Chimerization of human ESC-derived extraembryonic cells with the mouse blastocyst.

It has been reported that human embryonic stem cells (hESCs) treated with BMP4 and inhibitors of TGFβ signaling (A83-01) and FGF signaling (PD173074), called BAP, can efficiently differentiate to extraembryonic (ExE) cells . Due to restricted access to human embryos, it is ethically impossible to test the developmental potential of ExE cells . Here, we demonstrate that most ExE cells expressed molecular markers for both trophoblasts (TBs) and amniotic cells (ACs).

Corrigendum: Heterologous vaccination with inactivated vaccine and mRNA vaccine augments antibodies against both spike and nucleocapsid proteins of SARS-CoV-2: a local study in Macao.

[This corrects the article DOI: 10.3389/fimmu.2023.

Developmental potency of human ES cell-derived mesenchymal stem cells revealed in mouse embryos following blastocyst injection.

Mesenchymal stem cells (MSCs) are present in almost all the tissues in the body, critical for their homeostasis and regeneration. However, the stemness of MSCs is mainly an in vitro observation, and lacking exclusive markers for endogenous MSCs makes it difficult to study the multipotency of MSCs in vivo, especially for human MSCs. To address this hurdle, we injected GFP-tagged human embryonic stem cell (hESC)-derived MSCs (EMSCs) into mouse blastocysts.

Nanoghosts: Harnessing Mesenchymal Stem Cell Membrane for Construction of Drug Delivery Platforms Via Optimized Biomimetics.

Mesenchymal stem cells (MSCs) are becoming hotspots for application in disease therapies recently, combining with biomaterials and drug delivery system. A major advantage of MSCs applied in drug delivery system is that these cells enable specific targeting and releasing of cargos to the disease sites. However, the potential tumor tropic effects of MSCs raised concerns on biosafety.

Heterologous vaccination with inactivated vaccine and mRNA vaccine augments antibodies against both spike and nucleocapsid proteins of SARS-CoV-2: a local study in Macao.

The mRNA vaccines (RVs) can reduce the severity and mortality of severe acute respiratory syndrome coronavirus (SARS-CoV-2). However, almost only the inactivated vaccines (IVs) but no RVs had been used in mainland China until most recently, and the relaxing of its anti-pandemic strategies in December 2022 increased concerns about new outbreaks. In comparison, many of the citizens in Macao Special Administrative Region of China received three doses of IV (3IV) or RV (3RV), or 2 doses of IV plus one booster of RV (2IV+1RV).

An Engineered Dermal Substitute with Mesenchymal Stem Cells Enhances Cutaneous Wound Healing.

The treatment of refractory cutaneous wounds remains to be a clinical challenge. There is growing evidence to show that mesenchymal stem cells (MSCs) have great potential in promoting wound healing. However, the therapeutic effects of MSCs are greatly dampened by their poor survival and engraftment in the wounds.

EGFR marks a subpopulation of dermal mesenchymal cells highly expressing IGF1 which enhances hair follicle regeneration.

The skin harbours transcriptionally and functionally heterogeneous mesenchymal cells that participate in various physiological activities by secreting biochemical cues. In this study, we aimed to identify a new subpopulation of dermal mesenchymal cells that enhance hair follicle regeneration through a paracrine mechanism. Integrated single-cell RNA sequencing (scRNA-seq) data analysis revealed epidermal growth factor receptor (EGFR) as a marker of distinct fibroblast subpopulation in the neonatal murine dermis.

Definitive Endodermal Cells Supply an in vitro Source of Mesenchymal Stem/Stromal Cells.

Mesenchymal stem/Stromal cells (MSCs) have great therapeutic potentials, and they have been isolated from various tissues and organs including definitive endoderm (DE) organs, such as the lung, liver and intestine. MSCs have been induced from human pluripotent stem cells (hPSCs) through multiple embryonic lineages, including the mesoderm, neural crest, and extraembryonic cells. However, it remains unclear whether hPSCs could give rise to MSCs in vitro through the endodermal lineage.

Distinct bulge stem cell populations maintain the pilosebaceous unit in a β-catenin-dependent manner.

The pilosebaceous unit (PSU) is composed of multiple compartments and the self-renewal of PSU depends on distinct hair follicle stem cell (HFSC) populations. However, the differential roles of the HFSCs in sebaceous gland (SG) renewal have not been completely understood. Here, we performed multiple lineage tracing analysis to unveil the contribution of different HFSC populations to PSU regeneration during the hair cycle and wound healing.

Nonpharmaceutical interventions reduce the incidence and mortality of COVID-19: A study based on the survey from the International COVID-19 Research Network (ICRN).

The recently emerged novel coronavirus, "severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)," caused a highly contagious disease called coronavirus disease 2019 (COVID-19). It has severely damaged the world's most developed countries and has turned into a major threat for low- and middle-income countries. Since its emergence in late 2019, medical interventions have been substantial, and most countries relied on public health measures collectively known as nonpharmaceutical interventions (NPIs).

Preclinical safety evaluation and tracing of human mesenchymal stromal cell spheroids following intravenous injection into cynomolgus monkeys.

We have previously demonstrated that mesenchymal stromal/stem cells (MSCs) in spheroids (MSC) tolerate ambient and hypoxic conditions for a prolonged time. Local administration of MSC, but not dissociated MSCs (MSC), promotes wound healing and relieves multiple sclerosis and osteoarthritis in mice and monkeys. These findings indicate an advantage of MSC over MSC in sustaining cell viability and efficacy following transplantation, which, however, does not appear to apply to intravenous (i.

Revealing the mystery of persistent smell loss in Long COVID patients.

COVID-19 is hopefully approaching its end in many countries as herd immunity develops and weaker strains of SARS-CoV-2 dominate. However, a new concern occurs over the long-term effects of COVID-19, collectively called "Long COVID", as some symptoms of the nervous system last even after patients recover from COVID-19. This review focuses on studies of anosmia, , impairment of smell, which is the most common sensory defect during the disease course and is caused by olfactory dysfunctions.

The global case fatality rate of coronavirus disease 2019 by continents and national income: A meta-analysis.

The aim of this study is to provide a more accurate representation of COVID-19's case fatality rate (CFR) by performing meta-analyses by continents and income, and by comparing the result with pooled estimates. We used multiple worldwide data sources on COVID-19 for every country reporting COVID-19 cases. On the basis of data, we performed random and fixed meta-analyses for CFR of COVID-19 by continents and income according to each individual calendar date.

Engineering of human mesenchymal stem cells resistant to multiple natural killer subtypes.

Mesenchymal stem cells (MSCs) as a therapeutic promise are often quickly cleared by innate immune cells of the host including natural killer (NK) cells. Efforts have been made to generate immune-escaping human embryonic stem cells (hESCs) where T cell immunity is evaded by defecting β-2-microglobulin (B2M), a common unit for human leukocyte antigen (HLA) class I, and NK cells are inhibited via ectopic expression of or . However, NK subtypes vary among recipients and even at different pathologic statuses.

mRNA vaccines for COVID-19: what, why and how.

The Coronavirus disease-19 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus -2 (SARS-CoV-2), has impacted human lives in the most profound ways with millions of infections and deaths. Scientists and pharmaceutical companies have been in race to produce vaccines against SARS-CoV-2. Vaccine generation usually demands years of developing and testing for efficacy and safety.

Human ESC-derived MSCs enhance fat engraftment by promoting adipocyte reaggregation, secreting CCL2 and mobilizing macrophages.

Mesenchymal stem cells (MSCs) derived from somatic tissues have been used to promote lipotransfer, a common practice in cosmetic surgery. However, the effect of lipotransfer varies, and the mechanism of action remains vague. To address these questions, we differentiated human embryonic stem cells, a stable and unlimited source, into MSCs (EMSCs).

Alternative splicing in mesenchymal stem cell differentiation.

The differentiation and maturation of mesenchymal stem cells (MSCs) to mesodermal and other lineages are known to be controlled by various extrinsic and intrinsic signals. The dysregulation of the MSC differentiation balance has been linked to several pathophysiological conditions, including obesity and osteoporosis. Previous research of the molecular mechanisms governing MSC differentiation has mostly focused on transcriptional regulation.

PI3K/Akt signaling pathway is essential for de novo hair follicle regeneration.

Background: Cultured epidermal stem cells (Epi-SCs) and skin-derived precursors (SKPs) were capable of reconstituting functional hair follicles after implantation, while the signaling pathways that regulate neogenic hair follicle formation are poorly investigated. In this study, we aimed to understand the interactions between Epi-SCs and SKPs during skin organoid formation and to uncover key signal pathways crucial for de novo hair follicle regeneration.

Methods: To track their fate after transplantation, Epi-SCs derived from neonatal C57BL/6 mice were labeled with tdTomato, and SKPs were isolated from neonatal C57BL/6/GFP mice.

COVID-19: what has been learned and to be learned about the novel coronavirus disease.

The outbreak of Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), has thus far killed over 3,000 people and infected over 80,000 in China and elsewhere in the world, resulting in catastrophe for humans. Similar to its homologous virus, SARS-CoV, which caused SARS in thousands of people in 2003, SARS-CoV-2 might also be transmitted from the bats and causes similar symptoms through a similar mechanism. However, COVID-19 has lower severity and mortality than SARS but is much more transmissive and affects more elderly individuals than youth and more men than women.

Stagewise keratinocyte differentiation from human embryonic stem cells by defined signal transduction modulators.

Keratinocyte is the predominant cell type in the epidermis of skin, and it provides the protective barrier function for the body. Various signaling pathways have been implicated in keratinocyte differentiation in animal models; However, their temporal regulation and interactions are still to be explored in pluripotent stem cell models. In this report, we use human embryonic stem cells to demonstrate that epidermal ectoderm and subsequent keratinocyte cell fate can be determined step by step under the regulation of defined factors.

Transplantation of human ESC-derived mesenchymal stem cell spheroids ameliorates spontaneous osteoarthritis in rhesus macaques.

It has been demonstrated that mesenchymal stem cells (MSCs) differentiated from human embryonic stem cells (hESCs), name EMSCs, can treat a variety of autoimmune and inflammatory diseases, with similar efficacies to those achieved with MSCs derived from somatic tissues such as bone marrow (BMSCs). The chance increases even higher for EMSCs, than somatic tissue derived MSCs​, to become a cell drug as the former can be produced in large scale from an unlimited hESC line with easier quality control and less biosafety concern. We have further demonstrated that both human ESCs and EMSCs, after aggregation to form spheroids, can tolerate hypoxic and ambient conditions (AC) for over 4 and 10 days, respectively, without loss of their viability and alteration of their functions.