Expression of IL-20 Receptor Subunit β Is Linked to EAE Neuropathology and CNS Neuroinflammation

The Role of Interleukin-24 and Downstream Pathways in Inflammatory and Autoimmune Diseases

Inflammatory and autoimmune diseases are pathological immune disorders and pose significant public health challenges due to their impact on individuals and society. Cytokine dysregulation plays a critical role in the development of these disorders. Interleukin (IL)-24, a member of the IL-10 cytokine family, can be secreted by various cell types, including immune and non-immune cells. The downstream effects of IL-24 upon binding to its receptors can occur in dependence on, or independently of, the Janus kinase (JAK)/signal transducer and the activator of transcription (STAT) signaling pathway. IL-24 and its downstream pathways influence crucial processes such as cell differentiation, proliferation, apoptosis, and inflammation, with its role varying across different diseases. On the one hand, IL-24 can inhibit the activation of pathogenic cells and autoimmune responses in autoimmune ocular diseases; on the other hand, IL-24 has been also implicated in promoting tissue damage by fostering immune cell activation and infiltration in psoriasis and allergic diseases. It suggests that IL-24, as a multifunctional cytokine, has complex regulatory functions in immune cells and related diseases. In this paper, we summarize the current knowledge on IL-24's immunomodulatory actions and its involvement in inflammatory and autoimmune disorders. Such insights may pave the way for novel therapeutic strategies for these diseases.

Unraveling the role of the IL-20 cytokine family in neurodegenerative diseases: Mechanisms and therapeutic insights

The IL-20 cytokine family, comprising IL-19, IL-20, IL-22, IL-24, and IL-26, has emerged as a critical player in the pathogenesis of neurodegenerative diseases due to its multiple roles in inflammation, tissue repair, and immune modulation. These cytokines signal through IL-20 receptor complexes (IL-20RA/IL-20RB and IL-22RA1/IL-20RB), triggering diverse immune processes. Recent evidence highlights their significant contributions to neuroinflammation and neurodegeneration in central nervous system disorders. IL-20 family cytokines impact microglial activation, which, when dysregulated, exacerbates neuronal damage. Specifically, IL-20 and IL-24 are linked to elevated pro-inflammatory markers in glial cells, promoting neurodegeneration. In contrast, IL-22 exhibits dual functionality, exerting protective and pathological roles depending on the inflammatory milieu. Key mechanisms involve the regulation of blood-brain barrier integrity, oxidative stress, and autophagy. IL-22 and IL-24 also protect neurons by enhancing antioxidant defenses and maintaining epithelial barrier function, while their dysregulation contributes to blood-brain barrier disruption and protein aggregate accumulation, hallmark features of Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Elevated IL-22 levels in Alzheimer's disease and IL-19's regulatory role in multiple sclerosis suggest they may serve as potential biomarkers and therapeutic targets. IL-26's role in amplifying inflammatory cascades further underscores the complexity of this cytokine family in neurodegenerative pathology. Therapeutically, strategies targeting IL-20 cytokines include monoclonal antibodies, receptor modulation, and recombinant cytokine administration. These approaches aim to mitigate neuroinflammation, restore immune balance, and protect neuronal integrity. This review underscores the IL-20 family's emerging relevance in neurodegenerative diseases, highlighting its potential for novel diagnostic and therapeutic strategies.

Transcript and Lipid Profile Alterations in Astrocyte-Neuron Mitochondrial Transfer Under Lipopolysaccharide Exposure: An In Vitro Study

Sepsis-associated encephalopathy (SAE) is a brain dysfunction for which no effective therapy currently exists. Recent studies suggest that transferring mitochondria from astrocytes to neurons may benefit SAE patients, though the underlying mechanism remains unclear. We cultured astrocytes and neurons from mice in vitro. Astrocytes were stimulated with lipopolysaccharide (LPS) for 24 h, and the astrocyte-conditioned medium (ACM) was collected. Neuronal cultures were then treated with ACM or mitochondria-depleted ACM (mdACM) for further analysis. Mitochondrial transfer was examined under a fluorescence microscope. Western blotting analyzed the protein expression of genes related to apoptosis and mitochondrial metabolism. RNA sequencing and mass spectrometry were employed to investigate the mechanisms underlying mitochondrial transfer. Astrocyte-derived mitochondria migrated toward and connected with LPS-exposed neurons. The addition of ACM significantly attenuated LPS-induced alterations in the proteins linked to apoptosis and mitochondrial dynamics. RNA sequencing revealed notable alterations in the transcript profile of neurons upon ACM treatment, highlighting the involvement of mitochondria metabolism, inflammation, and apoptosis-related factors. Additionally, mitochondrial transfer modified the lipid composition of neurons, increasing phosphatidylserine levels, which correlated with neuroinflammation and enriched pathways related to cytokine and MAPK signaling. Our findings suggest that astrocyte-neuron mitochondrial transfer holds therapeutic potential for alleviating SAE, possibly through the anti-inflammatory effects of lipids, particularly phosphatidylserine.

IL-20RA is Associated with the Risk of Diabetic Microangiopathy: A Bidirectional Mendelian Randomization Analysis and Clinical Validation

Objective

Studies have demonstrated a link between chronic inflammatory responses and diabetic microangiopathy, which include diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy. However, it remains unclear whether there is a causal association between circulating inflammatory cytokines and the development of diabetic microvascular complications. This study aimed to investigate whether altered genetically predicted concentrations of circulating inflammatory cytokines were associated with the development of diabetic microvascular complications using two-sample Mendelian randomization (MR) analysis and clinical validation.

Methods

Pooled data on diabetic nephropathy, diabetic retinopathy, diabetic neuropathy, and 91 circulating inflammatory cytokines were obtained from publicly available databases. The analysis was conducted mainly using the inverse variance weighting (IVW) method and the results were assessed based on the odds ratio (OR) and 95% confidence interval (CI). In addition, the stability and reliability of the results were verified using the leave-one-out method, heterogeneity tests, and horizontal pleiotropy. Finally, ELISA and RT-qPCR were utilized to assess the expression of relevant inflammatory cytokines associated with diabetic microvascular complications.

Results

Mendelian randomization analysis identified a total of 9 circulating inflammatory cytokines that exhibit causal associations with the diabetic microangiopathy, with IL-20RA being a common risk factor for all three conditions. Clinical studies have found elevated plasma IL-20RA concentrations in patients with diabetic peripheral neuropathy, and RT-qPCR testing of peripheral blood mononuclear cells revealed significantly higher IL-20RA mRNA expression in patients with diabetic peripheral neuropathy as compared to normal individuals.

Conclusion

This study highlights the potential role of specific inflammatory cytokines in the development of diabetic microangiopathy (diabetic nephropathy, diabetic retinopathy and diabetic neuropathy). Additionally, IL-20RA emerges as a potential common risk factor for three diabetic microvascular complications. These findings may provide novel insights into early prevention and new therapeutic strategies for diabetic microvascular complications.

B7-H3 in glioblastoma and beyond: significance and therapeutic strategies

Cancer has emerged as the second most prevalent disease and the leading cause of death, claiming the lives of 10 million individuals each year. The predominant varieties of cancer encompass breast, lung, colon, rectal, and prostate cancers. Among the more aggressive malignancies is glioblastoma, categorized as WHO stage 4 brain cancer. Following diagnosis, the typical life expectancy ranges from 12 to 15 months, as current established treatments like surgical intervention, radiotherapy, and chemotherapy using temozolomide exhibit limited effectiveness. Beyond conventional approaches, the exploration of immunotherapy for glioblastoma treatment is underway. A methodology involves CAR-T cells, monoclonal antibodies, ADCC and nanobodies sourced from camelids. Immunotherapy's recent focal point is the cellular ligand B7-H3, notably abundant in tumor cells while either scarce or absent in normal ones. Its expression elevates with cancer progression and serves as a promising prognostic marker. In this article, we delve into the essence of B7-H3, elucidating its function and involvement in signaling pathways. We delineate the receptors it binds to and its significance in glioblastoma and other cancer types. Lastly, we examine its role in immunotherapy and the utilization of nanobodies in this domain.

Targeted proteomics of cerebrospinal fluid in treatment naïve multiple sclerosis patients identifies immune biomarkers of clinical phenotypes

Multiple sclerosis (MS) is an inflammatory demyelinating disease with heterogeneous clinical presentations and variable long-term disability accumulation. There are currently no standard criteria to accurately predict disease outcomes. In this study we investigated the cross-sectional relationship between disease phenotype and immune-modulating cytokines and chemokines in cerebrospinal fluid (CSF). We analyzed CSF from 20 DMT-naïve MS patients using Olink Proteomics' Target 96 Inflammation panel and correlated the resulting analytes with respect to (1) disease subtype, (2) patient age and sex, (3) extent of clinical disability, and (4) MRI segmental brain volumes. We found that intrathecal IL-4 correlated with higher Expanded Disability Status Scale (EDSS) scores and longer 25-foot walk times, and CD8A correlated with decreased thalamic volumes and longer 9-hole peg test times. Male sex was associated with higher FGF-19 expression, and Tumefactive MS with elevated CCL4. Several inflammatory markers were correlated with older age at the time of LP. Finally, higher intrathecal IL-33 correlated with increased MS lesion burden and multi-compartment brain atrophy. This study confirms immune heterogeneity underlying CSF profiles in MS, but also identifies several inflammatory protein biomarkers that may be of use for predicting clinical outcomes in future algorithms.

Novel insight into MDA-7/IL-24: A potent therapeutic target for autoimmune and inflammatory diseases

Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24) is a pleiotropic member of the IL-10 family of cytokines, and is involved in multiple biological processes, including cell proliferation, cell differentiation, tissue fibrosis, the inflammatory response, and antitumor activity. MDA-7/IL-24 can regulate epithelial integrity, homeostasis, mucosal immunity and host resistance to various pathogens by enhancing immune and inflammatory responses. Our recent study revealed the mechanism of MDA-7/IL-24 in promoting airway inflammation and airway remodeling through activating the JAK/STAT3 and ERK signaling pathways in bronchial epithelial cells. Herein, we summarize the cellular sources, inducers, target cells, signaling pathways, and biological effects of MDA-7/IL-24 in several allergic and autoimmune diseases. This review also synopsizes recent advances in clinical research targeting MDA-7/IL-24 or its receptors. Based on these advancements, we emphasize its potential as a target for immunotherapy and discuss the challenges of developing immunotherapeutic drugs targeting MDA-7/IL-24 or its receptors in autoimmune and inflammatory disorders.

Exploration of the causal associations between circulating inflammatory proteins, immune cells, and neuromyelitis optica spectrum disorder: a bidirectional Mendelian randomization study and mediation analysis

Background

An increasing body of research has demonstrated a robust correlation between circulating inflammatory proteins and neuromyelitis optica spectrum disorders (NMOSD). However, whether this association is causal or whether immune cells act as mediators currently remains unclear.

Methods

We employed bidirectional two-sample Mendelian randomization (TSMR) analysis to examine the potential causal association between circulating inflammatory proteins, immune cells, and NMOSD using data from genome-wide association studies (GWAS). Five different methods for Mendelian randomization analyses were applied, with the inverse variance-weighted (IVW) method being the primary approach. Sensitivity analyses were further performed to assess the presence of horizontal pleiotropy and heterogeneity in the results. Finally, a two-step Mendelian randomization (MR) design was employed to examine the potential mediating effects of immune cells.

Results

A notable causal relationship was observed between three circulating inflammatory proteins (CSF-1, IL-24, and TNFRSF9) and genetically predicted NMOSD. Furthermore, two immune cell phenotypes, genetically predicted CD8 on naive CD8+ T cells, and Hematopoietic Stem Cell Absolute Count were negatively and positively associated with genetically predicted NMOSD, respectively, although they did not appear to function as mediators.

Conclusion

Circulating inflammatory proteins and immune cells are causally associated with NMOSD. Immune cells do not appear to mediate the pathway linking circulating inflammatory proteins to NMOSD.

A comparison of serum inflammatory parameters in progressive forms of multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disease of the central nervous system. Primary progressive MS (PPMS) is diagnosed in approximately 10-15 % of MS patients. Disease-modifying therapies (DMT) are less effective in modifying the course of progressive types of MS. It seems that inflammatory processes differ in the MS subtypes.

OBJECTIVES

The objective of this study was to assess differences in the inflammatory parameters between PPMS and other courses of MS.

MATERIALS AND METHODS

A total of 84 subjects were included in the study. The study group was divided according to the course of MS into the following categories: PPMS (n = 24); SPMS-secondary progressive multiple sclerosis (n = 14); RRMS-relapsing-remitting multiple sclerosis (n = 46). PPMS patients were further divided into treated with ocrelizumab and treatment-naive groups. The concentrations of serum inflammatory parameters were evaluated.

RESULTS

PPMS and SPMS significantly differed in the serum levels of sCD30, gp130, sIL-6R alpha, osteopontin, pentraxin-3 and sTNF-R1. The serum concentrations of IFN-alpha2, IL-10, IL-20, IL-29 and osteopontin significantly differed between PPMS and RRMS. The serum levels of BAFF, IL-19, IL-20, pentraxin-3, s-TNF-R1 and s-TNF-R2 significantly differed between PPMS treated with ocrelizumab and treatment-naive.

CONCLUSION

Although inflammatory processes take part in the pathogenesis of all types of MS, they differ between MS courses. Serum inflammatory parameters seem to be promising biomarkers in helping to differentiate courses of MS, and in assessing reactions to DMT treatment. Further investigations on their usage are required.

Grass carp IL-20 binds to IL-20R2 but induces STAT3 phosphorylation via IL-20R1

IL-20 is a pleiotropic cytokine that belongs to the IL-10 family and has a variety of biological functions in tissue homeostasis and regulation of host immune defenses. It signals through a heterodimeric receptor composed of a subunit with a long intracellular domain (R1 type receptor) and a subunit with a short intracellular domain (R2 type receptor). In this study, the R1 type receptor (CiIL-20R1/CRFB8) and the R2 type receptor (CiIL-20R2/CRFB16) were identified in grass carp Ctenopharyngodon idella. Expression analysis revealed that IL-20R2 was highly expressed in the gills and skin in healthy fish. Infection with Flavobacterium columnare resulted in the downregulation of both receptors in the gill at 48 and 72 h, whilst infection with grass carp reovirus induced their expression in the head kidney and spleen at 72 h. In the primary head kidney leucocytes, the expression levels of IL-20R1 and IL-20R2 were decreased after stimulation with 250 ng/mL IL-1β but not affected by IFN-γ. Co-immunoprecipitation analysis showed that CiIL-20R2/CRFB16 but not CiIL-20R1/CRFB8 bound to CiIL-20L. Furthermore, it was shown that CiIL-20R1/CRFB8 was responsible for activating the phosphorylation of STAT3, whilst CiIL-20R2/CRFB16 was not involved. Structural modeling analysis showed that key residues involved in the interaction between IL-20 and receptors were highly conserved between grass carp and humans, suggesting that the signal transduction and functions of IL-20/IL-20R axis are evolutionarily conserved.

Comparison and correlation study of synovial ultrasound indices and serum VEGF in rheumatoid wrist arthritis before and after treatment

OBJECTIVE

Rheumatoid wrist arthritis is a chronic autoimmune disease, resulting in joint deformity and functional impairment. We aimed to compare the wrist synovial ultrasound indices and serum vascular endothelial growth factor (VEGF) level in patients with RA before and after treatment, and to explore the correlation between the two.

METHODS

Forty patients with RA in wrist underwent ultrasound examination to determine wrist synovial thickness, synovial blood flow grade, and synovial artery resistive index (RI) before and after treatment. The serum level of VEGF was detected by enzyme-linked immunosorbent assay. Correlation between synovial ultrasound indices and serum VEGF level was assessed.

RESULTS

Pre-treatment synovial thickness, synovial artery RI, and serum VEGF level were 8.60 ± 2.82 mm, 0.62 ± 0.07, and 419.49 ± 19.27 pg/mL, respectively. The corresponding post-treatment levels were 4.05 ± 1.89 mm, 0.83 ± 0.10, and 199.30 ± 16.18 pg/mL. Pre-treatment distribution of synovial blood flow grades was as follows: grade 0, nil; grade I, 1 case; grade II, 17 cases; grade III, 22 cases. The post-treatment distribution was as follows: grade 0, 6 cases; grade I, 23 cases; grade II, 11 cases; and grade III, nil. There were significant differences between pre- and post-treatment wrist synovial thickness, artery RI, and blood flow grading. Wrist synovial thickness and synovial blood flow grade showed a strong positive correlation with serum VEGF level (P < 0.01). There was strong negative correlation between wrist synovial artery RI and serum VEGF level (P < 0.01).

CONCLUSION

The strong correlation between wrist synovial ultrasound indicators and serum VEGF may be clinically useful for diagnosis and therapy.

Chemokine-Driven Migration of Pro-Inflammatory CD4+ T Cells in CNS Autoimmune Disease

Pro-inflammatory CD4⁺ T helper (Th) cells drive the pathogenesis of many autoimmune conditions. Recent advances have modified views of the phenotype of pro-inflammatory Th cells in autoimmunity, extending the breadth of known Th cell subsets that operate as drivers of these responses. Heterogeneity and plasticity within Th1 and Th17 cells, and the discovery of subsets of Th cells dedicated to production of other pro-inflammatory cytokines such as GM-CSF have led to these advances. Here, we review recent progress in this area and focus specifically upon evidence for chemokine receptors that drive recruitment of these various pro-inflammatory Th cell subsets to sites of autoimmune inflammation in the CNS. We discuss expression of specific chemokine receptors by subsets of pro-inflammatory Th cells and highlight which receptors may be tractable targets of therapeutic interventions to limit pathogenic Th cell recruitment in autoimmunity.

Combination of Genomic and Transcriptomic Approaches Highlights Vascular and Circadian Clock Components in Multiple Sclerosis

Aiming at exploring vascular components in multiple sclerosis (MS) with brain outflow disturbance, we combined transcriptome analysis in MS internal jugular vein (IJV) wall with WES in MS families with vertical transmission of disease. Main results were the differential expression in IJV wall of 16 MS-GWAS genes and of seven genes (GRIN2A, GRIN2B, IL20RB, IL26, PER3, PITX2, and PPARGC1A) not previously indicated by GWAS but encoding for proteins functionally interacting with MS candidate gene products. Strikingly, 22/23 genes have been previously associated with vascular or neuronal traits/diseases, nine encoded for transcriptional factors/regulators and six (CAMK2G, GRIN2A, GRIN2B, N1RD1, PER3, PPARGC1A) for circadian entrainment/rhythm components. Among the WES low-frequency (MAF ≤ 0.04) SNPs (n = 7) filtered in the 16 genes, the NR1D1 rs17616365 showed significantly different MAF in the Network for Italian Genomes affected cohort than in the 1000 Genome Project Tuscany samples. This pattern was also detected in five nonintronic variants (GRIN2B rs1805482, PER3 rs2640909, PPARGC1A rs2970847, rs8192678, and rs3755863) in genes coding for functional partners. Overall, the study proposes specific markers and low-frequency variants that might help (i) to understand perturbed biological processes in vascular tissues contributing to MS disease, and (ii) to characterize MS susceptibility genes for functional association with disease-pathways.