Protective Effects of Sinomenine Against Ankylosing Spondylitis and the Underlying Molecular Mechanisms

No evidence of a genetic causal relationship between ankylosing spondylitis and iron homeostasis: A two-sample Mendelian randomization study

Background

Ankylosing spondylitis (AS) is an immune-mediated chronic inflammatory disease that leads to bone hyperplasia and spinal ankylosis. Iron homeostasis plays a very important role in the inflammatory response and is closely related to the pathogenesis of AS. This study aimed to use large-scale genome-wide association study (GWAS) summary data to study the genetic causal relationship between AS and iron homeostasis using Mendelian randomization (MR).

Methods

Genome-wide association study summary data of AS and iron homeostasis-related indicators were obtained from the FinnGen consortium and the DeCODE genetics database, respectively. We used four iron homeostasis-related indicators: ferritin, serum iron, total iron binding capacity (TIBC), and transferrin saturation (TSAT) for two-sample MR analyses to test for genetic causal association with AS using the "TwoSampleMR" package of the R software (version 4.1.2). The random-effects inverse variance weighted (IVW) method was the main analysis method used for MR. We examined the MR analysis results for heterogeneity, horizontal pleiotropy, and possible outliers. In addition, we confirmed the robustness of the MR analysis by testing whether the results were affected by a single SNP and whether they followed a normal distribution.

Results

The random-effects IVW results showed that ferritin [p = 0.225, OR 95% confidence interval (CI) = 0.836 (0.627-1.116)], serum iron [p = 0.714, OR 95% CI = 0.948 (0.714-1.260)], TIBC [p = 0.380, OR 95% CI = 0.917 (0.755-1.113)], and TSAT [p = 0.674, OR 95% CI = 0.942 (0.713-1.244)] have no genetic causal relationship with AS. We detected no heterogeneity，horizontal pleiotropy and possible outliers in our MR analysis (p > 0.05). In addition, our MR analysis results were not affected by a single SNP, and were normally distributed.

Conclusion

Our study did not detect a genetic causal relationship between AS and iron homeostasis. Nonetheless, this does not rule out a relationship between the two at other mechanistic levels.

Ferroptosis in inflammatory arthritis: A promising future

Ferroptosis is a kind of regulatory cell death (RCD) caused by iron accumulation and lipid peroxidation, which is characterized by mitochondrial morphological changes and has a complex regulatory network. Ferroptosis has been gradually emphasized in the pathogenesis of inflammatory arthritis. In this review, we summarized the relevant research on ferroptosis in various inflammatory arthritis including rheumatoid arthritis (RA), osteoarthritis, gout arthritis, and ankylosing spondylitis, and focused on the relationship between RA and ferroptosis. In patients with RA and animal models of RA, there was evidence of iron overload and lipid peroxidation, as well as mitochondrial dysfunction that may be associated with ferroptosis. Ferroptosis inducers have shown good application prospects in tumor therapy, and some anti-rheumatic drugs such as methotrexate and sulfasalazine have been shown to have ferroptosis modulating effects. These phenomena suggest that the role of ferroptosis in the pathogenesis of inflammatory arthritis will be worth further study. The development of therapeutic strategies targeting ferroptosis for patients with inflammatory arthritis may be a promising future.

Protective effect of sinomenine against inflammation and oxidative stress in gestational diabetes mellitus in female rats via TLR4/MyD88/NF-κB signaling pathway

Gestational diabetes mellitus (GDM) is a dangerous complication of pregnancy which is induced via dysfunction in glucose metabolism during pregnancy. Sinomenine (SM) has already proved an antidiabetic effect against streptozotocin (STZ)-induced diabetes mellitus (DM) in rats. In this protocol, we examined the protective effect of SM against STZ-induced GDM in rats. Wistar rats were divided into three groups and STZ (40 mg/kg) was used to induce GDM. At the end of the experimental protocol, bodyweight, pub weight, and survival rate were estimated. Blood glucose level (BGL), fasting insulin (FINS), free fatty acid (FFA), Hemoglobin A1C (HbA1c), and C-peptide were measured. Lipid, antioxidant, inflammatory cytokines, and inflammatory mediators were also determined. RT-PCR was used for estimation of the role of TLR4/MyD88/NF-κB signaling pathway. SM treatment significantly (p < .001) reduced BGL, hepatic glycogen, and improved the levels of FINS, C-peptide, FFA, and HbA1c. SM significantly (p < .001) suppressed the levels of total cholesterol (TC), low-density lipoprotein (LDL), triglycerides (TG), coronary artery index (CAI), very low-density lipoprotein (VLDL), atherogenic index (AI), and boosted high-density lipoprotein (HDL) levels. SM significantly (p < .001) decreased the lipid peroxidation (LPO) level and enhanced glutathione peroxidase (GPx), total antioxidant capacity (TAC), glutathione S-transferase (GST), superoxide dismutase (SOD), respectively. It reduced the levels of inflammatory cytokines including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and inflammatory mediators viz., nuclear kappa B factors (NF-κB). SM significantly (p < .001) reduced the mRNA expression of Myd88, NLRP3, TLR4, and NF-κB, which were boosted in the GDM group rats. These findings suggest that SM could be a probable drug to be used for treating GDM via inhibition of the TLR4 signaling pathway. PRACTICAL APPLICATIONS: It is well known that gestational diabetes mellitus (GDM) is a dangerous health problem during the pregnancy. SM reduced the glucose level; boosted the level of fasting insulin (FINS) and bodyweight. SM significantly improved the number of pubs and their survival rates. SM suppressed oxidative stress and inflammation via activation of TLR4/MyD88/NF-κB signaling pathway. According to our research, SM can be used as a preventive drug in the treatment of GDM during pregnancy.

Punicalagin Exerts Protective Effects against Ankylosing Spondylitis by Regulating NF-κB-TH17/JAK2/STAT3 Signaling and Oxidative Stress

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by sacroiliitis and spinal rigidity of the axial joints. The role of oxidative stress and increased proinflammatory cytokines is well documented in AS pathogenesis. Punicalagin (2,3-hexahydroxydiphenoyl-gallagyl-D-glucose), an ellagitannin widely present in pomegranates, is found to exhibit potent anti-inflammatory, antiproliferative, and antioxidative effects. The present study was undertaken to investigate the effects of punicalagin in a rodent model of AS.

Methods

BALB/c mice induced spondylitis were sacrificed 24 h after the last injection of proteoglycan extract. Histological scoring was done to assess the degree of the disease. The expression of JAK2/STAT3 proteins and proteins of the nuclear factor-κB (NF-κB) pathway was determined by immunoblotting. Serum levels of inflammatory mediators—TNF-α, IL-1β, IL-6, IL-17A, and IL-23—were assessed. Levels of lipid peroxidation and reactive oxygen species (ROS) were quantified. Antioxidant status as a measure of activities of antioxidant enzymes—catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD)—was determined.

Results

Punicalagin effectively improved antioxidant status and decreased lipid peroxidation, ROS production, and serum levels of inflammatory mediators. NF-κB pathway and JAK2/STAT3 signaling were significantly (p < 0.05) downregulated. Punicalagin effectively regulated the production of cytokines by the Th17 cells and the IL-17A/IL-23 axis.

Conclusion

The observations suggest that punicalagin exerts a protective role in AS via reducing oxidative stress and regulating NF-κB/TH17/JAK2/STAT3 signal. Punicalagin thus could be explored further as a potent candidate compound in the treatment of AS.

Sinomenine Alleviates Murine Experimental Autoimmune Encephalomyelitis Model of Multiple Sclerosis through Inhibiting NLRP3 Inflammasome

Multiple sclerosis (MS) is known as a chronic neuroinflammatory disorder typified by an immune-mediated demyelination process with ensuing axonal damage and loss. Sinomenine is a natural alkaloid with different therapeutic benefits, including anti-inflammatory and immunosuppressive activities. In this study, possible beneficial effects of sinomenine in an MOG-induced model of MS were determined. Sinomenine was given to MOG_35-55-immunized C57BL/6 mice at doses of 25 or 100 mg/kg/day after onset of MS clinical signs till day 30 post-immunization. Analyzed data showed that sinomenine reduces severity of the clinical signs and to some extent decreases tissue level of pro-inflammatory cytokines IL-1β, IL-6, IL-18, TNFα, IL-17A, and increases level of anti-inflammatory IL-10. In addition, sinomenine successfully attenuated tissue levels of inflammasome NLRP3, ASC, and caspase 1 besides its reduction of intensity of neuroinflammation, demyelination, and axonal damage and loss in lumbar spinal cord specimens. Furthermore, immunoreactivity for MBP decreased and increased for GFAP and Iba1 after MOG-immunization, which was in part reversed upon sinomenine administration. Overall, sinomenine decreases EAE severity, which is attributed to its alleviation of microglial and astrocytic mobilization, demyelination, and axonal damage along with its suppression of neuroinflammation, and its beneficial effect is also associated with its inhibitory effects on inflammasome and pyroptotic pathways; this may be of potential benefit for the primary progressive phenotype of MS.

Efficacy and Safety of Sinomenine Preparation for Ankylosing Spondylitis: A Systematic Review and Meta-Analysis of Clinical Randomized Controlled Trials

OBJECTIVES

To systematically evaluate the efficacy and safety of sinomenine preparation (SP) for treating ankylosing spondylitis (AS).

METHODS

Clinical randomized controlled trials (RCTs) of SP for treating AS were systematically identified in six electronic databases including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), and Wanfang Databases from the inception up to 31 October 2019. Cochrane's risk of bias tool was used to assess the methodological quality and Review Manager 5.3 software was used to analyze data.

RESULTS

A total of 12 RCTs involving 835 patients were finally included. According to interventions, RCTs were divided into two types. The intervention in 10 RCTs was SP combined with conventional pharmacotherapy (CPT) versus CPT and that in 2 RCTs was SP alone versus CPT. The results of the meta-analysis showed that, compared with CPT alone, SP combined with oral CPT has better improvement in BASDAI (WMD = -1.84, 95% CI [-3.31, -0.37], P=0.01), morning stiffness time (WMD = -13.46, 95% CI [-16.12, -10.79], P < 0.00001), the Schober test (WMD = 1.26, 95% CI [0.72, 1.80], P < 0.00001), the occipital wall test (WMD = -0.55, 95% CI [-0.96, -0.14], P=0.009), the finger-to-ground distance (WMD = -3.28, 95% CI [-5.64, -0.93], P=0.006), 15 m walking time (WMD = -8.81, 95% CI [-13.42, -4.20], P=0.0002), the C-reactive protein (CRP) (WMD = -1.84, 95% CI [-3.24, -0.45], P=0.01), and the total effective rate (RR = 1.10, 95% CI [1.01, 1.20], P=0.03). Besides, it also showed that oral SP alone may be more effective in improving morning stiffness time (WMD = -31.89, 95% CI [-34.91, -28.87], P < 0.00001) compared with CPT alone. However, this study cannot provide evidence that loading the injectable SP based on CPT can significantly increase the efficacy due to the insufficient number of studies included. In terms of adverse events, there was no statistically significant difference between the experimental group and the control group.

CONCLUSIONS

This study shows that oral SP may be effective and safe in the treatment of AS. Due to the low methodological quality of the included RCTs and the limitations of the meta-analysis, it is still necessary to carry out more multicenter, large-sample, and high-quality RCTs to further verify the conclusions. The review protocol was registered on PROSPERO (CRD42018099170), and the review was constructed following the PRISMA guidelines (Annex 1).

Modified Closing-Opening Wedge Osteotomy to Correct Kyphosis in Ankylosing Spondylitis

Background

The aim of this study was to analyze the clinical and radiological outcomes of modified closing-opening wedge osteotomy (mCOWO) for correcting kyphosis in ankylosing spondylitis (AS) patients.

Material/Methods

From April 2012 to April 2017, records of consecutive patients who underwent mCOWO were reviewed. The clinical and radiological outcomes were analyzed preoperatively, postoperatively, and at the most recent follow-up.

Results

Eleven AS patients underwent mCOWO, with a mean follow-up of 19.4 months (range, 12–45 months). The average sagittal vertical axis (SVA) was corrected from 191.9 mm preoperatively to 75.9 mm postoperatively (P<0.05) and 78.9 mm at the most recent follow-up (P<0.05). The average correction angles at the osteotomy site were 44.5° postoperatively and 45.0° at the most recent follow-up (P>0.05). Sagittal translation (ST) occurred in 2 patients, and 5 mm was the maximum. There was no neurologic damage. Solid fusion was observed at the most recent follow-up in all patients.

Conclusions

Modified closing-opening wedge osteotomy (mCOWO) is an effective technique for correcting kyphosis in patients with AS.