Interleukin-35 Gene-Modified Mesenchymal Stem Cells Protect Concanavalin A-Induced Fulminant Hepatitis by Decreasing the Interferon Gamma Level

Mesenchymal Stem Cell Therapy in Acute Liver Failure

Acute liver failure (ALF) is a severe liver disease syndrome with rapid deterioration and high mortality. Liver transplantation is the most effective treatment, but the lack of donor livers and the high cost of transplantation limit its broad application. In recent years, there has been no breakthrough in the treatment of ALF, and the application of stem cells in the treatment of ALF is a crucial research field. Mesenchymal stem cells (MSCs) are widely used in disease treatment research due to their abundant sources, low immunogenicity, and no ethical restrictions. Although MSCs are effective for treating ALF, the application of MSCs to ALF needs to be further studied and optimized. In this review, we discuss the potential mechanisms of MSCs therapy for ALF, summarize some methods to enhance the efficacy of MSCs, and explore optimal approaches for MSC transplantation.

Celecoxib abrogates concanavalin A-induced hepatitis in mice: Possible involvement of Nrf2/HO-1, JNK signaling pathways and COX-2 expression

Concanavalin A (ConA) is an established model for inducing autoimmune hepatitis (AIH) in mice, mimicking clinical features in human. The aimof the current study is to explore the possible protective effect of celecoxib, a cyclooxygenase-2 inhibitor,on immunological responses elicited in the ConA model of acute hepatitis. ConA (20 mg/kg) was administered intravenously to adult male mice for 6 h. Prior to ConA intoxication, mice in the treatedgroups received daily doses of celecoxib (30 and 60 mg/kg in CMC) for 7 days. Results revealed that administration of celecoxib 60 mg/kg for 7 days significantly protected the liver from ConA-induced liver damage revealed by significant decrease in ALT and AST serum levels. Celecoxib 30 and 60 mg/kg pretreatment enhanced oxidant/antioxidant hemostasis by significantreduction of MDA and NO content and increase hepatic GSH contents and SOD activity. In addition, celecoxib 30 and 60 mg/kg caused significant increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and the stress protein heme oxygenase-1 (HO-1) levels. Moreover, celecoxib 30 and 60 mg/kg inhibited the release of proinflammatory markers including IL-1β and TNF-α along with significant decrease in p-JNK, AKT phosphorylation ratio and caspase-3 expression. Besides, Con A was correlated to high expression of cyclooxygenase COX-2 and this increasing was improved by administration of celecoxib. These changes were in good agreement with improvement in histological deterioration. The protective effect of celecoxib was also associated with significant reduction of autophagy biomarkers (Beclin-1 and LC3II). In conclusion, celecoxib showed antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagy activity against Con A-induced immune-mediated hepatitis. These effects could be produced by modulation of Nrf2/HO-1, IL-1B /p-JNK/p-AKT, JNK/caspase-3, and Beclin-1/LC3II signaling pathways.

Recent advances in pre-conditioned mesenchymal stem/stromal cell (MSCs) therapy in organ failure; a comprehensive review of preclinical studies

Mesenchymal stem/stromal cells (MSCs)-based therapy brings the reassuring capability to regenerative medicine through their self-renewal and multilineage potency. Also, they secret a diversity of mediators, which are complicated in moderation of deregulated immune responses, and yielding angiogenesis in vivo. Nonetheless, MSCs may lose biological performance after procurement and prolonged expansion in vitro. Also, following transplantation and migration to target tissue, they encounter a harsh milieu accompanied by death signals because of the lack of proper tensegrity structure between the cells and matrix. Accordingly, pre-conditioning of MSCs is strongly suggested to upgrade their performances in vivo, leading to more favored transplantation efficacy in regenerative medicine. Indeed, MSCs ex vivo pre-conditioning by hypoxia, inflammatory stimulus, or other factors/conditions may stimulate their survival, proliferation, migration, exosome secretion, and pro-angiogenic and anti-inflammatory characteristics in vivo. In this review, we deliver an overview of the pre-conditioning methods that are considered a strategy for improving the therapeutic efficacy of MSCs in organ failures, in particular, renal, heart, lung, and liver.

Mesenchymal stem cells-based therapy in liver diseases

Multiple immune cells and their products in the liver together form a complex and unique immune microenvironment, and preclinical models have demonstrated the importance of imbalances in the hepatic immune microenvironment in liver inflammatory diseases and immunocompromised liver diseases. Various immunotherapies have been attempted to modulate the hepatic immune microenvironment for the purpose of treating liver diseases. Mesenchymal stem cells (MSCs) have a comprehensive and plastic immunomodulatory capacity. On the one hand, they have been tried for the treatment of inflammatory liver diseases because of their excellent immunosuppressive capacity; On the other hand, MSCs have immune-enhancing properties in immunocompromised settings and can be modified into cellular carriers for targeted transport of immune enhancers by genetic modification, physical and chemical loading, and thus they are also used in the treatment of immunocompromised liver diseases such as chronic viral infections and hepatocellular carcinoma. In this review, we discuss the immunological basis and recent strategies of MSCs for the treatment of the aforementioned liver diseases. Specifically, we update the immune microenvironment of the liver and summarize the distinct mechanisms of immune microenvironment imbalance in inflammatory diseases and immunocompromised liver diseases, and how MSCs can fully exploit their immunotherapeutic role in liver diseases with both immune imbalance patterns.

Serum Interleukins as Potential Prognostic Biomarkers in HBV-Related Acute-on-Chronic Liver Failure

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is relatively common in China and has complex pathogenesis, difficult clinical treatment, and poor prognosis. Immune status is an important factor affecting ACLF prognosis. Interleukins are a family of secreted lymphocyte factors that interact with a host of cell types including immune cells. These signaling molecules play important roles in transmitting information; regulating immune cells; mediating the activation, proliferation, and differentiation of T and B cells; and modulating inflammatory responses. Many studies have investigated the correlation between interleukin expression and the prognosis of HBV-ACLF. This review focuses on the potential use of interleukins as prognostic biomarkers in HBV-ACLF. References were mainly identified through PubMed and CNKI search, including relevant studies published until December 2021. We have summarized reports of several promising diagnostic interleukin biomarkers that predict susceptibility to HBV-ACLF. The use of biomarkers to understand early prognosis can help devise different therapeutic measures and improve patient survival. Ongoing research on prognostic biomarkers of HBV-ACLF is promising, and future preclinical and clinical studies are warranted.

Association between Mesenchymal Stem Cells and COVID-19 Therapy: Systematic Review and Current Trends

Background

The novel coronavirus first emerged in Wuhan, China, and quickly spread across the globe, spanning various countries and resulting in a worldwide pandemic by the end of December 2019. Given the current advances in treatments available for COVID-19, mesenchymal stem cell (MSC) therapy seems to be a prospective option for management of ARDS observed in COVID-19 patients. This present study is aimed at exploring the therapeutic potential and safety of using MSC obtained by isolation from health cord tissues in the treatment of patients with COVID-19.

Methods

A systematic search was done based on the guidelines of the PRISMA 2020 statement. A literature search was executed using controlled vocabulary and indexing of trials to evaluate all the relevant studies involving the use of medical subject headings (MeSH) in electronic databases like PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and clinicaltrials.gov up to 31 December 2021. The protocol was registered in the PROSPERO register with ID CRD42022301666. Findings. After screening finally, 22 remaining articles were included in this systematic review. The studies revealed that MSC exosomes are found to be superior to MSC alone in terms of safety owing to being smaller with a lesser immunological response which leads to free movement in blood capillaries without clumping and also cannot further divide, thus reducing the oncogenic potential of MSC-derived exosomes as compared to MSC only. The studies demonstrated that the lungs healed with the use of exosomes compared to how they presented initially at the hospital. MSCs are found to increase the angiogenesis process and alveolar reepithelization, reducing markers like TNF alpha, TGF beta, and COL I and III, reducing the growth of myofibroblasts and increasing survivability of endothelium leading to attenuated pulmonary fibrosis and even reversing them. Interpretation. We can conclude that the use of mesenchymal stem cells or their derived exosomes is safe and well-tolerated in patients with COVID-19. It improves different parameters of oxygenation and helps in the healing of the lungs. The viral load along with different inflammatory cells and biomarkers of inflammation tend to decrease. Chest X-ray, CT scan, and different radiological tools are used to show improvement and reduced ongoing destructive processes.

Mesenchymal stromal cells (MSCs) and their exosome in acute liver failure (ALF): a comprehensive review

Recently, mesenchymal stromal cells (MSCs) and their derivative exosome have become a promising approach in the context of liver diseases therapy, in particular, acute liver failure (ALF). In addition to their differentiation into hepatocytes in vivo, which is partially involved in liver regeneration, MSCs support liver regeneration as a result of their appreciated competencies, such as antiapoptotic, immunomodulatory, antifibrotic, and also antioxidant attributes. Further, MSCs-secreted molecules inspire hepatocyte proliferation in vivo, facilitating damaged tissue recovery in ALF. Given these properties, various MSCs-based approaches have evolved and resulted in encouraging outcomes in ALF animal models and also displayed safety and also modest efficacy in human studies, providing a new avenue for ALF therapy. Irrespective of MSCs-derived exosome, MSCs-based strategies in ALF include administration of native MSCs, genetically modified MSCs, pretreated MSCs, MSCs delivery using biomaterials, and also MSCs in combination with and other therapeutic molecules or modalities. Herein, we will deliver an overview regarding the therapeutic effects of the MSCs and their exosomes in ALF. As well, we will discuss recent progress in preclinical and clinical studies and current challenges in MSCs-based therapies in ALF, with a special focus on in vivo reports.

Mesenchymal Stem Cells and Their Small Extracellular Vesicles as Crucial Immunological Efficacy for Hepatic Diseases

Mesenchymal stem cell small extracellular vesicles (MSC-sEVs) are a priority for researchers because of their role in tissue regeneration. sEVs act as paracrine factors and carry various cargos, revealing the state of the parent cells and contributing to cell–cell communication during both physiological and pathological circumstances. Hepatic diseases are mainly characterized by inflammatory cell infiltration and hepatocyte necrosis and fibrosis, bringing the focus onto immune regulation and other regulatory mechanisms of MSCs/MSC-sEVs. Increasing evidence suggests that MSCs and their sEVs protect against acute and chronic liver injury by inducing macrophages (MΦ) to transform into the M2 subtype, accelerating regulatory T/B (Treg/Breg) cell activation and promoting immunosuppression. MSCs/MSC-sEVs also prevent the proliferation and differentiation of T cells, B cells, dendritic cells (DCs), and natural killer (NK) cells. This review summarizes the potential roles for MSCs/MSC-sEVs, including immunomodulation and tissue regeneration, in various liver diseases. There is also a specific focus on the use of MSC-sEVs for targeted drug delivery to treat hepatitis.

Human Wharton's jelly-derived mesenchymal stem cells alleviate concanavalin A-induced fulminant hepatitis by repressing NF-κB signaling and glycolysis

Background

Fulminant hepatitis is a severe life-threatening clinical condition with rapid progressive loss of liver function. It is characterized by massive activation and infiltration of immune cells into the liver and disturbance of inflammatory cytokine production. Mesenchymal stem cells (MSCs) showed potent immunomodulatory properties. Transplantation of MSCs is suggested as a promising therapeutic approach for a host of inflammatory conditions.

Methods

In the current study, a well-established concanavalin A (Con A)-induced fulminant hepatitis mouse model was used to investigate the effects of transplanting human umbilical cord Wharton's jelly-derived MSCs (hWJ-MSCs) on fulminant hepatitis.

Results

We showed that hWJ-MSCs effectively alleviate fulminant hepatitis in mouse models, primarily through inhibiting T cell immunity. RNA sequencing of liver tissues and human T cells co-cultured with hWJ-MSCs showed that NF-κB signaling and glycolysis are two main pathways mediating the protective role of hWJ-MSCs on both Con A-induced hepatitis in vivo and T cell activation in vitro.

Conclusion

In summary, our data confirmed the potent therapeutic role of MSCs-derived from Wharton's jelly of human umbilical cord on Con A-induced fulminant hepatitis, and uncovered new mechanisms that glycolysis metabolic shift mediates suppression of T cell immunity by hWJ-MSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02560-x.

Mycobacterium tuberculosis (MTB) antigen-induced upregulation of interleukin-35 expression in patients with MTB infection: In vitro blockade of the effects of interleukin-35 on T lymphocyte subsets

Immunosuppressive interleukin-35 (IL-35) serum concentrations were analyzed in patients with active pulmonary Mycobacterium tuberculosis (MTB) infections (PTB), PTB patients after two months treatment (stable PTB) and healthy controls. IL-35 concentrations were highest in active PTB followed by stable PTB cases and lowest in healthy control participants (all P < 0.01). The same trents were found for supernatants of isolated blood mononuclear cells (PBMCs), with additional enhancements after MTB antigen stimulation only for PBMCs of active and stable PTB patients (P < 0.001), for EBI3 and IL-12a transcriptions in PBMCs (P < 0.001) and percentages of EBI3 expressing (CD4 + CD25 + Foxp3+) regulatory T cells (Treg) (P < 0.001). IL-35 antibody applications significantly reversed MTB antigen stimulated IL-35 and IL-10 expression in PBMCs of active and stable PTB patients, and reduced Foxp3 expression in CD4 + CD25 + cells and EBI3 expression in Treg cells, but had no effects on healthy control cells. The percentages of Th1 and Th17 cells in CD4 + cells were enhanced after MTB antigen stimulation of cells taken from active and stable PTB patients, which were partly increased only for Th1 cells after IL-35 antibody exposure. MTB antigen-driven upregulation of IL-35 may lead to reduced immune surveillance in PTB patients.

Stem cell therapies for autoimmune hepatitis

Autoimmune hepatitis is a chronic inflammatory hepatic disorder which may cause liver fibrosis. Appropriate treatment of autoimmune hepatitis is therefore important. Adult stem cells have been investigated as therapies for a variety of disorders in latest years. Hematopoietic stem cells (HSCs) were the first known adult stem cells (ASCs) and can give rise to all of the cell types in the blood and immune system. Originally, HSC transplantation was served as a therapy for hematological malignancies, but more recently researchers have found the treatment to have positive effects in autoimmune diseases such as multiple sclerosis. Mesenchymal stem cells (MSCs) are ASCs which can be extracted from different tissues, such as bone marrow, adipose tissue, umbilical cord, and dental pulp. MSCs interact with several immune response pathways either by direct cell-to-cell interactions or by the secretion of soluble factors. These characteristics make MSCs potentially valuable as a therapy for autoimmune diseases. Both ASC and ASC-derived exosomes have been investigated as a therapy for autoimmune hepatitis. This review aims to summarize studies focused on the effects of ASCs and their products on autoimmune hepatitis.

Application of Modified Mesenchymal Stem Cells Transplantation in the Treatment of Liver Injury

Acute and chronic hepatitis, cirrhosis, and other liver diseases pose a serious threat to human health; however, liver transplantation is the only reliable treatment for the terminal stage of liver diseases. Previous researchers have shown that mesenchymal stem cells (MSCs) are characterized by differentiation and paracrine effects, as well as anti-oxidative stress and immune regulation functions. When MSCs are transplanted into animals, they migrate to the injured liver tissue along with the circulation, to protect the liver and alleviate the injury through the paracrine, immune regulation and other characteristics, making mesenchymal stem cell transplantation a promising alternative therapy for liver diseases. Although the efficacy of MSCs transplantation has been confirmed in various animal models of liver injury, many researchers have also proposed various pretreatment methods to improve the efficacy of mesenchymal stem cell transplantation, but there is still lack a set of scientific methods system aimed at improving the efficacy of transplantation therapy in scientific research and clinical practice. In this review, we summarize the possible mechanisms of MSCs therapy and compare the existing methods of MSCs modification corresponding to the treatment mechanism, hoping to provide as a reference to help future researchers explore a safe and simple transplantation strategy.

VEGF165 gene-modified human umbilical cord blood mesenchymal stem cells protect against acute liver failure in rats

BACKGROUND

Human umbilical cord blood mesenchymal stem cells (HUCB-MSCs) can exert a protective effect in rat models of acute liver failure (ALF). Vascular endothelial growth factor 165 (VEGF₁₆₅ ) is the predominant VEGF isoform and possesses a strong pro-angiogenic function. In the present study, HUCB-MSC served as the gene delivery vehicle for the VEGF₁₆₅ gene, and we explored the therapeutic effects of this system on ALF.

METHODS

HUCB-MSCs were infected with an adenovirus expressing green fluorescent protein (GFP)-VEFG fusion protein (Ad-VEGF₁₆₅ ) to overexpress VEGF₁₆₅ or an adenovirus expressing GFP (Ad-GFP) as control. The control and modified HUCB-MSCs were then transplanted into ALF model rats. Liver function and liver pathological changes were assessed by biochemical tests and liver histology. Immunohistochemistry was carried out to determine the expression of, CD34, Ki67 and VEGF.

RESULTS

VEGF₁₆₅ overexpression enhanced the multipotency of HUCB-MSCs and promoted the homing and colonization of HUCB-MSC in the liver tissues of ALF rats. Furthermore, although HUCB-MSC transplantation ameliorated liver damage and promoted liver regeneration to some extent in ALF rats, Ad-VEGF₁₆₅ -HUCB-MSC transplantation showed stronger therapeutic effects on ALF.

CONCLUSIONS

In summary, transplantation of VEGF₁₆₅ -modified HUCB-MSCs exert stronger therapeutic effects on ALF than HUCB-MSCs. The present study provides a novel therapeutic approach for ALF.

LncRNA XIST Promoted OGD-Induced Neuronal Injury Through Modulating/miR-455-3p/TIPARP Axis

In recent years, the incidence of ischemic stroke has gradually increased, but its pathogenesis has not been fully elucidated. lncRNAs played an important role in the occurrence and regulation of disease, but the research on ischemic stroke is very limited. Therefore, the role of lncRNA in ischemic stroke needs further exploration. The mice model was built to obtain OGD-induced neuronal cells for the following experiments. The protein expression of TCDD inducible poly [ADP-ribose] polymerase (TIPARP), B-cell lymphoma-2 (Bcl-2) and Cleaved Caspase-3 (Cleaved-cas3) were detected with western blot. qRT-PCR was used to analyze expression of XIST, miR-455-3p and TIPARP. CCK-8 assay indicated the capacity of cell proliferation. Flow cytometry was applied to assess cell apoptosis rate. Moreover, dual-luciferase reporter assay and RIP assay were used to determine that the relationship among XIST, miR-455-3p and TIPARP. In this study, we found that oxygen-glucose deprivation (OGD) induced XIST expression, inhibited miR-455-3p expression and promoted TIPARP mRNA and protein expression in neurons. Furthermore, XIST could affect cell growth of OGD-induced neuronal cells. Further analysis showed that XIST could regulate TIPARP by binding to miR-455-3p, and overexpression of miR-455-3p or inhibition of TIPARP could reverse the effects of high XIST expression on OGD-induced neuronal cells. On the contrary, suppression of miR-455-3p or promotion of TIPARP could reverse the effects of low XIST expression on OGD-induced neuronal cells. XIST could affect cell proliferation and apoptosis through miR-455-3p/TIPARP axis in OGD-induced neuronal cells, providing a new regulatory network to understand the pathogenesis of hypoxia-induced neuronal injury.

Mesenchymal stem cells alleviate experimental immune-mediated liver injury via chitinase 3-like protein 1-mediated T cell suppression

Liver diseases with different pathogenesis share common pathways of immune-mediated injury. Chitinase-3-like protein 1 (CHI3L1) was induced in both acute and chronic liver injuries, and recent studies reported that it possesses an immunosuppressive ability. CHI3L1 was also expressed in mesenchymal stem cells (MSCs), thus we investigates the role of CHI3L1 in MSC-based therapy for immune-mediated liver injury here. We found that CHI3L1 was highly expressed in human umbilical cord MSCs (hUC-MSCs). Downregulating CHI3L1 mitigated the ability of hUC-MSCs to inhibit T cell activation, proliferation and inflammatory cytokine secretion in vitro. Using Concanavalin A (Con A)-induced liver injury mouse model, we found that silencing CHI3L1 significantly abrogated the hUC-MSCs-mediated alleviation of liver injury, accompanying by weakened suppressive effects on infiltration and activation of hepatic T cells, and secretion of pro-inflammatory cytokines. In addition, recombinant CHI3L1 (rCHI3L1) administration inhibited the proliferation and function of activated T cells, and alleviated the Con A-induced liver injury in mice. Mechanistically, gene set enrichment analysis showed that JAK/STAT signalling pathway was one of the most significantly enriched gene pathways in T cells co-cultured with hUC-MSCs with CHI3L1 knockdown, and further study revealed that CHI3L1 secreted by hUC-MSCs inhibited the STAT1/3 signalling in T cells by upregulating peroxisome proliferator-activated receptor δ (PPARδ). Collectively, our data showed that CHI3L1 was a novel MSC-secreted immunosuppressive factor and provided new insights into therapeutic treatment of immune-mediated liver injury.

Mesenchymal stem cell-based treatment in autoimmune liver diseases: underlying roles, advantages and challenges

Autoimmune liver disease (AILD) is a series of chronic liver diseases with abnormal immune responses, including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). The treatment options for AILD remain limited, and the adverse side effects of the drugs that are typically used for treatment frequently lead to a low quality of life for AILD patients. Moreover, AILD patients may have a poor prognosis, especially those with an incomplete response to first-line treatment. Mesenchymal stem cells (MSCs) are pluripotent stem cells with low immunogenicity and can be conveniently harvested. MSC-based therapy is emerging as a promising approach for treating liver diseases based on their advantageous characteristics of immunomodulation, anti-fibrosis effects, and differentiation to hepatocytes, and accumulating evidence has revealed the positive effects of MSC therapy in AILD. In this review, we first summarize the mechanisms, safety, and efficacy of MSC treatment for AILD based on work in animal and clinical studies. We also discuss the challenges of MSC therapy in clinical applications. In summary, although promising data from preclinical studies are now available, MSC therapy is currently far for being applied in clinical practice, thus developing MSC therapy in AILD is still challenging and warrants further research.

The Role of IL-35 in the Pathophysiological Processes of Liver Disease

It is known that liver diseases have several characteristics of massive lipid accumulation and lipid metabolic disorder, and are divided into liver inflammation, liver fibrosis, liver cirrhosis (LC), and hepatocellular carcinoma (HCC) in patients. Interleukin (IL)-35, a new-discovered cytokine, can protect the liver from the environmental attack by increasing the ratio of Tregs (T regulatory cells) which can increase the anti-inflammatory cytokines and inhibit the proliferation of immune cellular. Interestingly, two opposite mechanisms (pro-inflammatory and anti-inflammatory) have connection with the ultimate formation of liver diseases, which suggest that IL-35 may play crucial function in the process of liver diseases through immunosuppressive regulation. Besides, some obvious advantages also imply that IL-35 can be considered as a new therapeutic target to control the progression of liver diseases, while its mechanism of function still needs further research.

Interleukin-35: An emerging player in the progression of liver diseases

Interleukin-35(IL-35), a newly identified immunosuppressive cytokine, has recently been shown to play a significant role in the progression of various autoimmune diseases and malignant tumors. The liver is the largest organ in the body and is generally regarded as an important lymphoid organ by an increasing number of immunologists. A number of reports have demonstrated that IL-35 plays essential roles in maintaining the immune homeostasis of the liver microenvironment. This review summarizes the existing studies of IL-35 in liver diseases, including viral hepatitis, immune liver injury, liver cirrhosis and carcinoma. We aimed to provide a comprehensive overview of the vital roles of IL-35 in hepatic damage and explore new alternative therapeutic targets for these diseases.

Interleukin-35 Suppresses CD8+ T Cell Activity in Patients with Viral Hepatitis-Induced Acute-on-Chronic Liver Failure

BACKGROUND

Interleukin (IL)-35 is a newly indentified cytokine and induces immunotolerance via suppression of CD8⁺ T cell activity in chronic viral hepatitis.

AIMS

To investigate the modulatory function of IL-35 to CD8⁺ T cells in viral hepatitis-induced acute-on-chronic liver failure (ACLF).

METHODS

Fifty-five ACLF patients and 21 healthy controls were enrolled. Serum IL-35 concentration was measured by ELISA. Absolute accounts for T cells, immune checkpoint molecules, and cytotoxic molecules in CD8⁺ T cells were measured by flow cytometry and real-time PCR, respectively. Direct and indirect contact co-culture systems between CD8⁺ T cells and HepG2 cells were set up. The regulatory function of IL-35 to CD8⁺ T cells was assessed by measuring lactate dehydrogenase expression and cytokine production.

RESULTS

Serum IL-35 concentration was elevated in ACLF patients and positively correlated with total bilirubin, but negatively correlated with prothrombin time activity. Peripheral CD8⁺ T cells showed exhausted phenotype in ACLF patients, which manifested as up-regulation of programmed death-1 (PD-1), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), and lymphocyte activation gene-3 (LAG-3) but down-regulation of perforin, granzyme B, and FasL. Recombinant IL-35 stimulation dampened cytotoxicity and interferon-γ production in both direct and indirect contact co-culture systems. This process was accompanied by elevation of PD-1, CTLA-4, and LAG3, as well as reduction of perforin, granzyme B, and FasL in CD8⁺ T cells.

CONCLUSION

Elevated IL-35 suppressed both cytolytic and non-cytolytic activity of CD8⁺ T cells in ACLF patients.

Interleukin-35 has a tumor-promoting role in hepatocellular carcinoma

Hepatic inflammatory response is a risk factor for liver cancer initiation and progression. Interleukin (IL)-35 is the newest member of the IL-12 cytokine family, and has been reported to play an essential role in the immunosuppressive liver microenvironment. Herein we focus on the expression profiles of IL-35 in hepatocellular carcinoma (HCC) and effects on local immune status. HCC transcriptome array data were downloaded from Gene Expression Omnibus (GEO). Analysis was performed by BRB-Array Tools and Ingenuity Pathway Analysis (IPA) software. Serum IL-35 level was detected by AimPlet bead-based immunoassay. In-situ IL-35 detection was performed by immunohistochemical staining and Western blot. The n-vitro effect of IL-35 on CD4⁺ or CD8⁺ T cell function was detected by flow cytometry. Our results showed that there were large amounts of IL-35 expressed in HCC serum and tumor tissues. IL-35 expression affects the transcript of thousands of genes, most differentially expressed genes (DEGs), in tumor tissues correlated with T cell immunity. The IL-35 high-expression group exhibited enhancement of regulatory T cells (T_regs ) and impairment of cytolytic T cells. In-vitro experiments proved that exogenous IL-35 stimulated the expression of programmed cell death 1 (PD-1) and lymphocyte activation gene-3 (LAG3) in CD4⁺ and CD8⁺ T cells. In addition, the stimulating effect was time-dependent. Furthermore, IL-35 inhibited interferon (IFN)-γ secretion by CD4⁺ and CD8⁺ T cells. Elevated IL-35 had an immune suppressive role in HCC tumor microenvironments through affecting inhibitor receptor expression and cytokine secretion of CD4⁺ and CD8⁺ T cells. Dissection of the precise targets and underlying molecular mechanisms would mean alternative treatments for HCC patients.

Lentivirus-mediated IL-10-expressing Bone Marrow Mesenchymal Stem Cells promote corneal allograft survival via upregulating lncRNA 003946 in a rat model of corneal allograft rejection

Rationale: Corneal transplantation is an effective treatment to corneal blindness. However, the immune rejection imperils corneal allograft survival. An interventional modality is urgently needed to inhibit immune rejection and promote allograft survival. In our previous study, subconjunctival injections of bone marrow-derived mesenchymal stem cells (BM-MSCs) into a rat model of corneal allograft rejection extended allograft survival for 2 d. In this study, we sought to generate IL-10-overexpressing BM-MSCs, aiming to boost the survival-promoting effects of BM-MSCs on corneal allografts and explore the molecular and cellular mechanisms underlying augmented protection. Methods: A population of IL-10-overexpressing BM-MSCs (designated as IL-10-BM-MSCs) were generated by lentivirus transduction and FACS purification. The self-renewal, multi-differentiation, and immunoinhibitory capabilities of IL-10-BM-MSCs were examined by conventional assays. The IL-10-BM-MSCs were subconjunctivally injected into the model of corneal allograft rejection, and the allografts were monitored on a daily basis. The expression profiling of long noncoding RNA (lncRNA) in the allografts was revealed by RNA sequencing and verified by quantitative real-time PCR. The infiltrating immune cell type predominantly upregulating the lncRNA expression was identified by RNAscope in situ hybridization. The function of the upregulated lncRNA was proved by loss- and gain-of-function experiments both in vivo and in vitro. Results: The IL-10-BM-MSCs possessed an enhanced immunoinhibitory capability and unabated self-renewal and multi-differentiation potentials as compared to plain BM-MSCs. The subconjunctivally injected IL-10-BM-MSCs reduced immune cell infiltration and doubled allograft survival time (20 d) as compared to IL-10 protein or plain BM-MSCs in the corneal allograft rejection model. Further, IL-10-BM-MSCs significantly upregulated lncRNA 003946 expression in CD68⁺ macrophages infiltrating corneal allografts. Silencing and overexpressing lncRNA 003946 in macrophage cultures abolished and mimicked the IL-10-BM-MSCs' suppressing effects on the macrophages' antigen presentation, respectively. In parallel, knocking down and overexpressing the lncRNA in vivo abrogated and simulated the survival-promoting effects of IL-10-BM-MSCs on corneal allografts, respectively. Conclusion: The remarkable protective effects of IL-10-BM-MSCs support further developing them into an effective interventional modality against corneal allograft rejection. IL-10-BM-MSCs promote corneal allograft survival mainly through upregulating a novel lncRNA expression in graft-infiltrating CD68⁺ macrophages. LncRNA, for the first time, is integrated into an IL-10-BM-MSC-driven immunomodulatory axis against the immune rejection to corneal allograft.

Interleukin-12p35 knockout promotes macrophage differentiation, aggravates vascular dysfunction, and elevates blood pressure in angiotensin II-infused mice

AIMS

Numerous studies have demonstrated that inflammation is involved in the progression of hypertension. Inflammatory cytokines interleukin (IL)-12 and IL-35 belong to the IL-12 cytokine family and share the same IL-12p35 subunit. Accumulating evidence has demonstrated that IL-12p35 knockout (IL-12p35 KO) leads to cardiovascular disease by regulating the inflammatory response. This study aimed to investigate whether IL-12p35 KO elevates blood pressure in a hypertension mouse model.

METHODS AND RESULTS

Mice with angiotensin (Ang) II infusion showed marked aortic IL-12p35 expression; thus, aortic macrophages may be the main source of IL-12p35. Wild-type and IL-12p35 KO mice were infused with Ang II or saline. IL-12p35 KO promoted M1 macrophage differentiation, amplified the inflammatory response, aggravated vascular dysfunction, and elevated blood pressure in Ang II-treated mice. Then, some Ang II-infused mice were given phosphate buffer saline, mouse recombinant IL-12 (rIL-12), or rIL-35, and the results showed that rIL-12 but not rIL-35 treatment had an antihypertensive effect on Ang II-infused mice. In addition, detection of human plasma IL-12 levels in hypertensive patients and control subjects showed that IL-12 was significantly increased in hypertensive patients when compared with control subjects. In hypertensive patients, IL-12 levels were positively correlated with blood pressure.

CONCLUSION

IL-12p35 KO amplifies the inflammatory response and promotes blood pressure elevation in Ang II-treated mice. In addition, IL-12, but not IL-35, plays a protective role in the Ang II-induced hypertension model. Thus, IL-12 may be a novel therapeutic agent for the prevention and treatment of clinical hypertension.

Identifying the Therapeutic Significance of Mesenchymal Stem Cells

The pleiotropic behavior of mesenchymal stem cells (MSCs) has gained global attention due to their immense potential for immunosuppression and their therapeutic role in immune disorders. MSCs migrate towards inflamed microenvironments, produce anti-inflammatory cytokines and conceal themselves from the innate immune system. These signatures are the reason for the uprising in the sciences of cellular therapy in the last decades. Irrespective of their therapeutic role in immune disorders, some factors limit beneficial effects such as inconsistency of cell characteristics, erratic protocols, deviating dosages, and diverse transfusion patterns. Conclusive protocols for cell culture, differentiation, expansion, and cryopreservation of MSCs are of the utmost importance for a better understanding of MSCs in therapeutic applications. In this review, we address the immunomodulatory properties and immunosuppressive actions of MSCs. Also, we sum up the results of the enhancement, utilization, and therapeutic responses of MSCs in treating inflammatory diseases, metabolic disorders and diabetes.

Mesenchymal stem cells: a promising way in therapies of graft-versus-host disease

It is well acknowledged that allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for numerous malignant blood diseases, which has also been applied to autoimmune diseases for more than a decade. Whereas graft-versus-host disease (GVHD) occurs after allogeneic hematopoietic stem cell transplantation (allo-HSCT) as a common serious complication, seriously affecting the efficacy of transplantation. Mesenchymal stem cells (MSCs) derived from a wealth of sources can easily isolate and expand with low immunogenicity. MSCs also have paracrine and immune regulatory functions, leading to a broad application prospect in treatment and tissue engineering. This review focuses on immunoregulatory function of MSCs, factors affecting mesenchymal stem cells to exert immunosuppressive effects, clinical application of MSCs in GVHD and researches on MSC-derived extracellular vesicles (EVs). The latest research progress on MSC in related fields is reviewed as well. The relevant literature from PubMed databases is reviewed in this article.

STAT4: an immunoregulator contributing to diverse human diseases

Signal transducer and activator of transcription 4 (STAT4) is a member of the STAT family and localizes to the cytoplasm. STAT4 is phosphorylated after a variety of cytokines bind to the membrane, and then dimerized STAT4 translocates to the nucleus to regulate gene expression. We reviewed the essential role played by STAT4 in a wide variety of cells and the pathogenesis of diverse human diseases, especially many kinds of autoimmune and inflammatory diseases, via activation by different cytokines through the Janus kinase (JAK)-STAT signaling pathway.

Mesenchymal stromal cells promote liver regeneration through regulation of immune cells

The liver is sensitive to pathogen-induced acute or chronic liver injury, and liver transplantation (LT) is the only effective strategy for end-stage liver diseases. However, the clinical application is limited by a shortage of liver organs, immunological rejection and high cost. Mesenchymal stromal cell (MSC)-based therapy has gradually become a hot topic for promoting liver regeneration and repairing liver injury in various liver diseases, since MSCs are reported to migrate toward injured tissues, undergo hepatogenic differentiation, inhibit inflammatory factor release and enhance the proliferation of liver cells in vivo. MSCs exert immunoregulatory effects through cell-cell contact and the secretion of anti-inflammatory factors to inhibit liver inflammation and promote liver regeneration. In addition, MSCs are reported to effectively inhibit the activation of cells of the innate immune system, including macrophages, natural killer (NK) cells, dendritic cells (DCs), monocytes and other immune cells, and inhibit the activation of cells of the adaptive immune system, including T lymphocytes, B lymphocytes and subsets of T cells or B cells. In the current review, we mainly focus on the potential effects and mechanisms of MSCs in inhibiting the activation of immune cells to attenuate liver injury in models or patients with acute liver failure (ALF), nonalcoholic fatty liver disease (NAFLD), and liver fibrosis and in patients or models after LT. We highlight that MSC transplantation may replace general therapies for eliminating acute or chronic liver injury in the near future.

Mycophenolate mofetil attenuates concanavalin A-induced acute liver injury through modulation of TLR4/NF-κB and Nrf2/HO-1 pathways

BACKGROUND

Acute liver injury (ALI) is a serious health condition associated with rising morbidity and sudden progression. This study was designed to investigate the possible hepatocurative potential of two dose levels (30 and 60 mg/kg) of Mycophenolate mofetil (MMF), an immune-suppressant agent, against Concanavalin A (Con A)-induced ALI in mice.

METHOD

A single dose of Con A (20 mg/kg, IV) was used to induce ALI in mice. MMF (30 mg/kg and 60 mg/kg) was administered orally for 4 days post Con A injection.

RESULTS

MMF (30 mg/kg) failed to cause significant amelioration in Con A-induced ALI while MMF (60 mg/kg) significantly alleviated Con A-induced ALI. Administration of MMF (60 mg/kg) significantly decreased Con A-induced increase in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Additionally, MMF significantly restored the disrupted oxidant/antioxidants status induced by Con A. MMF caused marked increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels. Moreover, MMF significantly reduced Con A-induced increase in the expression of hepatic toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ) and interleukin-1β (Il-1β). Also, MMF administration significantly decreased Con A-induced increase in the immune-expression of pro-apoptotic Bcl-2-associated X protein (Bax) and markedly increased Con A-induced decrease in the anti-apoptotic B-cell lymphoma 2 protein (Bcl2).

CONCLUSION

The observed ameliorative effect of MMF against Con A-induce ALI may be contributed to its anti-inflammatory, anti-oxidant and anti-apoptotic potentials taking into consideration that TLR4/NF-κB and Nrf2/HO-1 are the main implicated pathways. Schematic diagram summarizing the possible mechanisms underlying the ameliorative potential of Mycophenolate Mofetil against Con A-induced acute liver injury. Bax Bcl-2-associated X protein, Bcl2 B-cell lymphoma 2, MMF Mycophenolate mofetil, Con A Concanavalin A, GSH reduced glutathione, HO-1 Heme oxygenase-1, IL-1β Interleukin-1β, IFN-γ Interferon-γ, MDA Malondialdehyde, NF-κB Nuclear Factor Kappa B, Nrf2 Nuclear factor erythroid 2-related factor 2, NO Nitric Oxide, SOD Superoxide Dismutase, TLR4 Toll-like receptor 4, TNF-α tumor necrosis factor-α.

Inhibition of cardiac allograft rejection in mice using interleukin-35-modified mesenchymal stem cells

Interleukin-35 (IL-35) is a cytokine recently discovered to play a potent immunosuppressive role by intensifying the functions of regulatory T cells and inhibiting the proliferation and functions of T helper 1 and T helper 17 cells. Mesenchymal stem cells (MSCs) have recently emerged as promising candidates for cell-based immune therapy, and our previous study showed that IL-35 gene modification can effectively enhance the therapeutic effect of MSCs in vitro. In this study, we isolated adipose tissue-derived MSCs in vitro and infected them with lentiviral vectors overexpressing the IL-35 gene, thereby creating IL-35-MSCs. Subsequently, IL-35-MSCs were then injected into mice of the allogeneic heterotopic abdominal heart transplant model to determine their effect on allograft rejection. The results showed that IL-35-MSCs could continuously secrete IL-35 in vivo and in vitro, successfully alleviate allograft rejection and prolong graft survival. In addition, compared to MSCs, IL-35-MSCs showed a stronger immunosuppressive ability and further reduced the percentage of Th17 cells, increased the proportion of CD4⁺ Foxp3⁺ T cells, and regulated Th1/Th2 balance in heart transplant mice. These findings suggest that IL-35-MSCs have more advantages than MSCs in inhibiting graft rejection and may thus provide a new approach for inducing immune tolerance during transplantation.

Mesenchymal stem cells overexpressing IL-35: a novel immunosuppressive strategy and therapeutic target for inducing transplant tolerance

Inducing donor-specific immunological tolerance, which avoids the complications of long-term immunosuppression, is an important goal in organ transplantation. Interleukin-35 (IL-35), a cytokine identified in 2007, is mainly secreted by regulatory T cells (Tregs) and is essential for Tregs to exert their maximal immunoregulatory activity in vitro and in vivo. A growing number of studies show that IL-35 plays an important role in autoimmune diseases and infectious diseases. Recent research has shown that IL-35 could effectively alleviate allograft rejection and has the potential to be a novel therapeutic strategy for graft rejection. With increasing study of immunoregulation, cell-based therapy has become a novel approach to attenuate rejection after transplantation. Mesenchymal stem cells (MSCs), which exhibit important properties of multilineage differentiation, tissue repair, and immunoregulation, have recently emerged as attractive candidates for cell-based therapeutics, especially in transplantation. Accumulating evidence demonstrates that the therapeutic abilities of MSCs can be amplified by gene modification. Therefore, researchers have constructed IL-35 gene-modified MSCs and explored their functions and mechanisms in some disease models. In this review, we discuss the potential tolerance-inducing effects of MSCs in transplantation and briefly introduce the immunoregulatory functions of the IL-35 gene-modified MSCs.

Interleukin-12p35 Knock Out Aggravates Doxorubicin-Induced Cardiac Injury and Dysfunction by Aggravating the Inflammatory Response, Oxidative Stress, Apoptosis and Autophagy in Mice

Background

Recent evidence has demonstrated that interleukin 12p35 knockout (IL-12p35 KO) is involved in cardiac diseases by regulating the inflammatory response. The involvement of inflammatory cells has also been observed in doxorubicin (DOX)-induced cardiac injury. This study aimed to investigate whether IL-12p35 KO affects DOX-induced cardiac injury and the underlying mechanisms.

Methods

First, the effect of DOX treatment on cardiac IL-12p35 expression was assessed. In addition, to investigate the effect of IL-12p35 KO on DOX-induced cardiac injury, IL-12p35 KO mice were treated with DOX. Because IL-12p35 is the mutual subunit of IL-12 and IL-35, to determine the cytokine that mediates the effect of IL-12p35 KO on DOX-induced cardiac injury, mice were given phosphate-buffered saline (PBS), mouse recombinant IL-12 (rIL-12) or rIL-35 before treatment with DOX.

Results

DOX treatment significantly increased the level of cardiac IL-12p35 expression. In addition, IL-12p35 KO mice exhibited higher serum and heart lactate dehydrogenase levels, higher serum and heart creatine kinase myocardial bound levels, and greater cardiac dysfunction than DOX-treated mice. Furthermore, IL-12p35 KO further increased M1 macrophage and decreased M2 macrophage differentiation, aggravated the imbalance of oxidants and antioxidants, and further activated the mitochondrial apoptotic pathway and endoplasmic reticulum stress autophagy pathway. Both rIL-12 and rIL-35 protected against DOX-induced cardiac injury by alleviating the inflammatory response, oxidative stress, apoptosis and autophagy.

Conclusions

IL-12p35 KO aggravated DOX-induced cardiac injury by amplifying the levels of inflammation, oxidative stress, apoptosis and autophagy. (234 words).

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IL-12p35 KO aggravates DOX-induced cardiac injury and dysfunction.

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IL-12p35 further increases the DOX-induced imbalance in inflammation, oxidative stress, apoptosis and autophagy.

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Both exogenous rIL-12 and rIL-35 relieved cardiac injury mediated by DOX.

CD4+ T helper (Th) cells are closely related to cardiac injury; regulatory T cells (Tregs) are a new subset of Th cells, and IL-35 is the functional cytokine of Tregs. Cardiac injury mediated by DOX is the most serious complication during chemotherapy, and there are no good preventive measures. This study aimed to investigate whether IL-35 can reduce cardiac injury induced by DOX during chemotherapy. In addition to IL-35, IL-12p35 KO can cancel the biological effect of IL-12; therefore, we also determined whether IL-12 participates in DOX-induced cardiac injury and the underlying mechanisms.

Adoptive immunotherapy for autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease caused by an autoimmune disorder, which has attracted more and more attention due to its unique clinical and pathological features. European epidemiological data show that the incidence of AIH is increasing year by year, but its pathogenesis is not yet clear, and the targeted treatments are limited. Immunotherapy of autoimmune hepatitis has been extensively studied in recent years, especially in the area of adoptive immunotherapy. In this paper, we summarize the functional mechanism and clinical applications of adoptive immunotherapy with different kinds of immunocompetent cells in the treatment of AIH.