Extended in vitro culture of primary human mesenchymal stem cells downregulates Brca1-related genes and impairs DNA double-strand break recognition

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.

Comparison of different gene addition strategies to modify placental derived-mesenchymal stromal cells to produce FVIII

Introduction

Placenta-derived mesenchymal cells (PLCs) endogenously produce FVIII, which makes them ideally suited for cell-based fVIII gene delivery. We have previously reported that human PLCs can be efficiently modified with a lentiviral vector encoding a bioengineered, expression/secretion-optimized fVIII transgene (ET3) and durably produce clinically relevant levels of functionally active FVIII. The objective of the present study was to investigate whether CRISPR/Cas9 can be used to achieve location-specific insertion of a fVIII transgene into a genomic safe harbor, thereby eliminating the potential risks arising from the semi-random genomic integration inherent to lentiviral vectors. We hypothesized this approach would improve the safety of the PLC-based gene delivery platform and might also enhance the therapeutic effect by eliminating chromatin-related transgene silencing.

Methods

We used CRISPR/Cas9 to attempt to insert the bioengineered fVIII transgene "lcoET3" into the AAVS1 site of PLCs (CRISPR-lcoET3) and determined their subsequent levels of FVIII production, comparing results with this approach to those achieved using lentivector transduction (LV-lcoET3) and plasmid transfection (Plasmid-lcoET3). In addition, since liver-derived sinusoidal endothelial cells (LSECs) are the native site of FVIII production in the body, we also performed parallel studies in human (h)LSECs).

Results

PLCs and hLSECs can both be transduced (LV-lcoET3) with very high efficiency and produce high levels of biologically active FVIII. Surprisingly, both cell types were largely refractory to CRISPR/Cas9-mediated knockin of the lcoET3 fVIII transgene in the AAVS1 genome locus. However, successful insertion of an RFP reporter into this locus using an identical procedure suggests the failure to achieve knockin of the lcoET3 expression cassette at this site is likely a function of its large size. Importantly, using plasmids, alone or to introduce the CRISPR/Cas9 "machinery", resulted in dramatic upregulation of TLR 3, TLR 7, and BiP in PLCs, compromising their unique immune-inertness.

Discussion

Although we did not achieve our primary objective, our results validate the utility of both PLCs and hLSECs as cell-based delivery vehicles for a fVIII transgene, and they highlight the hurdles that remain to be overcome before primary human cells can be gene-edited with sufficient efficiency for use in cell-based gene therapy to treat HA.

Bone Marrow Mesenchymal Stem Cells (BMSCs) Promote the Metastasis of Thyroid Papillary Cancer by Inhibiting Poly-Pyrimidine Tract Binding Protein 1 (PTBP1)

We aimed to explore the mechanism underlying the role of bone marrow mesenchymal stem cells (BMSCs) in the invasion of papillary thyroid cancer (PTC) cells. BMSCs were co-cultured with PTC cells WRO or normal thyroid follicular epithelial cells T3TD followed by analysis of cell migration and proliferation by Transwell assay and MTT assay. Cells were transfected with shRNA or overexpression of PTBP1, followed by measuring cell proliferation and invasion and PTBP1 expression by RT-qPCR and Western blot. Co-cultivation with MSC promoted the malignant transformation of WRO, inhibited the RNA-binding protein PTBP1 and activation of GS3Kβ/Akt. In addition, silencing of PTBP1 accelerated cell invason and induced overexpression of EMT proteins, while overexpression of PTBP1 inhibited cell proliferation and migration. In conclusion, BMSCs might promote PTC invasion and metastasis by inhibiting PTBP1 expression, providing a novel insight into the treatment of PTC.

Psoriasis treatment using minimally manipulated umbilical cord-derived mesenchymal stem cells: A case report

BACKGROUND

Psoriasis is a chronic autoimmune disease that usually manifests as a red scaly epidermis, induration, and hyperproliferation of basal keratinocytes. About 2% of the world’s population suffers from psoriasis but there are no clear therapeutics yet. Recently, mesenchymal stem cells (MSCs) have been regarded as a therapeutic alternative for autoimmune diseases, as they possess immunosuppressive effects without risks. Human umbilical cord-derived MSCs effectively regulate immune cells and are characterized by low immunogenicity, which has many advantages in treating immune diseases.

CASE SUMMARY

The patient was a 47-year-old male, diagnosed with psoriasis in 1995. He had received various treatments for 25 years, but the psoriatic condition was not significantly improved. He was given three rounds of minimally manipulated umbilical cord-derived MSCs over 2 wk. The erythema gradually disappeared. Three months after the 1^st round, all erythema completely disappeared, and the psoriasis did not recur.

CONCLUSION

Minimally manipulated umbilical cord-derived MSC transplantation can potentially treat patients who suffer from psoriasis.

Alopecia treatment using minimally manipulated human umbilical cord-derived mesenchymal stem cells: Three case reports and review of literature

BACKGROUND

Alopecia areata (AA) is a common autoimmune disease characterized by hair loss. AA appears in extensive forms, such as progressive and diffusing hair loss (diffuse AA), a total loss of scalp hair (alopecia totalis), and complete loss of hair over the entire body (alopecia universalis). Recently, mesenchymal stem cells (MSCs) have been identified as a therapeutic alternative for autoimmune diseases. For this reason, preclinical and case studies of AA and related diseases using MSCs have been conducted.

CASE SUMMARY

Case 1: A 55-year-old woman suffered from AA in two areas of the scalp. She was given 15 rounds of minimally manipulated umbilical cord-MSCs (MM-UC-MSCs) over 6 mo. The AA gradually improved 3 mo after the first round. The patient was cured, and AA did not recur. Case 2: A 30-year-old woman, with history of local steroid hormone injections, suffered from AA in one area on the scalp. She was given two rounds of MM-UC-MSCs over 1 mo. The AA immediately improved after the first round. The patient was cured, and AA did not recur. Case 3: A 20-year-old woman, who was diagnosed with alopecia universalis at the age of 12, was given 14 rounds of MM-UC-MSCs over 12 mo. Her hair began to grow about 3 mo after the first round. The patient was cured, and alopecia universalis did not recur.

CONCLUSION

MM-UC-MSC transplantation potentially treats patients who suffer from AA and related diseases.

Role of ex vivo Expanded Mesenchymal Stromal Cells in Determining Hematopoietic Stem Cell Transplantation Outcome

Overall, the human organism requires the production of ∼1 trillion new blood cells per day. Such goal is achieved via hematopoiesis occurring within the bone marrow (BM) under the tight regulation of hematopoietic stem and progenitor cell (HSPC) homeostasis made by the BM microenvironment. The BM niche is defined by the close interactions of HSPCs and non-hematopoietic cells of different origin, which control the maintenance of HSPCs and orchestrate hematopoiesis in response to the body’s requirements. The activity of the BM niche is regulated by specific signaling pathways in physiological conditions and in case of stress, including the one induced by the HSPC transplantation (HSCT) procedures. HSCT is the curative option for several hematological and non-hematological diseases, despite being associated with early and late complications, mainly due to a low level of HSPC engraftment, impaired hematopoietic recovery, immune-mediated graft rejection, and graft-versus-host disease (GvHD) in case of allogenic transplant. Mesenchymal stromal cells (MSCs) are key elements of the BM niche, regulating HSPC homeostasis by direct contact and secreting several paracrine factors. In this review, we will explore the several mechanisms through which MSCs impact on the supportive activity of the BM niche and regulate HSPC homeostasis. We will further discuss how the growing understanding of such mechanisms have impacted, under a clinical point of view, on the transplantation field. In more recent years, these results have instructed the design of clinical trials to ameliorate the outcome of HSCT, especially in the allogenic setting, and when low doses of HSPCs were available for transplantation.

DNA damage and repair in differentiation of stem cells and cells of connective cell lineages: A trigger or a complication?

The review summarizes literature data on the role of DNA breaks and DNA repair in the differentiation of pluripotent stem cells (PSC) and connective cell lineages. PSC, including embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC), are rapidly dividing cells with highly active DNA damage response (DDR) mechanisms to ensure the stability and integrity of the DNA. In PSCs, the most common DDR mechanism is error-free homologous recombination (HR) that is primarily active during the S phase of the cell cycle, whereas in quiescent, slow-dividing or non-dividing tissue progenitors and terminally differentiated cells, errorprone non-homologous end joining (NHEJ) mechanism of the double-strand break (DSB) repair is dominating. Thus, it seems that reprogramming and differentiation induce DNA strand breaks in stem cells which itself may trigger the differentiation process. Somatic cell reprogramming to iPSCs is preceded by a transient increase of the DSBs induced presumably by the caspase-dependent DNase or reactive oxygen species. In general, pluripotent stem cells possess stronger DNA repair systems compared to differentiated cells. Nonetheless, during a prolonged cell culture propagation, DNA breaks can accumulate due to the DNA polymerase stalling. Consequently, the DNA damage might trigger the differentiation of stem cells or replicative senescence of somatic cells. The differentiation process per se is often accompanied by a decrease in the DNA repair capacity. Thus, the differentiation might be triggered by DNA breaks, alternatively, the breaks can be a consequence of the decay in the DNA repair capacity of differentiated cells.