Sulforaphane delays diabetes-induced retinal photoreceptor cell degeneration

Diabetic retinopathy (DR) is a serious neurodegenerative disease that is induced by hyperglycaemia. Oxidative stress, inflammation and endoplasmic reticulum (ER) stress are involved in the development of DR. Sulforaphane (SF) is widely found in cruciferous plants and has a protective effect against retinal neurodegeneration in diabetes, but the mechanism is unclear. In this study, we investigated the mechanism by which SF protects against photoreceptor degeneration in diabetes. In vivo, a mouse model of diabetes was established by streptozotocin (STZ) injection, and the mice were treated with/without SF. Electroretinography (ERG) and H&E staining were used to evaluate retinal function and morphology. In vitro, 661w cells were treated with AGEs with/without SF. Cell viability and apoptosis were analysed by CCK-8 assay and flow cytometry. The expression of proteins and genes was assessed by western blot and qRT-PCR. The amplitude of the a-wave was decreased and the morphology was changed in the diabetic mice, and these changes were delayed by SF treatment. The percentage of apoptotic cells was increased and the cell viability was decreased after the treatment of 661w cells with AGEs. Moreover, the expression of GRP78, Txnip and TNFα was increased, however, this increased expression was reversed by SF treatment via AMPK pathway activation. Taken together, these data show that SF can delay photoreceptor degeneration in diabetes, and the underlying mechanism is related to the inhibition of ER stress, inflammation and Txnip expression through the activation of the AMPK pathway.

Fuzheng Huayu Capsule Attenuates Hepatic Fibrosis by Inhibiting Activation of Hepatic Stellate Cells

Aim

To investigate the mechanisms of Fuzheng Huayu (FZHY) Capsule in the treatment of hepatitis B (HBV)- associated fibrosis, HBV patients were divided into two groups, 50 cases were in the nucleotide analogues (NAs) group, while additional 50 cases were in the NAs + FZHY group.

Methods

We assessed the curative effects of antifibrosis through liver function, FibroScan test, and liver biopsy and detected the ratio of lymphocyte subsets by flow cytometry. Peripheral blood lymphocyte and CD8⁺T, CD4⁺T, and natural killer cell subsets collected from patients were cocultured with LX-2 cells. Activation of LX-2 cells, production of the extracellular matrix, apoptosis, and proliferation of LX-2 cells were determined. Chronic liver injury models were established by ConA treatment.

Results

It is evident that FZHY treatment significantly increased the percentage of NK cells, the rate of death, and apoptosis of LX-2 cells and decreased the FibroScan liver stiffness measurement value. The expressions of α-SMA and procollagen type I mRNA in LX-2 cells of the FZHY treatment group as downregulated when they were cocultured with lymphocytes compared to those from the NAs group. The proliferation of LX-2 cells in the FZHY treatment group was inhibited compared to that in the NAs group. In a mouse model of hepatic fibrosis, PBLs and IHLs from ConA exposure plus FZHY treatment inhibited the ability of JS-1 cells to express α-SMA.

Conclusions

FZHY Capsule improved the disordered cellular immunity and postponed liver fibrosis possibly through inhibiting the interaction between lymphocyte and hepatic stellate cells.

Studies on the Antidiabetic and Antinephritic Activities of Paecilomyces hepiali Water Extract in Diet-Streptozotocin-Induced Diabetic Sprague Dawley Rats

Paecilomyces hepiali is a fungus widely used in Asian countries for various potential pharmacological activities. The present study aims to evaluate the antidiabetic and antinephritic effects of the Paecilomyces hepiali mycelium water extract (PHC) in diabetic rat, which is established by eight-week high-fat diet administration followed by one-week tail intravenous injection of 25 mg/kg streptozotocin (STZ). After four-week 0.12 g/kg metformin and PHC at doses of 0.08, 0.4, and 2.0 g/kg treatment, an increment of body weight, a decrement of plasma glucose, low levels of total cholesterol, and low density lipoprotein cholesterol in diabetic rats were observed. PHC promotes glucose metabolism by enhancing insulin, pyruvate kinase activity, and increasing the synthesis of glycogen. PHC normalized the disturbed levels of superoxide dismutase, methane dicarboxylic aldehyde, and glutathione peroxidase in kidney. The inhibitory effects on the levels of interleukin-2, interleukin-6, interleukin-10, and tumor necrosis factor-α in serum and kidney revealed the protection of PHC against diabetic nephropathy. Compared with nontreated diabetic rats, four-week PHC treatment resulted in a decrement on nuclear factor kappa B expression in kidney. These results show that Paecilomyces hepiali possesses antidiabetic and antinephritic effects which are related to the modulation of nuclear factor kappa B activity.

The proteasome inhibitor, MG132, attenuates diabetic nephropathy by inhibiting SnoN degradation in vivo and in vitro

Transforming growth factor-β (TGF-β) has been shown to be involved in diabetic nephropathy (DN). The SnoN protein can regulate TGF-β signaling through interaction with Smad proteins. Recent studies have shown that SnoN is mainly degraded by the ubiquitin-proteasome pathway. However, the role of SnoN in the regulation of TGF-β/Smad signaling in DN is still unclear. In this study, diabetic rats were randomly divided into a diabetic control group (DC group) and a proteasome inhibitor (MG132) diabetes therapy group (DT group). Kidney damage parameters and the expression of SnoN, Smurf2, and TGF-β were observed. Simultaneously, we cultured rat glomerular mesangial cells (GMCs) stimulated with high glucose, and SnoN and Arkadia expression were measured. Results demonstrated that 24-hour urine protein, ACR, BUN, and the expression of Smurf2 and TGF-β were significantly increased (P < 0.05), whereas SnoN was significantly decreased in the DC group (P < 0.05). However, these changes diminished after treatment with MG132. SnoN expression in GMCs decreased significantly (P < 0.05), but Arkadia expression gradually increased due to high glucose stimulation (P < 0.05), which could be almost completely reversed by MG132 (P < 0.05). The present results support the hypothesis that MG132 may alleviate kidney damage by inhibiting SnoN degradation and TGF-β activation, suggesting that the ubiquitin-proteasome pathway may become a new therapeutic target for DN.