Farrerol alleviates high glucose-induced renal mesangial cell injury through the ROS/Nox4/ERK1/2 pathway

Sambucus williamsii Hance maintains bone homeostasis in hyperglycemia-induced osteopenia by reversing oxidative stress via cGMP/PKG signal transduction

BACKGROUND

Sambucus williamsii Hance (SWH) has effectively been adopted to treat joint and bone disorders. Diabetes-induced osteopenia (DOP) is caused primarily by impaired bone formation as a result of hyperglycemia. We had previously demonstrated that SWH extract accelerated fracture healing and promoted osteoblastic MC3T3-E1 cell proliferation and osteogenic differentiation. This study assessed the impacts of SWH extract on diabetes-induced bone loss and explored the mechanisms underlying its osteoprotective effects.

METHODS

This work employed MC3T3-E1 cell line for evaluating how SWH extract affected osteogenesis, oxidative stress (OS), and the underlying mechanism in vitro. Streptozotocin-induced osteopenia mouse model was applied with the purpose of assessing SWH extract's osteoprotection on bone homeostasis in vivo.

RESULTS

The increased OS of MC3T3-E1 cells exposed to high glucose (HG) was largely because of the upregulation of pro-oxidant genes and the downregulation of antioxidant genes, whereas SWH extract reduced the OS by modulating NADPH oxidase-4 and thioredoxin-related genes by activating cyclic guanosine monophosphate (cGMP) production and increasing the level of cGMP-mediated protein kinase G type-2 (PKG2). The oral administration of SWH extract maintained bone homeostasis in type 1 diabetes mellitus (T1DM) mice by enhancing osteogenesis while decreasing OS. In bones from hyperglycemia-induced osteopenia mice and HG-treated MC3T3-E1 cells, the SWH extract achieved the osteoprotective effects through activating the cGMP/PKG2 signaling pathway, upregulating the level of antioxidant genes, as well as downregulating the level of pro-oxidant genes.

CONCLUSION

SWH extract exerts osteoprotective effects on hyperglycemia-induced osteopenia by reversing OS via cGMP/PKG signal transduction and is a potential therapy for DOP.

Farrerol prevents Angiotensin II-induced cardiac remodeling in vivo and in vitro

Cardiovascular disease has become the primary disease that threatens human health and is considered the leading cause of death. Cardiac remodeling, which is associated with cardiovascular disease, mainly manifests as cardiac hypertrophy, fibrosis, inflammation, and oxidative stress. Farrerol plays an important role in treating conditions such as inflammation, endothelial injury and tumors, and we speculated that Farrerol may also play an important role in mitigating cardiac hypertrophy and remodeling. We established a model of myocardial remodeling using Angiotensin II (Ang II) with concurrent intraperitoneal injection of Farrerol as an intervention. We used cardiac ultrasound, immunohistochemistry, Immunofluorescence, Wheat Germ Agglutinin, Dihydroethidium, Western Blot, qPCR and other methods to detect the role of Farrerol in cardiac remodeling. The results showed that Farrerol inhibited Ang II-induced cardiac hypertrophy; decreased the ratio of heart weight to tibia length in mice; reduced inflammation, fibrosis, and oxidative stress; and reduced the size of cardiomyocytes in vivo. Farrerol inhibited Ang II-induced cardiomyocyte hypertrophy, levels of oxidative stress, and the proliferation and migration of fibroblast in vitro. Our results revealed that Farrerol could inhibit Ang II-induced cardiac remodeling. Farrerol may therefore be a candidate drug for the treatment of myocardial remodeling.

Antioxidant, Anti-Apoptotic, and Anti-Inflammatory Effects of Farrerol in a Mouse Model of Obstructive Uropathy

Obstructive uropathy is a clinical condition that can lead to chronic kidney disease. However, treatments that can prevent the progression of renal injury and fibrosis are limited. Farrerol (FA) is a natural flavone with potent antioxidant and anti-inflammatory properties. Here, we investigated the effect of FA on renal injury and fibrosis in a mouse model of unilateral ureteral obstruction (UUO). Mice underwent a sham or UUO operation and received intraperitoneal injections of FA (20 mg/kg) daily for 8 consecutive days. Histochemistry, immunohistochemistry and immunofluorescence staining, TdT-mediated dUTP nick end labeling assay, Western blotting, gene expression analysis, and biochemical tests were performed. FA attenuated renal dysfunction (p < 0.05) and ameliorated renal tubular injury (p < 0.01) and interstitial fibrosis (p < 0.001) in UUO mice. FA alleviated 4-hydroxynonenal expression (p < 0.001) and malondialdehyde levels (p < 0.01) by regulating pro-oxidant and antioxidant enzymes. Apoptosis in the kidneys of UUO mice was inhibited by FA (p < 0.001), and this action was accompanied by decreased expression of cleaved caspase-3 (p < 0.01). Moreover, FA alleviated pro-inflammatory cytokine production (p < 0.001) and macrophage infiltration (p < 0.01) in the kidneys of UUO mice. These results suggest that FA ameliorates renal injury and fibrosis in the UUO model by inhibiting oxidative stress, apoptosis, and inflammation.

Ntrk1 promotes mesangial cell proliferation and inflammation in rat glomerulonephritis model by activating the STAT3 and p38/ERK MAPK signaling pathways

BACKGROUND

Mesangial proliferative glomerulonephritis (MsPGN) accounts for a main cause of chronic kidney disease (CKD), chronic renal failure and uremia. This paper aimed to examine the effect of Ntrk1 on MsPGN development, so as to identify a novel therapeutic target for MsPGN.

METHODS

The MsPGN rat model was constructed by single injection of Thy1.1 monoclonal antibody via the tail vein. Additionally, the Ntrk1 knockdown rat model was established by injection of Ntrk1-RNAi lentivirus via the tail vein. Periodic acid-schiff staining and immunohistochemistry (IHC) were performed on kidney tissues. Moreover, the rat urinary protein was detected. Mesangial cells were transfected and treated with p38 inhibitor (SB202190) and ERK inhibitor (PD98059). Meanwhile, the viability and proliferation of mesangial cells were analyzed by cell counting kit-8 (CCK-8) and 5-Ethynyl-2'-deoxyuridine assays. Gene expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western-blot (WB) assays.

RESULTS

The proliferation of mesangial cells was enhanced in glomerulus and Ki67 expression was up-regulated in renal tubule of MsPGN rats. The urine protein level increased in MsPGN rats. Pro-inflammatory factors and Ntrk1 expression were up-regulated in glomerulus of MsPGN rats. Ntrk1 up-regulation promoted the viability, proliferation, expression of pro-inflammatory factors and activation of the STAT3, p38 and ERK signaling pathways in mesangial cells. Ntrk1 knockdown reduced mesangial cell proliferation, urine protein, pro-inflammatory factors, activation of STAT3, p38 and ERK signaling pathways in glomerulus, and decreased Ki67 expression in renal tubule of MsPGN rats. Treatment with SB202190 and PD98059 reversed the effect of Ntrk1 on promoting the viability, proliferation and inflammatory response of mesangial cells.

CONCLUSION

Ntrk1 promoted mesangial cell proliferation and inflammation in MsPGN rats by activating the STAT3 and p38/ERK MAPK signaling pathways.

Mesangial cell: A hub in lupus nephritis

Lupus nephritis (LN) is a severe renal disease caused by the massive deposition of the immune complexes (ICs) in renal tissue, acting as one of the significant organ manifestations of systemic lupus erythematosus (SLE) and a substantial cause of death in clinical patients. As mesangium is one of the primary sites for IC deposition, mesangial cells (MCs) constantly undergo severe damage, resulting in excessive proliferation and increased extracellular matrix (ECM) production. In addition to playing a role in organizational structure, MCs are closely related to in situ immunomodulation by phagocytosis, antigen-presenting function, and inflammatory effects, aberrantly participating in the tissue-resident immune responses and leading to immune-mediated renal lesions. Notably, such renal-resident immune responses drive a second wave of MC damage, accelerating the development of LN. This review summarized the damage mechanisms and the in situ immune regulation of MCs in LN, facilitating the current drug research for exploring clinical treatment strategies.

Dual specificity phosphatase 22 suppresses mesangial cell hyperproliferation, fibrosis, inflammation and the MAPK signaling pathway in diabetic nephropathy

Dual specificity phosphatase 22 (DUSP22) regulates fibrosis and inflammation, which may be implicated in the development of diabetic nephropathy (DN). Hence, the current study aimed to assess the effect of DUSP22 on cell proliferation, apoptosis, fibrosis and inflammation in mouse mesangial cell line (SV40-MES13) under both high glucose (HG) and low glucose (LG) conditions. SV40-MES13 cells were treated with HG and LG, then HG-group cells were transfected with DUSP22 overexpression and control plasmids, meanwhile LG-group cells were transfected with DUSP22 and control siRNAs. Then, cell proliferation using Cell Counting Kit-8, cell apoptosis by TUNEL assay, protein expression using western blotting, inflammatory cytokines using ELISA and RNA using reverse transcription-quantitative PCR were determined. DUSP22 mRNA and protein were decreased in SV40-MES13 cells under the HG condition compared with those under the LG condition. Under the HG condition, DUSP22 overexpression suppressed SV40-MES13 cell proliferation at 48 and 72 h as well as Bcl2, but it facilitated TUNEL-reflected apoptotic rate and cleaved-caspase-3; besides, DUSP22 overexpression restrained proteins of fibronectin 1, collagen I, transforming growth factor beta 1, and their corresponding mRNAs. As to the inflammation, DUSP22 overexpression downregulated TNF-α, IL-1β, IL-6 and IL-12 under the HG condition. By contrast, DUSP22 siRNA promoted SV40-MES13 cell proliferation, fibrosis and inflammation, but attenuated apoptosis in SV40-MES13 cells under the LG condition. Additionally, DUSP22 overexpression inactivated phosphorylated (p)-ERK, p-JNK, and p-P38 in HG-treated SV40-MES13 cells; differently, DUSP22 small interfering RNA facilitated them under the LG condition. In conclusion, DUSP22 suppresses HG-induced mesangial cell hyperproliferation, fibrosis, inflammation and the MAPK pathway, implying its potency in DN treatment.

Sestrin2 attenuates renal damage by regulating Hippo pathway in diabetic nephropathy

Glomerular mesangial cell proliferation and extracellular matrix accumulation contribute to the progression of diabetic nephropathy (DN). As a conserved stress-inducible protein, sestrin2 (Sesn2) plays critical role in the regulation of oxidative stress, inflammation, autophagy, metabolism, and endoplasmic reticulum stress. In this study, we investigated the role of Sesn2 on renal damage in diabetic kidney using transgenic mice overexpressing Sesn2 and the effect of Sesn2 on mesangial cell proliferation and extracellular matrix accumulation in diabetic conditions and the possible molecular mechanisms involved. Sesn2 overexpression improved renal function and decreased glomerular hypertrophy, albuminuria, mesangial expansion, extracellular matrix accumulation, and TGF-β1 expression, as well as oxidative stress in diabetic mice. In vitro experiments, using human mesangial cells (HMCs), revealed that Sesn2 overexpression inhibited high glucose (HG)-induced proliferation, fibronectin and collagen IV production, and ROS generation. Meanwhile, Sesn2 overexpression restored phosphorylation levels of Lats1 and YAP and inhibited TEAD1 expression. Inhibition of Lats1 accelerated HG-induced proliferation and expression of fibronectin and collagen IV. Verteporfin, an inhibitor of YAP, suppressed HG-induced proliferation and expression of fibronectin and collagen IV. However, Sesn2 overexpression reversed Lats1 deficiency-induced Lats1 and YAP phosphorylation, nuclear expression levels of YAP and TEAD1, and proliferation and fibronectin and collagen IV expressions in HMCs exposed to HG. In addition, antioxidant NAC or tempol treatment promoted phosphorylation of Lats1 and YAP and inhibited TEAD1 expression, proliferation, and fibronectin and collagen IV accumulation in HG-treated HMCs. Taken together, Sesn2 overexpression inhibited mesangial cell proliferation and fibrosis via regulating Hippo pathway in diabetic nephropathy. Induction of Sesn2 may be a potential therapeutic target in diabetic nephropathy.

LncRNA HOTAIR facilitates high glucose-induced mesangial cell proliferation, fibrosis and oxidative stress in diabetic nephropathy via regulating miR-147a/WNT2B axis

BACKGROUND

Long non-coding RNAs (lncRNAs) have been shown to be involved in the regulation of many disease progression. However, the role of lncRNA HOX transcript antisense RNA (HOTAIR) in diabetic nephropathy (DN) remains unclear.

METHODS

High glucose (HG)-induced human mesangial cells (HMC) was used to construct DN cell models in vitro. HMC proliferation was evaluated by CCK8 assay and EDU staining. Protein levels of proliferation markers, fibrosis markers, and wingless-type family member 2B (WNT2B) were measured using western blot analysis. HMC oxidative stress was assessed by determining the levels of oxygen species and malondialdehyde, as well as superoxide dismutase activity. Relative expression levels of lncRNA HOTAIR, microRNA (miR)-147a, and WNT2B were examined using quantitative real-time PCR. The interaction between miR-147a and lncRNA HOTAIR or WNT2B was confirmed by dual-luciferase reporter assay and RIP assay.

RESULTS

Our data showed that lncRNA HOTAIR knockdown could inhibit the proliferation, fibrosis, and oxidative stress in HG-induced HMC. LncRNA HOTAIR could serve as a sponge of miR-147a. The inhibition effect of lncRNA HOTAIR silencing on the biological functions of HG-induced HMC could be reversed by miR-147a inhibitor. WNT2B was targeted by miR-147a, and its overexpression also overturned the suppressive effect of miR-147a on the proliferation, fibrosis, and oxidative stress of HG-induced HMC.

CONCLUSION

In total, our research pointed out that lncRNA HOTAIR could mediate miR-147a/WNT2B axis to promote DN progression.

The DR1‑CSE/H2S system inhibits renal fibrosis by downregulating the ERK1/2 signaling pathway in diabetic mice

Glomerular mesangial cell (MC) proliferation and extracellular matrix deposition are the main pathological changes in diabetic nephropathy. Hydrogen sulfide (H2S) inhibits the proliferation of MCs. Dopamine 1 receptors (DR1) are expressed in MCs and serve important physiological roles. However, it is unclear whether DR1 activation inhibits MC proliferation by increasing endogenous H2S. The present study found that the production of H2S and the expression of DR1 and cystathionine‑γ‑lyase (CSE) were decreased in the renal tissues of diabetic mice and high glucose (HG)‑induced MCs. SKF38393 (a DR1 agonist) increased the production of H2S and the expression of DR1 and CSE and NaHS (an exogenous H2S donor) only increased H2S production and CSE expression but not DR1 expression. HG increased the thickness of the glomerular basement membrane, cell viability and proliferation, the expression of cyclin D1, PCNA, collagen 1 and α‑smooth muscle actin and the activity of phosphorylated ERK1/2 and decreased the expression of P21 and MMP9. SKF38393 and NaHS reversed the effects of HG. PPG (a CSE inhibitor) abolished the beneficial effects of SKF38393. The beneficial effects of SKF38393 were similar to those of PD98059 (an ERK1/2 inhibitor). Taken together, the findings suggested that the DR1‑CSE/H2S pathway activation attenuated diabetic MC proliferation and extracellular matrix deposition by downregulating the ERK1/2 signaling pathway.

Farrerol suppresses the progression of laryngeal squamous cell carcinoma via the mitochondria-mediated pathway

PURPOSE

In the context of well-known inhibitory effects of Farrerol on the invasion of lung squamous cell carcinoma cells, the unexplored effect and regulatory mechanism of Farrerol on laryngeal squamous cell carcinoma (LSCC) emerged as the target in this study.

METHODS

After treatment with Farrerol alone, or together with MitoTempo, the viability, apoptosis, cell cycle distribution, migration, and invasion of LSCC cells were measured using MTT, flow cytometry, wound-healing, and transwell assays, respectively. Meanwhile, the levels of cytochrome C (Cyt C), Cleaved caspase-3/9, Cyclin D1, E-cadherin, N-cadherin, and Vimentin in LSCC cells were evaluated by Western blot; the reactive oxygen species (ROS) formation intensity and the disruption of mitochondrial membrane potential (MMP) of LSCC cells were assessed using flow cytometry; and the effect of Farrerol on xenograft tumor formation was evaluated in animal experiment.

RESULTS

Farrerol (10, 20, 50 μM) inhibited the viability, proliferation, cell cycle progression, migration and invasion, but promoted apoptosis, ROS formation intensity and disruption of MMP of LSCC cells. Moreover, Farrerol up-regulated Cyt C (in the cytoplasm), Cleaved caspase-3/9 and E-cadherin levels, but down-regulated Cyclin D1, N-cadherin and Vimentin levels in LSCC cells. Additionally, we uncovered that MitoTempo reversed the promoting effects of Farrerol on ROS formation intensity, apoptosis, and Cyt C and Cleaved caspase-3/9 levels in LSCC cells, while improving the disruption of MMP in Farrerol-treated LSCC cells. Also, Farrerol lessened the volume and weight of mice tumors.

CONCLUSIONS

Farrerol suppressed the migration, invasion, and induced the apoptosis of LSCC cells via the mitochondria-mediated pathway.

Gastrodin protects against high glucose-induced cardiomyocyte toxicity via GSK-3β-mediated nuclear translocation of Nrf2

Diabetic cardiomyopathy (DCM) is one of the major complications of diabetes that causes mortality and morbidity in diabetic patients. Gastrodin (GSTD) is a bioactive phenolic glucoside component of an ancient Chinese herb Tianma (Gastrodia elata Bl.), which is widely used for cardiovascular and cerebrovascular diseases by ancient Chinese. Up to now, whether GSTD has a beneficial effect on DCM is unclear. Therefore, this study aimed to investigate the effect of GSTD on high glucose-induced injury in H9c2 rat cardiomyocytes and HL-1 mouse cardiomyocytes, and its underlying mechanisms. High glucose (33 mM) treatment caused cardiomyocyte toxicity, oxidative stress and apoptosis in both H9c2 and HL-1 cells. Under both normal (5.5 mM glucose) and high glucose conditions, GSTD showed protective effect against high glucose-induced cytotoxicity and promoted the nuclear translocation of Nrf2 in a concentration and time-dependent manner in H9c2 and HL-1 cells. Knockdown of Nrf2 expression using siRNA specifically targeting Nrf2 attenuated the protective effect of GSTD. Furthermore, GSTD promoted the nuclear translocation of Nrf2 via activating glycogen synthase kinse-3β (GSK-3β) signaling pathway. 4-benzyl, 2-methyl, 1, 2, 4-thiadiazolidine, 3, 5 dione (TDZD-8), an inhibitor of GSK-3β, inhibited the nuclear translocation of Nrf2 induced by GSTD, and attenuated the protective effect of GSTD as Nrf2 knockdown did. In summary, GSTD could protect against high glucose-induced cardiomyocyte toxicity via GSK-3β-mediated nuclear translocation of Nrf2.