Regulation of alternative macrophage activation by MSCs derived hypoxic conditioned medium, via the TGF-β1/Smad3 pathway

Mesenchymal stromal cells for improvement of cardiac function following acute myocardial infarction: a matter of timing

Acute myocardial infarction (AMI) is the leading cause of cardiovascular death and remains the most common cause of heart failure. Reopening of the occluded artery, i.e., reperfusion, is the only way to save the myocardium. However, the expected benefits of reducing infarct size are disappointing due to the reperfusion paradox, which also induces specific cell death. These ischemia-reperfusion (I/R) lesions can account for up to 50% of final infarct size, a major determinant for both mortality and the risk of heart failure (morbidity). In this review, we provide a detailed description of the cell death and inflammation mechanisms as features of I/R injury and cardioprotective strategies such as ischemic postconditioning as well as their underlying mechanisms. Due to their biological properties, the use of mesenchymal stromal/stem cells (MSCs) has been considered a potential therapeutic approach in AMI. Despite promising results and evidence of safety in preclinical studies using MSCs, the effects reported in clinical trials are not conclusive and even inconsistent. These discrepancies were attributed to many parameters such as donor age, in vitro culture, and storage time as well as injection time window after AMI, which alter MSC therapeutic properties. In the context of AMI, future directions will be to generate MSCs with enhanced properties to limit cell death in myocardial tissue and thereby reduce infarct size and improve the healing phase to increase postinfarct myocardial performance.

Local transplantation of mesenchymal stem cells improves encephalo-myo-synangiosis-mediated collateral neovascularization in chronic brain ischemia

BACKGROUND

To explore whether local transplantation of mesenchymal stem cells (MSCs) in temporal muscle can promote collateral angiogenesis and to analyze its main mechanisms of promoting angiogenesis.

METHODS

Bilateral carotid artery stenosis (BCAS) treated mice were administrated with encephalo-myo-synangiosis (EMS), and bone marrow mesenchymal stem cells (BMSCs) were transplanted into the temporal muscle near the cerebral cortex. On the 30th day after EMS, the Morris water maze, immunofluorescence, laser speckle imaging, and light sheet microscopy were performed to evaluate angiogenesis; In addition, rats with bilateral common carotid artery occlusion were also followed by EMS surgery, and BMSCs from GFP reporter rats were transplanted into the temporal muscle to observe the survival time of BMSCs. Then, the concentrated BMSC-derived conditioned medium (BMSC-CM) was used to stimulate HUVECs and BMECs for ki-67 immunocytochemistry, CCK-8, transwell and chick chorioallantoic membrane assays. Finally, the cortical tissue near the temporal muscle was extracted after EMS, and proteome profiler (angiogenesis array) as well as RT-qPCR of mRNA or miRNA was performed.

RESULTS

The results of the Morris water maze 30 days after BMSC transplantation in BCAS mice during the EMS operation, showed that the cognitive impairment in the BCAS + EMS + BMSC group was alleviated (P < 0.05). The results of immunofluorescence, laser speckle imaging, and light sheet microscopy showed that the number of blood vessels, blood flow and astrocytes increased in the BCAS + EMS + BMSC group (P < 0.05). The BMSCs of GFP reporter rats were applied to EMS and showed that the transplanted BMSCs could survive for up to 14 days. Then, the results of ki-67 immunocytochemistry, CCK-8 and transwell assays showed that the concentrated BMSC-CM could promote the proliferation and migration of HUVECs and BMECs (P < 0.05). Finally, the results of proteome profiler (angiogenesis array) in the cerebral cortex showed that the several pro-angiogenesis factors (such as MMP-3, MMP-9, IGFBP-2 or IGFBP-3) were notably highly expressed in MSC transplantation group compared to others.

CONCLUSIONS

Local MSCs transplantation together with EMS surgery can promote angiogenesis and cognitive behavior in chronic brain ischemia mice. Our study illustrated that MSC local transplantation can be the potential therapeutical option for improving EMS treatment efficiency which might be translated into clinical application.

Mannosylated polydopamine nanoparticles alleviate radiation- induced pulmonary fibrosis by targeting M2 macrophages and inhibiting the TGF-β1/Smad3 signaling pathway

Radiation-induced pulmonary fibrosis (RIPF), one type of pulmonary interstitial diseases, is frequently observed following radiation therapy for chest cancer or accidental radiation exposure. Current treatments against RIPF frequently fail to target lung effectively and the inhalation therapy is hard to penetrate airway mucus. Therefore, this study synthesized mannosylated polydopamine nanoparticles (MPDA NPs) through one-pot method to treat RIPF. Mannose was devised to target M2 macrophages in the lung through CD 206 receptor. MPDA NPs showed higher efficiency of penetrating mucus, cellular uptake and ROS-scavenging than original polydopamine nanoparticles (PDA NPs) in vitro. In RIPF mice, aerosol administration of MPDA NPs significantly alleviated the inflammatory, collagen deposition and fibrosis. The western blot analysis demonstrated that MPDA NPs inhibited TGF-β1/Smad3 signaling pathway against pulmonary fibrosis. Taken together this study provide a novel M2 macrophages-targeting nanodrugs through aerosol delivery for the prevention and targeted treatment for RIPF.

Epigallocatechin-3-Gallate Attenuates Myocardial Dysfunction via Inhibition of Endothelial-to-Mesenchymal Transition

Cardiac tissue damage following ischemia leads to cardiomyocyte apoptosis and myocardial fibrosis. Epigallocatechin-3-gallate (EGCG), an active polyphenol flavonoid or catechin, exerts bioactivity in tissues with various diseases and protects ischemic myocardium; however, its association with the endothelial-to-mesenchymal transition (EndMT) is unknown. Human umbilical vein endothelial cells (HUVECs) pretreated with transforming growth factor β2 (TGF-β2) and interleukin 1β (IL-1β) were treated with EGCG to verify cellular function. In addition, EGCG is involved in RhoA GTPase transmission, resulting in reduced cell mobility, oxidative stress, and inflammation-related factors. A mouse myocardial infarction (MI) model was used to confirm the association between EGCG and EndMT in vivo. In the EGCG-treated group, ischemic tissue was regenerated by regulating proteins involved in the EndMT process, and cardioprotection was induced by positively regulating apoptosis and fibrosis of cardiomyocytes. Furthermore, EGCG can reactivate myocardial function due to EndMT inhibition. In summary, our findings confirm that EGCG is an impact activator controlling the cardiac EndMT process derived from ischemic conditions and suggest that supplementation with EGCG may be beneficial in the prevention of cardiovascular disease.

Effects of the interactions between platelets with other cells in tumor growth and progression

It has been confirmed that platelets play a key role in tumorigenesis. Tumor-activated platelets can recruit blood cells and immune cells to migrate, establish an inflammatory tumor microenvironment at the sites of primary and metastatic tumors. On the other hand, they can also promote the differentiation of mesenchymal cells, which can accelerate the proliferation, genesis and migration of blood vessels. The role of platelets in tumors has been well studied. However, a growing number of studies suggest that interactions between platelets and immune cells (e.g., dendritic cells, natural killer cells, monocytes, and red blood cells) also play an important role in tumorigenesis and tumor development. In this review, we summarize the major cells that are closely associated with platelets and discuss the essential role of the interaction between platelets with these cells in tumorigenesis and tumor development.

Regulation of Inflammation-Mediated Endothelial to Mesenchymal Transition with Echinochrome a for Improving Myocardial Dysfunction

Endothelial-mesenchymal transition (EndMT) is a process by which endothelial cells (ECs) transition into mesenchymal cells (e.g., myofibroblasts and smooth muscle cells) and induce fibrosis of cells/tissues, due to ischemic conditions in the heart. Previously, we reported that echinochrome A (EchA) derived from sea urchin shells can modulate cardiovascular disease by promoting anti-inflammatory and antioxidant activity; however, the mechanism underlying these effects was unclear. We investigated the role of EchA in the EndMT process by treating human umbilical vein ECs (HUVECs) with TGF-β2 and IL-1β, and confirmed the regulation of cell migration, inflammatory, oxidative responses and mitochondrial dysfunction. Moreover, we developed an EndMT-induced myocardial infarction (MI) model to investigate the effect of EchA in vivo. After EchA was administered once a day for a total of 3 days, the histological and functional improvement of the myocardium was investigated to confirm the control of the EndMT. We concluded that EchA negatively regulates early or inflammation-related EndMT and reduces the myofibroblast proportion and fibrosis area, meaning that it may be a potential therapy for cardiac regeneration or cardioprotection from scar formation and cardiac fibrosis due to tissue granulation. Our findings encourage the study of marine bioactive compounds for the discovery of new therapeutics for recovering ischemic cardiac injuries.

Differentially hypomethylated cell-free DNA and coronary collateral circulation

BACKGROUND

The factors affecting cardioprotective collateral circulation are still incompletely understood. Recently, characteristics, such as CpG methylation of cell-free DNA (cfDNA), have been reported as markers with clinical utility. The aim of this study was to evaluate whether cfDNA methylation patterns are associated with the grade of coronary collateral circulation (CCC).

RESULT

In this case-control study, clinical and angiographic data were obtained from 143 patients (mean age, 58 years, male 71%) with chronic total coronary occlusion. Enzymatic methyl-sequencing (EM-seq) libraries were prepared using the cfDNA extracted from the plasma. Data were processed to obtain the average methylation fraction (AMF) tables of genomic regions from which blacklisted regions were removed. Unsupervised analysis of the obtained AMF values showed that some of the changes in methylation were due to CCC. Through random forest preparation process, 256 differentially methylated region (DMR) candidates showing strong association with CCC were selected. A random forest classifier was then constructed, and the area under the curve of the receiver operating characteristic curve indicated an appropriate predictive function for CCC. Finally, 20 DMRs were identified to have significantly different AMF values between the good and poor CCC groups. Particularly, the good CCC group exhibited hypomethylated DMRs. Pathway analysis revealed five pathways, including TGF-beta signaling, to be associated with good CCC.

CONCLUSION

These data have demonstrated that differential hypomethylation was identified in dozens of cfDNA regions in patients with good CCC. Our results support the clinical utility of noninvasively obtained epigenetic signatures for predicting collateral circulation in patients with vascular diseases.

Role of Mesenchymal Stem Cells and Their Paracrine Mediators in Macrophage Polarization: An Approach to Reduce Inflammation in Osteoarthritis

Osteoarthritis (OA) is a low-grade inflammatory disorder of the joints that causes deterioration of the cartilage, bone remodeling, formation of osteophytes, meniscal damage, and synovial inflammation (synovitis). The synovium is the primary site of inflammation in OA and is frequently characterized by hyperplasia of the synovial lining and infiltration of inflammatory cells, primarily macrophages. Macrophages play a crucial role in the early inflammatory response through the production of several inflammatory cytokines, chemokines, growth factors, and proteinases. These pro-inflammatory mediators are activators of numerous signaling pathways that trigger other cytokines to further recruit more macrophages to the joint, ultimately leading to pain and disease progression. Very few therapeutic alternatives are available for treating inflammation in OA due to the condition's low self-healing capacity and the lack of clear diagnostic biomarkers. In this review, we opted to explore the immunomodulatory properties of mesenchymal stem cells (MSCs) and their paracrine mediators-dependent as a therapeutic intervention for OA, with a primary focus on the practicality of polarizing macrophages as suppression of M1 macrophages and enhancement of M2 macrophages can significantly reduce OA symptoms.

1α,25-Dihydroxyvitamin D3 Promotes Angiogenesis After Cerebral Ischemia Injury in Rats by Upregulating the TGF-β/Smad2/3 Signaling Pathway

Stroke is a disease with high morbidity, disability and mortality, which seriously endangers the life span and quality of life of people worldwide. Angiogenesis and neuroprotection are the key to the functional recovery of penumbra function after acute cerebral infarction. In this study, we used the middle cerebral artery occlusion (MCAO) model to investigate the effects of 1α,25-dihydroxyvitamin D3 (1,25-D3) on transforming growth factor-β (TGF-β)/Smad2/3 signaling pathway. Cerebral infarct volume was measured by TTC staining. A laser speckle flow imaging system was used to measure cerebral blood flow (CBF) around the ischemic cortex of the infarction, followed by platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) and isolectin-B4 (IB4) immunofluorescence. The expression of vitamin D receptor (VDR), TGF-β, Smad2/3, p-Smad2, p-Smad3, and vascular endothelial growth factor (VEGF) was analyzed by western blot and RT-qPCR. Results showed that compared with the sham group, the cerebral infarction volume was significantly increased while the CBF was reduced remarkably in the MCAO group. 1,25-D3 reduced cerebral infarction volume, increased the recovery of CBF and expressions of VDR, TGF-β, p-Smad2, p-Smad3, and VEGF, significantly increased IB4⁺ tip cells and CD31⁺ vascular length in the peri-infarct area compared with the DMSO group. The VDR antagonist pyridoxal-5-phosphate (P5P) partially reversed the neuroprotective effects of 1,25-D3 described above. In summary, 1,25-D3 plays a neuroprotective role in stroke by activating VDR and promoting the activation of TGF-β, which in turn up-regulates the TGF-β/Smad2/3 signaling pathway, increases the release of VEGF and thus promotes angiogenesis, suggesting that this signaling pathway may be an effective target for ischemic stroke treatment. 1,25-D3 is considered to be a neuroprotective agent and is expected to be an effective drug for the treatment of ischemic stroke and related diseases.

Platelet Derived Vesicles Enhance the TGF-beta Signaling Pathway of M1 Macrophage

Macrophages, mainly divided into M1 pro-inflammatory and M2 anti-inflammatory types, play a key role in the transition from inflammation to repair after trauma. In chronic inflammation, such as diabetes and complex bone injury, or the process of certain inflammatory specific emergencies, the ratio of M1/M2 cell populations is imbalanced so that M1-macrophages cannot be converted into M2 macrophages in time, resulting in delayed trauma repair. Early and timely transformation of macrophages from the pro-inflammatory M1-type into the pro-reparative M2-type is an effective strategy to guide trauma repair and establish the original homeostasis. We prepared purified nano-platelet vesicles (NPVs) and assessed their effects on macrophage phenotype switching through transcriptome analysis. The results elucidate that NPVs promote pathways related to angiogenesis, collagen synthesis, cell adhesion, and migration in macrophages, and we speculate that these advantages may promote healing in traumatic diseases.

Colchicine-Containing Nanoparticles Attenuates Acute Myocardial Infarction Injury by Inhibiting Inflammation

PURPOSE

Anti-inflammatory therapy is important for reducing myocardial injury after acute myocardial infarction (MI). New anti-inflammatory drugs and their mechanism are necessary to be explored to improve clinical efficacy. We aimed to improve the efficacy of colchicine on attenuating MI injury by nano-drug delivery systems and to investigate the mechanism of anti-inflammatory.

METHODS

A colchicine-containing delivery system based on calcium carbonate nanoparticles (ColCaNPs) was synthesized. The protection against MI by ColCaNPs was evaluated using an in vivo rat model established by ligating the left anterior descending coronary artery. Macrophage polarization and the levels of inflammatory cytokines were determined using immunohistochemistry, Western blot, and ELISA analysis.

RESULTS

ColCaNP treatment showed about a 45% reduction in myocardial infarct size and attenuating myocardial fibrosis compared with groups without drug intervention after MI. Furthermore, ColCaNPs significantly decreased the levels of CRP, TNF-α, and IL-1β in serum and the expression of proinflammatory cytokine in myocardial tissues after MI (p < 0.05). We also found that ColCaNPs notably restrained pyroptosis and inhibited inflammatory response by modulating on M1/M2 macrophage polarization and suppressing TLR4/NFκB/NLRP3 signal pathway.

CONCLUSION

Colchicine-containing nanoparticles can protect against MI injury in a clinically relevant rat model by reducing inflammation. In addition, calcium carbonate nanoparticles can increase the cardioprotective effects of colchicine.