Marrow-derived mesenchymal stem cells regulate the inflammatory response and repair alveolar type II epithelial cells in acute lung injury of rats

Bone marrow mesenchymal stem cells alleviate liver fibrosis after rat liver transplantation through JAK1/STAT5 pathway

OBJECTIVE

The effectiveness of bone marrow mesenchymal stem cells (BMSCs) in post-transplantation liver fibrosis has not been studied. The aim of this study was to investigate the effect of BMSCs on liver fibrosis and their role in the Janus-activated kinase (JAK) 1/ signal transducer and activator of transcription (STAT) 5 pathway after liver transplantation (LT).

METHODS

A rat model of post-LT liver fibrosis induced by cold ischemia injury was successfully established. BMSCs were injected into the rats through the portal vein. Hepatic stellate cell (HSC)-T6 were co-cultured with BMSCs in vitro after hypoxia-reoxygenation. JAK1 inhibitor Abrocitinib and JAK1 agonist RO8191 were used to study the JAK1/STAT5 signaling pathway.

RESULTS

BMSCs significantly alleviated liver fibrosis caused by cold ischemia-reperfusion injury after rat LT in vivo. After BMSCs transplantation, the levels of JAK1 and p-STAT5 in rat liver were significantly reduced. After using Abrocitinib, the stage of liver fibrosis and the levels of collagen type I alpha 1 chain (COL1A1) and actin alpha 2 (ACTA2) decreased. After using RO8191, the stage of liver fibrosis and the levels of COL1A1 and ACTA2 increased. BMSCs significantly reduced the activation of HSC-T6 after hypoxia-reoxygenation in vitro. After co-culturing with BMSCs after HSC-T6 hypoxia-reoxygenation, the levels of JAK1 and p-STAT5 were significantly reduced. After the addition of Abrocitinib, the levels of COL1A1 and ACTA2 decreased in HSC-T6; in contrast, after adding RO8191, the levels of COL1A1 and ACTA2 increased in HSC-T6 after hypoxia-reoxygenation. After using anti-IL7 antibody or anti-IL7Rα in vivo and in vitro, the stage of liver fibrosis and the levels of COL1A1 and ACTA2 decreased as well as the phosphorylation level of STAT5.

CONCLUSIONS

BMSCs alleviate hepatic cell damage, reduce hepatic cell-derived IL7, downregulate IL7R/JAK1/STAT5 in HSCs, thereby reducing HSCs' activation and ultimately alleviating liver fibrosis after liver transplantation.

Wnt3a Enhances Mesenchymal Stem Cell Engraftment and Differentiation in a Chronic Obstructive Pulmonary Disease Rat Model

Background

Bone marrow mesenchymal stem cell (BMSC) therapy is a novel approach for treating COPD. However, the difficulty in engraftment and easy clearance of BMSCs in vivo has hindered their clinical application. Hence, exploring effective methods to improve the engraftment and differentiation rates of BMSCs in vivo is urgent.

Methods

We constructed BMSCs overexpressing Wnt3a by lentivirus infection and transplanted them into a COPD rat model. The damage level of COPD rat lung tissue was assessed by pathology analysis and inflammatory cytokines analysis. The engraftment of BMSC was detected by immunofluorescence staining. Statistical analysis was performed using GraphPad Prism 7.

Results

We found that Wnt3a significantly enhanced the engraftment rate of BMSCs in the lungs of rats and further increased their differentiation rate into type II alveolar epithelial cells. We also assessed the expression of inflammatory factors in the lung tissues of COPD rats and discovered that Wnt3a reduced the levels of the inflammatory factors IL-6 and IL-1β while increasing the level of the anti-inflammatory factor IL-10. Our study demonstrates that Wnt3a can improve the engraftment and differentiation rates of BMSCs in the host and further alleviate COPD symptoms by regulating the secretion of inflammatory factors.

Conclusion

Constructing BMSCs overexpressing Wnt3a could serve as a new strategy for stem cell therapy in COPD.

Mesenchymal Stem Cell-Derived Exosomes in Various Chronic Liver Diseases: Hype or Hope?

Chronic liver conditions are associated with high mortality rates and have a large adverse effect on human well-being as well as a significant financial burden. Currently, the only effective treatment available for the effects of liver failure and cirrhosis resulting from the progression of several chronic liver diseases is liver transplantation carried out at the original location. This implies that developing novel and effective treatments is imperative. Regenerative medicine has long been associated with stem cell therapy. Mesenchymal stem cells (MSCs), a type of cell with great differentiation potential, have become the preferred source for stem cell therapy. According to recent studies, MSCs' paracrine products-rather than their capacity for differentiation-play a significant therapeutic effect. MSC exosomes, a type of extracellular vesicle (MSC-EV), came into view as the paracrine substances of MSCs. According to research, MSC exosomes can maintain tissue homeostasis, which is necessary for healthy tissue function. All tissues contain them, and they take part in a variety of biological activities that support cellular activity and tissue regeneration in order to preserve tissue homeostasis. The outcomes support the use of MSCs and the exosomes they produce as a therapeutic option for a range of diseases. This review provides a brief overview of the source of MSC-EVs and outlines their physiological roles and biochemical capabilities. The elucidation of the role of MSC-EVs in the recovery and repair of hepatic tissues, as well as their contribution to maintaining tissue homeostasis, is discussed in relation to different chronic liver diseases. This review aims to provide new insights into the unique roles that MSC-EVs play in the treatment of chronic liver diseases.

Placental mesenchymal stem cells-secreted proenkephalin suppresses the p38 MAPK signaling to block hyperproliferation of keloid fibroblasts

BACKGROUND

Thanks to their multi-potency and secretory functions, mesenchymal stem cells (MSCs) have long been established as an ideal cell type for skin wound healing and a candidate therapeutic strategy for excessive pathological scarring in the meantime. This study focuses on the effect of placental MSCs (PMSCs) on the activity of keloid fibroblasts (KFs) and the potential involvement of proenkephalin (PENK).

METHODS

Secretory protein of PMSC that are lowly expressed in KFs were predicted by bioinformatics analyses. The expression of PENK in KFs was detected by RT-qPCR and western blot analysis. PMSCs were co-cultured with KFs and dermal fibroblasts (DFs) to examine their effect on proliferation, migration, invasion, and apoptosis of the distinct cell types. PENK secretion by PMSCs and its uptake by KFs were examined by ELISA, WB, and immunofluorescence staining. Loss-of-functions of PENK and p38-MAPK were induced to examine the activity of KFs in vitro and in mice.

RESULTS

PENK, a secretory protein of PMSCs, was conspicuously downregulated in KFs compared to normal DFs. PMSC stimulation suppressed proliferation, migration, invasion, and resistance to apoptosis of the co-cultured KFs but not DFs, which was ascribed to the upregulation of PENK protein in KFs. PMSCs-secreted PENK suppressed p38 phosphorylation in KFs. The proliferative and aggressive properties of KFs in vitro and the nodule-forming capacity of KFs in vivo were promoted upon PENK downregulation but suppressed by the p38 MAPK inhibitor SB202190.

CONCLUSION

This work unravels that PMSCs-secreted PENK suppresses the p38 MAPK signaling to block hyperproliferation of KFs.

Ssc-miR-141 Attenuates Hypoxia-Induced Alveolar Type II Epithelial Cell Injury in Tibetan Pigs by Targeting PDCD4

The Tibetan pig is an endemic economic animal in the plateau region of China, and has a unique adaptation mechanism to the plateau hypoxic environment. Research into microRNAs (miRNAs) involved in the mechanism underlying hypoxia adaptation of Tibetan pig is very limited. Therefore, we isolated alveolar type II epithelial (ATII) cells from the lungs of the Tibetan pig, cultured them in normoxia/hypoxia (21% O₂; 2% O₂) for 48 h, and performed high-throughput sequencing analysis. We identified a hypoxic stress-related ssc-miR-141 and predicted its target genes. The target genes of ssc-miR-141 were mainly enriched in mitogen-activated protein kinase (MAPK), autophagy-animal, and Ras signaling pathways. Further, we confirmed that PDCD4 may serve as the target gene of ssc-miR-141. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed to confirm the expression levels of ssc-miR-141 and PDCD4, and a dual-luciferase gene reporter system was used to verify the targeted linkage of ssc-miR-141 to PDCD4. The results showed that the expression level of ssc-miR-141 in the hypoxia group was higher than that in the normoxia group, while the expression level of PDCD4 tended to show the opposite trend and significantly decreased under hypoxia. These findings suggest that ssc-miR-141 is associated with hypoxia adaptation and provide a new insight into the role of miRNAs from ATII cells of Tibetan pig in hypoxia adaptation.

Extracellular vesicles in the pathogenesis and treatment of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common life-threatening lung diseases associated with acute and severe inflammation. Both have high mortality rates, and despite decades of research on clinical ALI/ARDS, there are no effective therapeutic strategies. Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury. Recently, studies on the role of extracellular vesicles (EVs) in regulating normal and pathophysiologic cell activities, including inflammation and injury responses, have attracted attention. Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes, which can be used to diagnose and predict the development of ALI/ARDS. EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function, and thereby promote cell proliferation and tissue regeneration. This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation, particularly ALI/ARDS.

Forthcoming complications in recovered COVID-19 patients with COPD and asthma; possible therapeutic opportunities

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been growing swiftly worldwide. Patients with background chronic pulmonary inflammations such as asthma or chronic obstructive pulmonary diseases (COPD) are likely to be infected with this virus. Of note, there is an argument that COVID-19 can remain with serious complications like fibrosis or other pathological changes in the pulmonary tissue of patients with chronic diseases. Along with conventional medications, regenerative medicine, and cell-based therapy could be alternative approaches to compensate for organ loss or restore injured sites using different stem cell types. Owing to unique differentiation capacity and paracrine activity, these cells can accelerate the healing procedure. In this review article, we have tried to scrutinize different reports related to the harmful effects of SARS-CoV-2 on patients with asthma and COPD, as well as the possible therapeutic effects of stem cells in the alleviation of post-COVID-19 complications. Video abstract.