Remifentanil attenuates sepsis-induced intestinal injury by inducing autophagy

Huang Lian Jie Du decoction attenuates inflammation in septic rats by activating autophagy and altering the intestinal microbiome

Aims

The aim of this study was to investigate the protective effect of HLJDD on septic rats and the underlying mechanisms.

Materials and methods

Adult male Sprague-Dawley (SD) adult rats (150-180 g) were randomly divided into the following 5 groups (n = 7 per group): the Sham group, caecal ligation and puncture (CLP) group, HLJDD + CLP (Huang Lian Jie Du Decoction, HLJDD) group (1 g/mL/100 g), HLJDD + Rap + CLP (H. Rap) group (Rap: 3 mg/kg), and HLJDD+3-MA + CLP (H. 3-MA) group (3-MA: 30 mg/kg). Rapamycin (Rap) and 3-methyladenosine (3-MA) were used to activate and inhibit autophagy, respectively. HLJDD was purchased from Beijing Tong Ren Tang Guiyang Branch and verified by experts as a genuine product. We used CLP to establish an animal model of sepsis in the last four groups. Survival was analysed by the Kaplan‒Meier method. Then, we examined autophagy-related genes (Atgs) and proteins using real-time PCR and Western blotting, respectively. The microstructure of the ileum and the number of autophagosomes were observed by transmission electron microscopy (TEM). Analyses of HE-stained pathological ileum and inflammatory factor levels were examined to assess the extent of septic injury. The effect of HLJDD on the gut microbiota was analysed by 16S rRNA gene sequencing of faeces.

Results

In this study, we identified the protective effects of HLJDD on mortality and inflammation in septic rats. Several key proteins, including LC3-II, Beclin-1 and p62, were examined and showed that HLJDD could effectively reverse the sepsis-induced decrease in autophagy. TEM was performed and the expression of Atgs was assessed to evaluate fluctuations in autophagy. Then, we examined the intestinal tight junction protein zona occludens (ZO-1), lipopolysaccharide (LPS) and inflammatory factors, and found that HLJDD effectively alleviated the increase in ZO-1 gene expression, the level of LPS and serum level of inflammatory factors caused by sepsis. These results were consistent with those obtained from pathological sectioning and TEM analysis. Moreover, autophagy activation effectively ameliorated sepsis, and autophagy inhibition exacerbated the systemic symptoms caused by infection. By examining the expression of key proteins upstream of the autophagy pathway, we found that HLJDD inhibited mTOR via the MAPK/PI3K signalling pathway to promote autophagy in septic rats. 16S rRNA sequencing revealed that HLJDD significantly affected the diversity and physiological function of the gut microbiota in septic rats.

Conclusions

The results of this study indicate that autophagy activation is a potential mechanism underlying the protective effect of HLJDD on the intestine in septic rats.

MicroRNA-483-3p Inhibitor Ameliorates Sepsis-Induced Intestinal Injury by Attenuating Cell Apoptosis and Cytotoxicity Via Regulating HIPK2

Sepsis is a life-threatening syndrome that can result in multi-organ dysfunction. MicroRNA (miR)-483-3p was previously demonstrated to be upregulated in sepsis patients; however, its specific functions in sepsis-triggered intestinal injury remain unclarified. Human intestinal epithelial NCM460 cell line was stimulated with lipopolysaccharide (LPS) to mimic sepsis-induced intestinal injury in vitro. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was utilized for examining cell apoptosis. Western blotting and real time quantitative polymerase chain reaction (RT-qPCR) were used for detecting molecular protein and RNA levels. LPS-induced cytotoxicity was determined by measuring concentrations of lactate dehydrogenase (LDH), diamine oxidase (DAO) and fatty acid binding protein 2 (FABP2). Luciferase reporter assay was utilized for verifying the interaction between miR-483-3p and homeodomain interacting protein kinase 2 (HIPK2). Inhibiting miR-483-3p alleviates LPS-triggered NCM460 cell apoptosis and cytotoxicity. miR-483-3p targeted HIPK2 in LPS-stimulated NCM460 cells. Knockdown of HIPK2 reversed the above effects mediated by miR-483-3p inhibitor. Inhibiting miR-483-3p ameliorates LPS-triggered apoptosis and cytotoxicity by targeting HIPK2.

Application and value of hydrogen sulfide modulated autophagy in sepsis

Sepsis is is anabnormalhost immune responsecausedbyinfection. Antibiotics, anti-viral drugs, and vasoactive drugs have always been used in the traditional treatment of sepsis, but there are no specific and effective drugs in clinical practice. Autophagy is a highly conservative process in biological evolution, and plays an important role in maintaining intracellular homeostasis and cellular self-renewal. Autophagy can remove and degrade misfolding proteins and damaged organelles in cells, providing materials for cell repair and self-renewal. Hydrogen sulfide (H2S) is a colorless gas that smells likerotteneggs. It is the third endogenous gas signal molecule discovered after nitric oxide and carbon monoxide and has become a research hotspot in recent years. H2S has a variety of biological functions and plays an important role in various physiological and pathological processes. Thereisgrowingevidencethat H2S can regulate autophagy. The intervention of autophagy is a promising therapeutic strategy to improve sepsis organ damage. This article reviews the organ protection of autophagy in sepsis and the role of H2S in regulating autophagy in sepsis, revealing that H2S intervention with autophagy may be a a worthy target in sepsis treatment.

Liensinine, a alkaloid from lotus plumule, mitigates lipopolysaccharide-induced sepsis-associated encephalopathy through modulation of nuclear factor erythroid 2-related factor-mediated inflammatory biomarkers and mitochondria apoptosis

The present study aims to investigate the role of liensinine in life-threatened sepsis-associated encephalopathy (SAE) mice and the underlying mechanism. Here, seventy-two mice were divided into six groups, including the control group, SAE group, liensinine-treated group, and three doses of liensinine-treated SAE groups. Lipopolysaccharide triggered cerebrum necrosis and disrupted the integrity and permeability of blood-brain barrier (BBB). While liensinine restored cerebrum structure and improved BBB integrity with upregulated tight junction proteins, decreased evans blue leakage and fibrinogen expression with decreased matrix metalloproteinases 2/9 in serum, thereby reducing BBB permeability. Moreover, lipopolysaccharide triggered cerebrum oxidative stress and inflammation, whereas liensinine enhanced antioxidant enzymes activities and weakened malondialdehyde through nuclear factor erythroid 2-related factor. Meanwhile, liensinine inhibited inflammation by activating inducible nitric oxide synthase. Tunel staining combined with transmission electron microscope indicated that lipopolysaccharide induced cerebrum apoptosis, whereas liensinine blocked apoptosis through decreasing B-cell lymphoma-2 associated X (Bax) expression and cytochrome C (Cyto-c) release, increasing B-cell lymphoma-2 (Bcl-2) expression, blocking apoptosome assembly, inhibiting caspase-3 activation, thereby suppressing intrinsic mitochondria apoptosis. Recovering of inflammatory homeostasis and inhibition of mitochondria apoptosis by liensinine ultimately restored cognitive function in SAE mice. Altogether, liensinine attenuated lipopolysaccharide-induced SAE via modulation of Nrf2-mediated inflammatory biomarkers and mitochondria apoptosis.

CXCR3 Inhibition Blocks the NF-κB Signaling Pathway by Elevating Autophagy to Ameliorate Lipopolysaccharide-Induced Intestinal Dysfunction in Mice

Autophagy is a cellular catabolic process in the evolutionarily conservative turnover of intracellular substances in eukaryotes, which is involved in both immune homeostasis and injury repairment. CXCR3 is an interferon-induced chemokine receptor that participates in immune regulation and inflammatory responses. However, CXCR3 regulating intestine injury via autophagy along with the precise underlying mechanism have yet to be elucidated. In the current study, we employed an LPS-induced inflammatory mouse model and confirmed that CXCR3 knockout significantly attenuates intestinal mucosal structural damage and increases tight junction protein expression. CXCR3 knockout alleviated the LPS-induced increase in the expression of inflammatory factors including TNF-α, IL-6, p-65, and JNK-1 and enhanced autophagy by elevating LC3II, ATG12, and PINK1/Parkin expression. Mechanistically, the function of CXCR3 regarding autophagy and immunity was investigated in IPEC-J2 cells. CXCR3 inhibition by AMG487 enhanced autophagy and reduced the inflammatory response, as well as blocked the NF-κB signaling pathway and elevated the expression of the tight junction protein marker Claudin-1. Correspondingly, these effects were abolished by autophagy inhibition with the selective blocker, 3-MA. Moreover, the immunofluorescence assay results further demonstrated that CXCR3 inhibition-mediated autophagy blocked p65 nuclear translocation, and the majority of Claudin-1 was located at the tight junctions. In conclusion, CXCR3 inhibition reversed LPS-induced intestinal barrier damage and alleviated the NF-κB signaling pathway via enhancing autophagy. These data provided a theoretical basis for elucidating the immunoregulatory mechanism by targeting CXCR3 to prevent intestinal dysfunction.

LncRNA MALAT1 promotes tenogenic differentiation of tendon-derived stem cells via regulating the miR-378a-3p/MAPK1 axis

Tendinopathy is a type of chronic injury caused by repeated pulling. Previous studies have reported that long non-coding RNA MALAT1 (MALAT1) regulates a variety of genes affecting bone metabolism. This study aimed to explore the role of the MALAT1 in tendon injury in vivo and in vitro. Human tendon-derived stem cells (TDSCs) were treated with TGF β1. Eighteen Sprague-Dawley rats were used to establish the tendinopathy animal model. Sirius Red staining and colorimetric assays were conducted to analyze the collagen content. RT-qPCR was performed to measure the mRNA levels. Western blotting was performed to measure the MAPK1 protein levels. Additionally, hematoxylin and eosin (HE) and immunohistochemical staining were used to analyze the cell number and the content of collagen type 1 and Thbs, respectively. MALAT1 expression was upregulated in TGF β1 treated TDSCs, and MALAT1 knockdown downregulated Scleraxis, Mohawk homeobox, Collagen 1A1, Fibromodulin, Matrix metallopeptidase 3, and Thrombospondin 4 in TGF β1 treated TDSCs. Bioinformatics analysis showed that miR-378a-3p was the target of MALAT1 and MAPK1, and dual-luciferase reporter assay indicated that both MALAT1 and MAPK1 could bind to miR-378a-3p. Furthermore, miR-378a-3p knockdown reversed the effect of si-MALAT1, whereas overexpression of MAPK1 reversed the effect of the miR-378a-3p mimic. Finally, MALAT1 expression was downregulated in tendinopathy rats, and MALAT1 overexpression healed tendon injury in them. MALAT1 regulated the tenogenic differentiation of TDSCs by regulating the miR-378a-3p/MAPK1 axis. Our results therefore indicate that targeting the MALAT1/miR-378a-3p/MAPK1 axis may be a promising avenue for the treatment of tendinopathy.

Curcumin relieved the rheumatoid arthritis progression via modulating the linc00052/miR-126-5p/PIAS2 axis

Curcumin, with its antioxidant, anti-inflammatory, and antitumor properties, is widely used in the treatment of bone disorders, including rheumatoid arthritis (RA). We investigated the effects of curcumin on fibroblast-like synoviocytes in RA and its underlying mechanism. mRNA and microRNA (miRNA) expression levels were determined using reverse transcription-quantitative polymerase chain reaction. Cellular functions were detected using cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell, and flow cytometric assays. Enzyme-linked immunosorbent assay was performed to measure the cytokine release. Western blotting was used to determine the protein expression levels. An in vivo assay was performed to verify the role of linc00052 in RA. Curcumin promoted apoptosis and inhibited the growth, migration, and invasion of RA fibroblast-like synovial (RAFLS) cells. Curcumin treatment suppressed the inflammatory response of RAFLS cells. Moreover, curcumin increased linc00052 levels, and linc00052 knockdown reversed the effects of curcumin. Additionally, linc00052 functioned as a competing endogenous RNA to upregulate the expression of the protein inhibitor of activated STAT 2 (PIAS2) by sponging miR-126-5p. Curcumin inhibited the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. In vivo assays showed that curcumin decreased the arthritis score and improved inflammatory infiltration and synovial cell proliferation. These results reveal that curcumin protects against RA by regulating the inc00052/miR-126-5p/PIAS2 axis through JAK2/STAT3 signaling pathway.

Butorphanol tartrate mitigates cellular senescence against tumor necrosis factor –α (TNF-α) in human HC-A chondrocytes

Aging is an important risk factor for osteoarthritis (OA). Butorphanol is a preoperative sedative and analgesic that possesses anti-inflammatory activity. However, the effect of butorphanol on OA has not been reported. Here we aimed to explore the effect of butorphanol tartrate on the cellular senescence of human chondrocyte-articular (HC-A) cells in response to tumor necrosis factor-α (TNF-α) stimulation. Butorphanol tartrate attenuated the TNF-α-caused cellular senescence of HC-A cells, with decreased positive senescence-associated-β-galactosidase (SA-β-gal) staining and elevated telomerase activity. Butorphanol tartrate prevented TNF-α-caused cell cycle arrest in the G0/G1 phase in HC-A cells and decreased p21 expression. The TNF-α-induced production of interleukin (IL)-6 and IL-8 in HC-A cells were mitigated by butorphanol tartrate. In addition, butorphanol tartrate reduced p-NF-κB p65/total p65 and p-STAT3/STAT3 ratios in HC-A cells cultured with TNF-α. Taken together, butorphanol tartrate protected HC-A cells from TNF-α-caused cellular senescence through inactivation of NF-κB and STAT3. These results imply that butorphanol tartrate might be used as a potential agent for the treatment of aging-related OA.

Mitophagy alleviates ischemia/reperfusion-induced microvascular damage through improving mitochondrial quality control

The coronary arteries mainly function to perfuse the myocardium. When coronary artery resistance increases, myocardial perfusion decreases and myocardial remodeling occurs. Mitochondrial damage has been regarded as the primary cause of microvascular dysfunction. In the present study, we explored the effects of mitophagy activation on microvascular damage. Hypoxia/reoxygenation injury induced mitochondrial oxidative stress, thereby promoting mitochondrial dysfunction in endothelial cells. Mitochondrial impairment induced apoptosis, reducing the viability and proliferation of endothelial cells. However, supplementation with the mitophagy inducer urolithin A (UA) preserved mitochondrial function by reducing mitochondrial oxidative stress and stabilizing the mitochondrial membrane potential in endothelial cells. UA also sustained the viability and improved the proliferative capacity of endothelial cells by suppressing apoptotic factors and upregulating cyclins D and E. In addition, UA inhibited mitochondrial fission and restored mitochondrial fusion, which reduced the proportion of fragmented mitochondria within endothelial cells. UA enhanced mitochondrial biogenesis in endothelial cells by upregulating sirtuin 3 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha. These results suggested that activation of mitophagy may reduce hypoxia/reoxygenation-induced cardiac microvascular damage by improving mitochondrial quality control and increasing cell viability and proliferation.