Rhubarb Protect Against Tubulointerstitial Fibrosis by Inhibiting TGF-β/Smad Pathway and Improving Abnormal Metabolome in Chronic Kidney Disease

Effect of Kangxianling Decoction on Expression of TGF-β1/Smads and Extracellular Matrix Deposition

Kangxianling (KXL) decoction is a traditional Chinese herbal formulation which has been used to treat early and midterm chronic renal failure. Renal fibrosis is a common characteristic of progressive chronic kidney diseases (CKD). The formation of renal fibrosis is caused by kidney trauma, infection, and immune response. The pathophysiological mechanism of renal fibrosis was mainly due to increased collagen synthesis in the kidney, decreased degradation, and a large amount of extracellular matrix (ECM) deposition. The purpose of this study was intended to evaluate the effect of Kangxianling decoction on expression of TGF-β1/Smad signaling pathway in renal fibrosis rats. 50 specific pathogen-free Sprague Dawley (SPF SD) rats were randomly divided into five groups: control group, sham group, 5/6 nephrectomy model group, 5/6 nephrectomy model plus KXL decoction (21g /kg) group, and 5/6 nephrectomy model plus Losartan Potassium (LP) (33.3 g/kg) group. The rats were all sacrificed after two months and the left kidney tissue was sampled. HE staining was used to observe the renal pathological changes and the score of kidney damage was made. Masson staining was used to observe the degree of renal fibrosis. Immunohistochemical staining, western blot, and qRT-PCR were used to detect the expression levels of related molecules in TGF-β1/Smad signaling pathway. The results suggested that KXL could lighten renal histopathology damage, downregulate the expression of TGF-β1 (transforming growth factor-β1), Smad2/3, CTGF (connective tissue growth factor), Collagen I, and Collagen III, and upregulate the expression level of Smad7.

Huangqi-Danshen Decoction Ameliorates Adenine-Induced Chronic Kidney Disease by Modulating Mitochondrial Dynamics

Chronic kidney disease (CKD) is a leading public health problem with high morbidity and mortality. However, the therapies remain limited. Traditional Chinese medicine (TCM) has been used for treating kidney disease for thousands of years and is an effective alternative treatment for CKD patients in China and other Asian countries. In the present study, we aimed to investigate the effect and mechanism of Huangqi-Danshen decoction (HDD), a TCM herbal decoction, on treating CKD. CKD rat model was induced by adding 0.75% adenine to the diet for 4 weeks. HDD extract was administrated orally to CKD rats at the dose of 4.7 g/kg/d for consecutive 4 weeks in adenine-induced CKD rats. Kidney function was evaluated by the levels of serum creatinine (Scr) and blood urea nitrogen (BUN). The pathological changes of kidney tissues were observed by periodic acid-Schiff (PAS) and Masson's trichrome staining. The proteins expression of renal fibrosis and mitochondrial dynamics were determined and quantified by Western blot analysis. CKD rats showed obvious decline in renal function as evidenced by increased levels of Scr and BUN, which were blunted by HDD treatment. HDD could also improve tubular atrophy and interstitial fibrosis of CKD rats. Moreover, HDD downregulated fibronectin, type IV collagen, and α-smooth muscle actin expression in CKD rats. Furthermore, mitochondrial dynamics was disturbed in CKD rats, which manifested as increased mitochondrial fission and decreased mitochondrial fusion. HDD treatment restored mitochondrial dynamics in CKD rats by repressing dynamin-related protein 1 and Mid 49/51 expression, promoting mitofusin 2 expression, and suppressing optic atrophy 1 proteolysis. In conclusion, HDD could significantly retard CKD progression through modulating mitochondrial dynamics.

Polydatin suppresses the development of lung inflammation and fibrosis by inhibiting activation of the NACHT domain-, leucine-rich repeat-, and pyd-containing protein 3 inflammasome and the nuclear factor-κB pathway after Mycoplasma pneumoniae infection

Mycoplasma pneumoniae (MP) can infect both the upper and lower respiratory tracts. Polydatin (PD), a traditional Chinese medicine, is known to have anti-inflammation and antifibrosis properties. However, the protective effects of PD against MP pneumonia (MPP) remain unclear. So, the aim of this study was to describe the therapeutic effects and underlying mechanisms of PD against MPP. BALB/c mice were assigned to three groups: a normal control group, MP infection group, or PD-treated MP infection group. BEAS-2B cells transfected with or without NACHT domain-, leucine-rich repeat-, and pyd-containing protein 3 (NLRP3) were used to confirm the protective mechanisms of PD. Immunohistochemical analysis, Western blot analysis, enzyme-linked immunosorbent assay, and flow cytometry were used in this study. The results showed that PD treatment suppressed MP-induced lung injury in mice by suppressing the expression of inflammatory factors and inhibiting the development of pulmonary fibrosis. Meanwhile, PD treatment inhibited activation of the NLRP3 inflammasome and nuclear factor κB (NF-κB) pathway. Overexpression of NLRP3 reversed the protective effect of PD against MP-induced injury of BEAS-2B cells. Taken together, these results indicate that PD treatment suppressed the inflammatory response and the development of pulmonary fibrosis by inhibiting the NLRP3 inflammasome and NF-κB pathway after MP infection.

Quercetin inhibits transforming growth factor β1-induced epithelial-mesenchymal transition in human retinal pigment epithelial cells via the Smad pathway

Purpose

The purpose of this study was to evaluate the effect and mechanism of quercetin on TGF-β1-induced retinal pigment epithelial (RPE) cell proliferation, migration, and extracellular matrix secretion.

Materials and methods

Cell counting kit-8, transwell, wound-healing assays, and ELISA were used to assess viability, migration, and collagen I secretion, respectively. Western blot analysis and qPCR were employed to detect mRNA and protein expression levels, respectively.

Results

Quercetin suppressed TGF-β1-induced cell proliferation, migration, and collagen I secretion. The results also showed that mRNA and protein expression of epithelial–mesenchymal transition (EMT)-related markers such as alpha-smooth muscle actin and N-cadherin was downregulated by quercetin in TGF-β1-treated RPE cells; conversely, quercetin upregulated the expression of E-cadherin and tight junction protein 1 (ZO-1). In addition, quercetin could inhibit mRNA and protein expression of matrix metalloproteinases. Quercetin may reverse the progression of EMT via the Smad2/3 pathway.

Conclusion

Our results demonstrate the protective effects of quercetin on RPE cell EMT, revealing a potential therapeutic agent for proliferative vitreoretinopathy treatment.

Amelioration of diabetic nephropathy in db/db mice treated with tibetan medicine formula Siwei Jianghuang Decoction Powder extract

Siwei Jianghuang Decoction Powder (SWJH) documented originally in the Four Medical Tantras-Blue Glaze exhibited beneficial effects on diabetic nephropathy (DN) via combined synergistically action of multiple formula components including Curcumae longae Rhizoma, Berberidis dictyophyllae Cortex, Phyllanthi Fructus and Tribuli Fructus. This study investigated the effects of SWJH on DN in db/db mice and possible underlying mechanisms. The ten weeks old db/db mice treated with SWJH by intra-gastric administration once a day for 8 weeks. After 8 weeks, body weight, water and food intake of mice were recorded. The level of fasting blood glucose (FBG) was measured. Serum creatinine (Scr), blood urea nitrogen (BUN), urine microalbumin (UMAlb), serum uric acid (UA) and urinary albumin excretion (UAE) were detected. An enzyme-linked immunosorbent assay was performed to test serum vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1). Real-time PCR and Western blot analysis were used to test mRNA and protein expression of hypoxia inducible factor-1α (HIF-1α), VEGF and TGF-β1 in kidney tissue. SWJH treatment significantly reduced the levels of FBG, Scr, BUN, UMAlb, UA and UAE and retarded renal fibrosis. SWJH treatment further significantly reduced serum TGF-β1 level and downregulated the expression of HIF-1α, VEGF and TGF-β1 at both mRNA and protein levels. Principal component analysis and partial least squares regression and hierarchical cluster analysis demonstrated that SWJH treatment significantly ameliorated renal damage in DN mice. These consequences suggested that SWJH formulations were effective in the treatment of DN through regulating the HIF-1α, VEGF and TGF-β1 overexpression.

Action Mechanisms and Therapeutic Targets of Renal Fibrosis

Renal fibrosis was a chronic and progressive process affecting kidneys in chronic kidney disease (CKD), regardless of cause. Although no effective targeted therapy yet existed to retard renal fibrosis, a number of important recent advances have highlighted the cellular and molecular mechanisms underlying the renal fibrosis. The advances including TGF-β/Smad pathway, oxidative stress and inflammation, hypoxia and gut microbiota-derived from uremic solutes were highlighted that could provide therapeutic targets. New therapeutic targets and strategies that are particularly promising for development of new treatments for patients with CKD were also highlighted.