ALBERT

Description: Background Cell therapy provides hope for treatment of advanced liver failure. Proliferating human hepatocytes (ProliHHs) were derived from primary human hepatocytes (PHH) and as potential alternative for cell therapy in liver diseases. Due to the continuous decline of mature hepatic genes and increase of progenitor like genes during ProliHHs expanding, it is challenge to monitor the critical changes of the whole process. Raman microspectroscopy is a noninvasive, label free analytical technique with high sensitivity capacity. In this study, we evaluated the potential and feasibility to identify ProliHHs from PHH with Raman spectroscopy. Methods Raman spectra were collected at least 600 single spectrum for PHH and ProliHHs at different stages (Passage 1 to Passage 4). Linear discriminant analysis and a two-layer machine learning model were used to analyze the Raman spectroscopy data. Significant differences in Raman bands were validated by the associated conventional kits. Results Linear discriminant analysis successfully classified ProliHHs at different stages and PHH. A two-layer machine learning model was established and the overall accuracy was at 84.6%. Significant differences in Raman bands have been found within different ProliHHs cell groups, especially changes at 1003 cm−1, 1206 cm−1 and 1440 cm−1. These changes were linked with reactive oxygen species, hydroxyproline and triglyceride levels in ProliHHs, and the hypothesis were consistent with the corresponding assay results. Conclusions In brief, Raman spectroscopy was successfully employed to identify different stages of ProliHHs during dedifferentiation process. The approach can simultaneously trace multiple changes of cellular components from somatic cells to progenitor cells.

Description: Intrauterine adhesion refers to endometrial repair disorders which are usually caused by uterine injury and may lead to a series of complications such as abnormal menstrual bleeding, recurrent abortion and secondary infertility. At present, therapeutic approaches to intrauterine adhesion are limited due to the lack of effective methods to promote regeneration following severe endometrial injury. Therefore, to develop new methods to prevent endometrial injury and intrauterine adhesion has become an urgent need. For severely damaged endometrium, the loss of stem cells in the endometrium may affect its regeneration. This article aimed to discuss the characteristics of various stem cells and their applications for uterine tissue regeneration.

Description: Background Although numerous studies demonstrate the role of cancer stem cells in occurrence, recurrence, and distant metastases in gastric cancer (GC), little is known about the evolving genetic and epigenetic changes in the stem and progenitor cells. The purpose of this study was to identify the stem cell subtypes in GC and examine their clinical relevance. Methods Two publicly available datasets were used to identify GC stem cell subtypes, and consensus clustering was performed by unsupervised machine learning methods. The cancer stem cell (CSC) typing-related risk scoring (RS) model was established through multivariate Cox regression analysis. Results Cross-platform dataset-based two stable GC stem cell subtypes, namely low stem cell enrichment (SCE_L) and high stem cell enrichment (SCE_H), were prudently identified. Gene set enrichment analysis revealed that the classical oncogenic pathways, immune-related pathways, and regulation of stem cell division were active in SCE_H; ferroptosis, NK cell activation, and post-mutation repair pathways were active in SCE_L. GC stem cell subtypes could accurately predict clinical outcomes in patients, tumor microenvironment cell-infiltration characteristics, somatic mutation landscape, and potential responses to immunotherapy, targeted therapy, and chemotherapy. Additionally, a CSC typing-related RS model was established; it was strongly independent and could accurately predict the patient’s overall survival. Conclusions This study demonstrated the complex oncogenic mechanisms underlying GC. The findings provide a basis and reference for the diagnosis and treatment of GC.

Description: Objective To evaluate the safety and efficacy of intra-articular (IA) injection of allogeneic adipose-derived stem cells (ADSCs) ELIXCYTE® for knee osteoarthritis. Methods This was a patient-blind, randomized, active-control trial consisted of 4 arms including hyaluronic acid (HA) control and 3 ELIXCYTE® doses. A total of 64 subjects were screened, and 57 subjects were randomized. The primary endpoints included the changes from baseline to post-treatment visit of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score at Week 24 and the incidence of adverse events (AEs) and serious adverse events (SAEs). Results No ELIXCYTE®-related serious adverse events were reported during 96 weeks of follow-up and no suspected unexpected serious adverse reaction (SUSAR) or death was reported. The changes of the primary endpoint, WOMAC pain score at Week 24, showed significant differences in all ELIXCYTE® groups, as well as in HA groups between post-treatment visit and baseline. The ELIXCYTE® groups revealed significant decreases at Week 4 compared to HA group in WOMAC total scores, stiffness scores, functional limitation scores suggested the potential of ELIXCYTE® in earlier onset compared to those from HA. The significant differences of visual analog scale (VAS) pain score and Knee Society Clinical Rating System (KSCRS) functional activities score at Week 48 after ELIXCYTE® administration suggested the potential of ELIXCYTE® in the longer duration of the effectiveness compared to HA group. Conclusions ELIXCYTE® for knee osteoarthritis treatment was effective, safe, and well-tolerated. The efficacy results were showed that ELIXCYTE® conferred the earlier onset of reductions in pain scores and improvements in functional scores than HA group. Trial registration: ClinicalTrials.gov Identifier: NCT02784964. Registered 16 May, 2016—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02784964

Description: Background Vitamin D is important for the mineralization of bones by stimulating osteoblast differentiation of bone marrow mesenchymal stem cells (BMMSCs). BMMSCs are a target of vitamin D action, and the metabolism of 25(OH)D3 to biologically active 1α,25(OH)2D3 in BMMSCs promotes osteoblastogenesis in an autocrine/paracrine manner. Our previous study with human BMMSCs showed that megalin is required for the 25(OH)D3-DBP complex to enter cells and for 25(OH)D3 to stimulate osteoblast differentiation in BMMSCs. Furthermore, we reported that leptin up-regulates megalin in those cells. Leptin is a known inhibitor of PI3K/AKT-dependent chaperone-mediated autophagy (CMA). In this study, we tested the hypothesis that leptin acts synergistically with 25(OH)D3 to promote osteoblastogenesis in rat BMMSCs by a mechanism that entails inhibition of PI3K/AKT-dependent CMA. Methods BMMSCs were isolated from rat bone marrow (4-week-old male SD rats); qRT-PCR and western immunoblots or immunofluorescence were used to evaluate the expression of megalin, ALP, COL1A1, RUNX2, OSX, OSP, and CMA in rBMMSCs. The osteoblast differentiation was evaluated by ALP activity, ALP staining, and calcium deposition. The viability of rBMMSCs was assessed with the CCK-8 kit. Biosynthesis of 1α,25(OH)2D3 was measured by a Rat 1α,25(OH)2D3 ELISA Kit. Results The combination of leptin and 25(OH)D3 treatment significantly enhanced osteoblast differentiation as shown by ALP activity, ALP staining, and calcium deposition, the expression of osteogenic genes ALP, COL1A1, RUNX2, OSX, and OSP by qRT-PCR and western immunoblots in rBMMSCs. Leptin enhanced the expression of megalin and synthesis of 1α,25(OH)2D3 in rBMMSCs. Our data showed that leptin inhibited CMA activity of rBMMSCs by activating PI3K/AKT signal pathway; the ability of leptin to enhance 25(OH)D3 promoted osteoblast differentiation of rBMMSCs was weakened by the PI3K/AKT signal pathway inhibitor. Conclusions Our data reveal the mechanism by which leptin and 25(OH)D3 promote osteoblast differentiation in rBMMSCs. Leptin promoted the expression of megalin by inhibiting CMA, increased the utilization of 25(OH)D3 by rBMMSCs, and enhanced the ability of 25(OH)D3 to induce osteoblast differentiation of rBMMSCs. PI3K/AKT is at least partially involved in the regulation of CMA. These data indicate the importance of megalin in BMMSCs for vitamin D’s role in skeletal health.

Description: The corneal endothelium plays a key role in maintaining corneal transparency. Its dysfunction is currently treated with penetrating or lamellar keratoplasty. Advanced cell therapy methods seek to address the persistent global deficiency of donor corneas by enabling the renewal of the endothelial monolayer with tissue-engineered grafts. This review provides an overview of recently published literature on the preparation of endothelial grafts for transplantation derived from cadaveric corneas that have developed over the last decade (2010–2021). Factors such as the most suitable donor parameters, culture substrates and media, endothelial graft storage conditions, and transplantation methods are discussed. Despite efforts to utilize alternative cellular sources, such as induced pluripotent cells, cadaveric corneas appear to be the best source of cells for graft preparation to date. However, native endothelial cells have a limited natural proliferative capacity, and they often undergo rapid phenotype changes in ex vivo culture. This is the main reason why no culture protocol for a clinical-grade endothelial graft prepared from cadaveric corneas has been standardized so far. Currently, the most established ex vivo culture protocol involves the peel-and-digest method of cell isolation and cell culture by the dual media method, including the repeated alternation of high and low mitogenic conditions. Culture media are enriched by additional substances, such as signaling pathway (Rho-associated protein kinase, TGF-β, etc.) inhibitors, to stimulate proliferation and inhibit unwanted morphological changes, particularly the endothelial-to-mesenchymal transition. To date, this promising approach has led to the development of endothelial grafts for the first in-human clinical trial in Japan. In addition to the lack of a standard culture protocol, endothelial-specific markers are still missing to confirm the endothelial phenotype in a graft ready for clinical use. Because the corneal endothelium appears to comprise phenotypically heterogeneous populations of cells, the genomic and proteomic expression of recently proposed endothelial-specific markers, such as Cadherin-2, CD166, or SLC4A11, must be confirmed by additional studies. The preparation of endothelial grafts is still challenging today, but advances in tissue engineering and surgery over the past decade hold promise for the successful treatment of endothelial dysfunctions in more patients worldwide.

Description: Background Diabetic cutaneous ulcers (DCU) are a complication of diabetes with diabetic foot ulcers being the most common, and the wounds are difficult to heal, increasing the risk of bacterial infection. Cell-based therapy utilizing mesenchymal stem cells (MSCs) is currently being investigated as a therapeutic avenue for both chronic diabetic ulcers and severe burns. Wharton’s jelly mesenchymal stem cell (WJMSC) with PF-127 hydrogel and sodium ascorbyl phosphate (SAP) improved skin wound healing in mice. Whether this combination strategy is helpful to diabetic ulcers wound healing remains to be explored. Methods Firstly, the WJMSCs embedded in PF-127 and SAP combination were transplanted onto excisional cutaneous wound bed in type 2 diabetic Sprague Dawley (SD) rats. Two weeks after transplantation, the skin tissue was collected for histological and immunohistochemical analysis. Further, overexpressing-EGFP WJMSCs were performed to investigate cell engraftment in the diabetic cutaneous ulcer. The apoptosis of WJMSCs which encapsulated with combination of PF-127 and SAP was detected by TUNEL fluorescence assay and RT-PCR in vitro. And the mitochondrial damage induced by oxidative stress assessed by MitoTracker and CMH2DCFDA fluorescence assay. Results In diabetic cutaneous wound rat model, PF-127 plus SAP-encapsulated WJMSCs transplantation promoted diabetic wound healing, indicating improving dermis regeneration and collagen deposition. In diabetic wound healing, less pro-inflammatory M1 macrophages, more anti-inflammatory M2 tissue-healing macrophages, and neovascularization were observed in PF-127 + SAP + WJMSCs group compared with other groups. SAP supplementation alleviated the apoptosis ratio of WJMSCs embedded in the PF-127 in vitro and promoted cell survival in vivo. Conclusion PF-127 plus SAP combination facilitates WJMSCs-mediated diabetic wound healing in rat through promoting cell survival, the macrophage transformation, and angiogenesis. Our findings may potentially provide a helpful therapeutic strategy for patients with diabetic cutaneous ulcer.

Description: End-stage liver disease (ESLD) is characterized by the deterioration of liver function and a subsequent high mortality rate. Studies have investigated the use of adult stem cells to treat ESLD. Here, a systematic review and meta-analysis was conducted to determine the efficacy of a combination therapy with adult stem cell transplantation and traditional medicine for treating ESLD. Four databases—including PubMed, Web of Science, Embase, and Cochrane Library—were investigated for studies published before January 31, 2021. The main outcome indicators were liver function index, model for end-stage liver disease (MELD) scores, and Child‒Turcotte‒Pugh (CTP) scores. Altogether, 1604 articles were retrieved, of which eight met the eligibility criteria; these studies included data for 579 patients with ESLD. Combination of adult stem cell transplantation with conventional medicine significantly improved its efficacy with respect to liver function index, CTP and MELD scores, but this effect gradually decreased over time. Moreover, a single injection of stem cells was more effective than two injections with respect to MELD and CTP scores and total bilirubin (TBIL) and albumin (ALB) levels, with no significant difference in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. With respect to the TBIL levels, patients receiving mononuclear cells (MNCs) experienced a significantly greater therapeutic effect—starting from twenty-four weeks after the treatment—whereas with respect to ALB levels, CD34+ autologous peripheral blood stem cells (CD34+ APBSCs) and MNCs had similar therapeutic effects. Severe complications associated with adult stem cell treatment were not observed. Although the benefits of combination therapy with respect to improving liver function were slightly better than those of the traditional treatment alone, they gradually decreased over time.Systematic review registration: PROSPERO registration number: CRD42021238576.

Description: Exosomes are extracellular vesicles secreted by various cells, mainly composed of lipid bilayers without organelles. In recent years, an increasing number of researchers have focused on the use of exosomes for drug delivery. Targeted drug delivery in the body is a promising method for treating many refractory diseases such as tumors and Alzheimer's disease (AD). Finding a suitable drug delivery carrier in the body has become a popular research today. In various drug delivery studies, the exosomes secreted by mesenchymal stem cells (MSC-EXOs) have been broadly researched due to their immune properties, tumor-homing properties, and elastic properties. While MSC-EXOs have apparent advantages, some unresolved problems also exist. This article reviews the studies on MSC-EXOs for drug delivery, summarizes the characteristics of MSC-EXOs, and introduces the primary production and purification methods and drug loading methods to provide solutions for existing problems and suggestions for future studies.

Description: Background The adult mammalian retina does not have the capacity to regenerate cells lost due to damage or disease. Therefore, retinal injuries and blinding diseases result in irreversible vision loss. However, retinal stem cells (RSCs), which participate in retinogenesis during development, persist in a quiescent state in the ciliary epithelium (CE) of the adult mammalian eye. Moreover, RSCs retain the ability to generate all retinal cell types when cultured in vitro, including photoreceptors. Therefore, it may be possible to activate endogenous RSCs to induce retinal neurogenesis in vivo and restore vision in the adult mammalian eye. Methods To investigate if endogenous RSCs can be activated, we performed combinatorial intravitreal injections of antagonists to BMP and sFRP2 proteins (two proposed mediators of RSC quiescence in vivo), with or without growth factors FGF and Insulin. We also investigated the effects of chemically-induced N-methyl-N-Nitrosourea (MNU) retinal degeneration on RSC activation, both alone and in combination withthe injected factors. Further, we employed inducible Msx1-CreERT2 genetic lineage labeling of the CE followed by stimulation paradigms to determine if activated endogenous RSCs could migrate into the retina and differentiate into retinal neurons. Results We found that in vivo antagonism of BMP and sFRP2 proteins induced CE cells in the RSC niche to proliferate and expanded the RSC population. BMP and sFRP2 antagonism also enhanced CE cell proliferation in response to exogenous growth factor stimulation and MNU-induced retinal degeneration. Furthermore, Msx1-CreERT2 genetic lineage tracing revealed that CE cells migrated into the retina following stimulation and/or injury, where they expressed markers of mature photoreceptors and retinal ganglion cells. Conclusions Together, these results indicate that endogenous adult mammalian RSCs may have latent regenerative potential that can be activated by modulating the RSC niche and hold promise as a means for endogenous retinal cell therapy to repair the retina and improve vision.