Administration of Cripto in GRP78 overexpressed human MSCs enhances stem cell viability and angiogenesis during human MSC transplantation therapy

Nitric oxide-based treatments improve wound healing associated with diabetes mellitus

Non-healing wounds are long-term complications of diabetes mellitus (DM) that increase mortality risk and amputation-related disability and decrease the quality of life. Nitric oxide (NO·)-based treatments (i.e., use of both systemic and topical NO· donors, NO· precursors, and NO· inducers) have received more attention as complementary approaches in treatments of DM wounds. Here, we aimed to highlight the potential benefits of NO·-based treatments on DM wounds through a literature review of experimental and clinical evidence. Various topical NO·-based treatments have been used. In rodents, topical NO·-based therapy facilitates wound healing, manifested as an increased healing rate and a decreased half-closure time. The wound healing effect of NO·-based treatments is attributed to increasing local blood flow, angiogenesis induction, collagen synthesis and deposition, re-epithelization, anti-inflammatory and anti-oxidative properties, and potent broad-spectrum antibacterial effects. The existing literature lacks human clinical evidence on the safety and efficacy of NO·-based treatments for DM wounds. Translating experimental favors of NO·-based treatments of DM wounds into human clinical practice needs conducting clinical trials with well-predefined effect sizes, i.e., wound reduction area, rate of wound healing, and hospital length of stay.

Endothelial cell-derived extracellular vesicles modulate the therapeutic efficacy of mesenchymal stem cells through IDH2/TET pathway in ARDS

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe and fatal disease. Although mesenchymal stem cell (MSC)-based therapy has shown remarkable efficacy in treating ARDS in animal experiments, clinical outcomes have been unsatisfactory, which may be attributed to the influence of the lung microenvironment during MSC administration. Extracellular vesicles (EVs) derived from endothelial cells (EC-EVs) are important components of the lung microenvironment and play a crucial role in ARDS. However, the effect of EC-EVs on MSC therapy is still unclear. In this study, we established lipopolysaccharide (LPS) - induced acute lung injury model to evaluate the impact of EC-EVs on the reparative effects of bone marrow-derived MSC (BM-MSC) transplantation on lung injury and to unravel the underlying mechanisms.

METHODS

EVs were isolated from bronchoalveolar lavage fluid of mice with LPS - induced acute lung injury and patients with ARDS using ultracentrifugation. and the changes of EC-EVs were analysed using nanoflow cytometry analysis. In vitro assays were performed to establish the impact of EC-EVs on MSC functions, including cell viability and migration, while in vivo studies were performed to validate the therapeutic effect of EC-EVs on MSCs. RNA-Seq analysis, small interfering RNA (siRNA), and a recombinant lentivirus were used to investigate the underlying mechanisms.

RESULTS

Compared with that in non-ARDS patients, the quantity of EC-EVs in the lung microenvironment was significantly greater in patients with ARDS. EVs derived from lipopolysaccharide-stimulated endothelial cells (LPS-EVs) significantly decreased the viability and migration of BM-MSCs. Furthermore, engrafting BM-MSCs pretreated with LPS-EVs promoted the release of inflammatory cytokines and increased pulmonary microvascular permeability, aggravating lung injury. Mechanistically, LPS-EVs reduced the expression level of isocitrate dehydrogenase 2 (IDH2), which catalyses the formation of α-ketoglutarate (α-KG), an intermediate product of the tricarboxylic acid (TCA) cycle, in BM-MSCs. α-KG is a cofactor for ten-eleven translocation (TET) enzymes, which catalyse DNA hydroxymethylation in BM-MSCs.

CONCLUSIONS

This study revealed that EC-EVs in the lung microenvironment during ARDS can affect the therapeutic efficacy of BM-MSCs through the IDH2/TET pathway, providing potential strategies for improving the therapeutic efficacy of MSC-based therapy in the clinic.

GRP78 improves the therapeutic effect of mesenchymal stem cells on hemorrhagic shock-induced liver injury: Involvement of the NF-кB and HO-1/Nrf-2 pathways

Mesenchymal stem cells (MSCs) are a popular cell source for repairing the liver. Improving the survival rate and colonization time of MSCs may significantly improve the therapeutic outcomes of MSCs. Studies showed that 78-kDa glucose-regulated protein (GRP78) expression improves cell viability and migration. This study aims to examine whether GRP78 overexpression improves the efficacy of rat bone marrow-derived MSCs (rBMSCs) in HS-induced liver damage. Bone marrow was isolated from the femurs and tibias of rats. rBMSCs were transfected with a GFP-labeled GRP78 expression vector. Flow cytometry, transwell invasion assay, scratch assay immunoblotting, TUNEL assay, MTT assay, and ELISA were carried out. The results showed that GRP78 overexpression enhanced the migration and invasion of rBMSCs. Moreover, GRP78-overexpressing rBMSCs relieved liver damage, repressed liver oxidative stress, and inhibited apoptosis. We found that overexpression of GRP78 in rBMSCs inhibited activation of the NLRP3 inflammasome, significantly decreased the levels of inflammatory factors, and decreased the expression of CD68. Notably, GRP78 overexpression activated the Nrf-2/HO-1 pathway and inhibited the NF-κB pathway. High expression of GRP78 efficiently enhanced the effect of rBMSC therapy. GRP78 may be a potential target to improve the therapeutic efficacy of BMSCs.

Gastric Cancer Cell-Derived Exosomal GRP78 Enhances Angiogenesis upon Stimulation of Vascular Endothelial Cells

Exosomes containing glucose-regulated protein 78 (GRP78) are involved in cancer malignancy. GRP78 is thought to promote the tumor microenvironment, leading to angiogenesis. No direct evidence for this role has been reported, however, mainly because of difficulties in accurately measuring the GRP78 concentration in the exosomes. Recently, exosomal GRP78 concentrations were successfully measured using an ultrasensitive ELISA. In the present study, GRP78 concentrations in exosomes collected from gastric cancer AGS cells with overexpression of GRP78 (OE), knockdown of GRP78 (KD), or mock GRP78 (mock) were quantified. These three types of exosomes were then incubated with vascular endothelial cells to examine their effects on endothelial cell angiogenesis. Based on the results of a tube formation assay, GRP78-OE exosomes accelerated angiogenesis compared with GRP78-KD or GRP78-mock exosomes. To investigate the mechanisms underlying this effect, we examined the Ser473 phosphorylation state ratio of AKT, which is involved in the angiogenesis process, and found that AKT phosphorylation was increased by GRP78-OE exosome application to the endothelial cells. An MTT assay showed that GRP78-OE exosome treatment increased the proliferation rate of endothelial cells, and a wound healing assay showed that this treatment increased the migration capacity of the endothelial cells. These findings demonstrated that GRP78-containing exosomes promote the tumor microenvironment and induce angiogenesis.

Whence CRIPTO: The Reemergence of an Oncofetal Factor in 'Wounds' That Fail to Heal

There exists a set of factors termed oncofetal proteins that play key roles in ontogeny before they decline or disappear as the organism's tissues achieve homeostasis, only to then re-emerge in cancer. Although the unique therapeutic potential presented by such factors has been recognized for more than a century, their clinical utility has yet to be fully realized1. This review highlights the small signaling protein CRIPTO encoded by the tumor derived growth factor 1 (TDGF1/Tdgf1) gene, an oft cited oncofetal protein whose presence in the cancer literature as a tumor promoter, diagnostic marker and viable therapeutic target continues to grow. We touch lightly on features well established and well-reviewed since its discovery more than 30 years ago, including CRIPTO's early developmental roles and modulation of SMAD2/3 activation by a selected set of transforming growth factor β (TGF-β) family ligands. We predominantly focus instead on more recent and less well understood additions to the CRIPTO signaling repertoire, on its potential upstream regulators and on new conceptual ground for understanding its mode of action in the multicellular and often stressful contexts of neoplastic transformation and progression. We ask whence it re-emerges in cancer and where it 'hides' between the time of its fetal activity and its oncogenic reemergence. In this regard, we examine CRIPTO's restriction to rare cells in the adult, its potential for paracrine crosstalk, and its emerging role in inflammation and tissue regeneration-roles it may reprise in tumorigenesis, acting on subsets of tumor cells to foster cancer initiation and progression. We also consider critical gaps in knowledge and resources that stand between the recent, exciting momentum in the CRIPTO field and highly actionable CRIPTO manipulation for cancer therapy and beyond.

Is there a place for mesenchymal stromal cell-based therapies in the therapeutic armamentarium against COVID-19?

The COVID-19 pandemic, caused by the rapid global spread of the novel coronavirus (SARS-CoV-2), has caused healthcare systems to collapse and led to hundreds of thousands of deaths. The clinical spectrum of COVID-19 is not only limited to local pneumonia but also represents multiple organ involvement, with potential for systemic complications. One year after the pandemic, pathophysiological knowledge has evolved, and many therapeutic advances have occurred, but mortality rates are still elevated in severe/critical COVID-19 cases. Mesenchymal stromal cells (MSCs) can exert immunomodulatory, antiviral, and pro-regenerative paracrine/endocrine actions and are therefore promising candidates for MSC-based therapies. In this review, we discuss the rationale for MSC-based therapies based on currently available preclinical and clinical evidence of safety, potential efficacy, and mechanisms of action. Finally, we present a critical analysis of the risks, limitations, challenges, and opportunities that place MSC-based products as a therapeutic strategy that may complement the current arsenal against COVID-19 and reduce the pandemic's unmet medical needs.

Natural Products in the Prevention of Metabolic Diseases: Lessons Learned from the 20th KAST Frontier Scientists Workshop

The incidence of metabolic and chronic diseases including cancer, obesity, inflammation-related diseases sharply increased in the 21st century. Major underlying causes for these diseases are inflammation and oxidative stress. Accordingly, natural products and their bioactive components are obvious therapeutic agents for these diseases, given their antioxidant and anti-inflammatory properties. Research in this area has been significantly expanded to include chemical identification of these compounds using advanced analytical techniques, determining their mechanism of action, food fortification and supplement development, and enhancing their bioavailability and bioactivity using nanotechnology. These timely topics were discussed at the 20th Frontier Scientists Workshop sponsored by the Korean Academy of Science and Technology, held at the University of Hawaii at Manoa on 23 November 2019. Scientists from South Korea and the U.S. shared their recent research under the overarching theme of Bioactive Compounds, Nanoparticles, and Disease Prevention. This review summarizes presentations at the workshop to provide current knowledge of the role of natural products in the prevention and treatment of metabolic diseases.

MiR-138-1-3p alters the stemness and radiosensitivity of tumor cells by targeting CRIPTO and the JAK2/STAT3 pathway in nasopharyngeal carcinoma

Background

Tumor resistance to radiotherapy is one of the main obstacles to the clinical treatment of nasopharyngeal carcinoma (NPC). Improving the radiosensitivity of tumor cells has an important clinical significance in treatment of clinical NPC. This study aimed to identify that miR-138-1-3p as a novel therapeutic target in radioresistant NPC cells and found its targets, CRIPTO and the JAK2/STAT3 pathway.

Methods

Radioresistant C666-IR and HK-1R cells were derived from the NPC cell lines C666-1 and HK-1. The different microRNAs (miRNAs) and their targeting genes were analyzed between C666-1 and C666-IR cells using microarray bioinformatics. Western blot, qRT-PCR, gene transfection, Luciferase reporter assay, and confocal laser scanning microscopy were applied for the analysis of the different genes.

Results

MiR-138-1-3p was found to target CRIPTO, which involved in the epithelial-mesenchymal transition (EMT) and JAK2/STAT3 signaling pathways. The luciferase reporter assay confirmed that miR-138-1-3p targeted CRIPTO and downregulated the expression of CRIPTO. Furthermore, miR-138-1-3p affected the stability of the CRIPTO-GRP78 complex on the cell membrane and also reversed the radioresistant characteristics of NPC stem cells, which affected EMT and the JAK2/STAT3 signaling pathway.

Conclusions

The miR-138-1-3p is a small molecule that can modulate radiosensitivity in the radioresistant C666-IR and HK-1R NPC cell lines by inhibiting EMT and targeting CRIPTO to reduce the activation of the JAK2/STAT3 pathway.

Cell surface GRP78 signaling: An emerging role as a transcriptional modulator in cancer

Cancer cells acquire dysregulated gene expression to establish specific transcriptional dependencies and their underlying mechanisms that are ultimately responsible for this addictions have not been fully elucidated. Glucose-regulated protein 78 (GRP78) is a stress-inducible, multifunctional, prosurvival, endoplasmic reticulum chaperone in the heat shock protein 70 family. Expression of cell surface GRP78 (CS-GRP78) is associated with increased malignant behavior and resistance to chemotherapy and radiotherapy by endowing various cancer cells with increased proliferative ability, altered metabolism, improved survival, and augmented invasive and metastatic potential. Emerging evidence has highlighted an unusual role of CS-GRP78 in regulating transcription factors (TFs) by mediating various signaling pathways involved in malignant transformation, metabolic reprogramming, and tumor progression. During the last decade, we targeted CS-GRP78 with C38 monoclonal antibody (C38 Mab) in numerous studies, which have highlighted the epigenetic interplay between CS-GRP78 and various TFs including c-MYC, Yes-associated protein/transcriptional coactivator with PDZ-binding motif, c-Fos, and histone acetylation to potentiate subsequent modulation of tumorigenesis, invasion, and metastasis. Here, we summarize the current state of knowledge about the role of CS-GRP78 in cancer development and progression, including epigenetic regulation and sheds light on CS-GRP78 as vulnerable target for cancer therapy. Overall, this review focuses on the mechanisms of TFs that are behind the transcriptional dysregulation in cancer and lays the groundwork for rational therapeutic use of C38 Mab based on CS-GRP78 biology.

Administration of Cripto in GRP78 overexpressed human MSCs enhances stem cell viability and angiogenesis during human MSC transplantation therapy

OBJECTIVES

The purpose of this study was to explore the effectiveness of concurrent GRP78 overexpression combined with Cripto on hMSC proliferation and migration both in vitro and in vivo. Specifically, we explored whether the treatment enhances effectiveness of hMSC transplantation in ischaemic tissue.

MATERIALS AND METHODS

Human MSCs obtained from human adipose tissue were cultured in α-minimum essential medium (Hyclone, Logan, UT, USA) supplemented with 10% (v/v) foetal bovine serum (Hyclone), 100 U mL^-1 penicillin and 100 μg mL^-1 streptomycin. Murine hindlimb ischaemic model was generated with 8-week-old male nude BALB/c mice (Biogenomics, Seoul, Korea) maintained under a 12-h light/dark cycle following the established protocol with minor modification. Cellular injection was performed no later than 3 hour after surgery. Lipofectamine transfection, single-cell cultivation assay, transwell assay, scratch wound-healing migration assay, immunohistochemistry and western blotting assays were performed.

RESULTS

Overexpression of GRP78 along with Cripto enhanced hMSC proliferation, migration and invasion. It increased interaction of surface GRP78 receptor with Cripto via JAK2/STAT3 pathway. We confirmed our proposed mechanism by showing that treatment with GRP78 antibody blocks the enhancement in vitro. In vivo, we observed that Cripto induced by the hypoxic environment in hindlimb ischaemic model interacts with the overexpressed GRP78 and increases hMSC proliferation, migration and invasion potentials as well as angiogenesis around transplanted ischaemic site via cytokine secretions.

CONCLUSIONS

These results demonstrate supporting evidences that GRP78-Cripto combination technique offers novel strategy to enhance MSC proliferation, migration and invasion potentials as well as angiogenesis around ischaemic site, ultimately facilitating MSC-based transplantation therapy in ischaemic conditions.