Anti-fibrotic effects of different sources of MSC in bleomycin-induced lung fibrosis in C57BL6 male mice

The potential ameliorating effect of vitamin E on bleomycin - induced lung fibrosis in adult albino rats

Lung fibrosis is a critical interstitial lung disease with poor prognosis. There is an urgent need to develop a proper and cost-effective therapeutic modality that can reverse and/or ameliorate lung fibrosis. Vitamin E is one of the widely investigated dietary antioxidants which has been linked to improvement of many health problems. The current study was conducted to evaluate the possible roles of vitamin E in prevention and treatment of bleomycin (BLM) induced lung fibrosis. Physiological, anatomical, histopathological and immunohistochemical studies were done to assess and compare between the structure and function of the lung tissue in lung fibrosis model, early and late treated groups with vitamin E. Furthermore, measurement of transforming growth factor-β(TGF-β), E-cadherin, Smad-3, BAX, BCL2, malondialdehyde (MDA), and superoxide dismutase (SOD) were done. The study revealed that administration of vitamin E helped to improve signs of lung fibrosis, as reflected by amelioration of structure and functions of lungs as well as the decrease in TGF-β levels and inhibition of α-SMA/collagen I profibrotic pathway. These findings highlight the importance of administration of vitamin E as a prophylactic agent prior to BLM therapy and as an adjuvant treatment in cases of lung fibrosis.

Homeobox B4 optimizes the therapeutic effect of bone marrow mesenchymal stem cells on endotoxin-associated acute lung injury in rats

BACKGROUND

Alveolar capillary endothelial cell (EC) injury has a pivotal role in driving acute respiratory distress syndrome (ARDS) progression and maintaining endothelial homeostasis. A previous ex vivo study revealed that overexpression of homeobox B4 (HOXB4) in bone marrow mesenchymal stem cells (BMSCs) enhanced protection against lipopolysaccharide (LPS)-induced EC injury by activating the Wnt/β-catenin pathway. This in vivo study was performed to verify whether BMSCs overexpressing HOXB4 exert similar protective effects on LPS-induced acute lung injury (ALI) in an animal model.

METHODS

The ALI rat model was established by intraperitoneal injection of LPS. Wildtype BMSCs or BMSCs overexpressing HOXB4 were then injected via the tail vein. The lung characteristics of rats were visualized by computed tomography. Lung histopathological characteristics and collagen deposition were assessed by hematoxylin-eosin and Masson's staining, respectively, which were combined with the lung wet/dry ratio and proinflammatory factor levels in bronchoalveolar lavage fluid to further evaluate therapeutic effects. Expression of β-catenin and VE-cadherin was assessed by western blotting and immunofluorescence.

RESULTS

Compared with wildtype BMSCs, overexpression of HOXB4 optimized the therapeutic effects of BMSCs, which manifested as improvements in lung exudation and histopathological features, reduced lung collagen deposition, amelioration of lung permeability, attenuation of lung inflammation, and enhanced expression of β-catenin and VE-cadherin proteins.

CONCLUSIONS

HOXB4-overexpressing BMSCs optimized the protective effect against LPS-induced ALI by partially activating Wnt/β-catenin signaling.

Ameliorative Potential of Bone Marrow-Derived Mesenchymal Stem Cells Versus Prednisolone in a Rat Model of Lung Fibrosis: A Histological, Immunohistochemical, and Biochemical Study

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease of unknown origin with limited treatment options and poor prognosis. The encouraging findings from preclinical investigations utilizing mesenchymal stem cells (MSCs) indicated that they could serve as a promising therapeutic alternative for managing chronic lung conditions, such as IPF. The objective of this study was to compare the efficiency of bone marrow-derived MSCs (BM-MSCs) versus prednisolone, the standard anti-inflammatory medication, in rats with bleomycin (BLM)-induced lung fibrosis. Four groups were created: a control group, a BLM group, a prednisolone-treated group, and a BM-MSCs-treated group. To induce lung fibrosis, 5 mg/kg of BLM was administered intratracheally. BLM significantly increased serum levels of pro-inflammatory cytokines and oxidative stress markers. The disturbed lung structure was also revealed by light and transmission electron microscopic studies. Upregulation in the immune expression of alpha-smooth muscle actin, transforming growth factor beta-1, and Bax was demonstrated. Interestingly, all findings significantly regressed on treatment with prednisolone and BM-MSCs. However, treatment with BM-MSCs showed better results than with prednisolone. In conclusion, BM-MSCs could be a promising approach for managing lung fibrosis.

Endometrial mesenchymal stromal/stem cells improve regeneration of injured endometrium in mice

BACKGROUND

The monthly regeneration of human endometrial tissue is maintained by the presence of human endometrial mesenchymal stromal/stem cells (eMSC), a cell population co-expressing the perivascular markers CD140b and CD146. Endometrial regeneration is impaired in the presence of intrauterine adhesions, leading to infertility, recurrent pregnancy loss and placental abnormalities. Several types of somatic stem cells have been used to repair the damaged endometrium in animal models, reporting successful pregnancy. However, the ability of endometrial stem cells to repair the damaged endometrium remains unknown.

METHODS

Electrocoagulation was applied to the left uterine horn of NOD/SCID mice causing endometrial injury. Human eMSC or PBS was then injected into the left injured horn while the right normal horn served as controls. Mice were sacrificed at different timepoints (Day 3, 7 and 14) and the endometrial morphological changes as well as the degree of endometrial injury and repair were observed by histological staining. Gene expression of various inflammatory markers was assessed using qPCR. The functionality of the repaired endometrium was evaluated by fertility test.

RESULTS

Human eMSC successfully incorporated into the injured uterine horn, which displayed significant morphological restoration. Also, endometrium in the eMSC group showed better cell proliferation and glands formation than the PBS group. Although the number of blood vessels were similar between the two groups, gene expression of VEGF-α significantly increased in the eMSC group. Moreover, eMSC had a positive impact on the regeneration of both stromal and epithelial components of the mouse endometrium, indicated by significantly higher vimentin and CK19 protein expression. Reduced endometrial fibrosis and down-regulation of fibrosis markers were also observed in the eMSC group. The eMSC group had a significantly higher gene expression of anti-inflammatory factor Il-10 and lower mRNA level of pro-inflammatory factors Ifng and Il-2, indicating the role of eMSC in regulation of inflammatory reactions. The eMSC group showed higher implantation sites than the PBS group, suggesting better endometrial receptivity with the presence of newly emerged endometrial lining.

CONCLUSIONS

Our findings suggest eMSC improves regeneration of injured endometrium in mice.

The Plastic Interplay between Lung Regeneration Phenomena and Fibrotic Evolution: Current Challenges and Novel Therapeutic Perspectives

Interstitial lung diseases (ILDs) are a heterogeneous group of pulmonary disorders characterized by variable degrees of inflammation, interstitial thickening, and fibrosis leading to distortion of the pulmonary architecture and gas exchange impairment. Among them, idiopathic pulmonary fibrosis (IPF) displays the worst prognosis. The only therapeutic options consist of the two antifibrotic drugs, pirfenidone and nintedanib, which limit fibrosis progression but do not reverse the lung damage. The shift of the pathogenetic paradigm from inflammatory disease to epithelium-derived disease has definitively established the primary role of type II alveolar cells, which lose their epithelial phenotype and acquire a mesenchymal phenotype with production of collagen and extracellular matrix (EMC) deposition. Some predisposing environmental and genetic factors (e.g., smoke, pollution, gastroesophageal reflux, variants of telomere and surfactant genes) leading to accelerated senescence set a pro-fibrogentic microenvironment and contribute to the loss of regenerative properties of type II epithelial cells in response to pathogenic noxae. This review provides a complete overview of the different pathogenetic mechanisms leading to the development of IPF. Then, we summarize the currently approved therapies and the main clinical trials ongoing. Finally, we explore the potentialities offered by agents not only interfering with the processes of fibrosis but also restoring the physiological properties of alveolar regeneration, with a particular focus on potentialities and concerns about cell therapies based on mesenchymal stem cells (MSCs), whose anti-inflammatory and immunomodulant properties have been exploited in other fibrotic diseases, such as graft versus host disease (GVHD) and COVID-19-related ARDS.

The Regenerative Power of Stem Cells: Treating Bleomycin-Induced Lung Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease with no known cure, characterized by the formation of scar tissue in the lungs, leading to respiratory failure. Although the exact cause of IPF remains unclear, the condition is thought to result from a combination of genetic and environmental factors. One of the most widely used animal models to study IPF is the bleomycin-induced lung injury model in mice. In this model, the administration of the chemotherapeutic agent bleomycin causes pulmonary inflammation and fibrosis, which closely mimics the pathological features of human IPF. Numerous recent investigations have explored the functions of various categories of stem cells in the healing process of lung injury induced by bleomycin in mice, documenting the beneficial effects and challenges of this approach. Differentiation of stem cells into various cell types and their ability to modulate tissue microenvironment is an emerging aspect of the regenerative therapies. This review article aims to provide a comprehensive overview of the role of stem cells in repairing bleomycin-induced lung injury. It delves into the mechanisms through which various types of stem cells, including mesenchymal stem cells, embryonic stem cells, induced pluripotent stem cells, and lung resident stem cells, exert their therapeutic effects in this specific model. We have also discussed the unique set of intermediate markers and signaling factors that can influence the proliferation and differentiation of alveolar epithelial cells both during lung repair and homeostasis. Finally, we highlight the challenges and opportunities associated with translating stem cell therapy to the clinic for IPF patients. The novelty and implications of this review extend beyond the understanding of the potential of stem cells in treating IPF to the broader field of regenerative medicine. We believe that the review paves the way for further advancements in stem cell therapies, offering hope for patients suffering from this debilitating and currently incurable disease.

Research progress on mesenchymal stem cells and their exosomes in systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease with an unknown etiology. Clinically, it is characterized by localized or diffuse skin thickening and fibrosis. The pathogenesis of SSc includes microvascular injury, autoimmune-mediated inflammation, and fibroblast activation. These processes interact and contribute to the diverse clinicopathology and presentation of SSc. Given the limited effectiveness and substantial side effects of traditional treatments, the treatment strategy for SSc has several disadvantages. Mesenchymal stem cells (MSCs) are expected to serve as effective treatment options owing to their significant immunomodulatory, antifibrotic, and pro-angiogenic effects. Exosomes, secreted by MSCs via paracrine signaling, mirror the effect of MSCs as well as offer the benefit of targeted delivery, minimal immunogenicity, robust reparability, good safety and stability, and easy storage and transport. This enables them to circumvent the limitations of the MSCs. When using exosomes, it is crucial to consider preparation methods, quality standards, and suitable drug delivery systems, among other technical issues. Therefore, this review aims to summarize the latest research progress on MSCs and exosomes in SSc, offering novel ideas for treating SSc.

Wharton's jelly mesenchymal stem cells: a concise review of their secretome and prospective clinical applications

Accumulating evidence indicates that most primary Wharton's jelly mesenchymal stem cells (WJ-MSCs) therapeutic potential is due to their paracrine activity, i.e., their ability to modulate their microenvironment by releasing bioactive molecules and factors collectively known as secretome. These bioactive molecules and factors can either be released directly into the surrounding microenvironment or can be embedded within the membrane-bound extracellular bioactive nano-sized (usually 30-150 nm) messenger particles or vesicles of endosomal origin with specific route of biogenesis, known as exosomes or carried by relatively larger particles (100 nm-1 μm) formed by outward blebbing of plasma membrane called microvesicles (MVs); exosomes and MVs are collectively known as extracellular vesicles (EVs). The bioactive molecules and factors found in secretome are of various types, including cytokines, chemokines, cytoskeletal proteins, integrins, growth factors, angiogenic mediators, hormones, metabolites, and regulatory nucleic acid molecules. As expected, the secretome performs different biological functions, such as immunomodulation, tissue replenishment, cellular homeostasis, besides possessing anti-inflammatory and anti-fibrotic effects. This review highlights the current advances in research on the WJ-MSCs' secretome and its prospective clinical applications.

Current status and prospects of basic research and clinical application of mesenchymal stem cells in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a common and clinically devastating disease that causes respiratory failure. Morbidity and mortality of patients in intensive care units are stubbornly high, and various complications severely affect the quality of life of survivors. The pathophysiology of ARDS includes increased alveolar-capillary membrane permeability, an influx of protein-rich pulmonary edema fluid, and surfactant dysfunction leading to severe hypoxemia. At present, the main treatment for ARDS is mechanical treatment combined with diuretics to reduce pulmonary edema, which primarily improves symptoms, but the prognosis of patients with ARDS is still very poor. Mesenchymal stem cells (MSCs) are stromal cells that possess the capacity to self-renew and also exhibit multilineage differentiation. MSCs can be isolated from a variety of tissues, such as the umbilical cord, endometrial polyps, menstrual blood, bone marrow, and adipose tissues. Studies have confirmed the critical healing and immunomodulatory properties of MSCs in the treatment of a variety of diseases. Recently, the potential of stem cells in treating ARDS has been explored via basic research and clinical trials. The efficacy of MSCs has been shown in a variety of in vivo models of ARDS, reducing bacterial pneumonia and ischemia-reperfusion injury while promoting the repair of ventilator-induced lung injury. This article reviews the current basic research findings and clinical applications of MSCs in the treatment of ARDS in order to emphasize the clinical prospects of MSCs.

Cellular and Molecular Mechanisms in Idiopathic Pulmonary Fibrosis

The respiratory system is a well-organized multicellular organ, and disruption of cellular homeostasis or abnormal tissue repair caused by genetic deficiency and exposure to risk factors lead to life-threatening pulmonary disease including idiopathic pulmonary fibrosis (IPF). Although there is no clear etiology as the name reflected, its pathological progress is closely related to uncoordinated cellular and molecular signals. Here, we review the advances in our understanding of the role of lung tissue cells in IPF pathology including epithelial cells, mesenchymal stem cells, fibroblasts, immune cells, and endothelial cells. These advances summarize the role of various cell components and signaling pathways in the pathogenesis of idiopathic pulmonary fibrosis, which is helpful to further study the pathological mechanism of the disease, provide new opportunities for disease prevention and treatment, and is expected to improve the survival rate and quality of life of patients.

Extracellular Vesicles Derived from Mesenchymal Stem Cells: A Potential Biodrug for Acute Respiratory Distress Syndrome Treatment

Acute respiratory distress syndrome (ARDS) is a severe respiratory disease associated with high morbidity and mortality in the clinic. In the face of limited treatment options for ARDS, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have recently shown promise. They regulate levels of growth factors, cytokines, and other internal therapeutic molecules. The possible therapeutic mechanisms of MSC-EVs include anti-inflammatory, cell injury repair, alveolar fluid clearance, and microbe clearance. The potent therapeutic ability and biocompatibility of MSC-EVs have enabled them as an alternative option to ameliorate ARDS. In this review, recent advances, therapeutic mechanisms, advantages and limitations, as well as improvements of using MSC-EVs to treat ARDS are summarized. This review is expected to provide a brief view of the potential applications of MSC-EVs as novel biodrugs to treat ARDS.

Adipose tissue-derived mesenchymal stem cells attenuate lung inflammation and fibrosis in the bleomycin-induced pulmonary fibrosis rat model via caveolin-1/NF-kB signaling axis

Stem cells have emerged as promising therapeutic options for several human diseases, including pulmonary fibrosis (PF). In this study, we investigated the therapeutic effects of adipose tissue-derived mesenchymal stem cells (ADMSCs) in the bleomycin-induced PF model rats and the underlying mechanisms. The PF model rats were generated by intratracheal injections of 5 mg/kg bleomycin sulfate. The ADMSC group rats were generated by injecting 2×10(6) ADMSCs via the tail vein at 0, 12, and 24 h after bleomycin injection. The control, PF, and ADMSC group rats were sacrificed on day 21 after bleomycin injections and the changes in lung histology and the levels of pro-inflammatory cytokines, collagen I, and caveolin-1 (Cav-1), and the activity of the NF-kappaB signaling pathway in the lung tissues was assessed by hematoxylin-eosin staining, ELISA, and western blotting assays. The lung tissues of the PF model rats showed significant infiltration of neutrophils, tissue destruction, and collagen deposition, but these effects were abrogated by the ADMSCs. The levels of pro-inflammatory cytokines such as IL-6, IL-1beta, and TGF-beta1 were elevated in the lung tissues and the bronchoalveolar lavage fluid (BALF) of the bleomycin-induced PF model rats, but these effects were reversed by the ADMSCs. The lung tissues of the PF model rats showed significant downregulation of Cav-1 and significantly higher activation of the pro-inflammatory NF-kappaB pathway. However, administration of the ADMSCs restored the expression levels of Cav-1 and suppressed the NF-kappaB signaling pathway in the lungs of the bleomycin-induced PF model rats. In conclusion, this study demonstrated that the ADMSCs protected against bleomycin-induced PF in the rat model by modulating the Cav-1/NF-kappaB axis.

Mesenchymal Stem Cell-Derived Extracellular Vesicles as Idiopathic Pulmonary Fibrosis Microenvironment Targeted Delivery

Idiopathic pulmonary fibrosis (IPF) affects an increasing number of people globally, yet treatment options remain limited. At present, conventional treatments depending on drug therapy do not show an ideal effect in reversing the lung damage or extending the lives of IPF patients. In recent years, more and more attention has focused on extracellular vesicles (EVs) which show extraordinary therapeutic effects in inflammation, fibrosis disease, and tissue damage repair in many kinds of disease therapy. More importantly, EVs can be modified or used as a drug or cytokine delivery tool, targeting injury sites to enhance treatment efficiency. In light of this, the treatment strategy of mesenchymal stem cell-extracellular vesicles (MSC-EVs) targeting the pulmonary microenvironment for IPF provides a new idea for the treatment of IPF. In this review, we summarized the inflammation, immune dysregulation, and extracellular matrix microenvironment (ECM) disorders in the IPF microenvironment in order to reveal the treatment strategy of MSC-EVs targeting the pulmonary microenvironment for IPF.

Stem cells for treatment of liver fibrosis/cirrhosis: clinical progress and therapeutic potential

Cost-effective treatment strategies for liver fibrosis or cirrhosis are limited. Many clinical trials of stem cells for liver disease shown that stem cells might be a potential therapeutic approach. This review will summarize the published clinical trials of stem cells for the treatment of liver fibrosis/cirrhosis and provide the latest overview of various cell sources, cell doses, and delivery methods. We also describe the limitations and strengths of various stem cells in clinical applications. Furthermore, to clarify how stem cells play a therapeutic role in liver fibrosis, we discuss the molecular mechanisms of stem cells for treatment of liver fibrosis, including liver regeneration, immunoregulation, resistance to injury, myofibroblast repression, and extracellular matrix degradation. We provide a perspective for the prospects of future clinical implementation of stem cells.

Application of Wharton jelly-derived mesenchymal stem cells in patients with pulmonary fibrosis

Pulmonary fibrosis is a devastating disease that eventually leads to death and respiratory failure. Despite the wide range of drugs, including corticosteroids, endothelin antagonist, and pirfenidone, there is no effective treatment, and the only main goal of treatment is to alleviate the symptoms as much as possible to slow down the progression of the disease and improve the quality of life. Lung transplantation may be a treatment option for a few people if pulmonary fibrosis develops and there is no established treatment. Pulmonary fibrosis caused by the COVID19 virus is another problem that we face in most patients despite the efforts of the international medical communities. Therefore, achieving alternative treatment for patients is a great success. Today, basic research using stem cells on pulmonary fibrosis has published promising results. New stem cell-based therapies can be helpful in patients with pulmonary fibrosis. Wharton jelly-derived mesenchymal stem cells are easily isolated in large quantities and made available for clinical trials without causing ethical problems. These cells have higher flexibility and proliferation potential than other cells isolated from different sources and differentiated into various cells in laboratory environments. More clinical trials are needed to determine the safety and efficacy of these cells. This study will investigate the cellular and molecular mechanisms and possible effects of Wharton jelly-derived mesenchymal stem cells in pulmonary fibrosis.

Human amniotic mesenchymal stem cells combined with PPCNg facilitate injured endometrial regeneration

BACKGROUND

Caused by the injury to the endometrial basal layer, intrauterine adhesions (IUA) are characterized by uterine cavity obliteration, leading to impaired fertility. Human amniotic mesenchymal stem cells (hAMSCs) have the potential to promote endometrial regeneration mainly through paracrine ability. PPCNg is a thermoresponsive biomaterial consisted of Poly (polyethylene glycol citrate-co-N-isopropylacrylamide) (PPCN) mixed with gelatin, which has been reported as a scaffold for stem cell transplantation. This study aims to investigate the therapeutic effect of hAMSCs combined with PPCNg transplantation in promoting the regeneration of injured endometrium.

METHODS

hAMSCs were cultured in different concentrates of PPCNg in vitro, and their proliferation, apoptosis and cell cycle were examined by CCK-8 assay and flow cytometry. Immunofluorescence was used to determine the MSCs specific surface markers. The expression of pluripotent genes was analyzed by qRT-PCR. The multiple-lineage differentiation potential was further evaluated by detecting the differentiation-related genes using qRT-PCR and specific staining. The Sprague-Dawley (SD) rat IUA model was established with 95% ethanol. hAMSCs combined with PPCNg were transplanted through intrauterine injection. The retention of DiR-labeled hAMSCs was observed by vivo fluorescence imaging. The endometrium morphology was assessed using hematoxylin and eosin (H&E) and Masson staining. Immunohistochemistry staining was performed to detect biomarkers related to endometrial proliferation, re-epithelialization, angiogenesis and endometrial receptivity. The function of regenerated endometrium was evaluated by pregnancy tests.

RESULTS

hAMSCs maintained normal cell proliferation, apoptosis and cell cycle in PPCNg. Immunofluorescence and qRT-PCR showed that hAMSCs cultured in PPCNg and hAMSCs cultured alone expressed the same surface markers and pluripotent genes. hAMSCs exhibited normal multilineage differentiation potential in PPCNg. Vivo fluorescence imaging results revealed that the fluorescence intensity of hAMSCs combined with PPCNg intrauterine transplantation was stronger than that of direct hAMSCs intrauterine transplantation. Histological assays showed the increase in the thickness of endometrial and the number of endometrial glands, and the remarkably decrease in the fibrosis area in the PPCNg/hAMSCs group. The expressions of Ki-67, CK7, CK19, VEGF, ER and PR were significantly increased in the PPCNg/hAMSCs group. Moreover, the number of implanted embryos and pregnancy rate were significantly higher in the PPCNg/hAMSCs group than in the hAMSCs group.

CONCLUSIONS

PPCNg is suitable for growth, phenotype maintenance and multilineage differentiation of hAMSCs. hAMSCs combined with PPCNg intrauterine transplantation can facilitate the regeneration of injured endometrium by improving utilization rates of hAMSCs, and eventually restore reproductive capacity.

Wnt/β-Catenin Participates in the Repair of Acute Respiratory Distress Syndrome-Associated Early Pulmonary Fibrosis via Mesenchymal Stem Cell Microvesicles

Purpose

The main aim of the present study was to establish whether mesenchymal stem cell microvesicles (MSC MVs) exert anti-fibrotic effects and investigate the mechanisms underlying these effects in a mouse model of acute respiratory distress syndrome (ARDS)-associated early pulmonary fibrosis.

Methods

An ARDS-associated pulmonary fibrosis model was established in mice by an intratracheal injection of lipopolysaccharide (LPS). At 1, 3, and 7 days after LPS-mediated injury, the lungs of mice treated with MSC MVs and untreated controls were carefully excised and fibrosis was assessed based on the extent of collagen deposition. In addition, the development of epithelial–mesenchymal transition (EMT) was evaluated based on loss of E-cadherin and zona occludens-1 (ZO-1) along with the acquisition of α-smooth muscle actin (α-SMA) and N-cadherin. Nuclear translocation and β-catenin expression analyses were also used to evaluate activation of the Wnt/β-catenin signaling pathway.

Results

Blue-stained collagen fibers were evident as early as 7 days after LPS injection. Treatment with MSC MVs suppressed pathological progression to a significant extent. MSC MVs markedly reversed the upregulation of N-cadherin and α-SMA and attenuated the downregulation of E-cadherin and ZO-1. The expression and nuclear translocation of β-catenin were clearly decreased on day 7 after MSC MV treatment.

Conclusion

Analyses indicated that MSC MVs could ameliorate ARDS-associated early pulmonary fibrosis via the suppression of EMT and might be related to Wnt/β-catenin transition signaling.

Anti-Inflammatory, Antioxidant, and Antifibrotic Effects of Gingival-Derived MSCs on Bleomycin-Induced Pulmonary Fibrosis in Mice

BACKGROUND

Mesenchymal stem cell (MSC) intervention has been associated with lung protection. We attempted to determine whether mouse gingival-derived mesenchymal stem cells (GMSCs) could protect against bleomycin-induced pulmonary fibrosis.

METHODS

Mice were divided into three groups: control (Con), bleomycin (Bl), and bleomycin + MSCs (Bl + MSCs). Mice were treated with 5 mg/kg bleomycin via transtracheal instillation to induce pulmonary fibrosis. We assessed the following parameters: histopathological severity of injury in the lung, liver, kidney, and aortic tissues; the degree of pulmonary fibrosis; pulmonary inflammation; pulmonary oedema; profibrotic factor levels in bronchoalveolar lavage fluid (BALF) and lung tissue; oxidative stress-related indicators and apoptotic index in lung tissue; and gene expression levels of IL-1β, IL-8, TNF-α, lysophosphatidic acid (LPA), lysophosphatidic acid receptor 1 (LPA1), TGF-β, matrix metalloproteinase 9 (MMP-9), neutrophil elastase (NE), MPO, and IL-10 in lung tissue.

RESULTS

GMSC intervention attenuated bleomycin-induced pulmonary fibrosis, pulmonary inflammation, pulmonary oedema, and apoptosis. Bleomycin instillation notably increased expression levels of the IL-1β, IL-8, TNF-α, LPA, LPA1, TGF-β, MMP-9, NE, and MPO genes and attenuated expression levels of the IL-10 gene in lung tissue, and these effects were reversed by GMSC intervention. Bleomycin instillation notably upregulated MDA and MPO levels and downregulated GSH and SOD levels in lung tissue, and these effects were reversed by GMSC intervention. GMSC intervention prevented upregulation of neutrophil content in the lung, liver, and kidney tissues and the apoptotic index in lung tissue.

CONCLUSIONS

GMSC intervention exhibits anti-inflammatory and antioxidant capacities. Deleterious accumulation of neutrophils, which is reduced by GMSC intervention, is a key component of bleomycin-induced pulmonary fibrosis. GMSC intervention impairs bleomycin-induced NE, MMP-9, LPA, APL1, and TGF-β release.

Mitochondria in Focus: From Function to Therapeutic Strategies in Chronic Lung Diseases

Mitochondria are essential organelles for cell metabolism, growth, and function. Mitochondria in lung cells have important roles in regulating surfactant production, mucociliary function, mucus secretion, senescence, immunologic defense, and regeneration. Disruption in mitochondrial physiology can be the central point in several pathophysiologic pathways of chronic lung diseases such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and asthma. In this review, we summarize how mitochondria morphology, dynamics, redox signaling, mitophagy, and interaction with the endoplasmic reticulum are involved in chronic lung diseases and highlight strategies focused on mitochondrial therapy (mito-therapy) that could be tested as a potential therapeutic target for lung diseases.

Application of adipose-derived stem cells in treating fibrosis

Fibrosis is the hyperactivation of fibroblasts that results in excessive accumulation of extracellular matrix, which is involved in numerous pathological changes and diseases. Adipose-derived stem cells (ASCs) are promising seed cells for regenerative medicine due to their bountiful source, low immunogenicity and lack of ethical issues. Their anti-fibrosis, immunomodulation, angiogenesis and other therapeutic effects have made them suitable for treating fibrosis-related diseases. Here, we review the literature on ASCs treating fibrosis, elaborate and discuss their mechanisms of action, changes in disease environment, ways to enhance therapeutic effects, as well as current preclinical and clinical studies, in order to provide a general picture of ASCs treating fibrotic diseases.

Mesenchymal stem cell therapy in pulmonary fibrosis: a meta-analysis of preclinical studies

BACKGROUND

Pulmonary fibrosis (PF) is a devastating disease characterized by remodeling of lung architecture and abnormal deposition of fibroblasts in parenchymal tissue and ultimately results in respiratory failure and death. Preclinical studies suggest that mesenchymal stem cell (MSC) administration may be a safe and promising option in treating PF. The objective of our meta-analysis is to assess the efficacy of MSC therapy in preclinical models of PF.

METHODS

We performed a comprehensive literature search in PubMed, EMBASE, Web of Science, and Cochrane Library databases from inception to March 17, 2021. Studies that assessed the efficacy of MSC therapy to animals with PF were included. The SYRCLE bias risk tool was employed to evaluate the bias of included studies. The primary outcomes included survival rate and pulmonary fibrosis scores. Meta-analysis was conducted via Cochrane Collaboration Review Manager (version 5.4) and Stata 14.0 statistical software.

RESULTS

A total of 1120 articles were reviewed, of which 24 articles met inclusion criteria. Of these, 12 studies evaluated the survival rate and 20 studies evaluated pulmonary fibrosis scores. Compared to the control group, MSC therapy was associated with an improvement in survival rate (odds ratios (OR) 3.10, 95% confidence interval (CI) 2.06 to 4.67, P < 0.001, I² = 0%) and a significant reduction in pulmonary fibrosis scores (weighted mean difference (WMD) 2.05, 95% CI -2.58 to -1.51, P < 0.001, I² = 90%).

CONCLUSIONS

MSC therapy is a safe and effective method that can significantly improve the survival and pulmonary fibrosis of PF animals. These results provide an important basis for future translational clinical studies.

Matrix metalloproteinases inhibitors in idiopathic pulmonary fibrosis: Medicinal chemistry perspectives

Idiopathic pulmonary fibrosis (IPF) is a lethal disease with limited therapeutic options and a particularly poor prognosis. Matrix metalloproteinases (MMPs), promising targets for the treatment of IPF, have been identified as playing a pivotal role in IPF. Although the pathological processes of MMPs and IPF have been verified, there are no MMP inhibitors for the treatment of IPF in the clinic. In this review, we will present the latest developments in MMP inhibitors, including pharmacophores, binding modes, selectivity and optimization strategies. In addition, we will also discuss the future development direction of MMP inhibitors based on emerging tools and techniques.

Therapeutic Applications of Mesenchymal Stem Cells in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is an interstitial disease of unknown etiology characterized by progressive pulmonary fibrosis. Pirfenidone and nintedanib are the only drugs that can prolong the time to disease progression, slow down the decline in lung function, and prolong survival. However, they do not offer a cure and are associated with tolerability issues. The pluripotency of mesenchymal stem cells (MSCs) and their ability to regulate immunity, inhibit inflammation, and promote epithelial tissue repair highlight the promise of MSC therapy for treating interstitial lung disease. However, optimal protocols are lacking for multi-parameter selection in MSC therapy. This review summarizes preclinical studies on MSC transplantation for the treatment of interstitial lung disease and clinical studies with known results. An analysis of relevant factors for the optimization of treatment plans is presented, including MSCs with different sources, administration routes and timing, dosages, frequencies, and pretreatments with MSCs. This review proposes an optimized plan for guiding the design of future clinical research to identify therapeutic options for this complex disease.