Berberine mitigates IL-21/IL-21R mediated autophagic influx in fibroblast-like synoviocytes and regulates Th17/Treg imbalance in rheumatoid arthritis

• Published in: Apoptosis (London) Vol. 24; no. 7-8; pp. 644 - 661
• Main Authors: Dinesh, Palani, Rasool, MahaboobKhan
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2019; Springer; Springer Nature B.V
• Subjects: 1-Phosphatidylinositol 3-kinase; Activation; AKT protein; Animals; Antirheumatic Agents - pharmacology; Apoptosis; Apoptosis Regulatory Proteins - genetics; Apoptosis Regulatory Proteins - metabolism; Aromatic compounds; Arthritis; Arthritis, Rheumatoid - chemically induced; Arthritis, Rheumatoid - immunology; Arthritis, Rheumatoid - pathology; Autophagy; Autophagy - drug effects; Bax protein; Bcl-2 protein; Bcl-x protein; Berberine; Berberine - pharmacology; Biochemistry; Biomedical and Life Sciences; Biomedicine; Cancer Research; CCAAT/enhancer-binding protein; CD25 antigen; CD4 antigen; Cell Biology; Cell Differentiation - drug effects; Cell Movement - drug effects; Cell proliferation; Cell Proliferation - drug effects; Cytochrome; Cytochrome P-450; Cytochrome P450; Cytochromes P450; Disease Models, Animal; Fibroblasts; Forkhead protein; Foxp3 protein; Gene Silencing; Health aspects; Helper cells; Homology; Inflammation; Inhibition; Interleukin 21; Interleukins - metabolism; Interleukins - pharmacology; Lymphocytes; Lymphocytes B; Lymphocytes T; Lymphoma; Oncology; Phagocytosis; Phosphatidylethanolamine; Proteins; Rats; Rats, Wistar; Receptors, Aryl Hydrocarbon - genetics; Receptors, Aryl Hydrocarbon - metabolism; Receptors, Interleukin-21 - metabolism; Rheumatoid arthritis; Rheumatoid factor; Signaling; Spleen - drug effects; Spleen - immunology; Synoviocytes; Synoviocytes - drug effects; Synoviocytes - pathology; T cells; T-Lymphocytes, Regulatory - pathology; Th17 Cells - pathology; Virology; AhR; Foxp3; p62; IL-21/IL-21R; RORγt
• ISSN: 1360-8185; 1573-675X
• DOI: 10.1007/s10495-019-01548-6

In our previous study, we explored the therapeutic effect of berberine (BBR) against IL-21/IL-21R mediated inflammatory proliferation of adjuvant-induced arthritic fibroblast-like synoviocytes (AA-FLS) through the PI3K/Akt pathway. The current study was designed to explore the therapeutic potential of BBR (15–45 µM) against IL-21/IL-21R mediated autophagy in AA-FLS mediated through PI3K/Akt signaling and Th17/Treg imbalance. Upon IL-21 stimulation, AA-FLS expressed elevated levels of autophagy-related 5 (Atg5), Beclin-1 and LC3-phosphatidylethanolamine conjugate 3-II (LC3-II) through the utilization of p62 and inhibition of C/EBP homologous protein (CHOP). BBR (15–45 µM) inhibited autophagy in AA-FLS cells mediated through PI3K/Akt signaling via suppressing autophagic elements, p62 sequestration and induction of CHOP in a dose-dependent manner. Moreover, IL-21 promoted the uncontrolled proliferation of AA-FLS through induction of B cell lymphoma-2 (Bcl-2) and diminished expression of Bcl-2 associated X protein (BAX) via PI3K/Akt signaling. BBR inhibited the proliferation of AA-FLS via promoting apoptosis through increased expression of BAX and diminished Bcl-2 transcription factor levels. Furthermore, T cells stimulated with IL-21 induced CD4 + CD196 + Th17 cells proliferation through RORγt activation mediated in a PI3K/Akt dependent manner. BBR inhibited the proliferation of Th17 cells through downregulation of RORγt in a concentration-dependent manner. BBR also promoted the differentiation of CD4 + CD25 + Treg cells through induction of forkhead box P3 (Foxp3) activation via aryl hydrocarbon receptor (AhR) and upregulation of cytochrome P450 family 1, subfamily A, polypeptide 1 (CYP1A1). Collectively, we conclude that BBR might attenuate AA-FLS proliferation through inhibition of IL-21/IL-21R dependent autophagy and regulates the Th17/Treg imbalance in RA.