OBJECTIVE: To review the role and research progress of mechanotransduction signaling pathway in distraction osteogenesis, so as to provide theoretical basis and reference for clinical treatment. METHODS: The role and research progress of mechanotransduction signaling pathway in distraction osteogenesis were summarized by extensive review of relevant literature at home and abroad. RESULTS: The mechanotransduction signaling pathway plays a central role of "sensation-transformation-execution" in distraction osteogenesis, and activates a series of molecular mechanisms to promote the regeneration and remodeling of bone tissue by integrating external mechanical signals. Mechanical stimuli are converted into mechanotransduction signals through the perception of integrins, Piezo1 ion channels and bone cell networks. Activate downstream molecules are transduce through signal pathways such as Wnt/β-catenin, transforming growth factor β/bone morphogenetic protein-Smad, mitogen-activated protein kinase, protein kinase Hippo-Yes-associated protein/transcriptional coactivator with PDZ-binding motif, and phosphatidylinositol 3-kinase/ protein kinase B, so as to achieve the effects of promoting osteoblasts proliferation, accelerating endochondral ossification, regulating bone resorption and the like, thereby promoting the regeneration of new bone in the distraction area. The study of mechanotransduction signaling pathways in distraction osteogenesis is expected to optimize the mechanical parameters of distraction osteogenesis and provide targeted intervention strategies for accelerating new bone regeneration and mineralization in the distraction zone. However, the specific mechanism of mechanotransduction signaling pathway in distraction osteogenesis remains to be further elucidated, and artificial intelligence and multi-omics analysis may be the future development direction of mechanotransduction signaling pathway. CONCLUSION In distraction osteogenesis, mechanotransduction signal transduction is the core mechanism of bone regeneration in the distraction zone, which regulates cell behavior and tissue regeneration by converting mechanical stimulation into biochemical signals.
Mechanotransduction, Cellular/physiology* ; Osteogenesis, Distraction/methods* ; Humans ; Signal Transduction ; Bone Regeneration ; Animals ; Osteoblasts/metabolism* ; Osteogenesis ; Transforming Growth Factor beta/metabolism* ; Ion Channels/metabolism* ; Integrins/metabolism* ; beta Catenin/metabolism* ; Bone Morphogenetic Proteins/metabolism* ; Smad Proteins/metabolism*

OBJECTIVES: To investigate the inhibitory effect of Danshen Injection on endothelial-mesenchymal transition (EndMT) induced by peritoneal dialysis fluid in HMrSV5 cells and the role of the TGF‑β/Smad signaling pathway in mediating this effect. METHODS: HMrSV5 cells cultured in 40% peritoneal dialysis solution for 72 h to induce EndMT were treated with 0.05%, 0.1% and 0.5% Danshen Injection. CCK-8 assay was used to assess the changes in viability of the treated cells, and the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), and vascular endothelial growth factor (VEGF) in the cell supernatant were detected using ELISA; Western blotting was performed to detect the protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), p-Smad 2/3, and Smad 7 in the cells. RESULTS: Culture in 40% peritoneal dialysis fluid for 72 induced significant EndMT in HMrSV5 cells, which exhibited obviously lowered cell viability. Danshen Injection within the concentration range of 0.025%-1.5% did not significantly affect the viability of the cells. Exposure of HMrSV5 cells to peritoneal dialysis fluid for 72 h significantly increased the production of IL-6, TNF‑α, TGF‑β and VEGF, upregulated the protein expressions of α‑SMA and p-Smad 2/3, and lowered the expressions of E-cadherin and Smad7 proteins. Treatment of the exposed cells with Danshen injection significantly increased cell viability and cellular expressions of E-cadherin and Smad 7 proteins and reduced the production of IL-6, TNF-α, TGF-β and VEGF and the protein expressions of α‑SMA and p-Smad 2/3. CONCLUSIONS Danshen Injection can suppress peritoneal dialysis fluid-induced EndMT in HMrSV5 cells possibly by regulating the TGF-β/Smad signaling pathway.
Signal Transduction/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Transforming Growth Factor beta/metabolism* ; Humans ; Peritoneal Dialysis/adverse effects* ; Salvia miltiorrhiza ; Epithelial-Mesenchymal Transition/drug effects* ; Smad Proteins/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Cell Line ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Cadherins/metabolism* ; Actins/metabolism* ; Dialysis Solutions ; Endothelial-Mesenchymal Transition

Diabetic kidney disease is an important microvascular complication of diabetes and the leading cause of end-stage renal disease. Its pathological characteristics mainly include epithelial mesenchymal transition(EMT) in glomerulus, podocyte apoptosis and autophagy, and damage of glomerular filtration barrier. Transforming growth factor-β(TGF-β)/Smad signaling pathway is specifically regulated by a variety of mechanisms, and is a classic pathway involved in physiological activities such as apoptosis, proliferation and differentiation. At present, many studies have found that TGF-β/Smad signaling pathway plays a key role in the pathogenesis of diabetic kidney disease. Traditional Chinese medicine has significant advantages in the treatment of diabetic kidney disease for its multi-component, multi-target and multi-pathway characteristics, and some traditional Chinese medicine extracts, traditional Chinese medicines and traditional Chinese medicine compound prescription improve the renal injury of diabetic kidney disease by regulating TGF-β/Smad signaling pathway. This study clarified the mechanism of TGF-β/Smad signaling pathway in diabetic kidney disease by expounding the relationship between the key targets of the pathway and diabetic kidney disease, and summarized the research progress of traditional Chinese medicine in the treatment of diabetic kidney disease by interfering with TGF-β/Smad signaling pathway in recent years, to provide reference for drug research and clinical treatment of diabetic kidney disease in the future.
Humans ; Diabetic Nephropathies/genetics* ; Medicine, Chinese Traditional ; Kidney/pathology* ; Transforming Growth Factor beta/metabolism* ; Signal Transduction ; Epithelial-Mesenchymal Transition ; Smad Proteins/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Diabetes Mellitus/genetics*

OBJECTIVE: To observe the effect of amygdalin on liver fibrosis in a liver fibrosis mouse model, and the underlying mechanisms were partly dissected in vivo and in vitro. METHODS: Thirty-two male mice were randomly divided into 4 groups, including control, model, low- and high-dose amygdalin-treated groups, 8 mice in each group. Except the control group, mice in the other groups were injected intraperitoneally with 10% carbon tetrachloride (CCl₄)-olive oil solution 3 times a week for 6 weeks to induce liver fibrosis. At the first 3 weeks, amygdalin (1.35 and 2.7 mg/kg body weight) were administered by gavage once a day. Mice in the control group received equal quantities of subcutaneous olive oil and intragastric water from the fourth week. At the end of 6 weeks, liver tissue samples were harvested to detect the content of hydroxyproline (Hyp). Hematoxylin and eosin and Sirius red staining were used to observe the inflammation and fibrosis of liver tissue. The expressions of collagen I (Col-I), alpha-smooth muscle actin (α-SMA), CD31 and transforming growth factor β (TGF-β)/Smad signaling pathway were observed by immunohistochemistry, quantitative real-time polymerase chain reaction and Western blot, respectively. The activation models of hepatic stellate cells, JS-1 and LX-2 cells induced by TGF-β1 were used in vitro with or without different concentrations of amygdalin (0.1, 1, 10 µmol/L). LSECs. The effect of different concentrations of amygdalin on the expressions of liver sinusoidal endothelial cells (LSECs) dedifferentiation markers CD31 and CD44 were observed. RESULTS: High-dose of amygdalin significantly reduced the Hyp content and percentage of collagen positive area, and decreased the mRNA and protein expressions of Col-I, α-SMA, CD31 and p-Smad2/3 in liver tissues of mice compared to the model group (P<0.01). Amygdalin down-regulated the expressions of Col-I and α-SMA in JS-1 and LX-2 cells, and TGFβ R1, TGFβ R2 and p-Smad2/3 in LX-2 cells compared to the model group (P<0.05 or P<0.01). Moreover, 1 and 10 µmol/L amygdalin inhibited the mRNA and protein expressions of CD31 in LSECs and increased CD44 expression compared to the model group (P<0.05 or P<0.01). CONCLUSIONS Amygdalin can dramatically alleviate liver fibrosis induced by CCl₄ in mice and inhibit TGF-β/Smad signaling pathway, consequently suppressing HSCs activation and LSECs dedifferentiation to improve angiogenesis.
Rats ; Male ; Mice ; Animals ; Transforming Growth Factor beta/metabolism* ; Amygdalin/therapeutic use* ; Endothelial Cells/metabolism* ; Olive Oil/therapeutic use* ; Rats, Wistar ; Smad Proteins/metabolism* ; Liver Cirrhosis/metabolism* ; Liver ; Transforming Growth Factor beta1/metabolism* ; Signal Transduction ; Collagen Type I/metabolism* ; Carbon Tetrachloride ; Hepatic Stellate Cells

OBJECTIVE: To investigate the effect of hydronidone on CCl₄-induced liver fibrosis in rats and explore the possible mechanism. METHODS: Sixty-six male SD rats were randomized into 5 groups, including a control group (n=10), a liver fibrosis model group (n=20), 2 hydronidone dose groups (100 and 250 mg/kg; n=12), and a pirfenidone (250 mg/kg) treatment group (n= 12). Rat models of liver fibrosis were established by subcutaneous injection of CCl₄ in all but the control group. Hydronidone and pirfenidone were given daily at the indicated doses by intragastric administration for 6 weeks. After the treatments, serum samples were collected from the rats for detecting liver function parameters, and hydroxyproline content in the liver tissue was determined. Inflammation and fibrosis in the liver tissue were observed using HE staining and Sirius Red staining. In the cell experiment, human hepatic stellate cell line LX-2 was stimulated with TGF-β1 and treated with hydronidone or pirfenidone, and the expression levels of α-SMA, collagen type I and phosphorylated Smad3, phosphorylated p38, phosphorylated ERK1/2 and phosphorylated Akt were detected with Western blotting. RESULTS: In the rat models of liver fibrosis, treatment with hydronidone obviously improved the liver functions, reduced the content of hydroxyproline in the liver tissue, and significantly alleviated liver fibrosis (P < 0.05). In LX-2 cells, hydronidone dose-dependently decreased the expression levels of α-SMA and collagen type I. In TGF- β1-stimulated cells, the phosphorylation levels of Smad3, P38, ERK, and Akt increased progressively with the extension of the treatment time, but this effect was significantly attenuated by treatment with hydronidone (P < 0.05). CONCLUSION Hydronidone can inhibit the phosphorylation of the proteins in the TGF-β signaling pathway, thereby preventing TGF-β1-mediated activation of hepatic stellate cells, which may be a possible mechanism by which hydronidone alleviates CCl₄-induced liver fibrosis in rats.
Animals ; Male ; Rats ; Carbon Tetrachloride/metabolism* ; Collagen Type I ; Hepatic Stellate Cells/pathology* ; Hydroxyproline/therapeutic use* ; Liver Cirrhosis ; Phosphorylation ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Smad Proteins/metabolism* ; Transforming Growth Factor beta1/metabolism*

The purpose of this study was to investigate the effect of Geniposide on hepatic fibrosis and activation of hepatic stellate cells (HSCs) and to explore possible underlying mechanism. Human HSCs (LX-2) were treated with 5 ng/mL transforming growth factor-β1 (TGF-β1), followed by co-culture with Geniposide at various concentrations (0, 1, 2.5, 5, 10, 20, 40, 60, 80, 100 μmol/L). Cell viability was determined by MTT assay. Then, LX-2 cells were divided into control, TGF-β1 (5 ng/mL) and TGF-β1 + Geniposide (20 μmol/L) groups, and the gene and protein expression of collagen I, fibronectin, α-smooth muscle actin (α-SMA), p-Smad2 and p-Smad3 was detected by qPCR and Western blot, respectively. BALB/c mice were treated with CCl₄ (25%, 1 mL/kg) to generate a model of hepatic fibrosis (CCl₄ group), and the control group and CCl₄ + Geniposide group were administered with olive oil and CCl₄ + 40 mg/kg Geniposide, respectively. After 4 weeks of treatment, the liver function and serum hepatic fibrosis indexes of mice were detected, histological observation was performed by HE and Masson staining, and α-SMA expression in the tissue was analyzed by immunohistochemistry. Western blot was utilized for the determination of the protein expression of α-SMA, TGF-β1, p-Smad2 and p-Smad3. The results showed that Geniposide inhibited LX-2 cell proliferation. In addition, Geniposide significantly downregulated the gene and protein expression of collagen I, fibronectin and α-SMA and the expression of TGF-β1/Smad signaling-related proteins induced by TGF-β1 in vitro. Histological observations showed that Geniposide significantly inhibited CCl₄-induced hepatic fibrosis, HSC activation and expression of TGF-β1/Smad signaling-related proteins in mice. In summary, Geniposide prevents the hepatic fibrosis and HSC activation possibly through the inhibition of the TGF-β1/Smad signaling pathway.
Animals ; Collagen Type I/metabolism* ; Fibronectins ; Hepatic Stellate Cells/pathology* ; Iridoids ; Liver Cirrhosis/pathology* ; Mice ; Signal Transduction ; Smad Proteins/pharmacology* ; Transforming Growth Factor beta1/metabolism*

OBJECTIVE: To investigate the inhibitory effect of Linggui Zhugan Decoction (LZD, ) on the ventricular remodeling (VR) after acute myocardial infarction (AMI) and related mRNA and proteins expression in transforming growth factor-beta 1 (TGF-β)/Smad signaling pathway, and explain its putative mechanism. METHODS: A VR model was generated by ligation of coronary artery in mice. Two weeks after surgery, 60 mice were randomly divided into the model group, the sham-operation group (distilled water), the positive control group (2.4 mg/kg simvastatin), and the low-, medium- and high-dose LZD groups (2.1, 4.2, 8.4 g crude drug/kg, respectively) by a random number table, 10 mice in each group. Mice in each group was treated for 4 weeks. Changes of hemodynamics indices and cardiac weight index were detected by the PowerLab data acquisition and analysis recording instrument. Morphology changes of myocardial tissue were observed by hematoxylin-eosin and Masson staining. The expressions of TGF-β, Smad2, Smad3, p-Smad2 and p-Smad3 in myocardial tissue were detected by Western blotting. The mRNA expressions of TGF-β, Smad2 and Smad3 were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expressions of matrix metalloprotein 2 (MMP2), MMP9, collagen I and collagen III were observed by immunohistochemical methods. RESULTS: VR mice showed significant dysfunction in hemodynamic indices and cardiac structure and function. Compared with the shamoperation group, myocardial tissue damage, interstitial fibrosis occurred in the model mice, left ventricular systolic pressure (LVSP), left ventricular pressure maximum contraction rate (+dp/dt) and left ventricular pressure maximum relaxation rate (-dp/dt) decreased significantly (all P<0.01), while left ventricular end-diastolic pressure (LVEDP), cardiac weight index and left ventricular weight index elevated significantly, meanwhile TGF-β, p-Smad2, p-Smad3, Smad2, Smad3, MMP2, MMP9, collagen I, collagen III protein expressions in myocardial tissue and TGF-β, Smad2 and Smad3 mRNA expressions increased significantly (all P<0.01). Compared with the model group, LZD could significantly improve the pathological changes of myocardial tissue, increase LVSP, +dp/dtmax and -dp/dtmax, lower LVEDP, reduce the whole heart weight index and left ventricular weight index and inhibit the over-expressions of TGF-β, p-Smad2, p-Smad3, Smad2, Smad3, MMP2, MMP9, collagen I and collagen III proteins in myocardial tissue and mRNA expressions of TGF-β, Smad2 and Smad3 (P<0.05 or P<0.01). CONCLUSION LZD can significantly suppress VR induced by AMI, and its underlying mechanism may be associated with its inhibitory effect on the TGF-β1/Smad signaling pathway.
Animals ; Disease Models, Animal ; Male ; Myocardial Infarction ; complications ; Plant Extracts ; pharmacology ; Rats, Sprague-Dawley ; Smad Proteins ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Ventricular Remodeling ; drug effects

This paper was aimed to observe the interventional effect of Sedum sarmentosum total flavanones on hepatic fibrosis and its possible mechanism through the subcutaneous injection of CCl_4 in rats. Sixty male SD rats were randomly divided into normal control group, model group, low-dose, medium-dose, high-dose S. sarmentosum total flavanones groups(100, 200, 400 mg·kg~(-1)) and silymarin group(200 mg·kg~(-1)). The model of liver fibrosis was established by subcutaneous injection of rats with 40% CCl_4. After the modeling, the drug groups were intragastrically administered with corresponding drugs once a day for consecutively five weeks, while the normal group and the model group were given 0.9% sodium chloride solution during the same period. After the experiment, the general conditions of rats and the pathological changes of liver tissues were observed, and the contents of serum ALT, AST, HA and LN were measured. Besides, the expressions of the protein and relevant mRNA of Smad2/3, Smad4 and α-SMA in rats were detected. Compared with model group, S. sarmentosum total flavanones could significantly increase the rats' body weight, inhibit the increase of liver and spleen index in rats of liver fibrosis, reduce the levels of ALT, AST, HA and LN, and alleviate pathological changes. Meanwhile, compared with the model group, the protein expressions of Smad2/3, Smad4 and α-SMA as well as relevant mRNA expressions in S. sarmentosum total flavanones group were obviously decreased, while Smad7 expression was markedly increased. As a result, S. sarmentosum total flavanones could significantly alleviate CCl_4-induced liver fibrosis, and its anti-hepatic fibrosis mechanism may be related to intervention with Smads pathway, so as to inhibit the activation of HSC.
Animals ; Carbon Tetrachloride ; Drugs, Chinese Herbal/therapeutic use* ; Flavanones/therapeutic use* ; Hepatic Stellate Cells/drug effects* ; Liver ; Liver Cirrhosis/drug therapy* ; Male ; Rats ; Rats, Sprague-Dawley ; Sedum/chemistry* ; Signal Transduction ; Smad Proteins/metabolism*

OBJECTIVE: To evaluate the efficacy of rapmycin for treatment of experimental autoimmune encephalomyelitis (EAE) in mice and explore the underlying mechanism. METHODS: An EAE model was established in C57BL/6 mice. After immunization, the mice were divided into model group and rapamycin groups treated daily with low-dose (0.3 mg/kg) or high-dose (1 mg/kg) rapamycin. The clinical scores of the mice were observed using Knoz score, the infiltration of IL-17 cells in the central nervous system (CNS) was determined using immunohistochemistry; the differentiation of peripheral Treg cells was analyzed using flow cytometry, and the changes in the levels of cytokines were detected with ELISA; the changes in the expressions of p-Smad2 and p- smad3 were investigated using Western blotting. RESULTS: High-dose rapamycin significantly improved the neurological deficits scores of EAE mice. In high-dose rapamycin group, the scores in the onset stage, peak stage and remission stage were 0.14±0.38, 0.43±1.13 and 0.14±0.37, respectively, as compared with 1.14±0.69, 2.14±1.06 and 2.2±0.75 in the model group. The infiltration of inflammatory IL-17 cells was significantly lower in high-dose rapamycin group than in the model group (43±1.83 153.5±7.02). High-dose rapamycin obviously inhibited the production of IL-12, IFN-γ, IL-17 and IL-23 and induced the anti-inflammatory cytokines IL-10 and TGF-β. The percentage of Treg in CD4+ T cells was significantly higher in high- dose rapamycin group than in the model group (10.17 ± 0.68 3.52 ± 0.32). In the experiment, combined treatments of the lymphocytes isolated from the mice with rapamycin and TGF-β induced a significant increase in the number of Treg cells (13.66±1.89) compared with the treatment with rapamycin (6.23±0.80) or TGF-β (4.87±0.85) alone. Rapamycin also obviously up-regulated the expression of p-Smad2 and p-Smad3 in the lymphocytes. CONCLUSIONS Rapamycin can promote the differentiation of Treg cells by up-regulating the expression of p-Smad2 and p-smad3 to improve neurological deficits in mice with EAE.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; therapeutic use ; Cell Differentiation ; drug effects ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; metabolism ; Interferon-gamma ; metabolism ; Interleukins ; metabolism ; Lymphocytes ; cytology ; Mice ; Mice, Inbred C57BL ; Sirolimus ; administration & dosage ; therapeutic use ; Smad Proteins ; metabolism ; T-Lymphocytes, Regulatory ; cytology ; drug effects ; Transforming Growth Factor beta ; metabolism ; Up-Regulation

OBJECTIVE: The purpose of this study is to investigate the potential effects of sclerostin (SOST) on the biological funtions and related mechanisms of cementoblasts under mechanical stress. METHODS: OCCM-30 cells were treated with varying doses of SOST (0, 25, 50, and 100 ng·mL⁻¹) and were loaded with uniaxial compressive stress (2 000 μ strain with a frequency of 0.5 Hz) for six hours. Western blot was utilized to detect the expressions of β-catenin, p-smad1/5/8, and smad1/5/8 proteins. Alkaline phosphatase (ALP) activity was determined, and reverse transcription polymerase chain reaction was used to measure the expressions of runt-related transcription factor 2 (Runx-2), osteocalcin (OCN), bone sialoproteins (BSP), receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) mRNA. RESULTS: The expression of p-smad
1/5/8 was significantly downregulated with increasing SOST. β-catenin and smad1/5/8 exhibited no difference. ALP activity decreased under mechanical compressive stress with increasing SOST concentrations. Runx-2 expression was reduced with increasing SOST concentrations, and a similar trend was observed for the BSP and OCN expressions. When the SOST concentration was enhanced, RANKL expression gradually increased, whereas the expression of OPG decreased. CONCLUSIONS Under mechanical comprehensive stress, SOST can adjust the bone morphogenetic protein (BMP) /smad signal pathway. Osteosclerosis inhibits the mineralization of cementoblasts under mechanical compressive stress, which may be achieved by inhibiting the expressions of osteogenesis factors (Runx2, OCN, BSP, and others) and by promoting the ratio of cementoclast-related factors (RANKL/OPG) through BMP signal pathways.
Bone Morphogenetic Proteins ; metabolism ; Core Binding Factor Alpha 1 Subunit ; Dental Cementum ; Osteocalcin ; Smad Proteins ; metabolism ; Stress, Mechanical