Mesenchymal stem cell transplantation in systemic lupus erythematous, a mesenchymal stem cell disorder

Prospects for the Application of Transplantation With Human Amniotic Membrane Epithelial Stem Cells in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multi-organ and systemic autoimmune disease characterized by an imbalance of humoral and cellular immunity. The efficacy and side effects of traditional glucocorticoid and immunosuppressant therapy remain controversial. Recent studies have revealed abnormalities in mesenchymal stem cells (MSCs) in SLE, leading to the application of bone marrow-derived MSCs (BM-MSCs) transplantation technique for SLE treatment. However, autologous transplantation using BM-MSCs from SLE patients has shown suboptimal efficacy due to their dysfunction, while allogeneic mesenchymal stem cell transplantation (MSCT) still faces challenges, such as donor degeneration, genetic instability, and immune rejection. Therefore, exploring new sources of stem cells is crucial for overcoming these limitations in clinical applications. Human amniotic epithelial stem cells (hAESCs), derived from the eighth-day blastocyst, possess strong characteristics including good differentiation potential, immune tolerance with low antigen-presenting ability, and unique immune properties. Hence, hAESCs hold great promise for the treatment of not only SLE but also other autoimmune diseases.

Association of interleukin 33 gene polymorphisms with susceptibility and regulation of inflammatory mediators in Systemic lupus erythematosus patients

BACKGROUND

Studies have indicated the involvement of interleukin (IL)-33 in the pathogenesis of Systemic lupus erythematosus (SLE). This research intended to evaluate the association of IL33 gene rs1929992 and rs7044343 Single nucleotide polymorphisms (SNPs) with risk of SLE. In addition, the association between these SNPs and inflammatory cytokines was determined.

METHODS

In this study, 200 SLE cases and 200 healthy subjects were recruited. Using allelic discrimination Real-time PCR, IL33 gene rs1929992 and rs7044343 SNPs were genotyped. The mRNA expression levels of IL-1β, IL-6, IL-33, TNF-α were determined in the peripheral blood mononuclear cells (PBMCs). The serum levels of cytokines were also measured.

RESULTS

The G allele (OR = 1.57, CI: 1.18-2.08, P = 0.0017), GG genotype (OR = 2.52, CI: 1.33-4.77, P = 0.0043), and GA genotype (OR = 2.12, CI: 1.34-3.34, P = 0.0011) of rs1929992 SNP was significantly associated with an increased SLE risk. The C allele (OR = 1.44, CI: 1.08-1.90; P = 0.0105), CC genotype (OR = 2.07, CI: 1.15-3.71; P = 0.0146), and CT genotype (OR = 1.61, CI: 1.02-2.53, P = 0.0395) of rs7044343 was significantly associated with increased SLE risk. The PBMC mRNA expression and serum levels of IL-1β, IL-6, IL-33, TNF-α were significantly increased in the SLE patients compared to controls. However, there was no significant difference in the mRNA expression and serum levels of IL-1β, IL-6, IL-33, and TNF-α among the SLE patients with three genotypes for both rs1929992 and rs7044343 polymorphisms.

CONCLUSIONS

IL33 gene rs1929992 and rs7044343 SNPs are involved in SLE pathogenesis but they might not influence on the inflammatory pathway.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.

The role of mesenchymal stem cell transplantation for ischemic stroke and recent research developments

Ischemic stroke is a common cerebrovascular disease that seriously affects human health. However, most patients do not practice self-care and cannot rely on the current clinical treatment for guaranteed functional recovery. Stem cell transplantation is an emerging treatment studied in various central nervous system diseases. More importantly, animal studies show that transplantation of mesenchymal stem cells (MSCs) can alleviate neurological deficits and bring hope to patients suffering from ischemic stroke. This paper reviews the biological characteristics of MSCs and discusses the mechanism and progression of MSC transplantation to provide new therapeutic directions for ischemic stroke.

Trehalose improves palmitic acid-induced apoptosis of osteoblasts by regulating SIRT3-medicated autophagy via the AMPK/mTOR/ULK1 pathway

Accumulation of lipid substances decreased the activity of osteoblasts. Trehalose is a typical stress metabolite to form a protective membrane on cell surface which has been demonstrated to regulate lipid metabolism. This activity of Trehalose indicates the potential effect of osteoporosis treatment. Our study aimed to determine the therapeutic effect of Trehalose in high fat-induced osteoporosis. We used palmitic acid (PA) to mimic the state of high fat and observed the apoptosis ratio of osteoblasts increased. After adding Trehalose, the apoptosis ratio decreased obviously. Autophagy is a regulatory means involved in the process of apoptosis. We detected the autophagy protein and found that the expression of Beclin-1, Atg5, and LC3 II increased, and p62 decreased after Trehalose treatment. When adding an autophagy inhibitor (3-MA), the expression of Beclin-1, Atg5, and LC3 II decreased, and p62 increased. These results indicated autophagy was an important factor involved in the preventive effect of Trehalose in PA-induced apoptosis. SIRT3 is a mitochondrial gene that can inhibit apoptosis, which has been reported to promote autophagy. We used SIRT3-siRNA to silence the expression of SIRT3 and found the effect of Trehalose was counteracted. The apoptosis ratio increased and the expression of Beclin-1, Atg5, and LC3 II decreased, p62 increased. Additionally, we also fed the mice with a high-fat diet (HFD) and intragastrical Trehalose. The results showed that Trehalose could inhibit the bone mass loss with HFD. Our study revealed the effect and mechanism of Trehalose in the treatment of osteoporosis.

Mesenchymal Stem Cell-Derived Secretome: A Potential Therapeutic Option for Autoimmune and Immune-Mediated Inflammatory Diseases

Immune-mediated inflammatory diseases (IMIDs) encompass several entities such as "classic" autoimmune disorders or immune-mediated diseases with autoinflammatory characteristics. Adult stem cells including mesenchymal stem cells (MSCs) are by far the most commonly used type in clinical practice. However, due to the possible side effects of MSC-based treatments, there is an increase in interest in the MSC-secretome (containing large extracellular vesicles, microvesicles, and exosomes) as an alternative therapeutic option in IMIDs. A wide spectrum of MSC-secretome-related biological activities has been proven thus far including anti-inflammatory, anti-apoptotic, and immunomodulatory properties. In comparison with MSCs, the secretome is less immunogenic but exerts similar biological actions, so it can be considered as an ideal cell-free therapeutic alternative. Additionally, since the composition of the MSC-secretome can be engineered, for a future perspective, it could also be viewed as part of a potential delivery system within nanomedicine, allowing us to specifically target dysfunctional cells or tissues. Although many encouraging results from pre-clinical studies have recently been obtained that strongly support the application of the MSC-secretome in IMIDs, human studies with MSC-secretome administration are still in their infancy. This article reviews the immunomodulatory effects of the MSC-secretome in IMIDs and provides insight into the interpretation of its beneficial biological actions.

Universal or Personalized Mesenchymal Stem Cell Therapies: Impact of Age, Sex, and Biological Source

Mesenchymal stem/stromal cells (MSCs) hold great promise for the treatment of autoimmune conditions given their immunomodulatory properties. Based on the low immunogenicity of MSCs, it is tempting to consider the expansion of MSCs from a “universal donor” in culture prior to their allogeneic applications for immediate care. This raises the critical question of the criteria we should use to select the best “universal donor”. It is also imperative we compare the “universal” approach with a “personalized” one for clinical value. In addition to the call for MHC-matching, recent studies suggest that factors including age, sex, and biological sources of MSCs can have significant impact on therapy outcome. Here, we will review findings from these studies, which shed light on the variables that can guide the important choice of “universal” or “personalized” MSC therapy for autoimmune diseases.

Extracellular Vesicles Released from Stem Cells as a New Therapeutic Strategy for Primary and Secondary Glomerulonephritis

Current treatment of primary and secondary glomerulopathies is hampered by many limits and a significant proportion of these disorders still evolves towards end-stage renal disease. A possible answer to this unmet challenge could be represented by therapies with stem cells, which include a variety of progenitor cell types derived from embryonic or adult tissues. Stem cell self-renewal and multi-lineage differentiation ability explain their potential to protect and regenerate injured cells, including kidney tubular cells, podocytes and endothelial cells. In addition, a broad spectrum of anti-inflammatory and immunomodulatory actions appears to interfere with the pathogenic mechanisms of glomerulonephritis. Of note, mesenchymal stromal cells have been particularly investigated as therapy for Lupus Nephritis and Diabetic Nephropathy, whereas initial evidence suggest their beneficial effects in primary glomerulopathies such as IgA nephritis. Extracellular vesicles mediate a complex intercellular communication network, shuttling proteins, nucleic acids and other bioactive molecules from origin to target cells to modulate their functions. Stem cell-derived extracellular vesicles recapitulate beneficial cytoprotective, reparative and immunomodulatory properties of parental cells and are increasingly recognized as a cell-free alternative to stem cell-based therapies for different diseases including glomerulonephritis, also considering the low risk for potential adverse effects such as maldifferentiation and tumorigenesis. We herein summarize the renoprotective potential of therapies with stem cells and extracellular vesicles derived from progenitor cells in glomerulonephritis, with a focus on their different mechanisms of actions. Technological progress and growing knowledge are paving the way for wider clinical application of regenerative medicine to primary and secondary glomerulonephritis: this multi-level, pleiotropic therapy may open new scenarios overcoming the limits and side effects of traditional treatments, although the promising results of experimental models need to be confirmed in the clinical setting.

Allogeneic adipose-derived mesenchymal stromal cell transplantation for refractory lupus nephritis: Results of a phase I clinical trial

BACKGROUND

Mesenchymal stromal/stem cells (MSCs) are known for their immunomodulatory properties. This study was performed to analyse the effects of MSC transplantation on treatment-resistant lupus nephritis (LN).

METHODS

In this phase I trial, nine biopsy-proven LN patients refractory to standard treatments underwent systemic infusion of 2 × 10⁶ allogeneic adipose-derived (AD) MSCs/kg and were followed for 12 months post-intervention.

RESULTS

The treatment protocol resulted in no major adverse events. Urine protein levels significantly decreased during the first month post-intervention (baseline vs. month 1 (median): 1800 vs. 1020, P = 0.008), followed by a gradual increase but remained significantly lower than baseline only up to the 3rd month. During the first 3 months post-intervention, complete renal response (proteinuria < 0.5 g/24 h) and partial response (proteinuria > 0.5 g/24 h, but > 50% decrease in proteinuria) were observed in 33.3% and 44.4% of the patients, respectively, though these rates declined thereafter. Median score of Systemic Lupus Erythematosus Disease Activity Index decreased significantly from 16 at the baseline to 6 at sixth months post-treatment (P = 0.007), though it slightly increased at the 12th month follow-up.

CONCLUSIONS

Allogenic AD-MSC transplantation was associated with favourable safety and efficient to reduce urine protein excretion and disease activity; however, the maximum effect (greatest improvement in outcomes) was observed at 1 month based on the proteinuria, and 6 months post-intervention based on disease activity scores. A single dose of AD-MSCs may not be adequate to maintain long-term remission of refractory LN, and so, additional doses may be required.

Prospects for Manipulation of Mesenchymal Stem Cells in Tumor Therapy: Anti-Angiogenesis Property on the Spotlight

The interactions between the tumor microenvironment and the tumor cells confers a condition that accelerate or decelerate the development of tumor. Of these cells, mesenchymal stem cells (MSCs) have the potential to modulate the tumor cells. MSCs have been established with double functions, whereby contribute to a tumorigenic or anti-tumor setting. Clinical studies have indicated the potential of MSCs to be used as tool in treating the human cancer cells. One of the advantageous features of MSCs that make them as a well-suited tool for cancer therapy is the natural tumor-trophic migration potential. A key specification of the tumor development has been stablished to be angiogenesis. As a result, manipulation of angiogenesis has become an attractive approach for cancer therapy. This review article will seek to clarify the anti-angiogenesis strategy in modulating the MSCs to treat the tumor cells.

Labial gland-derived mesenchymal stem cells and their exosomes ameliorate murine Sjögren's syndrome by modulating the balance of Treg and Th17 cells

Background

Sjögren's syndrome (SS) is a chronic, systemic autoimmune disorder characterized by sicca syndrome and/or systemic manifestations. The disease severely affects the health and life of patients, and the treatment of SS has always been a clinical challenge and essentially palliative. Mesenchymal stem cells (MSCs) have been reported to exert immunomodulatory effects and as a potential novel therapeutic strategy for SS. Labial gland-derived MSCs (LGMSCs) are a population of resident stem cells in the labial gland, first isolated by our group. Exosomes released by MSCs contain a large variety of bioactive molecules and considered to function as an extension of MSCs.

Methods

LGMSCs were isolated from patients who were needed surgery to remove the lip mucocele and LGMSCs derived exosomes (LGMSC-Exos) were isolated by ultracentrifugation. The non-obese diabetic (NOD) mice were treated with LGMSCs or LGMSC-Exos by tail vein injection. The saliva flow rate of mice was determined and salivary glands were dissected and stained with hematoxylin and eosin. In vitro, peripheral blood mononuclear cells (PBMCs) from SS patients were cocultured with LGMSCs or LGMSC-Exos. Percentage of T helper 17 (Th17) cells and regulatory T (Treg) cells were determined by flow cytometry. The serum levels of cytokines in NOD mice and in the supernatant of the co-culture system by ELISA.

Results

Treatment with LGMSCs or LGMSC-Exos reduced inflammatory infiltration in the salivary glands, and restored salivary gland secretory function in NOD mice. Importantly, LGMSCs or LGMSC-Exos were demonstrated to inhibit the differentiation of Th17 cells but promote the induction of Treg cells in NOD mice and PBMCs from SS patients in vitro, accompanied by reduced interleukin 17 (IL-17), interferon gamma, and IL-6 levels and enhanced transforming growth factor beta and IL-10 secretion by T cells.

Conclusions

LGMSCs are potential candidates for MSCs-based therapy and LGMSC-Exos might be utilized for establishing a new cell-free therapy against SS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02541-0.

Bone Marrow Multipotent Mesenchymal Stromal Cells as Autologous Therapy for Osteonecrosis: Effects of Age and Underlying Causes

Bone marrow (BM) is a reliable source of multipotent mesenchymal stromal cells (MSCs), which have been successfully used for treating osteonecrosis. Considering the functional advantages of BM-MSCs as bone and cartilage reparatory cells and supporting angiogenesis, several donor-related factors are also essential to consider when autologous BM-MSCs are used for such regenerative therapies. Aging is one of several factors contributing to the donor-related variability and found to be associated with a reduction of BM-MSC numbers. However, even within the same age group, other factors affecting MSC quantity and function remain incompletely understood. For patients with osteonecrosis, several underlying factors have been linked to the decrease of the proliferation of BM-MSCs as well as the impairment of their differentiation, migration, angiogenesis-support and immunoregulatory functions. This review discusses the quality and quantity of BM-MSCs in relation to the etiological conditions of osteonecrosis such as sickle cell disease, Gaucher disease, alcohol, corticosteroids, Systemic Lupus Erythematosus, diabetes, chronic renal disease and chemotherapy. A clear understanding of the regenerative potential of BM-MSCs is essential to optimize the cellular therapy of osteonecrosis and other bone damage conditions.

Calcium channels and their role in regenerative medicine

Stem cells hold indefinite self-renewable capability that can be differentiated into all desired cell types. Based on their plasticity potential, they are divided into totipotent (morula stage cells), pluripotent (embryonic stem cells), multipotent (hematopoietic stem cells, multipotent adult progenitor stem cells, and mesenchymal stem cells [MSCs]), and unipotent (progenitor cells that differentiate into a single lineage) cells. Though bone marrow is the primary source of multipotent stem cells in adults, other tissues such as adipose tissues, placenta, amniotic fluid, umbilical cord blood, periodontal ligament, and dental pulp also harbor stem cells that can be used for regenerative therapy. In addition, induced pluripotent stem cells also exhibit fundamental properties of self-renewal and differentiation into specialized cells, and thus could be another source for regenerative medicine. Several diseases including neurodegenerative diseases, cardiovascular diseases, autoimmune diseases, virus infection (also coronavirus disease 2019) have limited success with conventional medicine, and stem cell transplantation is assumed to be the best therapy to treat these disorders. Importantly, MSCs, are by far the best for regenerative medicine due to their limited immune modulation and adequate tissue repair. Moreover, MSCs have the potential to migrate towards the damaged area, which is regulated by various factors and signaling processes. Recent studies have shown that extracellular calcium (Ca²⁺) promotes the proliferation of MSCs, and thus can assist in transplantation therapy. Ca²⁺ signaling is a highly adaptable intracellular signal that contains several components such as cell-surface receptors, Ca²⁺ channels/pumps/exchangers, Ca²⁺ buffers, and Ca²⁺ sensors, which together are essential for the appropriate functioning of stem cells and thus modulate their proliferative and regenerative capacity, which will be discussed in this review.

Regulatory Effect of Mesenchymal Stem Cells on T Cell Phenotypes in Autoimmune Diseases

Research on mesenchymal stem cells (MSCs) starts from the earliest assumption that cells derived from the bone marrow have the ability to repair tissues. Several scientists have since documented the crucial role of bone marrow-derived MSCs (BM-MSCs) in processes such as embryonic bone and cartilage formation, adult fracture and tissue repair, and immunomodulatory activities in therapeutic applications. In addition to BM-MSCs, several sources of MSCs have been reported to possess tissue repair and immunoregulatory abilities, making them potential treatment options for many diseases. Therefore, the therapeutic potential of MSCs in various diseases including autoimmune conditions has been explored. In addition to an imbalance of T cell subsets in most patients with autoimmune diseases, they also exhibit complex disease manifestations, overlapping symptoms among diseases, and difficult treatment. MSCs can regulate T cell subsets to restore their immune homeostasis toward disease resolution in autoimmune conditions. This review summarizes the role of MSCs in relieving autoimmune diseases via the regulation of T cell phenotypes.

Human Umbilical Cord Mesenchymal Stem Cells Improve Ovarian Function in Chemotherapy-Induced Premature Ovarian Failure Mice Through Inhibiting Apoptosis and Inflammation via a Paracrine Mechanism

Human umbilical cord mesenchymal stem cell (UC-MSC) application is a promising arising therapy for the treatment of premature ovarian failure (POF). However, little is known about the inflammation regulatory effects of human umbilical cord MSCs (UC-MSCs) on chemotherapy-induced ovarian damage, regardless of in vivo or in vitro. This study was designed to investigate the therapeutic effects of UC-MSC transplantation and underlying mechanisms regarding both apoptosis and inflammation in POF mice. The chemotherapy-induced POF models were induced by intraperitoneal injection of cyclophosphamide. Ovarian function parameters, granulosa cell (GC) apoptosis, and inflammation were examined. Morphological staining showed that UC-MSC treatment increased the ovary size, and the numbers of primary and secondary follicles, but decreased the number of atretic follicles. Estradiol levels in the UC-MSC-treated group were increased while follicle-stimulating hormone levels were reduced compared to those in the POF group. UC-MSCs inhibited cyclophosphamide-induced GC apoptosis and inflammation. Meanwhile, phosphorylation of AKT and P38 was elevated after UC-MSC treatment. Tracking of UC-MSCs in vivo indicated that transplanted UC-MSCs were only located in the interstitium of ovaries rather than in follicles. Importantly, UC-MSC-derived extracellular vesicles protected GCs from alkylating agent-induced apoptosis and inflammation in vitro. Our results suggest that UC-MSC transplantation can reduce ovary injury and improve ovarian function in chemotherapy-induced POF mice through anti-apoptotic and anti-inflammatory effects via a paracrine mechanism.

An Update for Mesenchymal Stem Cell Therapy in Lupus Nephritis

Background

Lupus nephritis (LN) is the most severe organ manifestations of systemic lupus erythematosus (SLE). Although increased knowledge of the disease pathogenesis has improved treatment options, outcomes have plateaued as current immunosuppressive therapies have failed to prevent disease relapse in more than half of treated patients. Thus, there is still an urgent need for novel therapy. Mesenchymal stem cells (MSCs) possess a potently immunosuppressive regulation on immune responses, and intravenous transplantation of MSCs ameliorates disease symptoms and has emerged as a potential beneficial therapy for LN. The objective of this review is to discuss the defective functions of MSCs in LN patients and the application of MSCs in the treatment of both LN animal models and patients.

Summary

Bone marrow MSCs from SLE patients exhibit impaired capabilities of migration, differentiation, and immune regulation and display senescent phenotype. Allogeneic MSCs suppress autoimmunity and restore renal function in mouse models and patients with LN by inducing regulatory immune cells and suppressing Th1, Th17, T follicular helper cell, and B-cell responses. In addition, MSCs can home to the kidney and integrate into tubular cells and differentiate into mesangial cells.

Key Messages

The efficacy of MSCs in the LN treatment remains to be confirmed, and future advances from stem cell science can be expected to pinpoint significant MSC subpopulations, as well as specific mechanisms of action, leading the way to the use of more potent stimulated or primed pretreated MSCs to treat LN.

Targeting the Protective Arm of the Renin-Angiotensin System to Reduce Systemic Lupus Erythematosus Related Pathologies in MRL-lpr Mice

Patients with Systemic Lupus Erythematosus (SLE) suffer from a chronic inflammatory autoimmune disease that results from the body's immune system targeting healthy tissues which causes damage to various organ systems. Patients with lupus are still in need of effective therapies to treat this complex, multi-system disease. Because polymorphisms in ACE are associated with the activity of SLE and lupus nephritis and based on well-documented renal-protective effects of Renin Angiotensin System (RAS)-modifying therapies, ACE-I are now widely used in patients with SLE with significant efficacy. Our research explores alternate ways of modifying the RAS as a potential for systemic therapeutic benefit in the MRL-lpr mouse model of SLE. These therapeutics include; angiotensin (1-7) [A(1-7)], Nor-Leu-3 Angiotensin (1-7) (NorLeu), Losartan (ARB), and Lisinopril (ACE-I). Daily systemic treatment with all of these RAS-modifying therapies significantly reduced the onset and intensity in rash formation and swelling of the paw. Further, histology showed a corresponding decrease in hyperkeratosis and acanthosis in skin sections. Important immunological parameters such as decreased circulating anti-dsDNA antibodies, lymph node size, and T cell activation were observed. As expected, the development of glomerular pathologies was also attenuated by RAS-modifying therapy. Improved number and health of mesenchymal stem cells (MSCs), as well as reduction in oxidative stress and inflammation may be contributing to the reduction in SLE pathologies. Several studies have already characterized the protective role of ACE-I and ARBs in mouse models of SLE, here we focus on the protective arm of RAS. A(1-7) in particular demonstrates several protective effects that go beyond those seen with ACE-Is and ARBs; an important finding considering that ACE-Is and ARBs are teratogenic and can cause hypotension in this population. These results offer a foundation for further pharmaceutical development of RAS-modifying therapies, that target the protective arm, as novel SLE therapeutics that do not rely on suppressing the immune system.

Targeting HMGB1 by ethyl pyruvate ameliorates systemic lupus erythematosus and reverses the senescent phenotype of bone marrow-mesenchymal stem cells

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs and systems. Mesenchymal stem cells (MSCs) from SLE patients have demonstrated defects such as impaired growth, senescence phenotype and immunomodulatory functions. Some studies have suggested the close connection between inflammation microenvironment and cellular senescence. In the current study, we detected cytokines levels in bone marrow supernatant by the quantitative proteomics analysis, and found the expression of HMGB1 was remarkably increased in bone marrow from SLE patients. Senescence associated-β-galactosidase (SA-β-gal) staining, F-actin staining and flow cytometry were used to detect the senescence of cells. After stimulation of HMGB1 in normal MSCs, the ratio of SA-β-gal positive in BM-MSCs was increased, the organization of cytoskeleton was disordered, and TLR4-NF-κB signaling was activated. Finally, Ethyl pyruvate (EP) (40 mg/kg and 100 mg/kg, three times a week), a high security HMGB1 inhibitor, was injected intraperitoneally to treat MRL/lpr mice for 8 weeks. We demonstrated that EP alleviated the clinical aspects of lupus nephritis and prolonged survival of MRL/lpr mice. In the meantime, EP reversed the senescent phenotype of BM-MSCs from MRL/lpr mice. HMGB1 could be a promising target in SLE patients, and might be one of the reasons of recurrence after MSCs transplantation.

Characterization of the immunomodulatory properties of alveolar bone-derived mesenchymal stem cells

Background

Recently, mesenchymal stem cells (MSCs) have been shown to have immunomodulatory properties which hold promise for their clinical use to treat inflammatory conditions. Relative to bone marrow-derived MSCs (BMSCs), which are typically isolated from the iliac crest, we have recently demonstrated that MSCs can be predictably isolated from the alveolar bone (aBMSCs) by less invasive means. As such, the aim of this study was to characterize the immunomodulatory properties of aBMSCs relative to BMSCs.

Methods

aBMSCs isolated from the human alveolar bone and BMSCs isolated from the human bone marrow of the iliac crest were cultured in the same conditions. Cytokine arrays and enzyme-linked immunosorbent assays (ELISA) of a conditioned medium were used to evaluate differences in the secretion of cytokines. In different functional assays, aBMSCs and BMSCs were cocultured with different types of immune cells including THP-1 monocytes, macrophages, and peripheral blood mononuclear cells (PBMCs) to evaluate their effects on important immune cell functions including proliferation, differentiation, and activation.

Results

The protein arrays identified interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 to be the major cytokines secreted by aBMSCs and BMSCs. ELISA determined that aBMSCs secreted 268.64 ± 46.96 pg/mL of IL-6 and 196.14 ± 97.31 pg/mL of MCP-1 per microgram of DNA, while BMSCs secreted 774.86 ± 414.29 pg/mL of IL-6 and 856.37 ± 433.03 pg/mL of MCP-1 per microgram of DNA. The results of the coculture studies showed that aBMSCs exhibited immunosuppressive effects on monocyte activation and T cell activation and proliferation similar to BMSCs. Both aBMSCs and BMSCs drove macrophages into an anti-inflammatory phenotype with increased phagocytic ability. Taken together, these data suggest that aBMSCs have potent immunomodulatory properties comparable to those of BMSCs.

Conclusions

The findings of this study have important implications for the development of immunomodulatory stem cell therapies aimed to treat inflammatory conditions using aBMSCs, a more feasible tissue source of MSCs.

Human umbilical cord mesenchymal stem cells confer potent immunosuppressive effects in Sjögren's syndrome by inducing regulatory T cells

BACKGROUND

Primary Sjögren's syndrome (SS) is a lymphoproliferative disease with a chronic autoimmune disorder characterized by mononuclear cell (MNC) infiltration of notably the lacrimal and salivary glands. As mesenchymal stem cells (MSCs) regulate series of immunological responses partially by regulating proportion of CD4⁺ T cells and inducing an immunosuppressive local milieu, umbilical cord MSCs (UC-MSCs) are being considered as a novel source for cell-based therapies against primary SS. This study aimed to investigate the feasibility of UC-MSCs in treatment of SS and to explore the possible mechanism(s) with the special emphasis on regulatory T cells (Tregs).

METHODS

Potent immunosuppressive effects of human UC-MSCs on SS were explored in vivo and in vitro. To study the effects of human UC-MSCs on the development and progression of SS, human UC-MSCs were administered before disease onset (preventive protocol) and after disease occurrence (therapeutic protocol) in non-obese diabetic (NOD) mice. In human study, the effect of human UC-MSCs on T cells from SS patients was studied.

RESULTS

In both protocols, the histopathology of submandibular and sublingual salivary glands showed decreased inflammatory infiltrates. In vitro, human UC-MSCs exhibited potent suppressive effects on responses of MNCs in NOD mice and T cells in SS patients. Such inhibitory effects were coupled with decreased production of proinflammtory cytokines interferon-γ, interleukin (IL)-6, tumor necrosis factor-α and increased production of IL-10 (n = 10, p < .01). The frequency of CD4⁺Foxp3⁺T cells in the spleen of NOD recipients was elevated (n = 6, p < .05).

CONCLUSION

Human UC-MSCs are capable of inducing CD4⁺Foxp3⁺ T cells in both NOD mice and human in vitro. Human UC-MSCs effectively interfere with the autoimmune attack in the course of SS by inducing an in vivo state of T cell unresponsiveness and the upregulation of Tregs.

Mesenchymal stem cells for the prevention of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease in preterm infants who have been treated with supplemental oxygen and mechanical ventilation. Despite major advances in perinatal and neonatal medicine, limited progress has been made in reducing BPD rates. The use of mesenchymal stem cells (MSC) is a promising and innovative therapy for several diseases because they are easy to extract and they have low immunogenicity, anti-inflammatory properties, and regenerative ability. According to several pre-clinical studies that have used BPD animal models, one mechanism of action for MSC in BPD is mainly due to the paracrine effects of MSC-derived humoral factors, such as interleukin (IL)-6, IL-8, vascular endothelial growth factor, collagen, and elastin, rather than the multilineage and regenerative capacities of MSC. Cell-free preparations derived from MSC, including conditioned media and exosomes, remain a pre-clinical technology despite their great clinical potential. A first-in-human clinical trial of MSC treatment for BPD was performed as a phase I dose-escalation trial using umbilical cord blood-derived MSC. That trial demonstrated the short- and long-term safety and feasibility of MSC, given that significantly reduced inflammatory marker expression was observed in tracheal aspirates. As of recently, several clinical trials of MSC use for BPD are ongoing or are planned in some countries to investigate the efficacy of MSC in the prevention or treatment of BPD in premature infants. Many clinicians are currently awaiting the results from these trials so that MSC can be used clinically for human BPD.

The Role of Mesenchymal Stem Cells in Atherosclerosis: Prospects for Therapy via the Modulation of Inflammatory Milieu

Atherosclerosis is a chronic, inflammatory disease that mainly affects the arterial intima. The disease is more prevalent in middle-age and older individuals with one or more cardiovascular risk factors, including dyslipidemia, hypertension, diabetes, smoking, obesity, and others. The beginning and development of atherosclerosis has been associated with several immune components, including infiltration of inflammatory cells, monocyte/macrophage-derived foam cells, and inflammatory cytokines and chemokines. Mesenchymal stem cells (MSCs) originate from several tissue sources of the body and have self-renewal and multipotent differentiation characteristics. They also have immunomodulatory and anti-inflammatory properties. Recently, it was shown that MSCs have a regulatory role in plasma lipid levels. In addition, MSCs have shown to have promising potential in terms of treatment strategies for several diseases, including those with an inflammatory component. In this regard, transplantation of MSCs to patients with atherosclerosis has been proposed as a novel strategy in the treatment of this disease. In this review, we summarize the current advancements regarding MSCs for the treatment of atherosclerosis.

Molecular and Cellular Bases of Immunosenescence, Inflammation, and Cardiovascular Complications Mimicking "Inflammaging" in Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an archetype of systemic autoimmune disease, characterized by the presence of diverse autoantibodies and chronic inflammation. There are multiple factors involved in lupus pathogenesis, including genetic/epigenetic predisposition, sexual hormone imbalance, environmental stimulants, mental/psychological stresses, and undefined events. Recently, many authors noted that "inflammaging", consisting of immunosenescence and inflammation, is a common feature in aging people and patients with SLE. It is conceivable that chronic oxidative stresses originating from mitochondrial dysfunction, defective bioenergetics, abnormal immunometabolism, and premature telomere erosion may accelerate immune cell senescence in patients with SLE. The mitochondrial dysfunctions in SLE have been extensively investigated in recent years. The molecular basis of normoglycemic metabolic syndrome has been found to be relevant to the production of advanced glycosylated and nitrosative end products. Besides, immunosenescence, autoimmunity, endothelial cell damage, and decreased tissue regeneration could be the results of premature telomere erosion in patients with SLE. Herein, the molecular and cellular bases of inflammaging and cardiovascular complications in SLE patients will be extensively reviewed from the aspects of mitochondrial dysfunctions, abnormal bioenergetics/immunometabolism, and telomere/telomerase disequilibrium.

In vitro modulatory effect of dehydroepiandrosterone sulfate on apoptosis and expression of apoptosis-related genes in patients with systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus‌ (SLE) is an autoimmune disease characterized by hyperactive B cells that produce various autoantibodies. Sex hormones have been documented to influence the development of SLE, in which women with SLE have low plasma level of dehydroepiandrosterone sulfate (DHEAS). A strong conclusion about the effect of DHEAS on apoptosis in SLE patients has not been provided. The aim of this study was to assess apoptotic effects of DHEAS on peripheral blood lymphocytes (PBLs) from SLE patients.

METHODS

Twenty SLE patients and 20 age- and sex-matched healthy controls were included into this study. Concentration of DHEAS was measured using enzyme-linked immunosorbent assay in serum from all participants. Freshly isolated PBLs from each individual were treated with 7.5-µmol of DHEAS for 24 hr in cell culture medium to assess the effect of DHEAS on apoptosis using fluorescein isothiocyante-conjugated annexin V and propidium iodide. The messenger RNA (mRNA) expression level of apoptosis-related genes (Fas, Fas-L, Bcl-2, and Bax) in PBLs was measured using real-time PCR before and after treating with DHEAS.

RESULTS

Level of DHEAS was low in SLE patients compared with healthy controls (p < 0.05). After treating with DHEAS, the percentage of apoptotic cells in SLE patients was decreased in comparison with healthy controls. DHEAS treatment increased the mRNA expression level of Bcl-2 in PBLs from SLE patients.

CONCLUSIONS

DHEAS reduced the apoptosis rate in PBLs from SLE patients and may decrease the load of autoantigens. Therefore, DHEAS might be considered as a therapeutic tool in SLE patients.

Induction Therapy for Lupus Nephritis: the Highlights

PURPOSE OF REVIEW

Lupus nephritis is a frequent complication of systemic lupus erythematosus and is more common and severe in children. This is a disease of the immune system characterized by T cell, B cell, and complement activation, as well as immune complex formation and deposition. The introduction of steroids and later cyclophosphamide transformed lupus nephritis from a fatal to a treatable condition. However, the standard therapies currently used for treatment carry significant toxicity and chronic kidney disease still remains a far too frequent outcome. To address these issues, we will review current and emerging induction therapies in LN.

RECENT FINDINGS

Several clinical trials have been undertaken to test more effective and safer drugs, often targeting mechanistic disease pathways. At present, it is difficult to identify an induction regimen that is more effective and less toxic than the standard of care; however, we believe continuing efforts in drug development will bring breakthrough agents to clinics.