Cardiac Differentiation of Mesenchymal Stem Cells: Impact of Biological and Chemical Inducers

PIM kinase inhibitors: an updated patent review (2016-present)

INTRODUCTION

PIM Kinases (PIM-1, PIM-2, and PIM-3) have been reported to play crucial role in signaling cascades that govern cell survival, proliferation, and differentiation. Over-expression of these kinases leads to hematological malignancies such as diffuse large B cell lymphomas (DLBCL), multiple myeloma, leukemia, lymphoma and prostate cancer etc. PIM kinases as biomarkers and potential therapeutic targets have shown promise toward precision cancer therapy. The selective PIM-1, PIM-2, and/or PIM-3 isoform inhibitors have shown significant results in patients with advanced stages of cancer including relapsed/refractory cancer.

AREAS COVERED

A comprehensive literature review of PIM Kinases (PIM-1, PIM-2, and PIM-3) in oncogenesis, the patented PIM kinase inhibitors (2016-Present), and their pharmacological and structural insights have been highlighted.

EXPERT OPINION

Recently, PIM kinases viz. PIM-1, PIM-2, and PIM-3 (members of the serine/threonine protein kinase family) as therapeutic targets have attracted considerable interest in oncology especially in hematological malignancies. The patented PIM kinase inhibitors comprised of heterocyclic (fused)ring structure(s) like indole, pyridine, pyrazine, pyrazole, pyridazine, piperazine, thiazole, oxadiazole, quinoline, triazolo-pyridine, pyrazolo-pyridine, imidazo-pyridazine, oxadiazole-thione, pyrazolo-pyrimidine, triazolo-pyridazine, imidazo-pyridazine, pyrazolo-quinazoline and pyrazolo-pyridine etc. showed promising results in cancer chemotherapy.

Novel biphasic mechanism of the canonical Wnt signalling component PYGO2 promotes cardiomyocyte differentiation from hUC-MSCs

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are used to regenerate the myocardium during cardiac repair after myocardial infarction. However, the regulatory mechanism underlying their ability to form mesodermal cells and differentiate into cardiomyocytes remains unclear. Here, we established a human-derived MSCs line isolated from healthy umbilical cords and established a cell model of the natural state to examine the differentiation of hUC-MSCs into cardiomyocytes. Quantitative RT-PCR, western blotting, immunofluorescence, flow cytometry, RNA Seq, and inhibitors of canonical Wnt signalling were used to detect the germ-layer markers T and MIXL1; the markers of cardiac progenitor cells MESP1, GATA4, and NKX2.5 and the cardiomyocyte-marker cTnT to identify the molecular mechanism associated with PYGO2, a key component of the canonical Wnt signalling pathway that regulates the formation of cardiomyocyte-like cells. We demonstrated that PYGO2 promotes the formation of mesodermal-like cells and their differentiation into cardiomyocytes through the hUC-MSC-dependent canonical Wnt signalling by promoting the early-stage entry of β-catenin into the nucleus. Surprisingly, PYGO2 did not alter the expression of the canonical-Wnt, NOTCH, or BMP signalling pathways during the middle-late stages. In contrast, PI3K-Akt signalling promoted hUC-MSCs formation and their differentiation into cardiomyocyte-like cells. To the best of our knowledge, this is the first study to demonstrate that PYGO2 uses a biphasic mechanism to promote cardiomyocyte formation from hUC-MSCs.

Effect of CDM3 on co-culture of human-induced pluripotent stem cells with Matrigel-covered polycaprolactone to prepare cardiac patches

To promote the differentiation of human-induced pluripotent stem cells (hiPSCs) into myocardium through a standard chemically defined and small-molecule-based induction protocol (CDM3), and preliminarily prepare myocardial patches that provide experimental data and theoretical support for further maturation through other in vitro experiments and safety studies in vivo. After resuscitation, culture, and identification of hiPSCs, they were inoculated onto Matrigel-coated polycaprolactone (PCL). After 24 h, cell growth was observed by DAPI under a fluorescence microscope and the stemness of hiPSCs was identified by OCT4 fluorescence. After fixation, scanning electron microscopy was performed to observe the morphology of cells on the patch surface. On days 1, 3, 5, and 7 of culture, cell viability was determined by Cell Counting Kit-8 (CCK-8) assay and a curve was drawn to observe cell growth and proliferation. After co-culture with Matrigel-covered PCL for 24 h, hiPSCs were divided into control and CDM3 groups, and cultured for an additional 6 d. On the eighth day, cell growth was observed by DAPI under a fluorescence microscope, hiPSC stemness was identified by OCT4 fluorescence, and cardiomyocytes were identified by cardiac troponin T (cTnT) and α-actin expression. hiPSCs co-cultured with Matrigel-covered PCL for 24 h emitted green fluorescence indicating OCT4, showing that hiPSCs maintained their stemness on Matrigel-covered PCL scaffolds. DAPI emitted blue fluorescence, indicating that cells grew clonally with uniform cell morphology. Scanning electron microscopy showed that hiPSCs adhered and grew on PCL covered with Matrigel, with clearly visible cell outlines indicating normal morphology. Assessment of cell viability by the CCK-8 method showed that hiPSCs proliferated and grew on PCL scaffolds covered with Matrigel. After 6 d of culture, immunofluorescence showed that control group hiPSCs highly expressed the stem cell marker OCT4 but not myocardial markers cTnT or α-actin. In contrast, notable expression of myocardial markers cTnT and α-actin but not OCT4 occurred in the CDM3 group. hiPSCs can proliferate and grow on PCL scaffolds covered with Matrigel. Under the influence of CDM3, hiPSCs differentiated into cardiomyocyte-like cells, allowing the preliminary preparation of myocardial patches that can provide a better method for clinical treatment of myocardial infarction.

Direct Cardiac Reprogramming: Current Status and Future Prospects

Advances in cellular reprogramming articulated the path for direct cardiac lineage conversion, bypassing the pluripotent state. Direct cardiac reprogramming attracts major attention because of the low or nil regenerative ability of cardiomyocytes, resulting in permanent cell loss in various heart diseases. In the field of cardiology, balancing this loss of cardiomyocytes was highly challenging, even in the modern medical world. Soon after the discovery of cell reprogramming, direct cardiac reprogramming also became a promising alternative for heart regeneration. This review mainly focused on the various direct cardiac reprogramming approaches (integrative and non-integrative) for the derivation of induced autologous cardiomyocytes. It also explains the advancements in cardiac reprogramming over the decade with the pros and cons of each approach. Further, the review highlights the importance of clinically relevant (non-integrative) approaches and their challenges for the prospective applications for personalized medicine. Apart from direct cardiac reprogramming, it also discusses the other strategies for generating cardiomyocytes from different sources. The understanding of these strategies could pave the way for the efficient generation of integration-free functional autologous cardiomyocytes through direct cardiac reprogramming for various biomedical applications.

SDF-1/CXCR4-Mediated Stem Cell Mobilization Involved in Cardioprotective Effects of Electroacupuncture on Mouse with Myocardial Infarction

Stem cell-based therapeutic strategies have obtained a significant breakthrough in the treatment of cardiovascular diseases, particularly in myocardial infarction (MI). Nevertheless, limited retention and poor migration of stem cells are still problems for stem cell therapeutic development. Hence, there is an urgent need to develop new strategies that can mobilize stem cells to infarcted myocardial tissues effectively. Electroacupuncture (EA) intervention can improve cardiac function and alleviate myocardial injury after MI, but its molecular mechanism is still unclear. This study is aimed at observing the effects of EA treatment on the stem cell mobilization and revealing possible mechanisms in the MI model of mice. EA treatment at Neiguan (PC6) and Xinshu (BL15) acupoints was conducted on the second day after the ligation surgery. Then, the number of stem cells in peripheral blood after EA in MI mice and their cardiac function, infarct size, and collagen deposition was observed. We found that the number of CD34-, CD117-, Sca-1-, and CD90-positive cells increased at 6 h and declined at 24 h after EA intervention in the blood of MI mice. The expression of CXC chemokine receptor-4 (CXCR4) protein was upregulated at 6 h after EA treatment, while the ratio of LC3B II/I or p-ERK/ERK showed a reverse trend. In addition, there was obvious difference in EF and FS between wild-type mice and CXCR4+/− mice. The infarct size, collagen deposition, and apoptosis of the injured myocardium in CXCR4+/− mice increased but could be ameliorated by EA. In a word, our study demonstrates that EA alleviates myocardial injury via stem cell mobilization which may be regulated by the SDF-1/CXCR4 axis.

Mesenchymal Stem Cell Application and Its Therapeutic Mechanisms in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH), a common lethal subtype of stroke accounting for nearly 10–15% of the total stroke disease and affecting two million people worldwide, has a high mortality and disability rate and, thus, a major socioeconomic burden. However, there is no effective treatment available currently. The role of mesenchymal stem cells (MSCs) in regenerative medicine is well known owing to the simplicity of acquisition from various sources, low immunogenicity, adaptation to the autogenic and allogeneic systems, immunomodulation, self-recovery by secreting extracellular vesicles (EVs), regenerative repair, and antioxidative stress. MSC therapy provides an increasingly attractive therapeutic approach for ICH. Recently, the functions of MSCs such as neuroprotection, anti-inflammation, and improvement in synaptic plasticity have been widely researched in human and rodent models of ICH. MSC transplantation has been proven to improve ICH-induced injury, including the damage of nerve cells and oligodendrocytes, the activation of microglia and astrocytes, and the destruction of blood vessels. The improvement and recovery of neurological functions in rodent ICH models were demonstrated via the mechanisms such as neurogenesis, angiogenesis, anti-inflammation, anti-apoptosis, and synaptic plasticity. Here, we discuss the pathological mechanisms following ICH and the therapeutic mechanisms of MSC-based therapy to unravel new cues for future therapeutic strategies. Furthermore, some potential strategies for enhancing the therapeutic function of MSC transplantation have also been suggested.

Genome-wide methylome pattern predictive network analysis reveal mesenchymal stem cell's propensity to undergo cardiovascular lineage

Mesenchymal stem cells (MSCs) differentiation toward cardiovascular lineage prediction using the global methylome profile will highlight its prospective utility in regenerative medicine. We examined the propensity prediction to cardiovascular lineage using 5-Aza, a well-known cardiac lineage inducer. The customized 180 K microarray was performed and further analysis of global differentially methylated regions by Ingenuity pathway analysis (IPA) in both MSCs and 5-AC-treated MSCs. The cluster enrichment tools sorted differentially enriched genes and further annotated to construct the interactive networks. Prediction analysis revealed pathways pertaining to the cardiovascular lineage found active in the native MSCs, suggesting its higher propensity to undergo cardiac, smooth muscle cell, and endothelial lineages in vitro. Interestingly, gene interaction network also proposed majorly stemness gene network NANOG and KLF6, cardiac-specific transcription factors GATA4, NKX2.5, and TBX5 were upregulated in the native MSCs. Furthermore, the expression of cardiovascular lineage specific markers such as Brachury, CD105, CD90, CD31, KDR and various forms of ACTIN (cardiac, sarcomeric, smooth muscle) were validated in native MSCs using real time PCR and immunostaining and blotting analysis. In 5-AC-treated MSCs, mosaic interactive networks were observed to persuade towards osteogenesis and cardiac lineage, indicating that 5-AC treatment resulted in nonspecific lineage induction in MSCs, while MSCs by default have a higher propensity to undergo cardiovascular lineage.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03058-2.

Elastomeric Cardiowrap Scaffolds Functionalized with Mesenchymal Stem Cells-Derived Exosomes Induce a Positive Modulation in the Inflammatory and Wound Healing Response of Mesenchymal Stem Cell and Macrophage

A challenge in contractile restoration of myocardial scars is one of the principal aims in cardiovascular surgery. Recently, a new potent biological tool used within healing processes is represented by exosomes derived from mesenchymal stem cells (MSCs). These cells are the well-known extracellular nanovesicles released from cells to facilitate cell function and communication. In this work, a combination of elastomeric membranes and exosomes was obtained and tested as a bioimplant. Mesenchymal stem cells (MSCs) and macrophages were seeded into the scaffold (polycaprolactone) and filled with exosomes derived from MSCs. Cells were tested for proliferation with an MTT test, and for wound healing properties and macrophage polarization by gene expression. Moreover, morphological analyses of their ability to colonize the scaffolds surfaces have been further evaluated. Results confirm that exosomes were easily entrapped onto the surface of the elastomeric scaffolds, increasing the wound healing properties and collagen type I and vitronectin of the MSC, and improving the M2 phenotype of the macrophages, mainly thanks to the increase in miRNA124 and decrease in miRNA 125. We can conclude that the enrichment of elastomeric scaffolds functionalized with exosomes is as an effective strategy to improve myocardial regeneration.