Effects of Ghrelin on the Apoptosis of Rheumatoid Arthritis Fibroblast-Like Synoviocyte MH7A Cells

Liraglutide prevents cellular senescence in human retinal endothelial cells (HRECs) mediated by SIRT1: an implication in diabetes retinopathy

Diabetes mellitus (DM) is a chronic metabolic disorder affecting millions of people worldwide, characterized by dysregulated glucose homeostasis and hyperglycemia. Diabetic retinopathy (DR) is one of the serious multisystemic complications. Aging is an important risk factor for DR. Endothelial sirtuin 1 (SIRT1) plays an important role in regulating the pathophysiology of glucose metabolism, cellular senescence, and aging. Liraglutide, an analog of Glucagon-like peptide 1 (GLP-1), has been widely used in the treatment of DM. However, the effects of Liraglutide on DR are less reported. Here, we investigated whether treatment with Liraglutide has beneficial effects on high glucose (HG)-induced injury in human retinal microvascular endothelial cells (HRECs). First, we found that exposure to HG reduced the expression of glucagon-like peptide 1 receptor 1 (GLP-1R). Additionally, Liraglutide ameliorated HG-induced increase in the expression of vascular endothelial growth factor-A (VEGF-A) and interleukin 6 (IL-6). Importantly, Liraglutide ameliorated cellular senescence and increased telomerase activity in HG-challenged HRECs. Liraglutide also reduced the levels of p53 and p21. Mechanistically, Liraglutide restored the expression of SIRT1 against HG. In contrast, the knockdown of SIRT1 abolished the protective effects of Liraglutide in cellular senescence of HRECs. Our findings suggest that Liraglutide might possess a benefit on DR mediated by SIRT1.

Ghrelin in Focus: Dissecting Its Critical Roles in Gastrointestinal Pathologies and Therapies

This review elucidates the critical role of ghrelin, a peptide hormone mainly synthesized in the stomach in various gastrointestinal (GI) diseases. Ghrelin participates in diverse biological functions ranging from appetite regulation to impacting autophagy and apoptosis. In sepsis, it reduces intestinal barrier damage by inhibiting inflammatory responses, enhancing GI blood flow, and modulating cellular processes like autophagy and apoptosis. Notably, in inflammatory bowel disease (IBD), serum ghrelin levels serve as markers for distinguishing between active and remission phases, underscoring its potential in IBD treatment. In gastric cancer, ghrelin acts as an early risk marker, and due to its significant role in increasing the proliferation and migration of gastric cancer cells, the ghrelin-GHS-R axis is poised to become a target for gastric cancer treatment. The role of ghrelin in colorectal cancer (CRC) remains controversial; however, ghrelin analogs have demonstrated substantial benefits in treating cachexia associated with CRC, highlighting the therapeutic potential of ghrelin. Nonetheless, the complex interplay between ghrelin's protective and potential tumorigenic effects necessitates a cautious approach to its therapeutic application. In post-GI surgery scenarios, ghrelin and its analogs could be instrumental in enhancing recovery and reducing complications. This article accentuates ghrelin's multifunctionality, shedding light on its influence on disease mechanisms, including inflammatory responses and cancer progression, and examines its therapeutic potential in GI surgeries and disorders, advocating for continued research in this evolving field.

Emerging Relevance of Ghrelin in Programmed Cell Death and Its Application in Diseases

Ghrelin, comprising 28 amino acids, was initially discovered as a hormone that promotes growth hormones. The original focus was on the effects of ghrelin on controlling hunger and satiation. As the research further develops, the research scope of ghrelin has expanded to a wide range of systems and diseases. Nevertheless, the specific mechanisms remain incompletely understood. In recent years, substantial studies have demonstrated that ghrelin has anti-inflammatory, antioxidant, antiapoptotic, and other effects, which could affect the signaling pathways of various kinds of programmed cell death (PCD) in treating diseases. However, the regulatory mechanisms underlying the function of ghrelin in different kinds of PCD have not been thoroughly illuminated. This review describes the relationship between ghrelin and four kinds of PCD (apoptosis, necroptosis, autophagy, and pyroptosis) and then introduces the clinical applications based on the different features of ghrelin.

Ghrelin is associated with anti-mullerian hormone levels in Chinese systemic lupus erythematosus

PROBLEM

Ghrelin has been thought of as a potential link between energy homeostasis and fertility. The aim of this study was to evaluate levels of ghrelin in obese and non-obese systemic lupus erythematosus (SLE) patients, and to reveal a possible association between ghrelin and Anti-Mullerian hormone (AMH) in SLE patients.

METHOD OF STUDY

One hundred SLE patients (50 obese and 50 non-obese subjects) at childbearing age and 100 age-matched healthy controls (50 obese and 50 non-obese subjects) were included. Ghrelin and leptin were examined by enzyme-linked immunosorbent assay. AMH was tested through electrochemiluminescence. Demographics, clinical and laboratory indicators were obtained from medical records.

RESULTS

Ghrelin levels were significantly lower in obese SLE patients than non-obese SLE patients (P = .000) and obese controls (P = .002). Non-obese SLE patients and non-obese controls had similar ghrelin levels. Ghrelin levels were correlated positively with AMH (r = .2683, P = .0070) in SLE patients. And ghrelin were negatively associated with leptin (r = -.1969, P = .0496) and BMI (r = - .2401, P = .0161).

CONCLUSION

Our results provide evidence for a potential relationship between ghrelin and AMH in SLE patients, indicating that ghrelin may play a part in energy homeostasis and ovarian damage of SLE patients.

[Effects of Sidaxue, a Miao ethnomedicine recipe, on apoptosis and pyrolysis of human fibroblast-like synovial cells in rheumatoid arthritis]

OBJECTIVE

To investigate the effects of Sidaxue (SX), a recipe in Miao ethnomedicine, on apoptosis and pyrolysis of human fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS).

METHODS

The target proteins related with RA and those involved in cell apoptosis and pyroptosis were searched in different online databases, and Venny software was used to obtain apoptosis- and pyroptosis-related proteins in RA. RA-apoptosis-pyroptosis protein interaction (PPI) network was constructed to identity the key target proteins related with apoptosis and pyroptosis in RA. Autodock vina software was used to perform molecular docking to verify the binding ability of the main active ingredients in SX with the apoptosis- and pyroptosis-related proteins. In the cell experiment, MH7A cells were treated with 5 mg/L TGT (positive control) or 5, 10, 20, and 40 mg/L SX, and the changes in cell migration and invasion abilities and expressions of apoptosis- and pyroptosis-related proteins were examined using wound healing assay, Transwell assay, ELISA and Western blotting.

RESULTS

We identified 9 RA-related apoptotic target proteins, 15 RA-related pyroptosis target proteins, and 4 overlapping target proteins related with RA, apoptosis and pyroptosis. The main active ingredients in SX had a high affinity with the target proteins including TNF-α, Fas, and Bax. In MH7A cells, SX treatment concentration-dependently increased the cell inhibition rate at 24, 48 and 72 h (P < 0.05), and significantly lowered the cell migration ability at 6, 12 and 24 h (P < 0.05); treatment with 20 and 40 mg/L SX for 24 h obviously suppressed MH7A cell invasion (P < 0.05). SX treatment (20 and 40 mg/L) and TGT treatment both significantly lowered the expression levels of TNF-α, IL-1β, and IL-18 in the cells (P < 0.05). The Bax/Bcl-2 ratio and Fas and FasL expressions were increased significantly in cells treated with 20 and 40 mg/L SX (P < 0.05), and caspase-1 expression was decreased significantly in cells treated with 5 and 40 mg/L SX (P < 0.05).

CONCLUSION

SX can induce apoptosis and pyroptosison in RA-FLSs possibly by down-regulating the expressions of TNF-α, IL-1β and IL-18, up-regulating the expressions of Bax, Fas, and FasL, and inhibiting Bcl-2 and caspase-1 protein expressions.

Mechanism of miR-218-5p in autophagy, apoptosis and oxidative stress in rheumatoid arthritis synovial fibroblasts is mediated by KLF9 and JAK/STAT3 pathways

This study was aimed to investigate the effects of miR-218-5p on the proliferation, apoptosis, autophagy, and oxidative stress of rheumatoid arthritis synovial fibroblasts (RASFs), and the related mechanisms. Quantitative reverse transcription-PCR showed that the expression of miR-218-5p in rheumatoid arthritis synovial tissue was significantly higher than that in healthy synovial tissue. Compared with healthy synovial fibroblasts, miR-218-5p expression was obviously upregulated in RASFs, while KLF9 protein expression was markedly downregulated. Mechanistically, miR-218-5p could directly bind to the 3' untranslated region of KLF9 to inhibit the expression of KLF9. Additionally, transfection of miR-218-5p small interfering RNA (siRNA) inhibited the proliferation but promoted apoptosis and autophagy of RASFs. Simultaneously, miR-218-5p silencing reduced reactive oxygen species and malondialdehyde levels and increased superoxide dismutase and glutathione peroxidase activity to improve oxidative stress in RASFs. More importantly, the introduction of KLF9 siRNA reversed the effects of miR-218-5p siRNA transfection on RASF proliferation, apoptosis, autophagy, and oxidative stress. What is more, silencing miR-218-5p inhibited the activation of JAK2/STAT3 signaling pathway by targeting KLF9. Collectively, knockdown of miR-218-5p could regulate the proliferation, apoptosis, autophagy and oxidative stress of RASFs by increasing the expression of KLF9 and inhibiting the activation of the JAK2/STAT3 signaling pathway, which may provide a potential target for the mechanism research of RA.

Anti-inflammatory effects of Jingshu Keli capsule and its components on human synoviocyte MH7A cells

BACKGROUND

Jingshu Keli (JSKL), a traditional Chinese medicine (TCM) formula consisting of multiple active compounds, has been officially approved by National Medical Products Administration (NMPA) for treatment of cervical radiculopathy. It relieves pain, according to TCM theory, by activating blood circulation to dissipate blood stasis. The pain mainly stems from neurogenic inflammation caused by mechanical compression of the cervical nerve root. In addition, inflammation mediators also cause the development of other joint diseases, such as osteoarthritis (OA). The purpose of this paper was to evaluate the anti-inflammatory effects of JSKL and identify the biologically active herbs and compounds in vitro.

METHODS

Enzyme-linked immunosorbent assay (Elisa) was used to determine the expression of pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and interleukin 8 (IL-8), in the culture medium of human MH7A cells stimulated by lipopolysaccharides (LPS).

RESULTS

JSKL and three single-herb capsules, Cinnamomum cassia Presl (C.C.), Angelica Sinensis (Oliv.) Diels (A.S.) and Carthamus tinctorius L. (C.T.), significantly inhibited the secretion of TNF-α. If one of these three herbal components was removed, suppressing effect of the single-herb-deleted JSKL on TNF-α was abolished. Cinnamaldehyde (CIN) from C.C. was the most potent ingredient that inhibited the expression of IL-6 and IL-8 in the culture medium of both LPS-stimulated MH7A cells and primary synovial cells.

CONCLUSIONS

JSKL was found to possess anti-inflammatory effect in vitro; C.C., A.S. and C.T. were the principal and essential herbal components responsible for such activity; CIN from C.C. is one the most potent single compound among indicator components of JSKL recorded in 2015 Chinese pharmacopoeia. This study provided scientific evidence for the clinical application of JSKL as an agent for targeted treatment of cervical radiculopathy. Furthermore, CIN has potential to be used for the treatment of some inflammation-related orthopedic diseases, such as rheumatic arthritis and osteoarthritis.

Effect of electroacupuncture at the ST36 and GB39 acupoints on apoptosis by regulating the p53 signaling pathway in adjuvant arthritis rats

p53 and mouse double minute 2 homolog (MDM2) serve key regulatory roles in the apoptosis of synovial cells. The present study aimed to investigate the effects of electroacupuncture (EA) at the 'Zusanli' (ST36) and 'Xuanzhong' (GB39) acupoints on apoptosis in an adjuvant arthritis (AA) rat model. A total of 40 male Sprague‑Dawley rats were randomly divided into Control, AA, AA + EA and AA + sham EA groups (n=10 rats in each group). Rats in all the groups, with the exception of the control group, were injected with Complete™ Freund's adjuvant into the bilateral hindlimb footpad to establish the AA model. Rats in the AA + EA group were treated with EA at the ST36 and GB39 acupoints. Rats in the AA + sham EA group were treated with percutaneous electrical stimulation at a position of 5 mm away from the ST36 and GB39 acupoints. The arthritis index scores and hindlimb paw volumes of the rats in each group were recorded. Subsequently, pathological changes in the synovial tissue were evaluated by hematoxylin and eosin (H&E) staining, and the apoptotic rate of the synovial cells was detected by TUNEL staining. In addition, the expression levels of the apoptosis‑associated proteins, Bax, phorbol‑12‑myristate‑13‑acetate‑induced protein 1 (Noxa) and p53 upregulated modulator of apoptosis (PUMA), were determined by western blot analysis. The expression of both the gene and protein of p53 and MDM2 in synovial tissue was detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis, respectively. The results indicated that the arthritis index scores and hindlimb paw volumes upon EA stimulation were significantly decreased compared with those of the AA group (P<0.05). H&E staining revealed that the synovial inflammation of EA stimulation was significantly decreased compared with the AA group (P<0.05). The TUNEL assay results indicated that the apoptotic rate of synovial cells in the AA + EA group was significantly increased compared with that in the AA group (P<0.05). Furthermore, an increased expression of proapoptotic proteins was confirmed by the increased expression levels of Bax, Noxa and PUMA in the AA + EA group. The results of RT‑qPCR and western blot analysis demonstrated that, compared with the AA group, EA stimulation led to a marked increase in p53 (P<0.05) and a significant decrease in MDM2 (P<0.05) gene and protein expression. Taken together, these results demonstrated that EA performed on the ST36 and GB39 acupoints led to a significant amelioration in AA injury of model rats, by regulating the p53 signaling pathway and inducing apoptosis.

Ghrelin protects against contact dermatitis and psoriasiform skin inflammation by antagonizing TNF-α/NF-κB signaling pathways

Contact dermatitis and psoriasis are skin disorders caused by immune dysregulation, yet much remains unknown about their underlying mechanisms. Ghrelin, a recently discovered novel peptide and potential endogenous anti-inflammatory factor expressed in the epidermis, is involved in skin repair and disease. In this study, we investigated the expression pattern and therapeutic effect of ghrelin in both contact dermatitis and psoriasis mouse models induced by oxazolone (OXA) and imiquimod (IMQ), respectively, and in TNF-α-stimulated RAW264.7 macrophages, NHEKs and skin fibroblasts. Ghrelin expression was reduced in both the OXA-induced contact dermatitis and IMQ-induced psoriasis mouse models. Furthermore, treatment with ghrelin attenuated skin inflammation in both the contact dermatitis and psoriasis mouse models. Mice administered PBS after OXA- or IMQ-induced model generation exhibited typical skin inflammation, whereas ghrelin treatment in these mouse models substantially decreased the dermatitis phenotype. In addition, exogenous ghrelin attenuated the inflammatory reaction induced by TNF-α in RAW264.7 cells. Moreover, ghrelin administration limited activation of NF-κB signaling. In summary, ghrelin may represent a potential molecular target for the prevention and treatment of inflammatory skin diseases, including contact dermatitis and psoriasis.