Increased Levels of IL-34 in Acquired Immune-Mediated Neuropathies

Sex-specific differences in SLE - Significance in the experimental setting of inflammation and kidney damage in MRL-Faslpr mice

Animal models are an important tool in the research of chronic autoimmune diseases, like systemic lupus erythematosus (SLE). MRL-Faslpr mice are one of different lupus models that develop spontaneously an SLE-like disease with autoantibodies and immune complex deposition that leads into damage of different organs. In contrast to human SLE, both sexes of MRL-Faslpr mice develop a similar autoimmune disease. Due to the sex bias in human and the delayed disease progression in male MRL-Faslpr mice, the majority of studies have been performed in female mice. To determine the suitability of male MRL-Faslpr mice for SLE research, especially with regard to the 3 R-principle and animal welfare, analyses of phenotype, inflammation and damage with focus on kidney and spleen were performed in mice of both sexes. Female mice developed lymphadenopathy and skin lesions earlier as males. At an age of 3.5 month, more immune cells infiltrated kidney and spleen in females compared to males. At the age of 5 months, however, substantially less sex-specific differences were detected. Since other studies have shown differences between both sexes on other manifestations like autoimmune pancreatitis and Sjögren syndrome in MRL-Faslpr mice, the use of male mice as part of 3 R-principle and animal welfare must be carefully considered.

Cytokines and chemokines in patients with chronic inflammatory demyelinating polyradiculoneuropathy and multifocal motor neuropathy: A systematic review

Advances in the understanding of cytokines have revolutionized mechanistic treatments for chronic inflammatory and autoimmune diseases, as exemplified by rheumatoid arthritis. We conducted a systematic literature review on the role of cytokines and chemokines in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). Ovid Medline, EMBASE and Web of Science were searched until August 31, 2022 for human studies investigating cytokines levels in CIDP or MMN. Fifty-five articles on 1061 CIDP patients and 86 MMN patients were included, with a median of 18 patients per study (range 3-71). Studies differed in the inclusion criteria, type of assay, manufacturer, control subjects, and tested biological material. Only a minority of studies reported data on disease activity. Interleukin (IL)-6, IL-17, CXCL10, and tumor necrosis factor alpha (TNF-α), were elevated in CIDP compared to controls in most of the studies. IL-6 and TNF-α levels are also correlated with disability. In MMN patients, IL-1Ra was elevated in the majority of the reports. While acknowledging the challenges in comparing studies and the various limitations of the studies, including small patient numbers, particularly in MMN, our review suggests that IL-6, IL-17, CXCL10, and TNF-α might play a role in CIDP pathogenesis. Larger studies are needed in MMN.

Decreased Levels of Serum IL-34 Associated with Cognitive Impairment in Vascular Dementia

Objective

Interleukin- (IL-) 34 is a new type of cytokine with neuroprotective effects discovered in recent years. However, the relationship between IL-34 and vascular dementia (VaD) has not yet been elucidated. The purpose of this study is to determine whether IL-34 is involved in cognitive impairment of VaD.

Methods

From January 2017 to December 2020, 84 VaD patients and 60 healthy controls who attended Qingpu Branch of Zhongshan Hospital were prospectively included in the study. Once included in the study, demographic features of all research subjects are collected. They include age, gender, education, white blood cells (WBC), neutrophil, lymphocyte, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), triglycerides (TG), and total cholesterol (TC). Meanwhile, the Montreal Cognitive Assessment (MoCA) scale was used to assess the cognitive function of participants. The serum IL-34 level was determined by enzyme-linked immunosorbent assay (ELISA).

Results

There was no significant difference between the demographic features of VaD patients and healthy controls (p > 0.05). However, the serum IL-34 levels of VaD patients and healthy controls are 27.6 ± 3.9 pg/ml and 41.8 ± 6.0 pg/ml, respectively, and there is a significant statistical difference between them (p < 0.001). The results of bivariate correlation analysis showed that serum IL-34 levels were significantly positively correlated with MoCA scores (r = 0.371, p = 0.023). Further regression analysis showed that IL-34 was still correlated with MoCA after adjusting for demographic features (β = 0.276, p = 0038).

Conclusions

Serum IL-34 levels in VaD patients were significantly reduced, which may be an independent predictor of cognitive impairment in VaD patients.

Over-Expression of Immune-Related lncRNAs in Inflammatory Demyelinating Polyradiculoneuropathies

Long non-coding RNAs (lncRNAs) have crucial roles in the pathogenesis of immune-related disorders. However, their role in the pathobiology of inflammatory demyelinating polyradiculoneuropathies remains unclear. In the current study, we measured peripheral expression of four lncRNAs, namely TUG1, FAS-AS1, NEAT1, and GAS5, in patients with acute/chronic inflammatory demyelinating polyradiculoneuropathies (AIDP/CIDP) compared with healthy subjects. Notably, all lncRNAs were over-expressed in patients compared with controls (P < 0.0001 for all lncRNAs). When assessing their expressions in AIDP and CIDP groups separately, TUG1 and NEAT1 were up-regulated in both patient groups compared with controls, yet FAS-AS1 and GAS5 were only up-regulated in CIDP cases. There were remarkable pairwise correlations between expression levels of these lncRNAs in all study groups. Based on the above-mentioned data, we suggest participation of these for lncRNAs in the pathogenesis of inflammatory demyelinating polyradiculoneuropathies. Moreover, FAS-AS1 and GAS5 lncRNAs have type-specific roles in this regard. Future functional studies are needed to elaborate the molecular mechanisms of the contribution of these transcripts in AIDP/CIDP.