Stem cells: An overview with respect to cardiovascular and renal disease

Beta-human chorionic gonadotropin, carbohydrate antigen 19-9, cancer antigen 125, and carcinoembryonic antigen as prognostic and predictive biological markers in bladder cancer

INTRODUCTION

We evaluated the prognostic potential of the Beta-human chorionic gonadotropin (β-hCG), Carbohydrate Antigen 19-9 (CA19-9), Cancer Antigen 125 (CA125), and Carcinoembryonic Antigen (CEA) tumor markers for bladder cancer.

METHODS

We analyzed the records of 369 patients who underwent radical cystectomy for urothelial cancer (UC) between October 2012 until December 2019. Levels of CA19-9, CA125, CEA, and β-hCG before radical cystectomy were measured in all patient samples, and serum biomarker cutoff values were used as normal and elevated values.

RESULTS AND DISCUSSION

The proportion of abnormal β-hCG (P<0.001), CA19-9 (P<0.001), and CA125 (P=0.033) was significantly higher in locally advanced bladder UC than in organ-confined bladder UC. In patients with preoperative β-hCG and CA125 abnormality, there was poor prognosis of recurrence-free survival (RFS)(P=0.003, P=0.042) and overall survival (OS) (P=0.003, P=0.002). Using the Cox multivariate regression analysis, both β-hCG (HR: 3.88, 95% CI: 1.43-10.25) and CA125 (HR: 6.21, 95% CI: 1.34-32.16) were found to be significant independent factors for predicting OS and RFS. In addition, patients with a high number of increased tumor markers showed significantly worse OS ((P<0.001) and RFS (P=0.002) than patients with a low number of increased tumor markers. In conclusion, serum β-hCG and CA125 levels could potentially be used for UC prognosis in patients undergoing radical cystectomy. To assess their usefulness in evaluating long-term recurrence and survival, further treatment responses and large-scale additional studies are needed.

The role of cardiac microenvironment in cardiovascular diseases: implications for therapy

Due to aging populations and changes in lifestyle, cardiovascular diseases including cardiomyopathy, hypertension, and atherosclerosis, are the leading causes of death worldwide. The heart is a complicated organ composed of multicellular types, including cardiomyocytes, fibroblasts, endothelial cells, vascular smooth muscle cells, and immune cells. Cellular specialization and complex interplay between different cell types are crucial for the cardiac tissue homeostasis and coordinated function of the heart. Mounting studies have demonstrated that dysfunctional cells and disordered cardiac microenvironment are closely associated with the pathogenesis of various cardiovascular diseases. In this paper, we discuss the composition and the homeostasis of cardiac tissues, and focus on the role of cardiac environment and underlying molecular mechanisms in various cardiovascular diseases. Besides, we elucidate the novel treatment for cardiovascular diseases, including stem cell therapy and targeted therapy. Clarification of these issues may provide novel insights into the prevention and potential targets for cardiovascular diseases.

Epigenetic features in regulation of telomeres and telomerase in stem cells

The epigenetic nature of telomeres is still controversial and different human cell lines might show diverse histone marks at telomeres. Epigenetic modifications regulate telomere length and telomerase activity that influence telomere structure and maintenance. Telomerase is responsible for telomere elongation and maintenance and is minimally composed of the catalytic protein component, telomerase reverse transcriptase (TERT) and template forming RNA component, telomerase RNA (TERC). TERT promoter mutations may underpin some telomerase activation but regulation of the gene is not completely understood due to the complex interplay of epigenetic, transcriptional, and posttranscriptional modifications. Pluripotent stem cells (PSCs) can maintain an indefinite, immortal, proliferation potential through their endogenous telomerase activity, maintenance of telomere length, and a bypass of replicative senescence in vitro. Differentiation of PSCs results in silencing of the TERT gene and an overall reversion to a mortal, somatic cell phenotype. The precise mechanisms for this controlled transcriptional silencing are complex. Promoter methylation has been suggested to be associated with epigenetic control of telomerase regulation which presents an important prospect for understanding cancer and stem cell biology. Control of down-regulation of telomerase during differentiation of PSCs provides a convenient model for the study of its endogenous regulation. Telomerase reactivation has the potential to reverse tissue degeneration, drive repair, and form a component of future tissue engineering strategies. Taken together it becomes clear that PSCs provide a unique system to understand telomerase regulation fully and drive this knowledge forward into aging and therapeutic application.

miRNA-200b Signature in the Prevention of Skin Cancer Stem Cells by Polyphenol-enriched Blueberry Preparation

Exposure of the skin to solar UV radiation leads to inflammation, DNA damage, and dysregulation of cellular signaling pathways, which may cause skin cancer. Photochemoprevention with natural products is an effective strategy for the control of cutaneous neoplasia. Polyphenols have been proven to help prevent skin cancer and to inhibit the growth of cancer stem cells (CSCs) through epigenetic mechanisms, including modulation of microRNAs expression. Thus, the current study aimed to assess the effect of polyphenol enriched blueberry preparation (PEBP) or non-fermented blueberry juice (NBJ) on expression of miRNAs and target proteins associated with different clinicopathological characteristics of skin cancer such as stemness, motility, and invasiveness. We observed that PEBP significantly inhibited the proliferation of skin CSCs derived from different melanoma cell lines, HS 294T and B16F10. Moreover, PEBP was able to reduce the formation of melanophores. We also showed that the expression of the CD133⁺ stem cell marker in B16F10 and HS294T cell lines was significantly decreased after treating the cells with PEBP in comparison to the NBJ and control groups. Importantly, tumor suppressors' miR-200s, involved in the regulation of the epithelial-to-mesenchymal transition and metastasis, were strikingly upregulated. In addition, we have shown that a protein target of the tumor suppressor miR200b, ZEB1, was also significantly modulated. Thus, the results demonstrates that PEBP possesses potent anticancer and anti-metastatic potentials and may represent a novel chemopreventative agent against skin cancer.

Recent trends in stem cell-based therapies and applications of artificial intelligence in regenerative medicine

Stem cells are undifferentiated cells that can self-renew and differentiate into diverse types of mature and functional cells while maintaining their original identity. This profound potential of stem cells has been thoroughly investigated for its significance in regenerative medicine and has laid the foundation for cell-based therapies. Regenerative medicine is rapidly progressing in healthcare with the prospect of repair and restoration of specific organs or tissue injuries or chronic disease conditions where the body’s regenerative process is not sufficient to heal. In this review, the recent advances in stem cell-based therapies in regenerative medicine are discussed, emphasizing mesenchymal stem cell-based therapies as these cells have been extensively studied for clinical use. Recent applications of artificial intelligence algorithms in stem cell-based therapies, their limitation, and future prospects are highlighted.

Mesenchymal Stem Cell Therapy of Pulmonary Fibrosis: Improvement with Target Combination

Although the clinical application of new drugs has been shown to be effective in slowing disease progression and improving the quality of life in patients with pulmonary fibrosis, the damaged lung tissue does not recover with these drugs. Thus, there is an urgent need to establish regenerative therapy, such as stem cell therapy or tissue engineering. Moreover, the clinical application of mesenchymal stem cell (MSC) therapy has been shown to be safe in humans with idiopathic pulmonary fibrosis (IPF). It seems that a combination of MSC transplantation and pharmaceutical therapy might have additional benefits; however, the experimental design for its efficacy is still lacking. In this review, we provide an overview of the mechanisms that were identified when IPF was treated with MSC transplantation or new drugs. To maximize the therapeutic effect, we suggest that MSC transplantation is combined with drug application for synergistic effects. This review provides clinicians and scientists with the most efficient medical options, in the hope that this will spur on future research and lead to an eventual cure for this disease.

Translational opportunities in stem cell-based endodontic therapy: where are we and what are we missing?

Pulp regeneration is a biologic process occurring under specific circumstances. An endodontic treatment modality to accomplish pulp regeneration has emerged based on the response of undifferentiated cells that are often referred to as stem cells. The treatment itself is currently empirical based on clinicians' thoughts and observations. The demonstration of a variety of dental stem cells initiated basic research detailing the properties and behavior of these cells. Attempts are made to bridge gaps in knowledge regarding treatment strategies by translating basic stem cell research into practice. However, neither the patient population likely to benefit from pulp regeneration nor most clinical parameters are well described. Classic topics in endodontics (eg, indication/clinical diagnosis, disinfection/irrigation, and root canal preparation/pretreatment) have to be revisited under the premises of pulp regeneration. Furthermore, new topics like the development of new diagnostic tools or new clinical success criteria will emerge, and the translational research itself will generate new insight into pulp regeneration mechanisms.

Heart-on-a-chip based on stem cell biology

Heart diseases are one of the main causes of death around the world. The great challenge for scientists is to develop new therapeutic methods for these types of ailments. Stem cells (SCs) therapy could be one of a promising technique used for renewal of cardiac cells and treatment of heart diseases. Conventional in vitro techniques utilized for investigation of heart regeneration do not mimic natural cardiac physiology. Lab-on-a-chip systems may be the solution which could allow the creation of a heart muscle model, enabling the growth of cardiac cells in conditions similar to in vivo conditions. Microsystems can be also used for differentiation of stem cells into heart cells, successfully. It will help better understand of proliferation and regeneration ability of these cells. In this review, we present Heart-on-a-chip systems based on cardiac cell culture and stem cell biology. This review begins with the description of the physiological environment and the functions of the heart. Next, we shortly described conventional techniques of stem cells differentiation into the cardiac cells. This review is mostly focused on describing Lab-on-a-chip systems for cardiac tissue engineering. Therefore, in the next part of this article, the microsystems for both cardiac cell culture and SCs differentiation into cardiac cells are described. The section about SCs differentiation into the heart cells is divided in sections describing biochemical, physical and mechanical stimulations. Finally, we outline present challenges and future research concerning Heart-on-a-chip based on stem cell biology.

Biological parameters influencing the human umbilical cord-derived mesenchymal stem cells' response to retinoic acid

Human umbilical cord-derived mesenchymal stem cells (HUCMSCs) are multipotent fetal stem cells that differentiate into various cell lineages. In recent years, they have gained attention for therapeutic applications but very little is known about their sensitivity to chemical agents such as widely used retinoic acid (RA). As a morphogen inducing differentiation of mesenchymal stem cells, RA has for a long time been known to be a potent teratogen promoting craniofacial and limb abnormality in vertebrate embryos. Here, using MTT assay and EB/AO staining as well as TUNEL assay we show that RA in a concentration-dependent manner induces apoptosis through upregulating Caspase expression and increasing Bax/Bcl2 ratio. Moreover, different biological parameters such as initial time seeding, cell density, passage number and duration of RA treatment play a major role in HUCMSCs cytotoxic response to this agent.

Adrenomedullin as a growth and cell fate regulatory factor for adult neural stem cells

The use of stem cells as a strategy for tissue repair and regeneration is one of the biomedical research areas that has attracted more interest in the past few years. Despite the classic belief that the central nervous system (CNS) was immutable, now it is well known that cell turnover occurs in the mature CNS. Postnatal neurogenesis is subjected to tight regulation by many growth factors, cell signals, and transcription factors. An emerging molecule involved in this process is adrenomedullin (AM). AM, a 52-amino acid peptide which exerts a plethora of physiological functions, acts as a growth and cell fate regulatory factor for adult neural stem and progenitor cells. AM regulates the proliferation rate and the differentiation into neurons, astrocytes, and oligodendrocytes of stem/progenitor cells, probably through the PI3K/Akt pathway. The active peptides derived from the AM gene are able to regulate the cytoskeleton dynamics, which is extremely important for mature neural cell morphogenesis. In addition, a defective cytoskeleton may impair cell cycle and migration, so AM may contribute to neural stem cell growth regulation by allowing cells to pass through mitosis. Regulation of AM levels may contribute to program stem cells for their use in medical therapies.