OBJECTIVE: To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats. METHODS: Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β ₁ (TGF-β ₁), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ. RESULTS: The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β ₁, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression. CONCLUSION VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.
Rats ; Animals ; Chondrocytes/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha/metabolism* ; Collagen Type II/metabolism* ; Interleukin-6 ; Lipopolysaccharides/pharmacology* ; NF-E2-Related Factor 2/pharmacology* ; Inflammation/drug therapy* ; Osteoarthritis/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Dipeptides ; para-Aminobenzoates

OBJECTIVE: To investigate the mechanism by which arecoline regulates the level of miR-155-5p in macrophage-secreted exosomes to induce the transformation of human oral mucosal fibroblasts (HOMFs) into fibroblast phenotype. METHODS: Exosomes were harvested from human monocytic cell line THP-1 with or without arecoline treatment. The effects of arecoline-treated THP-1 cell culture supernatant (CS), THP-1-derived exosomes (EXO), exosome-depleted THP-1 cell supernatant (NES), miR-155-5p overexpression, and miR-155-5p inhibitor on migration ability of arecoline-treated HOMF cells were examined using Transwell migration assay. The polarization of THP-1 cells was detected using flow cytometry. DCFH-DA was used to detect the level of oxidative stress in the cells with different treatments. The mRNA and protein expressions of α- SMA, type I collagen and SOCS1 in the cells were detected with qRT-PCR and Western blotting. RESULTS: Flow cytometry showed that arecoline-treated THP-1 cells exhibited obvious polarization from M₀ to M₁. Both the supernatant and exosomes from arecoline-treated THP-1 cells significantly enhanced the migration ability of HOMF cells, increased intracellular oxidative stress, up-regulated the expressions of miR-155- 5p and the mRNA and protein levels of α-SMA and type I collagen, and lowered the mRNA and protein expressions of SOCS1. In HOMF cells treated with exosomes from arecoline- treated THP-1 cells, overexpression of miR-155-5p significantly enhanced cell migration ability and increased cellular expressions of α-SMA and type I collagen, and miR-155-5p inhibitor caused the opposite changes. CONCLUSION Arecoline can up-regulate miR-155-5p expression in THP-1 cells and inhibit the expression of SOCS1 protein in HOMF cells via the exosome pathway, thus promoting the fibrotic phenotype transformation of HOMF cells.
Humans ; Exosomes ; Arecoline/pharmacology* ; Collagen Type I ; Fibroblasts ; Macrophages ; MicroRNAs

OBJECTIVE: To establish a visual reporting system for evaluating the activity of collagen Ⅰ α 1 chain (COL1A1) gene promoter in immortalized human hepatic stellate cells, so as to estimate the activation status of the cells and provide a new cell model for the screening and study of anti-hepatic fibrosis drugs. METHODS: The promoter sequence of human COL1A1 was amplified from the genomic DNA of human hepatocarcinoma cell line HepG2. Based on the pLVX-AcGFP1-N1 plasmid, the recombinant plasmid pLVX-COL1A1-enhanced green fluorescent protein (EGFP) was constructed, in which the enhanced green fluorescent protein gene expression was regulated by the COL1A1 promoter. The monoclonal cell line was acquired by stably transfecting pLVX-COL1A1-EGFP into the immortalized human hepatic stellate cell line LX-2 by the lentivirus packaging system and screening. The cell line was treated with transforming growth factor-β1 (TGF-β1) or co-treated with TGF-β1 and drugs with potential anti-hepatic fibrosis effects. The EGFP fluorescence intensity in cells was analyzed by the fluorescence microscope and ImageJ 1.49 software using a semi-quantitative method. The COL1A1 and EGFP mRNA were detected by reverse transcription real-time quantitative PCR (RT-qPCR), and corresponding proteins were detected by Western blot. RESULTS: The recombinant plasmid pLVX-COL1A1-EGFP with the expression of EGFP regulated by COL1A1 promoter was successfully constructed. Kozak sequence was added to enhance the expression of EGFP, which was identified by double digestion and sequencing. The LX-2 monoclonal cell line LX-2-CE stably transfected with pLVX-COL1A1-EGFP was obtained. After co-treatment with TGF-β1 and 5 μmol/L dihydrotanshinone Ⅰ with potential anti-hepatic fibrosis effect for 24 h, the total fluorescence intensity and the average fluorescence intensity of LX-2-CE were lower than those in TGF-β1 single treatment group (P < 0.05), the intracellular mRNA and protein levels of COL1A1 and EGFP were also lower than those in the TGF-β1 single treatment group (P < 0.05). CONCLUSION A reporter system for estimating activation of hepatic stellate cells based on COL1A1 promoter regulated EGFP expression is successfully constructed, which could visually report the changes in COL1A1 expression, one of the activation-related markers of hepatic stellate cells, in vitro. It provides a new cell model for the screening and study of anti-hepatic fibrosis drugs.
Humans ; Transforming Growth Factor beta1/pharmacology* ; Hepatic Stellate Cells/pathology* ; Liver Cirrhosis/genetics* ; Collagen Type I/pharmacology* ; RNA, Messenger/metabolism*

Objective: To construct a new co-cultured liver cancer research model composed of activated hepatic stellate cells (aHSC) and liver cancer cells, explore the efficacy difference between it and traditional model, so as to establish a liver cancer research model in vitro and in vivo that can reflect the real clinical efficacy. Methods: A new co-culture model of liver cancer consisting of aHSC and liver cancer cells was constructed. The differences in efficacy between the new co-culture model and the traditional single cell model were compared by cytotoxicity test, cell migration test, drug retention test and in vivo tumor inhibition test. Western blot was used to detect the drug-resistant protein P-gp and epithelial-mesenchymal transition-related proteins. Masson staining was used to observe the deposition of collagen fibers in tumor tissues of tumor-bearing mice. CD31 immunohistochemical staining was used to observe the microvessel density in tumor tissues of tumor-bearing mice. Results: The cytotoxicity of single cell model and co-culture model was dose-dependent. With the increase of curcumin (CUR) concentration, the cell viability decreased, but the cell viability of single cell model decreased faster than that of co-culture model. When the concentration of CUR was 10 μg/ml, the cell viability of the co-culture model was 62.3% and the migration rate was (28.05±3.68)%, which were higher than those of the single cell model [38.5% and (14.91±5.92)%, both P<0.05]. Western blot analysis showed that the expressions of P-gp and vimentin were up-regulated in the co-culture model, which were 1.55 and 2.04 fold changes of the single cell model, respectively. The expression of E-cadherin was down-regulated, and the expression level of E-cadherin in the single cell model was 1.17 fold changes of the co-culture model. Drug retention experiment showed that the co-culture model could promote drug efflux and reduce drug retention. In vivo tumor inhibition experiment showed that the m-HSC+ H22 co-transplantation model had faster tumor growth and larger tumor volume than those of the H22 single cell transplantation model. After CUR treatment, the tumor growths of m-HSC+ H22 co-transplantation model and H22 single cell transplantation model were inhibited. Masson staining showed that the deposition of collagen fibers in tumor tissues of m-HSC+ H22 co-transplantation model mice was more than that of H22 single cell transplantation model. CD31 immunohistochemical staining showed that the microvessel density in tumor tissue of m-HSC+ H22 co-transplantation model was higher than that of H22 single cell transplantation model. Conclusions: The aHSC+ liver cancer cell co-culture model has strong proliferation and metastasis ability and is easy to be resistant to drugs. It is a new type of liver cancer treatment research model superior to the traditional single cell model.
Animals ; Mice ; Tumor Microenvironment ; Coculture Techniques ; Liver Neoplasms/pathology* ; Cadherins ; Curcumin/pharmacology* ; Collagen ; Cell Line, Tumor

Objective: JWH133, a cannabinoid type 2 receptor agonist, was tested for its ability to protect mice from bleomycin-induced pulmonary fibrosis. Methods: By using a random number generator, 24 C57BL/6J male mice were randomly divided into the control group, model group, JWH133 intervention group, and JWH133+a cannabinoid type-2 receptor antagonist (AM630) inhibitor group, with 6 mice in each group. A mouse pulmonary fibrosis model was established by tracheal instillation of bleomycin (5 mg/kg). Starting from the first day after modeling, the control group mice were intraperitoneally injected with 0.1 ml of 0.9% sodium chloride solution, and the model group mice were intraperitoneally injected with 0.1 ml of 0.9% sodium chloride solution. The JWH133 intervention group mice were intraperitoneally injected with 0.1 ml of JWH133 (2.5 mg/kg, dissolved in physiological saline), and the JWH133+AM630 antagonistic group mice were intraperitoneally injected with 0.1 ml of JWH133 (2.5 mg/kg) and AM630 (2.5 mg/kg). After 28 days, all mice were killed; the lung tissue was obtained, pathological changes were observed, and alveolar inflammation scores and Ashcroft scores were calculated. The content of type Ⅰ collagen in the lung tissue of the four groups of mice was measured using immunohistochemistry. The levels of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) in the serum of the four groups of mice were measured using enzyme-linked immunosorbent assay (ELISA), and the content of hydroxyproline (HYP) in the lung tissue of the four groups of mice was measured. Western blotting was used to measure the protein expression levels of type Ⅲ collagen, α-smooth muscle actin (α-SMA), extracellular signal regulated kinase (ERK1/2), phosphorylated P-ERK1/2 (P-ERK1/2), and phosphorylated ribosome S6 kinase type 1 (P-p90RSK) in the lung tissue of mice in the four groups. Real-time quantitative polymerase chain reaction was used to measure the expression levels of collagen Ⅰ, collagen Ⅲ, and α-SMA mRNA in the lung tissue of the four groups of mice. Results: Compared with the control group, the pathological changes in the lung tissue of the model group mice worsened, with an increase in alveolar inflammation score (3.833±0.408 vs. 0.833±0.408, P<0.05), an increase in Ashcroft score (7.333±0.516 vs. 2.000±0.633, P<0.05), an increase in type Ⅰ collagen absorbance value (0.065±0.008 vs. 0.018±0.006, P<0.05), an increase in inflammatory cell infiltration, and an increase in hydroxyproline levels [(1.551±0.051) μg/mg vs. (0.974±0.060) μg/mg, P<0.05]. Compared with the model group, the JWH133 intervention group showed reduced pathological changes in lung tissue, decreased alveolar inflammation score (1.833±0.408, P<0.05), decreased Ashcroft score (4.167±0.753, P<0.05), decreased type Ⅰ collagen absorbance value (0.032±0.004, P<0.05), reduced inflammatory cell infiltration, and decreased hydroxyproline levels [(1.148±0.055) μg/mg, P<0.05]. Compared with the JWH133 intervention group, the JWH133+AM630 antagonistic group showed more severe pathological changes in the lung tissue of mice, increased alveolar inflammation score and Ashcroft score, increased type Ⅰ collagen absorbance value, increased inflammatory cell infiltration, and increased hydroxyproline levels. Compared with the control group, the expression of α-SMA, type Ⅲ collagen, P-ERK1/2, and P-p90RSK proteins in the lung tissue of the model group mice increased, while the expression of type Ⅰ collagen, type Ⅲ collagen, and α-SMA mRNA increased. Compared with the model group, the protein expression of α-SMA (relative expression 0.60±0.17 vs. 1.34±0.19, P<0.05), type Ⅲ collagen (relative expression 0.52±0.09 vs. 1.35±0.14, P<0.05), P-ERK1/2 (relative expression 0.32±0.11 vs. 1.14±0.14, P<0.05), and P-p90RSK (relative expression 0.43±0.14 vs. 1.15±0.07, P<0.05) decreased in the JWH133 intervention group. The type Ⅰ collagen mRNA (2.190±0.362 vs. 5.078±0.792, P<0.05), type Ⅲ collagen mRNA (1.750±0.290 vs. 4.935±0.456, P<0.05), and α-SMA mRNA (1.588±0.060 vs. 5.192±0.506, P<0.05) decreased. Compared with the JWH133 intervention group, the JWH133+AM630 antagonistic group increased the expression of α-SMA, type Ⅲ collagen, P-ERK1/2, and P-p90RSK protein in the lung tissue of mice, and increased the expression of type Ⅲ collagen and α-SMA mRNA. Conclusion: In mice with bleomycin-induced pulmonary fibrosis, the cannabinoid type-2 receptor agonist JWH133 inhibited inflammation and improved extracellular matrix deposition, which alleviated lung fibrosis. The underlying mechanism of action may be related to the activation of the ERK1/2-RSK1 signaling pathway.
Mice ; Male ; Animals ; Pulmonary Fibrosis/pathology* ; Cannabinoid Receptor Agonists/metabolism* ; Collagen Type I/pharmacology* ; Collagen Type III/pharmacology* ; Hydroxyproline/pharmacology* ; Sodium Chloride/metabolism* ; Mice, Inbred C57BL ; Lung/pathology* ; Cannabinoids/adverse effects* ; Bleomycin/metabolism* ; Collagen/metabolism* ; Inflammation/pathology* ; RNA, Messenger/metabolism*

OBJECTIVE: To observe the effect of exosomes secreted by lipopolysaccharides (LPS)-stimulated macrophages on hepatic stellate cell activation and migration and explore the underlying molecular mechanism. METHODS: Human monocyte THP-1 cells were induced to differentiate into macrophages using propylene glycol methyl ether acetic acid (PMA, 100 ng/mL, 24 h) followed by stimulation with LPS, and the culture supernatant of macrophages was collected for extraction of the exosomes by ultracentrifugation. The expression of miR-155-5p in the exosomes was detected using qRT-PCR. A Transwell co-culture system was used to observe the effects of the macrophage-derived exosomes on LX2 cell (a hepatic stellate cell line) proliferation, migration, oxidative stress and the expression of fibrosis biomarkers, which were also observed in LX2 cells transfected with miR-155-5p-mimics or miR-155-5p-inhibitors. Western blotting was used to detect the expressions of SOCS1 and its downstream signal pathway proteins. RESULTS: Treatment with the exosomes from LPS-stimulated macrophages significantly enhanced the proliferation and migration ability of LX2 cells and increased the levels of oxidative stress and expressions of the fibrosis markers such as type Ⅰ collagen (P < 0.05). The expression of miR-155-5p in the exosomes secreted by macrophages was significantly increased after LPS treatment (P < 0.01). LX2 cells overexpressing miR-155-5p also exhibited significantly enhanced proliferation and migration with increased oxidative stress levels and expression of type Ⅰ collagen (P < 0.05), and interference of miR-155-5p expression produced the opposite effects. Western blotting showed that miR-155-5p overexpression obviously inhibited SOCS1 expression and promoted p-Smad2/3, Smad2/3 and RhoA protein expressions in LX2 cells (P < 0.05). CONCLUSION LPS stimulation of the macrophages increases miR-155-5p expression in the exosomes to promote activation and migration and increase oxidative stress and collagen production in hepatic stellate cells.
Humans ; Hepatic Stellate Cells ; Lipopolysaccharides/pharmacology* ; Collagen Type I ; Exosomes ; Macrophages ; MicroRNAs

OBJECTIVE: To investigate the effect of Heliotropium indicum L. (H. indicum L.) on uterine involution and its underlying mechanisms in both in vivo and in vitro study. METHODS: For in vivo studies, postpartum rats were randomly divided into 2 groups (n=24 for each): control group and treated group which were orally and daily administered with ethanolic extract of H. indicum L. (250 mg/kg body weight) until day 5 of postpartum. Uteri were collected for analysis of weight, cross-sectional area, collagen cross-sectional area, and collagen content on postpartum day 1, 3, and 5 (n=8 for each) from both groups. Blood samples were collected for hepatotoxicity and 17β-estradiol (E₂) measurement. For in vitro studies, the extract effects on uterine contraction at half maximum effective concentration of 2.50 mg/mL were studied in organ bath system for at least 20 min. RESULTS: Uterine parameters were significantly decreased after treated with extract of H. indicum L. (P<0.05). H. indicum L. extract significantly accelerated the reduction of those parameters and significantly decreased E₂ (P<0.05). The extract facilitated uterine involution with no hepatotoxicity. H. indicum L. extract significantly stimulated uterine contraction (P<0.05) and synergized with oxytocin, prostaglandin and its precursor, linoleic acid. By investigating the different sequencing of the extract with the additional stimulants (added before or after), the two showed antagonistic effects, but still showed potentiated force when compared with control (without the stimulants). CONCLUSIONS The underlying mechanisms by which H. indicum L. facilitated uterine involution might be due to reducing E₂ which induces collagenase activity, leading to decreases in uterine weight and size and stimulating uterine contraction. Our study provides new findings for future drug development for facilitating uterine involution with H. indicum L.
Pregnancy ; Female ; Rats ; Animals ; Heliotropium ; Uterus ; Plant Extracts/pharmacology* ; Oxytocin ; Collagen/pharmacology*

The present study was aimed to investigate the role and mechanism of glutaminolysis of cardiac fibroblasts (CFs) in hypertension-induced myocardial fibrosis. C57BL/6J mice were administered with a chronic infusion of angiotensin II (Ang II, 1.6 mg/kg per d) with a micro-osmotic pump to induce myocardial fibrosis. Masson staining was used to evaluate myocardial fibrosis. The mice were intraperitoneally injected with BPTES (12.5 mg/kg), a glutaminase 1 (GLS1)-specific inhibitor, to inhibit glutaminolysis simultaneously. Immunohistochemistry and Western blot were used to detect protein expression levels of GLS1, Collagen I and Collagen III in cardiac tissue. Neonatal Sprague-Dawley (SD) rat CFs were treated with 4 mmol/L glutamine (Gln) or BPTES (5 μmol/L) with or without Ang II (0.4 μmol/L) stimulation. The CFs were also treated with 2 mmol/L α-ketoglutarate (α-KG) under the stimulation of Ang II and BPTES. Wound healing test and CCK-8 were used to detect CFs migration and proliferation respectively. RT-qPCR and Western blot were used to detect mRNA and protein expression levels of GLS1, Collagen I and Collagen III. The results showed that blood pressure, heart weight and myocardial fibrosis were increased in Ang II-treated mice, and GLS1 expression in cardiac tissue was also significantly up-regulated. Gln significantly promoted the proliferation, migration, mRNA and protein expression of GLS1, Collagen I and Collagen III in the CFs with or without Ang II stimulation, whereas BPTES significantly decreased the above indices in the CFs. α-KG supplementation reversed the inhibitory effect of BPTES on the CFs under Ang II stimulation. Furthermore, in vivo intraperitoneal injection of BPTES alleviated cardiac fibrosis of Ang II-treated mice. In conclusion, glutaminolysis plays an important role in the process of cardiac fibrosis induced by Ang II. Targeted inhibition of glutaminolysis may be a new strategy for the treatment of myocardial fibrosis.
Rats ; Mice ; Animals ; Rats, Sprague-Dawley ; Angiotensin II/pharmacology* ; Fibroblasts ; Mice, Inbred C57BL ; Fibrosis ; Collagen/pharmacology* ; Collagen Type I/metabolism* ; RNA, Messenger/metabolism* ; Myocardium/pathology*

In this study, we investigated the effects of Panax notoginseng saponins (PNS) on pulmonary vascular remodeling and ADAM10/Notch3 pathway in pulmonary arterial hypertension (PAH). PAH rat model was established, and male Sprague Dawley (SD) rats were randomly divided into control group, monocrotaline (MCT) group and MCT+PNS group, with 10 rats in each group. Rats in the control group were intraperitoneally injected with equal volume of normal saline. Rats in the MCT group was injected intraperitoneally with 60 mg/kg MCT on the first day, and then with the same volume of normal saline every day. Rats in the MCT+PNS group was injected intraperitoneally with 60 mg/kg MCT on the first day, and then with 50 mg/kg PNS every day. The modeling time of each group lasted for 21 days. After the model was established, the mean pulmonary artery pressure (mPAP) was measured by right heart catheterization technique, the right ventricular hypertrophy index (RVHI) was calculated, the microscopic morphology and changes of pulmonary vascular wall were observed by HE and Masson staining, and the expressions of ADAM10, Notch3, Hes-1, P27, PCNA, Caspase-3 proteins and mRNA in pulmonary vascular tissue of rats were detected by Western blot and qPCR. The expression and localization of Notch3 and α-SMA were detected by immunofluorescence staining. The protein expression of ADAM10 was detected by immunohistochemical staining. The results showed that compared with the control group, mPAP, RVHI, pulmonary vessels and collagen fibers in the MCT group were significantly increased, the expressions of ADAM10, Notch3, Hes-1, and PCNA protein and mRNA were significantly increased, while the expressions of P27 and Caspase-3 protein and mRNA were decreased significantly. Compared with the MCT group, mPAP and RVHI were significantly decreased, pulmonary vessels were significantly improved and collagen fibers were significantly reduced, the expressions of protein and mRNA of ADAM10, Notch3, Hes-1, and PCNA were decreased in MCT+PNS group, but the expressions of protein and mRNA of P27 and Caspase-3 were increased slightly. The results of immunofluorescence showed that Notch3 and α-SMA staining could overlap, which proved that Notch3 was expressed in smooth muscle cells. The expression of Notch3 in the MCT group was increased significantly compared with that in the control group, while PNS intervention decreased the expression of Notch3. Immunohistochemical staining showed that compared with the control group, the amount of ADAM10 in the MCT group was increased significantly, and the expression of ADAM10 in the MCT+PNS group was decreased compared with the MCT group. These results indicate that PNS can improve the PAH induced by MCT in rats by inhibiting ADAM10/Notch3 signaling pathway.
Animals ; Male ; Rats ; Caspase 3/metabolism* ; Collagen ; Disease Models, Animal ; Hypertension, Pulmonary/drug therapy* ; Monocrotaline/adverse effects* ; Panax notoginseng/chemistry* ; Proliferating Cell Nuclear Antigen/pharmacology* ; Pulmonary Arterial Hypertension ; Pulmonary Artery/metabolism* ; Rats, Sprague-Dawley ; Receptor, Notch3/genetics* ; RNA, Messenger ; Saline Solution ; Signal Transduction ; Saponins/pharmacology*

Previous studies have shown that high blood glucose-induced chronic microinflammation can cause inflammatory podocyte injury in patients with diabetic kidney disease(DKD). Therein, necroptosis is a new form of podocyte death that is closely associated with renal fibrosis(RF). To explore the effects and mechanisms in vivo of total flavones of Abelmoschus manihot(TFA), an extract from traditional Chinese herbal medicine Abelmoschus manihot for treating kidney diseases, on podocyte necroptosis and RF in DKD, and to further reveal its scientific connotation with multi-pathway and multi-target, the authors randomly divided all rats into four groups: a namely normal group, a model group, a TFA group and a rapamycin(RAP) group. After the modified DKD rat models were successfully established, four group rats were given double-distilled water, TFA suspension and RAP suspension, respectively by gavage every day. At the end of the 4th week of drug treatment, all rats were sacrificed, and the samples of their urine, blood and kidneys were collected. And then, the various indicators related to podocyte necroptosis and RF in the DKD model rats were observed, detected and analyzed, respectively. The results indicated that, general condition, body weight(BW), serum creatinine(Scr), urinary albumin(UAlb), and kidney hypertrophy index(KHI) in these modified DKD model rats were both improved by TFA and RAP. Indicators of RF, including glomerular histomorphological characteristics, fibronectin(FN) and collagen type Ⅰ(collagen Ⅰ) staining extent in glomeruli, as well as the protein expression levels of FN, collagen Ⅰ, transforming growth factor-β1(TGF-β1) and Smad2/3 in the kidneys were improved respectively by TFA and RAP. Podocyte damage, including foot process form and the protein expression levels of podocin and CD2AP in the kidneys was improved by TFA and RAP. In addition, tumor necrosis factor-α(TNF-α)-mediated podocyte necroptosis in the kidneys, including the morphological characteristics of podocyte necroptosis, the extent and levels of the protein expression of TNF-α and phosphorylated mixed lineage kinase domain like pseudokinase(p-MLKL) was improved respectively by TFA and RAP. Among them, RAP had the better effect on p-MLKL. More importantly, the activation of the receptor interacting serine/threonine protein kinase 1(RIPK1)/RIPK3/MLKL signaling axis in the kidneys, including the expression levels of its key signaling molecules, such as phosphorylated receptor interacting serine/threonine protein kinase 1(p-RIPK1), p-RIPK3, p-MLKL and cysteinyl aspartate specific proteinase-8(caspase-8) was improved respectively by TFA and RAP. Among them, the effect of TFA on p-RIPK1 was superior. On the whole, in this study, the authors demonstrated that TFA alleviates podocyte necroptosis and RF in DKD through inhibiting the activation of the TNF-α-mediated RIPK1/RIPK3/MLKL signaling axis in diabetic kidneys. The authors' findings provide new pharmacological evidence to reveal the scientific connotation of TFA in treating RF in DKD in more depth.
Humans ; Rats ; Animals ; Diabetic Nephropathies/drug therapy* ; Abelmoschus ; Flavones/pharmacology* ; Podocytes ; Tumor Necrosis Factor-alpha/metabolism* ; Necroptosis ; Receptor-Interacting Protein Serine-Threonine Kinases/metabolism* ; Fibrosis ; Threonine/pharmacology* ; Collagen/metabolism* ; Serine/pharmacology* ; Diabetes Mellitus/drug therapy*