Smad7 alleviates glomerular mesangial cell proliferation via the ROS-NF-κB pathway

Astrocyte-derived exosomal lncRNA 4933431K23Rik modulates microglial phenotype and improves post-traumatic recovery via SMAD7 regulation

Astrocyte-microglial interaction plays a crucial role in brain injury-associated neuroinflammation. Our previous data illustrated that astrocytes secrete microRNA, leading to anti-inflammatory effects on microglia. Long non-coding RNAs participate in neuroinflammation regulation after traumatic brain injury. However, the effect of astrocytes on microglial phenotype via long non-coding RNAs and the underlying molecular mechanisms remain elusive. We used long non-coding RNA sequencing on murine astrocytes and found that exosomal long non-coding RNA 4933431K23Rik attenuated traumatic brain injury-induced microglial activation in vitro and in vivo and ameliorated cognitive function deficiency. Furthermore, microRNA and messenger RNA sequencing together with binding prediction illustrated that exosomal long non-coding RNA 4933431K23Rik up-regulates E2F7 and TFAP2C expression by sponging miR-10a-5p. Additionally, E2F7 and TFAP2C, as transcription factors, regulated microglial Smad7 expression. Using Cx3cr1-Smad7 overexpression of adeno-associated virus, microglia specifically overexpressed Smad7 in the attenuation of neuroinflammation, resulting in less cognitive deficiency after traumatic brain injury. Mechanically, overexpressed Smad7 physically binds to IκBα and inhibits its ubiquitination, preventing NF-κB signaling activation. The Smad7 activator asiaticoside alleviates neuroinflammation and protects neuronal function in traumatic brain injury mice. This study revealed that an exosomal long non-coding RNA from astrocytes attenuates microglial activation after traumatic brain injury by up-regulating Smad7, providing a potential therapeutic target.

Shenkang VII Recipe Attenuates Unilateral Ureteral Obstruction-induced Renal Fibrosis via TGF-β/Smad, NF-κB and SHH Signaling Pathway

This study aimed to explore the protective effects of the traditional Chinese Medicine formula Shenkang VII recipe (SK-7) on renal fibrosis and the mechanisms. Renal fibrosis was induced by unilateral ureteral obstruction (UUO) in rats. The rats were then divided into 5 groups: control group (Sham operation), UUO model group, UUO model plus low to high doses of SK-7 (0.5, 1.0, or 2.0 g/kg/day, for 14 days) groups. The animals were sacrificed on the 7th or 14th day. Kidney tissues were collected for histopathological examinations (hematoxylin and eosin and Masson's trichrome staining). Immunohistochemistry was used to detect the expression of collagen type III (Col III), fibronectin (FN), α-smooth muscle actin (α-SMA), TIMP metallopeptidase inhibitor 2 (TIMP2), matrix metallopeptidase 2 (MMP2), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and monocyte chemotactic protein-1 (MCP-1). The TGF-β1/Smad, NF-kB and Sonic hedgehog signaling proteins were detected by Western blotting. Our results showed that SK-7 prevented UUO-induced renal injury and accumulation of collagen fibrils. Renal fibrosis biomarkers Col III, FN, α-SMA and TIMP2 were increased in the rats after UUO and decreased by SK-7, while MMP2 was upregulated after treatment. SK-7 also suppressed the levels of TNF-α, IL-1β and MCP-1 in UUO rats. In addition, SK-7 inhibited activation of the TGF-β/Smad, NF-κB and sonic hedgehog signaling (SHH) pathways. Taken together, these findings suggest that SK-7 may regulate the synthesis and degradation of extracellular matrix, reduce inflammation and suppress the proliferation of fibroblasts, by blocking the TGF-β1/Smad, NF-κB and SHH signaling pathways to exert its anti-renal fibrosis effect in UUO rats.

Inhibition of microRNA-150-5p alleviates cardiac inflammation and fibrosis via targeting Smad7 in high glucose-treated cardiac fibroblasts

Hyperglycemia-induced cardiac fibrosis is a prominent characteristic of diabetic cardiomyopathy. Changes in proinflammatory cytokines have been shown to lead to cardiac fibrosis in patients with diabetes mellitus. This study aimed to investigate the role of miR-150-5p in mediating cardiac inflammation and fibrosis in cardiac fibroblasts (CFs). Herein, we found that high-glucose (HG) treatment significantly induced cardiac inflammation, as manifested by increased proinflammatory cytokine production (IL-1β) and NF-κB activity in CFs. Moreover, HG markedly aggravated cardiac fibrosis and increased levels of fibrotic markers (CTGF, FN, α-SMA) and extracellular matrix proteins (Col-I, Col-III) in CFs. At the same time, HG disturbed the TGF-β1/Smad signaling pathway, as evidenced by increases in TGF-β1 and p-Smad2/3 levels and decreases in Smad7 levels in CFs. Furthermore, we found that miR-150-5p was upregulated by HG, which negatively regulated Smad7 expression at the posttranscription level. Further study demonstrated that cardiac inflammation and fibrosis in CFs were corrected following miR-150-5p knockdown, but exacerbated by miR-150-5p overexpression. These data indicated that miR-150-5p inhibition could ameliorate NF-κB-related inflammation and TGF-β1/Smad-induced cardiac fibrosis through targeting Smad7. Thus, miR-150-5p may be a novel promising target for treating diabetic cardiomyopathy.

Critical roles of PI3K/Akt/NF‑κB survival axis in angiotensin II‑induced podocyte injury

Numerous studies have reported that angiotensin (Ang) II, nephrin, and podocin serve pivotal roles in podocyte injury, and thus can lead to the occurrence of proteinuria and the progression of kidney diseases. This study aimed to investigate the effects of Ang II on the production of nephrin and podocin, and their relationship with podocyte injury. We also aimed to determine whether nephrin, podocin and caspase-9 production depends on the PI3K/Akt/nuclear factor (NF)-κB signaling pathway in cultured mouse podocytes. We treated mouse podocytes with different doses of Ang II (10⁻⁹, 10⁻⁸, 10⁻⁷ and 10⁻⁶ mol/l) for 12, 24, and 48 h to analyse cell viability, and at 10⁻⁶ mol/l Ang II for 12, 24, and 48 h to evaluate cell apoptosis. Cells were treated with 10⁻⁶ mol/l of Ang II and/or LY294002 (inhibitor of Akt) or 740Y-P (activator of PI3K) for 48 h to detect Akt, phosphorylated (phospho)-Akt, p65 NF-κB, and phospho-p65 NF-κB, nephrin, podocin and caspase-9 expression, and podocyte apoptosis. Treatment with Ang II suppressed the viability and promoted the apoptosis of podocytes in a dose- and time-dependent manner. Ang II decreased phospho-Akt, phospho-p65 NF-κB, nephrin, and podocin and increased caspase-9 expression, while podocyte apoptosis was promoted. LY294002 further enhanced Ang II-induced downregulation of Akt and p65 NF-κB activation, as well as upregulation of caspase-9 mRNA and protein, and promoted the apoptosis of podocytes. Of note, 740Y-P restored Ang II-induced downregulation of Akt and p65 NF-κB activation, and upregulation of caspase-9, and decreased podocyte apoptosis. Interestingly, LY294002 and 740Y-P were determined to have no notable effects on the expression of nephrin and podocin. The data suggested that Ang II could regulate the expression of nephrin, podocin and caspase-9. Collectively, our findings suggested that the PI3K/Akt/NF-κB survival axis may serve a pivotal role in podocyte injury.

MicroRNA-181c Suppresses the Biological Progression of Osteosarcoma via Targeting SMAD7 and Regulating Transforming Growth Factor-β (TGF-β) Signaling Pathway

Background

Osteosarcoma is a primary bone aggressive cancer, affecting adolescents worldwide. Increasing evidence suggests that dysfunction of microRNAs (miRNAs) plays a pivotal role in malignancies. The aim of this study was to evaluate the potential functions of miR-181c and verifying its regulatory effects on SMAD7 in osteosarcoma.

Material/Methods

The expressions of miR-181c and SMAD7 in osteosarcoma were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, invasion and migration abilities were assessed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and Transwell assay. Bioinformatics analysis and luciferase reporter assay were used to explore the interaction between miR-181c and SMAD7. Western blot was performed to determine the functions of miR-181c on osteosarcoma cell epithelial-to-mesenchymal transition (EMT) and transforming growth factor-β (TGF-β) signaling pathway.

Results

Decreased expression levels of miR-181c and SMAD7 were identified in osteosarcoma using qRT-PCR. The downregulated miR-181c and SMAD7 expressions indicated poor prognosis of osteosarcoma patients. Moreover, miR-181c overexpression prominently repressed osteosarcoma cell proliferation, invasion, and migration abilities via modulating EMT and TGF-β signaling pathway. SMAD7 functioned as an important target for miR-181c in osteosarcoma cells. Furthermore, upregulation of miR-181c dramatically suppressed osteosarcoma tumorigenesis in vivo.

Conclusions

These findings indicated that miR-181c suppressed osteosarcoma progression, providing new insight into the pathogenesis and representing a potential therapeutic target for osteosarcoma.

Target Identification of Active Constituents of Shen Qi Wan to Treat Kidney Yang Deficiency Using Computational Target Fishing and Network Pharmacology

Background: Kidney yang deficiency syndrome (KYDS) is one of the most common syndromes treated with traditional Chinese medicine (TCM) among elderly patients. Shen Qi Wan (SQW) has been effectively used in treating various diseases associated with KYDS for hundreds of years. However, due to the complex composition of SQW, the mechanism of action remains unknown.

Purpose: To identify the mechanism of the SQW in the treatment of KYDS and determine the molecular targets of SQW.

Methods: The potential targets of active ingredients in SQW were predicted using PharmMapper. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out using the Molecule Annotation System (MAS3.0). The protein–protein interaction (PPI) network of these potential targets and “components-targets-pathways” interaction networks were constructed using Cytoscape. We also established a KYDS rat model induced by adenine to investigate the therapeutic effects of SQW. Body weight, rectal temperature, holding power, water intake, urinary output, blood urea nitrogen (BUN), serum creatinine (Scr), adrenocorticotrophic hormone (ACTH), cortisol (CORT), urine total protein (U-TP), and 17-hydroxy-corticosteroid (17-OHCS) were measured. Additionally, the mRNA expression levels of candidates were detected by qPCR.

Results: KYDS-caused changes in body weight, rectal temperature, holding power, water intake, urinary output, BUN, Scr, ACTH, CORT, U-TP, and 17-OHCS were corrected to the baseline values after SQW treatment. We selected the top 10 targets of each component and obtained 79 potential targets, which were mainly enriched in the proteolysis, protein binding, transferase activity, T cell receptor signaling pathway, and focal adhesion. SRC, MAPK14, HRAS, HSP90AA1, F2, LCK, CDK2, and MMP9 were identified as targets of SQW in the treatment of KYDS. The administration of SQW significantly suppressed the expression of SRC, HSP90AA1, LCK, and CDK2 and markedly increased the expression of MAPK14, MMP9, and F2. However, HRAS levels remained unchanged.

Conclusion: These findings demonstrated that SQW corrected hypothalamic–pituitary–target gland axis disorder in rats caused by KYDS. SRC, MAPK14, HRAS, HSP90AA1, F2, LCK, CDK2, and MMP9 were determined to the therapeutic target for the further investigation of SQW to ameliorate KYDS.

RhACE2 - playing an important role in inhibiting apoptosis induced by Ang II in HUVECs

BACKGROUND

Henoch-Schonlein purpura (HSP) is a common hemorrhagic disease, which manifests the inflammation in the body's most microvasculars. Angiotensin II (Ang II) can induce the damage and apoptosis of vascular endothelial cells while angiotensin converting enzyme 2 (ACE2) can antagonist the action of Ang II. However, the effect of ACE2 on Ang II-induced endothelial damage remains unknown.

OBJECTIVE

To evaluate the effect of recombinant human angiotensin converting enzyme 2 (rhACE2) on the Ang II-induced damage of human umbilical vein endothelial cells (HUVECs) and the release of inflammatory mediator in vitro.

METHODS

Cultured HUVECs were randomly divided into 6 groups: the control group, rhACE2 group, Ang II group, and Ang II+ rhACE2 groups (3 subgroups). The cell vitality, cell cycle, apoptosis rate of the HUVECs and the levels of reactive oxygen species (ROS), interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1) and lactate dehydrogenase (LDH) were measured, respectively.

RESULTS

Compared with the control group, the cell viability and the rate of S phase cells in Ang II group significantly decreased (P < .05) while the apoptosis percentage and the levels of ROS, IL-8, TNF-α, TGF-β1, and LDH in Ang II group significantly increased (P < .05). There were no significant differences between the control group and rhACE2 group. Compared with the Ang II group, the cell viability and the rate of S phase cells in Ang II+rhACE2 groups were higher (P < .05) and the apoptosis percentage, the level of ROS, IL-8, TNF-α, TGF-β1, LDH in Ang II+rhACE2 groups were lower (P < .05).

CONCLUSIONS

Ang II can induce the apoptosis of HUVECs and the release of inflammatory mediator, while rhACE2 can inhibit the detrimental effects of Ang II. The results of this study suggest that rhACE2 has a protective effect on HSP, which is probably a new way for the prevention and treatment of HSP.

Up-regulation of P-gp via NF-κB activation confers protection against oxidative damage in the retinal pigment epithelium cells

Dysfunction of retinal pigment epithelial (RPE) cells has been associated with the pathogenesis of age-related macular degeneration in relation to increased oxidative stress, subsequent mitochondrial dysfunction and cell death. Permeability-glycoprotein (P-gp), encoded by the multidrug resistance 1 gene (MDR1), is an active efflux pump involved in cell homeostasis and nuclear factor κB (NF-κB) shows potential involvement in P-gp regulation due to its binding to the promoter domains of MDR1 gene. This study sought to determine the role of P-gp expression regulated by NF-κB in RPE cells during oxidative stress. The human RPE D407 cells were exposed to increasing concentrations of hydrogen peroxide (H₂O₂) for 24 h. The small-interfering RNA (siRNA) transfection was used to down-regulate P-gp and NF-κB, and the expressions of P-gp and NF-κB p65 were determined by quantitative real-time PCR, western blot and immunofluorescence. The activity of NF-κB was detected by luciferase reporter assay. Mitochondrial membrane potential and cell death rate were detected by flow cytometry. We found that H₂O₂ exposure caused increasing rate of cell death and induced an elevated expression of P-gp as well as NF-κB activation and nucleus translocation in D407 cells. Inhibiting or silencing NF-κB led to a decrease in the oxidative-induced expression of P-gp. Down-regulation of P-gp by siRNA transfection further impaired the mitochondrial membrane potential and cell death rate in oxidative cells. Moreover, inhibition/knockdown of NF-κB decreased the high rate of cell death caused by H₂O₂. In conclusion, P-gp can provide moderate cytoprotection for the human RPE cells by ameliorating the mitochondrial dysfunction and NF-κB activation may be a potential regulator of P-gp expression response to oxidative stress.

Asiatic acid protects against cisplatin-induced acute kidney injury via anti-apoptosis and anti-inflammation

Cisplatin is a well-known chemotherapeutic drug applied for the treatment of numerous human cancers. However, the use of cisplatin in clinic is limited by certain serious side effects, such as nephrotoxicity. Unfortunately, there is currently no effective therapeutic approach to prevent cisplatin-induced AKI. Increasing evidence suggests that apoptosis of tubular epithelial cells and renal inflammation mainly determine the progression and outcome of cisplatin-induced AKI. Asiatic acid (AA) has been reported have the functions of anti-inflammation and anti-apoptosis, etc. But the effects of AA on kidney injury induced by cisplatin are still not known. The current study aimed to determine the potential renoprotective effects of AA on kidney injury induced by cisplatin. Twenty-four C57BL/6 male mice were randomly divided into four groups: normal control (CON), cisplatin-induced AKI (CIS), AKI with 50 mg/kg AA pretreatment (CIS + AA50), and AKI with 100 mg/kg AA pretreatment (CIS + AA100). Mice were anesthetized and sacrificed at 72 h after the cisplatin injection. Blood and kidney samples were collected for analyses. Compared with CON mice, cisplatin-treated mice exhibited severe tubular necrosis and elevated serum creatinine level. However, AA pretreatment (50 mg/kg or 100 mg/kg) markedly suppressed the elevated serum creatinine, blood urea nitrogen and histological changes. Moreover, AA pretreatment notably downregulated tubular expression of kidney injury molecule-1 (KIM-1) and the number of apoptotic cells, and upregulated the expression of the apoptosis inhibitor survivin and promoted tubular proliferation as evidenced by an increase in the number of proliferating cell nuclear antigen-positive cells. In addition, AA suppressed the enhanced mRNA expression of proinflammatory cytokines IL-1β, TNF-α, MCP-1 and caspase-1 in the kidneys. Furthermore, AA pretreatment inhibited NF-κB activation and the inflammatory response, which may result from Smad7 up-regulation. In conclusion, AA protects against cisplatin-induced AKI via anti-apoptosis and anti-inflammation.