Wutou decoction attenuates rheumatoid arthritis by modulating the Ahr/LOC101928120/SHC1 pathway

CONTEXT

Wutou decoction (WTD) is a Chinese herbal formula alleviating rheumatoid arthritis (RA). SHC adaptor protein 1 (SHC1) regulates apoptosis, inflammation, and the production of reactive oxygen species (ROS). The LOC101928120 gene is located near the SHC1 gene. Bioinformatics analysis showed that the long non-coding RNA LOC101928120 binds to histone deacetylase HDAC1 that might regulate SHC1 expression. The LOC101928120 gene might be targeted by the transcriptional factor Aryl hydrocarbon receptor (Ahr).

OBJECTIVE

This study determines the involvement of the Ahr/LOC101928120/SHC1 pathway in WTD alleviation of RA.

MATERIALS AND METHODS

Wistar rats were injected with complete Freund's adjuvant in the hind footpad to construe the RA model. WTD (9.8 g/kg/day) was administered intragastrically for 15 days. The CHON-001 chondrocyte cells were treated with IL-1β (10 ng/mL) alone or in combination with WTD (1 μg/mL). A RNA pull-down assay was performed to determine the interaction between LOC101928120 and HDAC1. Ahr targeting the LOC101928120 gene was detected using luciferase reporter and chromatin immunoprecipitation assays.

RESULTS

WTD alleviated the swelling of the hind paw in rats with RA and suppressed the chondrocyte apoptosis and ROS production caused by IL-1β. WTD decreased SHC1 but increased LOC101928120 in IL-1β-treated chondrocytes. SHC1 knockdown and LOC101928120 overexpression also showed the protection. However, LOC101928120 knockdown attenuated the protective effects of WTD. WTD stimulated Ahr, which promoted LOC101928120 transcription. LOC101928120 recruited HDAC1 to the promoter region of the SHC1 gene, thereby decreasing SHC1.

DISCUSSION AND CONCLUSION

This study revealed a new mechanism by which WTD alleviates RA by modulating the Ahr/LOC101928120/SHC1 pathway.

Curcumin reverses diabetic nephropathy in streptozotocin-induced diabetes in rats by inhibition of PKCβ/p66Shc axis and activation of FOXO-3a

This study investigated if the nephroprotective effect of Curcumin in streptozotocin-induced type 1 diabetes mellitus (DM) in rats involves downregulation/inhibition of p66Shc and examined the underlying mechanisms. Rats were divided into 4 groups (n = 12/group) as control, control + Curcumin (100 mg/kg), T1DM, and T1DM + Curcumin. Curcumin was administered orally to control or diabetic rats for 12 weeks daily. As compared to diabetic rats, Curcumin didn't affect either plasma glucose or insulin levels but significantly reduced serum levels of urea, blood urea nitrogen, and creatinine, and concurrently reduced albumin/protein urea and increased creatinine clearance. It also prevented the damage in renal tubules and mitochondria, mesangial cell expansion, the thickness of the basement membrane. Mechanistically, Curcumin reduced mRNA and protein levels of collagen I/III and transforming growth factor- β-1 (TGF-β1), reduced inflammatory cytokines levels, improved markers of mitochondrial function, and suppressed the release of cytochrome-c and the activation of caspase-3. In the kidneys of both control and diabetic rats, Curcumin reduced the levels of reactive oxygen species (ROS), increased mRNA levels of manganese superoxide dismutase (MnSOD) and gamma-glutamyl ligase, increased glutathione (GSH) and protein levels of Bcl-2 and MnSOD, and increased the nuclear levels of nuclear factor2 (Nrf2) and FOXO-3a. Besides, Curcumin reduced the nuclear activity of the nuclear factor-kappa B (NF-κB), downregulated protein kinase CβII (PKCβII), NADPH oxidase, and p66Shc, and decreased the activation of p66Shc. In conclusion, Curcumin prevents kidney damage in diabetic rats by activating Nrf2, inhibiting Nf-κB, suppressing NADPH oxidase, and downregulating/inhibiting PKCβII/p66Shc axis.