Isorhamnetin Downregulates MMP2 and MMP9 to Inhibit Development of Rheumatoid Arthritis through SRC/ERK/CREB Pathway.

OBJECTIVE: To investigate the effect of isorhamnetin on the pathology of rheumatoid arthritis (RA). METHODS: Tumor necrosis factor (TNF)- α -induced fibroblast-like synoviocytes (FLS) was exposed to additional isorhamnetin (10, 20 and 40 µ mol/L). Overexpression vectors for matrix metalloproteinase-2 (MMP2) or MMP9 or SRC were transfected to explore their roles in isorhamnetin-mediated RA-FLS function. RA-FLS viability, migration, and invasion were evaluated. Moreover, a collagen-induced arthritis (CIA) rat model was established. Rats were randomly divided to sham, CIA, low-, medium-, and high-dosage groups using a random number table (n=5 in each group) and administed with normal saline or additional isorhamnetin [2, 10, and 20 mg/(kg·day)] for 4 weeks, respectively. Arthritis index was calculated and synovial tissue inflammation was determined in CIA rats. The levels of MMP2, MMP9, TNF-α, interleukin-6 (IL-6), and IL-1 ß, as well as the phosphorylation levels of SRC, extracellular regulated kinase (ERK), and cyclic adenosine monophosphate response element-binding (CREB), were detected in RA-FLS and synovial tissue. Molecular docking was also used to analyze the binding of isorhamnetin to SRC. RESULTS: In in vitro studies, isorhamnetin inhibited RA-FLS viability, migration and invasion (P<0.05). Isorhamnetin downregulated the levels of MMP2, MMP9, TNF-α, IL-6, and IL-1 ß in RA-FLS (P<0.05). The overexpression of either MMP2 or MMP9 reversed isorhamnetin-inhibited RA-FLS migration and invasion, as well as the levels of TNF-α, IL-6, and IL-1 ß (P<0.05). Furthermore, isorhamnetin bound to SRC and reduced the phosphorylation of SRC, ERK, and CREB (P<0.05). SRC overexpression reversed the inhibitory effect of isorhamnetin on RA-FLS viability, migration and invasion, as well as the negative regulation of MMP2 and MMP9 (P<0.05). In in vivo studies, isorhamnetin decreased arthritis index scores (P<0.05) and alleviated synovial inflammation. Isorhamnetin reduced the levels of MMP2, MMP9, TNF-α, IL-6, and IL-1 ß, as well as the phosphorylation of SRC, ERK, and CREB in synovial tissue (P<0.05). Notably, the inhibitory effect of isorhamnetin was more pronounced at higher concentrations (P<0.05). CONCLUSION: Isorhamnetin exhibited anti-RA effects through modulating SRC/ERK/CREB and MMP2/MMP9 signaling pathways, suggesting that isorhamnetin may be a potential therapeutic agent for RA.

Psoralen synergizes with exosome-loaded SPC25 to alleviate senescence of nucleus pulposus cells in intervertebral disc degeneration.

OBJECTIVE: To explore the mechanism of psoralen synergized with exosomes (exos)-loaded SPC25 on nucleus pulposus (NP) cell senescence in intervertebral disc degeneration (IVDD). METHODS: IVDD cellular models were established on NP cells by tert-butyl hydroperoxide (TBHP) induction, followed by the treatment of psoralen or/and exos from adipose-derived stem cells (ADSCs) transfected with SPC25 overexpression vector (ADSCs-oe-SPC25-Exos). The viability, cell cycle, apoptosis, and senescence of NP cells were examined, accompanied by the expression measurement of aggrecan, COL2A1, Bcl-2, Bax, CDK2, p16, and p21. RESULTS: After TBHP-induced NP cells were treated with psoralen or ADSCs-oe-SPC25-Exos, cell proliferation and the expression of aggrecan, COL2A1, Bcl-2, and CDK2 were promoted; however, the expression of Bax, p16, p21, and inflammatory factors was decreased, and cell senescence, cycle arrest, and apoptosis were inhibited. Of note, psoralen combined with ADSCs-oe-SPC25-Exos further decelerated NP cell senescence and cycle arrest compared to psoralen or ADSCs-oe-SPC25-Exos alone. CONCLUSION: Combined treatment of psoralen and ADSCs-oe-SPC25-Exos exerted an alleviating effect on NP cell senescence, which may provide an insightful idea for IVDD treatment.

Psoralidin Induced Differentiation from Adipose-derived Stem Cells to Nucleus Pulposus-like Cells by TGF-ß/Smad Signaling.

BACKGROUND: Psoralidin (PL) could affect the differentiation of bone marrow mesenchymal stem cells (BMSCs). The role of PL is still unclear in adipose-derived stem cells (ADSCs). AIMS: This study aimed to investigate the effects of PL on ADSCs differentiation into nucleus pulposus-like cells and the TGF-ß/Smad signaling pathway. METHODS: The proliferation and apoptosis of ADSCs were detected. The nucleus pulposus cell-related markers (CD24, BASP1, KRT19, and Aggrecan) and TGF-ß/Smad signaling pathway indexes were analyzed. RESULTS: The results showed that compared to the control group, the cell activity was increased in the PL group, and the apoptosis rate was decreased. The mRNA and protein levels of nucleus pulposus cells markers (CD24, BASP1, KRT19, Aggrecan, and Collagen Type II) and TGF-ß/Smad signaling pathway-related indexes (TGF-ß, SMAD2, and SMAD3) were increased in PL group. After treatment with PL and TGF-ß silencing, the TGF-ß/Smad signaling pathway-related indicators (TGF-ß, SMAD2, and SMAD3) and nucleus pulposus cells markers (CD24, BASP1, KRT19, Aggrecan, and Collagen Type II) were found to be higher in the sh-TGF-ß +PL group than in the sh-TGF-ß group. CONCLUSION: In conclusion, our study showed that PL might induce the differentiation of ADSCs to nucleus pulposus cells through the TGF-ß/Smad signaling pathway. It might have the potential application value in the treatment of intervertebral disc degeneration.

A Study on the Pharmacological Effects and Mechanism of Rhodojaponin III in Rheumatoid Arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory disease with a high rate of disability accompanied by various complications. The pathogenesis of RA is complex with multiple targets and links. This study aims to investigate pharmacological effects and mechanism of Rhodojaponin III in RA. METHODS: The bovine type II collagen-induced arthritis (CIA) rat model and tumor necrosis factor-alpha (TNF-α) induced human umbilical vein endothelial cells (HUVECs) model were constructed. Different concentrations of Rhodojaponin III were utilized for intervention. The progression of CIA was assessed by the arthritis index (AI). Pathological changes in knee joints and synovium were observed. The expressions of angiogenesis-related cytokines were detected. The proliferation, migration, invasion, and angiogenesis of HUVECs were detected. The levels of pro-inflammatory cytokines were determined. The expressions of nuclear factor kappa B-inducing kinase (NIK) pathway-related proteins were analyzed. The binding of Rhodojaponin III to NIK was simulated by molecular docking. RESULTS: Rhodojaponin III suppressed cartilage damage and bone erosion in the knee joints. Rhodojaponin III inhibited expressions of platelet endothelial cell adhesion molecule-1 (CD31) and vascular endothelial cell growth factor (VEGF) to decrease vascular density. Rhodojaponin III suppressed the proliferation, migration, invasion, and angiogenesis of HUVECs, and decreased the levels of interleukin (IL)-6, IL-1ß, and TNF-α. Molecular docking showed that Rhodojaponin III could spontaneously bind to NIK. Rhodojaponin III decreased the expression of NIK, p52, and C-X-C motif chemokine ligand 12 (CXCL12) and the phosphorylation level of IκB kinase-alpha (IKKα) in the synovium of CIA rats and TNF-α-induced HUVECs. NIK overexpression reversed the inhibitory effect of Rhodojaponin III on activation of the NIK/NF-κB pathway, migration, invasion, and angiogenesis of HUVECs, and the secretion of pro-inflammatory cytokines. CONCLUSIONS: Rhodojaponin III affected the angiogenesis and inflammation of CIA rats and TNF-α-induced HUVECs by regulating the NIK/IKKα/CXCL12 pathway. These findings suggest that Rhodojaponin III has potential as a therapeutic agent for RA. Further studies are needed to explore its precise mechanism of action and evaluate its clinical efficacy.

Achyranthoside D (AD) improve intervertebral disc degeneration through affect the autophagy and the activation of PI3K/Akt/mTOR pathway.

PURPOSE: This study aims to explore the potential mechanism of Achyranthoside D (AD) in improving intervertebral disc (IVD) degeneration (IDD). METHODS: The IDD model of SD rats and nucleus pulposus cells (NPCs) was established by lumbar cone annulus puncture and tert-butyl peroxide, respectively. Cell proliferation was detected by CCK8 assay. Apoptosis was detected by flow cytometry and TUNEL staining. IVD tissue injury was observed by HE staining. Alcian blue staining observed the glycoprotein secretion in IVD. Monodansylcadaverin (MDC) staining was used to detect the formation of autophagosomes. The LC3 expression was tested by immunofluorescence. The type II collagen, aggrecan and MMP3 expression were detected by ELISA. RT-qPCR was used to detect the Casp 3, Bax, Bcl2, Acan, Col2a1 and Mmp3 expression. The LC3, P62, type II collagen, aggrecan, Beclin1, Akt, MMP3, p-mTOR, PI3K, mTOR, p-PI3K and p-Akt expression were analyzed by western blot. RESULTS: The IVD tissue damage and apoptosis occurred in the Model group, and the glycoprotein secretion decreased. Compared with Model group, AD-H group alleviated the injury of IVD tissue, inhibited the apoptosis of cells, and increased the secretion of glycoprotein. 40 µg/mL AD restored the proliferation activity of NPCs. Compared to the Normal group, the NPCs apoptosis increased, the Collagen II, aggrecan and Bcl2 expressions were significantly decreased, the MMP3, Bax and Casp 3 expression were significantly increased, and the LC-3 II/I expression in IVD tissues were increased significantly in Model group, all of which was reversed in AD group. AD promoted the p-Akt, p-PI3K, p-mTOR, LC-3 II/I and Beclin1 expression, inhibited the P62 expression to alleviate the damage of nucleus pulporeus cells and the degeneration of IVD. CONCLUSION: AD improved IDD by affecting the PI3K/Akt/mTOR pathway and autophagy.