according to segment of nephron. The role of autophagy during UUO remains unclear especially in distal tubules. In this study, we investigated the role of autophagy in distal tubules on renal TIF using conditional knockout mice in which Atg7 was genetically ablated specifically in distal tubular epithelial cell (TEC). In green fluorescent protein (GFP)-LC3 transgenic mice, GFP-LC3 puncta was highly expressed in distal tubular cells of the obstructed kidneys after UUO. Genetic deletion of Atg7 specifically in distal TEC increased renal tubulointerstial fibrosis and epithelial-mesenchymal transition-like phenotype change after UUO through Smad4-dependent transforming growth factor (TGF)-β pathway. Distal tubule-specific autophagy-deficient mice increased the accumulation of damaged mitochondria and SQSTM1/p62-positive aggregates in the obstructed kidney and resulted in increased expression of NLRP3 inflammasome, interleukin (IL) 1-β and caspase-1. Distal TEC-specific Atg7 deletion enhanced apoptosis of TECs after UUO. In summary, our data showed that autophagy in distal TEC plays a protective role in development of renal tubulointerstial fibrosis through regulating the expression of TGF-β an IL1-β after UUO.
Project description:Doxycycline (Dox), a semisynthetic antibiotic, has been reported to exert multiple immunomodulatory effects. Treatment with Dox has a satisfactory curative effect against leptospirosis. In addition to its antibacterial action, we supposed that Dox also modulated immune response in controlling leptospira infection. Using J774A.1 mouse macrophages, the effects of Dox on protein and mRNA levels of IL-1β and TNF-α were investigated after infection with live or sonicated Leptospira interrogans serovar Lai strain Lai (56601). Specifically, the level of IL-1β but not TNF-α was sharply decreased when treated with Dox in leptospira-infected macrophages. Western blot analysis showed that Dox suppressed the activation of leptospira-induced MAPK and NF-κB signaling pathways. Using NLRP3-deficient and NLRC4-deficient mice, the data showed that the expression of leptospira-induced IL-1β was mainly dependent on the presence of NLRP3 inflammasome in macrophages. Meanwhile, Dox suppressed leptospira-induced NLRP3 inflammasome priming with the upregulation of the Na/K-ATPase Pump β1 subunit. The inhibition effect of Dox on IL-1β was also conspicuous in cells with lipopolysaccharide and ATP stimulation. These results were confirmed in vivo, as peritoneal fluids of mice and organs of hamsters expressed less IL-1β after treatment of leptospiral infection with Dox. Our results indicated that Dox also modulated immune response to attenuate leptospira-induced IL-1β by suppressing p38, JNK, p65, and NLRP3 inflammasome priming.
Project description:Introduction: Mathematical model can be used to model complex biological processes, and have shown potential in describing apoptosis in chondrocytes. Method: In order to investigate the regulatory mechanisms of TNF signaling pathway in regulating chondrocyte apoptosis, a fractional-order differential equation model is proposed to describe the dynamic behavior and mutual interaction of apoptosis-related genes under the activation of TNF signaling pathway. Compared with the traditional molecular biology techniques, the proposed mathematical modeling has advantages to providing a more comprehensive understanding of the regulatory mechanisms of TNF signaling pathway in chondrocyte apoptosis. Result: In this paper, differentially expressed genes induced by IL-1β in human chondrocyte apoptosis are screened using high-throughput sequencing. It is found that they were significantly enriched in the TNF signaling pathway. Therefore, a mathematical model of the TNF signaling pathway is built. Using real-time PCR experiments, mRNA data is measured and used to identify the model parameters, as well as the correlation coefficient. Finally, the sensitivity of the model parameters is discussed by using numerical simulation methods, which can be used to predict the effects of different interventions and explore the optimal intervention strategies for regulating chondrocyte apoptosis. Discussion: Therefore, fractional-order differential equation modeling plays an important role in understanding the regulatory mechanisms of TNF signaling pathway in chondrocyte apoptosis and its potential clinical applications.
Project description:Neuroinflammation is an important reason for the occurrence and development of cognitive impairment. The Lentiviral vector Hsp22 was constructed for intracerebroventricular injection pretreatment, LPS was used to induce the cognitive impairment model in mice, and the Morris water maze was used to examine the changes in cognitive behavior in mice. LPS was used to induce BV-2 microglial cells, and plasmid pretreatment was used to overexpress Hsp22. HE staining, Nissl staining, immunohistochemistry, immunofluorescence, ELISA and protein blotting were used to examine microglial activation, changes in inflammatory factors, changes in pathway proteins and apoptosis. The results showed that LPS induced microglial expression of NLRP3/Caspase-1/IL-1β signaling pathway protein Iba1, and the inflammatory protein and inflammatory factors IL-1β, IL-6 and TNF-α, the expression of Bax increased significantly, Bcl2 expression decreased, and the learning and memory abilities of mice decreased significantly. Preconditioning with the Hsp22-overexpressing lentivirus attenuated LPS-induced activation of hippocampal microglia, the expression of inflammatory factors and pathway proteins, and apoptosis, and improved cognitive impairment in mice. In addition, plasmid-mediated Hsp22 overexpression reversed LPS-induced inflammation. These findings suggest that Hsp22 overexpression is a promising method for the treatment of cognitive impairment.
Project description:Glycine supplementation has been reported to alleviate lipopolysaccharide (LPS)-induced lung injury in mice. However, the underlying mechanisms responsible for this beneficial effect remain unknown. In the present study, male C57BL/6 mice were treated with aerosolized glycine (1000 mg in 5 mL of 0.9% saline) or vehicle (0.9% saline) once daily for 7 continuous days, and then were exposed to aerosolized LPS (5 mg in 5 mL of 0.9% saline) for 30 min to induce lung injury. Sera and lung tissues were collected 24 h post LPS challenge. Results showed that glycine pretreatment attenuated LPS-induced decreases of mucin at both protein and mRNA levels, reduced LPS-triggered upregulation of pro-inflammatory cytokines, such as tumor necrosis factor-? (TNF-?), interferons, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukins. Further study showed that glycine-reduced LPS challenge resulted in the upregulation of nuclear factor ?B (NF-?B), nucleotide binding domain (NOD)-like receptor protein 3 (NLRP3) inflammasome. In addition, LPS exposure led to the downregulation of NRF2 and downstream targets, which were significantly improved by glycine administration in the lung tissues. Our findings indicated that glycine pretreatment prevented LPS-induced lung injury by regulating both NLRP3 inflammasome and NRF2 signaling.
Project description:Estrogen plays critical roles in apical periodontitis and subsequent bone loss, however the mechanism is not clear yet. In this study, we aimed to study the underlying mechanism of estrogen in apical periodontitis using both clinic samples and animal model. Clinically, as estrogen physiologically declines in elder female patients (premenopausal verses postmenopausal patients), we found that the expression level of NLRP3/Caspase-1/IL-1β signaling pathway was elevated in the infected apical tissues of postmenopausal patients as compared to the premenopausal patients, suggesting that this pathway is involved in the estrogen-mediated apical periodontitis. Furthermore, by analyzing the well-established OVX (estrogen deficiency model) animal model, we confirmed that the expression level of NLRP3/Caspase-1/IL-1β signaling pathway was also elevated in the infection areas of apical periodontitis in OVX animals. Importantly, as the periodontitis progressed, the subsequent bone loss was aggravated significantly. Thus, taken all these data together, our results demonstrated that the NLRP3/Caspase-1/IL-1β signaling pathway is involved in the estrogen-mediated apical periodontitis and the consequent bone loss in both human being and animal model. This study may provide a potential target for female apical periodontitis therapy.
Project description:Idiopathic pulmonary fibrosis (IPF) is an aggressive interstitial lung disease associated with progressive and irreversible deterioration of respiratory functions that lacks curative therapies. Despite IPF being associated with a dysregulated immune response, current antifibrotics aim only at limiting fibroproliferation. Transcriptomic analyses show that the P2RX7/IL18/IFNG axis is downregulated in IPF patients and that P2RX7 has immunoregulatory functions. Using our positive modulator of P2RX7, we show that activation of the P2RX7/IL-18 axis in immune cells limits lung fibrosis progression in a mouse model by favoring an antifibrotic immune environment, with notably an enhanced IL-18-dependent IFN-γ production by lung T cells leading to a decreased production of IL-17 and TGFβ. Overall, we show the ability of the immune system to limit lung fibrosis progression by targeting the immunomodulator P2RX7. Hence, treatment with a small activator of P2RX7 may represent a promising strategy to help patients with lung fibrosis.
Project description:Aloe-emodin widely possesses antibacterial, anti-inflammatory, antioxidant, antiviral, and anti-infectious properties. This study investigated the effect of ethyl 2-succinate-anthraquinone (Luhui derivative, LHD) on inflammation. In vitro, a THP-1 macrophage inflammation model, made by 100 ng/ml phorbol-12-myristate-13-acetate (PMA) and 1 μg/ml LPS for 24 h, was constructed. The LHD group (6.25 μmol/L, 12.5 μmol/L, 25 μmol/L, 50 μmol/L) had no effect on THP-1 cell activity, and the expression of IL-6 mRNA was down-regulated in a concentration-dependent manner, of which the 25 μmol/L group had the best inhibitory effect. The migration of THP-1 macrophages induced by LPS was decreased by the LHD. Moreover, the LHD suppressed ROS fluorescence expression by inhibiting MDA expression and increasing SOD activity. In vivo, we revealed that the LHD, in different doses (6.25 mg/kg, 12.5 mg/kg, 25 mg/kg, 50 mg/kg), has a protective effect on stress physiological responses by assessing the body temperature of mice. Interestingly, acute lung injury (e.g., the structure of the alveoli disappeared and capillaries in the alveolar wall were dilated and congested) and liver damage (e.g., hepatocyte swelling, neutrophil infiltration, and hepatocyte apoptosis) were obviously improved at the same condition. Furthermore, we initially confirmed that the LHD can down-regulate the expression of NLRP3, IL-1β, and caspase-1 proteins, thereby mediating the NLRP3 inflammasome signaling pathway to produce anti-inflammatory effects. In conclusion, our results indicate that the LHD exerts anti-inflammatory activity via regulating the NLRP3 signaling pathway, inhibition of oxidative stress, and THP-1 macrophage migration.
Project description:Renal fibrosis is a common outcome of chronic kidney diseases and glycolysis drives the development of renal fibrosis in damaged kidneys. Ulinastatin (UTI) is a broad-spectrum protease inhibitor with anti-inflammatory and antioxidant properties with anti-fibrosis effects. In this study, we aimed to verify whether UTI could exert anti-renal fibrosis effects by inhibiting glycolysis and explored the potential mechanisms. Renal fibrosis was induced in mice via unilateral ureteral obstruction (UUO). Transforming growth factor-β1 stimulates human kidney proximal tubular epithelial cells to undergo fibrotic changes. Histopathological staining was used to observe the pathological changes in the kidneys. The levels of fibrosis biomarkers, glycolytic enzymes, and key signaling molecules were determined using gene and protein assays. Cellular energy metabolism was measured using Seahorse XF24 analyzer. Modulated the activity of adenylate-activated protein kinase (AMPK) and hypoxia-inducible factor-1α (HIF-1α) to confirm that AMPK can regulate HIF-1α-mediated glycolysis. Furthermore, UTI and AMPK knockdown were combined to verify whether UTI could attenuate glycolysis via the AMPK pathway. UTI pretreatment improved UUO-induced renal injury and fibrosis. The expression of fibrosis biomarkers and glycolytic enzymes was reduced by UTI at both mRNA and protein levels. UTI treatment decreased the rate of glycolysis and the production of glycolytic intermediates in fibrotic cells and tissues. Furthermore, AMPK can regulate HIF-1α-mediated glycolysis in renal tubular epithelial cells. Finally, the attenuation of glycolysis by UTI was related to AMPK/HIF-1α pathway, and this effect was inhibited by knockdown AMPK. UTI can effectively alleviate renal fibrosis, which may be partly attributed to the reduction of glycolysis by regulating AMPK/HIF-1α pathway.
Project description:Vascular remodeling plays an important role in the pathogenesis of diabetic cardiovascular complications. Previous published research has indicated that microRNA?24 (miR?24) is involved in diabetic vascular remodeling, but the underlying molecular mechanisms have yet to be fully elucidated. The aim of the present study was to investigate whether adenovirus?mediated miR?24 overexpression can suppress the NOD?like receptor family pyrin domain?containing 3 (NLRP3)?related inflammatory signaling pathway and attenuate diabetic vascular remodeling. The carotid arteries of diabetic rats were harvested and prepared for analysis. Reverse transcription?quantitative PCR and western blotting assays were used to detect the expressions of related mRNAs and proteins. Morphological examinations, including hematoxylin and eosin, immunohistochemical and Masson's trichrome staining, were also performed. The results of the present study demonstrated that miR?24 upregulation suppressed neointimal hyperplasia and accelerated reendothelialization in the injured arteries, lowered the expression of NLRP3, apoptosis?associated speck?like protein, caspase?1, proliferating cell nuclear antigen, CD45, interleukin (IL)?1?, IL?18 and tumor necrosis factor??, and increased the expression of CD31, smooth muscle (SM) ??actin and SM?myosin heavy chain. These data indicated that miR?24 overexpression can attenuate vascular remodeling in a diabetic rat model through suppressing the NLRP3/caspase?1/IL?1? signaling pathway.