Epigenetic Modifications in Generalized Autoimmune Epithelitis: Sjögren's Syndrome and Primary Biliary Cholangitis

Primary Sjögren's syndrome: new perspectives on salivary gland epithelial cells

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease primarily affecting exocrine glands such as the salivary glands, leading to impaired secretion and sicca symptoms. As the mainstay of salivation, salivary gland epithelial cells (SGECs) have an important role in the pathology of pSS. Emerging evidence suggests that the interplay between immunological factors and SGECs may not be the initial trigger or the sole mechanism responsible for xerostomia in pSS, challenging conventional perceptions. To deepen our understanding, current research regarding SGECs in pSS was reviewed. Among the extensive aberrations in cellular architecture and function, this review highlighted certain alterations of SGECs that were identified to occur independently of or in absence of lymphocytic infiltration. In particular, some of these alterations may serve as upstream factors of immuno-inflammatory responses. These findings underscore the significance of introspecting the pathogenesis of pSS and developing interventions targeting SGECs in the early stages of the disease.

Reasons why women are more likely to develop primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune disease of biliary stasis in which immune factors cause the gradual destruction of small bile ducts, biliary stasis, and eventually the development of liver fibrosis, cirrhosis, and even liver failure. One of the main characteristics of PBC is that it primarily affects middle-aged women, but the precise cause is still unknown. This article analyzes the unique causes and mechanisms of the female predominance of PBC and summarizes the potential causes.The female domination of PBC is reported to be primarily caused by sex hormones, environmental circumstances, and epigenetic changes, each of which has a different subtle impact on patients' gender disparities.

Belimumab treatment in autoimmune hepatitis and primary biliary cholangitis - a case series

Background

The majority of patients with autoimmune hepatitis (AIH) achieve complete remission with established treatment regiments. In patients with intolerance or insufficient response to these drugs, the remaining options are limited and novel treatment approaches necessary. In primary biliary cholangitis (PBC), ursodeoxycholic acid (UDCA) and fibrates have improved prognosis dramatically, but there remains a proportion of patients with refractory disease.In patients with refractory AIH and/or PBC, we used a novel treatment strategy with the anti-B cell activating factor, belimumab. The first three patients had concomitant Sjögren's disease. The connecting element between all three diseases is B cell activation, including elevated levels of the B cell activating factor (BAFF). Furthermore, belimumab has been shown to be beneficial in Sjögren's disease.

Aims and methods

To retrospectively investigate treatment response in six patients with AIH or PBC with or without concomitant Sjögren's disease treated with the anti-BAFF therapy belimumab at the University Hospital in Bern, Switzerland.

Results

In all three patients with AIH, belimumab improved disease control and helped by-pass or reduce problematic side effects from corticosteroids and calcineurin inhibitors. In PBC patients (n = 3), there was no clear improvement of liver function tests, despite reduction or normalization of IgM. All patients with concomitant Sjögren's disease (n = 3) had an improvement of sicca symptoms and two out of three patients experienced an initially marked reduction in fatigue, which lessened over time.

Conclusions

Belimumab may be a promising treatment option for patients with AIH and further investigations are needed. In PBC however, response was not convincing. The effects on sicca symptoms and fatigue were encouraging.

Therapeutic effect of modified zengye decoction on primary Sjogren’s syndrome and its effect on plasma exosomal proteins

Background: Modified Zengye Decoction (MZD), a traditional Chinese medicine, is an effective treatment for patients with primary Sjögren’s syndrome (pSS).

Purpose: To evaluate the efficacy of MZD and investigate its effect on plasma exosomal proteins.

Methods: Eighteen pSS patients were treated with MZD for 2 weeks. The therapeutic effect was evaluated by observing the changes in clinical symptoms, laboratory parameters, and plasma cytokines before and after treatment. Then, the differentially expressed proteins (DEPs) in the plasma exosomes before and after treatment were identified via label-free proteomics, while Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were used to analyze the possible biological functions and signaling pathways involved in the exosomal DEPs.

Results: MZD can effectively relieve the clinical symptoms of pSS patients, downregulate the plasma IgG and IgM levels, and inhibit plasma cytokine production. Thirteen DEPs were identified via label-free proteomics in the plasma exosomes before and after MZD treatment, of which 12 were downregulated proteins. GO analysis showed that these downregulated proteins were mainly related to the insulin response involved in dryness symptoms and the Gram-negative bacterial defense response and proteoglycan binding involved in infection. KEGG enrichment analysis showed that these downregulated proteins were primarily associated with the porphyrin metabolism involved in oteoarthrosis and the NF-κB and TLR4 pathways involved in infection.

Conclusion: MZD can effectively alleviate SS symptoms, while its mechanism may be associated with the reduced protein expression in insulin response, porphyrin metabolism, and the TLR4/NF-κB pathway.

Abnormal Epigenetic Regulations in the Immunocytes of Sjögren's Syndrome Patients and Therapeutic Potentials

Sjögren's syndrome (SjS), characterized by keratoconjunctivitis sicca and dry mouth, is a common autoimmune disease, especially in middle-aged women. The immunopathogenesis of SjS is caused by the sequential infiltration of T and B cells into exocrine glands, including salivary and lacrimal glands. Effector cytokines produced by these immunocytes, such as interferons (IFNs), IL-17, IL-22, IL-21, IL-4, TNF-α, BAFF and APRIL, play critical roles in promoting autoimmune responses and inducing tissue damages. Epigenetic regulations, including DNA methylation, histone modification and non-coding RNAs, have recently been comprehensively studied during the activation of various immunocytes. The deficiency of key epigenetic enzymes usually leads to aberrant immune activation. Epigenetic modifications in T and B cells are usually found to be altered during the immunopathogenesis of SjS, and they are closely correlated with autoimmune responses. In particular, the important role of methylation in activating IFN pathways during SjS progression has been revealed. Thus, according to the involvement of epigenetic regulations in SjS, target therapies to reverse the altered epigenetic modifications in auto-responsive T and B cells are worthy of being considered as a potential therapeutic strategy for SjS.