Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice.

BACKGROUND: Atherosclerosis (AS), a chronic inflammatory disease of blood vessels, is a major contributor to cardiovascular disease. Dental pulp stem cells (DPSCs) are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflammation-related diseases. Hepatocyte growth factor (HGF) is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases. AIM: To modify DPSCs with HGF (DPSC-HGF) and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout (ApoE-/-) mouse model and an in vitro cellular model. METHODS: ApoE-/- mice were fed with a high-fat diet (HFD) for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs (DPSC-Null) through tail vein at weeks 4, 7, and 11, respectively, and the therapeutic efficacy and mechanisms were analyzed by histopathology, flow cytometry, lipid and glucose measurements, real-time reverse transcription polymerase chain reaction (RT-PCR), and enzyme-linked immunosorbent assay at the different time points of the experiment. An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells (HAOECs), and indirect co-cultured with supernatant of DPSC-Null (DPSC-Null-CM) or DPSC-HGF-CM, and the effect and mechanisms were analyzed by flow cytometry, RT-PCR and western blot. Nuclear factor-κB (NF-κB) activators and inhibitors were also used to validate the related signaling pathways. RESULTS: DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors, and the percentage of macrophages in the aorta, and DPSC-HGF treatment had more pronounced effects. DPSCs treatment had no effect on serum lipoprotein levels. The FACS results showed that DPSCs treatment reduced the percentages of monocytes, neutrophils, and M1 macrophages in the peripheral blood and spleen. DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-α stimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway. CONCLUSION: This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/- mice on a HFD, and could be of greater value in stem cell-based treatments for AS.

Co-overexpression of OPN, IGF-1 and CNTF augment the therapeutic effect of DPSC on spinal cord injury.

Background aims: Spinal cord injury (SCI) is one of the most complex and destructive diseases of the nervous system, which can lead to permanent loss of tactile perception. But existing treatment methods have limited effects. To establish a novel method that may be therapeutic in repairing the injured spinal cord, gene-modified dental pulp stem cells (DPSCs) were injected in situ. Methods: Adenovirus carrying osteopontin (OPN), Insulin-like growth factor 1 (IGF-1) and cailiary-derived neurotrophic factor (CNTF) (Ad-OIC) was constructed. After modified with Ad-OIC, supernatant of DPSC were co-cultured with HT-22 cells and the effect of DPSC-OIC on the HT-22 cells were evaluated via Cell Counting Kit-8 (CCK-8) assay, Real-Time polymerase chain reaction (PCR) analysis, laser confocal microscopy and fluorescence activating cell sorter (FACS). DPSC-OIC were injected in the lesion area of injured spinal cord and the survival time of transplanted cells were measured by bioluminescence imaging system. The recovery of the injured spinal cord was evaluated by behavioral score, radiological evaluation and immunopathological analysis. Results: DPSC-OIC could enhance the proliferation and axon growth of HT-22 cells, and protect HT-22 cells from H2O2 induced apoptosis. The transplanted DPSC-Null or DPSC-OIC could survive for more than two weeks in local injection site. DPSC-OIC treatment could increase Basso-Mouse Scale (BMS) scores, improve Magnetic Resonance Imaging (MRI) manifestation and promote bladder function recovery. Less apoptotic neurons and more proliferative cells were found in the lesion area of DPSC-OIC treated spinal cord. Nestin+ cells and neural stem cell marker (Sox2) were both up-regulated after DPSC-OIC treatment. Additionally, inhibitory extracellular matrix proteoglycan Neural/Glial Antigen 2 (NG2) was down-regulated and axon growth promotive factor fibronectin was up-regulated after both DPSC-Null (DPSCs infected with Ad-Null) and DPSC-OIC treatments. Conclusions: DPSC-OIC could be a novel effective method for treating SCI.

Recombinant Neorudin for the Prevention of Deep-Vein Thrombosis After Spinal-Cord Injury.

Background: Whether anticoagulant therapy should be used after spinal-cord injury (SCI) surgery was controversial. The anticoagulation characteristics of a newly developed anticoagulant, recombinant neorudin (EPR-hirudin (EH)), were explored using a rat model of SCI to provide a basis for clinical anticoagulation therapy of SCI. Methods: A rat model of SCI was developed by Allen's method. Then, thrombosis in the inferior vena cava was induced by ligation. The low-bleeding characteristics of EH were explored by investigating dose-response and time-effect relationships, as well as multiple administration of EH, on thrombus formation complicated with SCI. Results: EH inhibited thrombosis in a dose-dependent manner by reducing the wet weight and dry weight of the thrombus. An inhibiting action of EH on thrombosis was most evident in the group given EH 2 h after SCI. After multiple intravenous doses of EH, thrombosis inhibition was improved to that observed with low molecular weight heparin (LMWH) (87% vs 90%). EH administration after SCI neither increased bleeding in the injured spine nor damaged to nerve function. Bleeding duration and activated partial thromboplastin time were increased in the high-dose EH group compared with that in the normal-saline group, but were lower than those in the LMWH group. Conclusion: EH can reduce thrombus formation in a rat model of SCI, and bleeding is decreased significantly compared with that using LMWH. EH may prevent thrombosis after SCI or spinal surgery.

Recent advances in the therapeutic efficacy of hepatocyte growth factor gene-modified mesenchymal stem cells in multiple disease settings.

Mesenchymal stem cell (MSC) therapy is considered a new treatment for a wide range of diseases and injuries, but challenges remain, such as poor survival, homing and engraftment rates, thus limiting the therapeutic efficacy of the transplanted MSCs. Many strategies have been developed to enhance the therapeutic efficacy of MSCs, such as preconditioning, co-transplantation with graft materials and gene modification. Hepatocyte growth factor (HGF) is secreted by MSCs, which plays an important role in MSC therapy. It has been reported that the modification of the HGF gene is beneficial to the therapeutic efficacy of MSCs, including diseases of the heart, lung, liver, urinary system, bone and skin, lower limb ischaemia and immune-related diseases. This review focused on studies involving HGF/MSCs both in vitro and in vivo. The characteristics of HGF/MSCs were summarized, and the mechanisms of their improved therapeutic efficacy were analysed. Furthermore, some insights are provided for HGF/MSCs' clinical application based on our understanding of the HGF gene and MSC therapy.

Comparison of CD146 +/- mesenchymal stem cells in improving premature ovarian failure.

BACKGROUND: Mesenchymal stem cells (MSCs) are a heterogeneous group of subpopulations with differentially expressed surface markers. CD146 + MSCs correlate with high therapeutic and secretory potency. However, their therapeutic efficacy and mechanisms in premature ovarian failure (POF) have not been explored. METHODS: The umbilical cord (UC)-derived CD146 +/- MSCs were sorted using magnetic beads. The proliferation of MSCs was assayed by dye670 staining and flow cytometry. A mouse POF model was established by injection of cyclophosphamide and busulfan, followed by treatment with CD146 +/- MSCs. The therapeutic effect of CD146 +/- MSCs was evaluated based on body weight, hormone levels, follicle count and reproductive ability. Differential gene expression was identified by mRNA sequencing and validated by RT-PCR. The lymphocyte percentage was detected by flow cytometry. RESULTS: CD146 +/- MSCs had similar morphology and surface marker expression. However, CD146 + MSCs exhibited a significantly stronger proliferation ability. Gene profiles revealed that CD146 + MSCs had a lower levels of immunoregulatory factor expression. CD146 + MSCs exhibited a stronger ability to inhibit T cell proliferation. CD146 +/- MSCs treatment markedly restored FSH and E2 hormone secretion level, reduced follicular atresia, and increased sinus follicle numbers in a mouse POF model. The recovery function of CD146 + MSCs in a reproductive assay was slightly improved than that of CD146 - MSCs. Ovary mRNA sequencing data indicated that UC-MSCs therapy improved ovarian endocrine locally, which was through PPAR and cholesterol metabolism pathways. The percentages of CD3, CD4, and CD8 lymphocytes were significantly reduced in the POF group compared to the control group. CD146 + MSCs treatment significantly reversed the changes in lymphocyte percentages. Meanwhile, CD146 - MSCs could not improve the decrease in CD4/8 ratio induced by chemotherapy. CONCLUSION: UC-MSCs therapy improved premature ovarian failure significantly. CD146 +/- MSCs both had similar therapeutic effects in repairing reproductive ability. CD146 + MSCs had advantages in modulating immunology and cell proliferation characteristics.

Long-term hypoxia inhibits the passage-dependent stemness decrease and senescence increase of human dental pulp stem cells.

Dental pulp stem cells (DPSCs) derived from discarded orthodontic teeth are easily obtained and have become a promising source for mesenchymal stem cell-based therapy. However, the pulp tissue is limited, and long-term culture induces cell senescence. Hypoxic culture was expected to be suitable for DPSC expansion, but the results have been contradictory. The aim of this study was to verify the effect of hypoxic culture on human DPSCs (hDPSCs). hDPSCs were isolated and cultured in normoxic (ambient O2 concentration) and hypoxic (5% O2) environments from passage 3 (P3) to P6. The biological characteristics of the cells at P4 (short-term culture) and P6 (long-term culture) were evaluated, including the expression of surface markers, cellular proliferation activity, cellular senescence, and spontaneous and induced differentiation. The results showed that the morphology, phenotype, and proliferation activity of hDPSCs were not affected by hypoxic culture. Long-term normoxic culture of hDPSCs induced cell stemness loss and cell senescence, while hypoxic culture could alleviate these effects. The expression of the stemness markers STRO-1 and OCT4 was increased and the number of senescent cells and the expression of the senescence-related genes P53 and TGF-ß were reduced by long-term hypoxic culture. Spontaneous osteogenic and adipogenic differentiation did not occur during long-term normoxic culture. However, hypoxic culture suppressed the expression of the osteogenic markers ALP and RUNX-2 and the adipogenic markers PPAR-γ and FABP4. The induced osteogenic and adipogenic differentiation was apparently reduced by hypoxic culture as well. Our findings indicate that long-term hypoxia culture is beneficial to the maintenance of hDPSCs' biological characteristics and provide some insights into their large-scale expansion.

Structure and activity of an anti-epidermal growth factor receptor antibody without galactose-α-1,3-galactose residues.

Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein, which has been considered as one of the key targets for cancer therapy. However, currently approved therapeutic anti-EGFR antibody may cause the hypersensitivity reaction induced by galactose-α-1,3-galactose (α-Gal) structure, which is inevitable in insect cell expression system. In this study, the Chinese hamster ovary cell line was used to produce a monoclonal antibody containing simplified glycosylation patterns (code: AB01). And cetuximab was used as a control. The two antibodies were highly similar in molecular weight, secondary structure, binding affinity and endocytosis behavior, whereas the glycotypes are extremely distinct. The flow cytometry assay suggested that AB01 induced cell cycle arrest in G1, thus inhibit cell proliferation. Moreover, both cetuximab and AB01 showed similar sensitivity for all tested cell lines in this research. In conclusion, AB01 could be a potential anti-EGFR drug candidate for cancer therapy.

Overexpression of Hepatocyte Growth Factor in Dental Pulp Stem Cells Ameliorates the Severity of Psoriasis by Reducing Inflammatory Responses.

Psoriasis is an autoimmune disease still lacking standard treatment, and it has been demonstrated that mesenchymal stem cells (MSCs) are capable of immunoregulation. The underlying mechanism might involve the secretion of soluble cytokines, such as hepatocyte growth factor (HGF). This study aims to investigate the therapeutic effect of HGF-overexpressed dental pulp stem cells (DPSCs) [DPSCs; HGF overexpressed DPSCs (HGF-DPSCs)] on imiquimod-induced psoriasis. DPSCs were isolated and transfected by adenovirus vector carrying HGF gene (Ad-HGF). The immunoregulatry abilities of DPSCs and HGF-DPSCs were investigated by coculture of the MSCs with peripheral blood mononuclear cells (PBMCs) under appropriated stimulation. The psoriatic mice were treated with saline control, DPSCs, or HGF-DPSCs. Then the mice spleens were collected and weighted. The psoriatic skin lesions were analyzed by Hematoxylin/Eosin and immunohistochemical staining for histopathological changes, and quantitative real-time polymerase chain reaction to detect the expression levels of CD4+ T cell-related transcription factors and cytokines. The mice blood serum was measured by MILLIPLEX analysis and enzyme-linked immunosorbent assay to evaluate the expression levels of inflammation cytokines. The coculture experiments showed HGF overexpression enhanced the immunoregulation abilities of DPSCs not by suppressing PBMCs' proliferation, but by downregulating T helper 1 (Th1), Th17 cells, and upregulating regulatory T (Treg) cells. In psoriatic skin lesions, the psoriasis-like erythema, scaling, and thickening were ameliorated; and the expression of cytokeratin 6 (CK6), and cytokeratin 17 (CK17) were downregulated by DPSCs and HGF-DPSCs treatment. HGF overexpression enhanced the decrease of spleen masses; enhanced the downregulation of the expression levels of interferon-gamma (IFN-γ), tumor necrosis factor-α, and interleukin (IL)-17A in the blood serums; enhanced the downregulation of T-box transcription factor 21 (T-bet), IFN-γ, retinoic acid-related orphan receptor-γt (RORγt), IL-17A, IL-17F, IL-23, and upregulation of Foxp3 and IL-10 in the psoriatic skin lesions. Therefore, HGF overexpression enhanced DPSCs' treatment effect on psoriasis mainly by reducing inflammatory responses. These findings might provide new immunoregulation strategies for psoriasis treatment.

A phase I, single and continuous dose administration study on the safety, tolerability, and pharmacokinetics of neorudin, a novel recombinant anticoagulant protein, in healthy subjects.

The aim of this study was to evaluate the tolerability, safety, and pharmacokinetics of single and continuous dose administration of recombinant neorudin (EPR-hirudin, EH) by intravenous administration in healthy subjects, and to provide a safe dosage range for phase II clinical research. Forty-four subjects received EH as a single dose of between 0.2 and 2.0 mg/kg by intravenous bolus and drip infusion. In addition, 18 healthy subjects were randomly divided into three dose groups (0.15, 0.30, and 0.45 mg/kg/h) with 6 subjects in each group for the continuous administration trial. Single or continuous doses of neorudin were generally well tolerated by healthy adult subjects. There were no serious adverse events (SAEs), and all adverse events (AEs) were mild to moderate. Moreover, no subjects withdrew from the trial because of AEs. There were no clinically relevant changes in physical examination results, clinical chemistry, urinalysis, or vital signs. The incidence of adverse events was not significantly related to drug dose or systemic exposure. After single-dose and continuous administration, the serum EH concentration reached its peak at 5 min, and the exposure increased with the increase in the administered dose. The mean half-life (T1/2 ), clearance (Cl), and apparent volume of distribution (Vd) of EH ranged from 1.7 to 2.5 h, 123.9 to 179.7 ml/h/kg, and 402.7 to 615.2 ml/kg, respectively. The demonstrated safety, tolerability, and pharmacokinetic characteristics of EH can be used to guide rational drug dosing and choose therapeutic regimens in subsequent clinical studies. Clinical trial registration: Chinadrugtrials.org identifier: CTR20160444.

Clinical-grade human dental pulp stem cells suppressed the activation of osteoarthritic macrophages and attenuated cartilaginous damage in a rabbit osteoarthritis model.

BACKGROUND: Although increasing evidence has demonstrated that human dental pulp stem cells (hDPSCs) are efficacious for the clinical treatment of skeletal disorders, the underlying mechanisms remain incompletely understood. Osteoarthritis (OA) is one of the most common degenerative disorders in joints and is characterized by gradual and irreversible cartilaginous tissue damage. Notably, immune factors were newly identified to be closely related to OA development. In this study, we explored the modulatory effects of clinical-grade hDPSCs on osteoarthritic macrophages and their protective effects on cartilaginous tissues in OA joints. METHODS: The cell morphology, immunophenotype, and inflammatory factor expression of osteoarthritic macrophages were explored by phase contrast microscope, transmission electron microscopy, immunostaining, flow cytometry, quantitative polymerase chain reaction, and enzyme linked immunosorbent assay, respectively. Additionally, the factors and signaling pathways that suppressed macrophage activation by hDPSCs were determined by enzyme-linked immunosorbent assay and western-blotting. Furthermore, hDPSCs were administered to a rabbit knee OA model via intra-articular injection. Macrophage activation in vivo and cartilaginous tissue damage were also evaluated by pathological analysis. RESULTS: We found that hDPSCs markedly inhibited osteoarthritic macrophage activation in vitro. The cell morphology, immunophenotype, and inflammatory factor expression of osteoarthritic macrophages changed into less inflammatory status in the presence of hDPSCs. Mechanistically, we observed that hDPSC-derived hepatocyte growth factor and transforming growth factor ß1 mediated the suppressive effects on osteoarthritic macrophages. Moreover, phosphorylation of MAPK pathway proteins contributed to osteoarthritic macrophage activation, and hDPSCs suppressed their activation by partially inactivating those pathways. Most importantly, injected hDPSCs inhibited macrophage activation in osteochondral tissues in a rabbit knee OA model in vivo. Further histological analysis showed that hDPSCs alleviated cartilaginous damage to knee joints. CONCLUSIONS: In summary, our findings reveal a novel function for hDPSCs in suppressing osteoarthritic macrophages and suggest that macrophages are efficient cellular targets of hDPSCs for alleviation of cartilaginous damage in OA. hDPSCs treat OA via an osteoarthritic macrophages-dependent mechanisms. hDPSCs suppress the activation of osteoarthritic macrophages in vitro and in vivo and alleviate cartilaginous lesions in OA models.

HGF-Modified Dental Pulp Stem Cells Mitigate the Inflammatory and Fibrotic Responses in Paraquat-Induced Acute Respiratory Distress Syndrome.

Paraquat (PQ) poisoning can cause acute lung injury and progress to pulmonary fibrosis and eventually death without effective therapy. Mesenchymal stem cells (MSCs) and hepatocyte growth factor (HGF) have been shown to partially reverse this damage. MSCs can be derived from bone marrow (BM-MSCs), adipose tissue (AD-MSCs), umbilical cord (UC-MSCs), dental pulp (DPSCs), and other sources. The biological characteristics of MSCs are specific to the tissue source. To develop an effective treatment for PQ poisoning, we compared the anti-inflammatory and antifibrotic effects of UC-MSCs and DPSCs and chose and modified a suitable source with HGF to investigate their therapeutic effects in vitro and in vivo. In this study, MSCs' supernatant was beneficial to the viability and proliferation of human lung epithelial cell BEAS-2B. Inflammatory and fibrosis-related cytokines were analyzed by real-time PCR. The results showed that MSCs' supernatant could suppress the expression of proinflammatory and profibrotic cytokines and increase the expression of anti-inflammatory and antifibrotic cytokines in BEAS-2B cells and human pulmonary fibroblast MRC-5. Extracellular vesicles (EVs) derived from MSCs performed more effectively than MSCs' supernatant. The effect of DPSCs was stronger than that of UC-MSCs and was further strengthened by HGF modification. PQ-poisoned mice were established, and UC-MSCs, DPSCs, and DPSCs-HGF were administered. Histopathological assessments revealed that DPSCs-HGF mitigated lung inflammation and collagen accumulation more effectively than the other treatments. DPSCs-HGF reduced lung permeability and increased the survival rate of PQ mice from 20% to 50%. Taken together, these results indicated that DPSCs can suppress inflammation and fibrosis in human lung cells better than UC-MSCs. The anti-inflammatory and antifibrotic effects were significantly enhanced by HGF modification. DPSCs-HGF ameliorated pulmonitis and pulmonary fibrosis in PQ mice, effectively improving the survival rate, which might be mediated by paracrine mechanisms. The results suggested that DPSCs-HGF transplantation was a potential therapeutic approach for PQ poisoning.

Dental Pulp Stem Cell-Derived Extracellular Vesicles Mitigate Haematopoietic Damage after Radiation.

Radiation therapy can cause haematopoietic damage, and mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) have been shown to reverse this damage. Our previous research showed that dental pulp stem cells (DPSCs) have a strong proliferation capacity and can produce abundant amounts of EVs to meet the requirements for use in vitro and in vivo. DPSCs derived EVs (DPSCs-EVs) are evaluated for their effect on reducing haematopoietic damage. Haematopoietic stem cell (HSC) numbers and function were assessed by flow cytometry, peripheral blood cell counts, histology and bone marrow transplantation. Epidermal growth factor (EGF) was used as a reference for evaluating the efficiency of EVs. miRNA microarray was employed to find out the changes of miRNA expression after cells being irradiated in vivo and the role they may play in mitigation the radiation caused injury. We observed the effect of DPSCs-EVs on promoting proliferation and inhibiting apoptosis of human umbilical vein endothelial cells (HUVECs) and FDC-P1 cells in vitro. We found that DPSCs-EVs and EGF could comparably inhibit the decrease in WBC, CFU count and KSL cells in vivo. We also verified that EVs could accelerate the recovery of long-term HSCs. In summary, DPSCs-EVs showed an apoptosis resistant effect on HUVECs and FDC-P1 cells after radiation injury in vitro. EVs from DPSCs were comparable to EGF in their ability to regulate haematopoietic regeneration after radiation injury in vivo. Radiation could alter the expression of some miRNAs in bone marrow cells, and EVs could correct these changes to some extent. Graphical abstract.

Pulp stem cells with hepatocyte growth factor overexpression exhibit dual effects in rheumatoid arthritis.

BACKGROUND: To investigate the therapeutic effect of human dental pulp stem cells (DPSCs) transfected with adenovirus expressing hepatocyte growth factor (HGF) in a mouse model of collagen-induced arthritis (CIA). METHODS: DPSCs were modified with Ad-HGF to produce HGF-overexpressing DPSCs, DPSCs-HGF. In experimental mouse CIA model, DPSCs-HGF and DPSCs-Null (modified with Ad-Null) were engrafted via intravenously after disease onset, which was determined by the presence of joint swelling. The therapeutic effects on joints were evaluated at 49 days after collagen injection by histopathological analysis and microcomputed tomography imaging. The inflammatory cytokines were analyzed both in sera and joints via MILLIPLEX kit and immunohistochemical staining, respectively, and the regulatory T cells (Tregs) were analyzed in peripheral blood by using flow cytometry. Furthermore, primary fibroblast-like synoviocytes were isolated, colony formation analysis and FACS were performed to evaluate the effect of HGF on the proliferation and cell cycle of FLSs. Western blot assay was carried out to clarify the signal pathway of HGF-cMet. RESULTS: We found that without HGF modification, DPSC transfusion was helpful in controlling autoimmune status, local synovitis, and bone erosion after intravenous administration. However, HGF-modified DPSCs have dual role in rheumatoid arthritis (RA). In the early phase, HGF overexpression inhibited RA progression by its immunosuppressive effects, while in the late phase, HGF promoted synovitis by activating fibroblast-like synoviocytes to produce pathogenic IL-6, accelerating cell proliferation and inducing apoptosis resistance via phosphorylating the c-Met/Akt pathway. The overall effect of HGF modification attenuated the therapeutic effect of DPSCs. CONCLUSIONS: Our study provides a comprehensive evaluation of the therapeutic effect of DPSCs in the mouse model and a primary answer to the divergence of whether HGF is harmful or helpful in RA.

Safety and efficacy assessment of allogeneic human dental pulp stem cells to treat patients with severe COVID-19: structured summary of a study protocol for a randomized controlled trial (Phase I / II).

OBJECTIVES: To assess the safety and therapeutic effects of allogeneic human dental pulp stem cells (DPSCs) in treating severe pneumonia caused by COVID-19. TRIAL DESIGN: This is a single centre, two arm ratio 1:1, triple blinded, randomized, placebo-controlled, parallel group, clinical trial. PARTICIPANTS: Twenty serious COVID-19 cases will be enrolled in the trial from April 6th to December 31st 2020. INCLUSION CRITERIA: hospitalised patients at Renmin Hospital of Wuhan University satisfy all criteria as below: 1)Adults aged 18-65 years;2)Voluntarily participate in this clinical trial and sign the "informed consent form" or have consent from a legal representative.3)Diagnosed with severe pneumonia of COVID-19: nucleic acid test SARS-CoV-2 positive; respiratory distress (respiratory rate > 30 times / min); hypoxia (resting oxygen saturation < 93% or arterial partial pressure of oxygen / oxygen concentration < 300 mmHg).4)COVID-19 featured lung lesions in chest X-ray image. EXCLUSION CRITERIA: Patients will be excluded from the study if they meet any of the following criteria. 1.Patients have received other experimental treatment for COVID-19 within the last 30 days;2.Patients have severe liver condition (e.g., Child Pugh score >=C or AST> 5 times of the upper limit);3.Patients with severe renal insufficiency (estimated glomerular filtration rate <=30mL / min/1.73 m2) or patients receiving continuous renal replacement therapy, hemodialysis, peritoneal dialysis;4.Patients who are co-infected with HIV, hepatitis B, tuberculosis, influenza virus, adenovirus or other respiratory infection viruses;5.Female patients who have no sexual protection in the last 30 days prior to the screening assessment;6.Pregnant or lactating women or women using estrogen contraception;7.Patients who are planning to become pregnant during the study period or within 6 months after the end of the study period;8.Other conditions that the researchers consider not suitable for participating in this clinical trial. INTERVENTION AND COMPARATOR: There will be two study groups: experimental and control. Both will receive all necessary routine treatment for COVID-19. The experimental group will receive an intravenous injection of dental pulp stem cells suspension (3.0x107 human DPSCs in 30ml saline solution) on day 1, 4 and 7; The control group will receive an equal amount of saline (placebo) on the same days. Clinical and laboratory observations will be performed for analysis during a period of 28 days for each case since the commencement of the study. MAIN OUTCOMES: 1. Primary outcome The primary outcome is Time To Clinical Improvement (TTCI). By definition, TTCI is the time (days) it takes to downgrade two levels from the following six ordered grades [(grade 1) discharge to (grade 6) death] in the clinical state of admission to the start of study treatments (hDPSCs or placebo). Six grades of ordered variables: GradeDescriptionGrade 1:Discharged of patient;Grade 2:Hospitalized without oxygen supplement;Grade 3:Hospitalized, oxygen supplement is required, but NIV / HFNC is not required;Grade 4:Hospitalized in intensive care unit, and NIV / HFNC treatment is required;Grade 5:Hospitalized in intensive care unit, requiring ECMO and/or IMV;Grade 6:Death. ABBREVIATIONS: NIV, non-invasive mechanical ventilation; HFNC, high-flow nasal catheter; IMV, invasive mechanical ventilation. 2. Secondary outcomes 2.1 vital signs: heart rate, blood pressure (systolic blood pressure, diastolic blood pressure). During the screening period, hospitalization every day (additional time points of D1, D4, D7 30min before injection, 2h ± 30min, 24h ± 30min after the injection) and follow-up period D90 ± 3 days. 2.2 Laboratory examinations: during the screening period, 30 minutes before D1, D4, D7 infusion, 2h ± 30min, 24h ± 30min after the end of infusion, D10, D14, D28 during hospitalization or discharge day and follow-up period D90 ± 3 days. 2.3 Blood routine: white blood cells, neutrophils, lymphocytes, monocytes, eosinophils, basophils, neutrophils, lymphocytes, monocytes, eosinophils Acidic granulocyte count, basophil count, red blood cell, hemoglobin, hematocrit, average volume of red blood cells, average red blood cell Hb content, average red blood cell Hb concentration, RDW standard deviation, RDW coefficient of variation, platelet count, platelet specific platelet average Volume, platelet distribution width,% of large platelets; 2.4 Liver and kidney function tests: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, prealbumin, total protein, albumin, globulin, white / globule ratio , Total bilirubin, direct bilirubin, cholinesterase, urea, creatinine, total carbon dioxide, uric acid glucose, potassium, sodium, chlorine, calcium, corrected calcium, magnesium, phosphorus, calcium and phosphorus product, anion gap, penetration Pressure, total cholesterol, triacylglycerol, high density lipoprotein cholesterol, Low density lipoprotein cholesterol, lipoprotein a, creatine kinase, lactate dehydrogenase, estimated glomerular filtration rate. 2.5 Inflammation indicators: hypersensitive C-reactive protein, serum amyloid (SAA); 2.6 Infectious disease testing: Hepatitis B (HBsAg, HBsAb, HBeAg, HBeAb, HBcAb), Hepatitis C (Anti-HCV), AIDS (HIVcombin), syphilis (Anti-TP), cytomegalovirus CMV-IgM, cytomegalovirus CMV-IgG; only during the screening period and follow-up period D90 ± 3. 2.7 Immunological testing: Collect peripheral blood to detect the phenotype of T lymphocyte, B lymphocyte, natural killer cell, Macrophage and neutrophil by using flow cytometry. Collect peripheral blood to detect the gene profile of mononuclear cells by using single-cell analyses. Collect peripheral blood serum to detect various immunoglobulin changes: IgA, IgG, IgM, total IgE; Collect peripheral blood serum to explore the changes of cytokines, Th1 cytokines (IL-1 ß, IL-2, TNF-a, ITN-γ), Th2 cytokines (IL-4, IL-6, IL -10). 2.8 Pregnancy test: blood ß-HCG, female subjects before menopause are examined during the screening period and follow-up period D90 ± 3. 2.9 Urine routine: color, clarity, urine sugar, bilirubin, ketone bodies, specific gravity, pH, urobilinogen, nitrite, protein, occult blood, leukocyte enzymes, red blood cells, white blood cells, epithelial cells, non-squamous epithelial cells , Transparent cast, pathological cast, crystal, fungus; 2.10 Stool Routine: color, traits, white blood cells, red blood cells, fat globules, eggs of parasites, fungi, occult blood (chemical method), occult blood (immune method), transferrin (2h ± 30min after the injection and not detected after discharge). RANDOMIZATION: Block randomization method will be applied by computer to allocate the participants into experimental and control groups. The random ratio is 1:1. BLINDING (MASKING): Participants, outcomes assessors and investigators (including personnel in laboratory and imaging department who issue the sample report or image observations) will be blinded. Injections of cell suspension and saline will be coded in accordance with the patient's randomisation group. The blind strategy is kept by an investigator who does not deliver the medical care or assess primary outcome results. NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): Twenty participants will be randomized to the experimental and control groups (10 per group). TRIAL STATUS: Protocol version number, hDPSC-CoVID-2019-02-2020 Version 2.0, March 13, 2020. Patients screening commenced on 16th April and an estimated date of the recruitment of the final participants will be around end of July. . TRIAL REGISTRATION: Registration: World Health Organization Trial Registry: ChiCTR2000031319; March 27,2020. ClinicalTrials.gov Identifier: NCT04336254; April 7, 2020 Other Study ID Numbers: hDPSC-CoVID-2019-02-2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

NUDT21 suppresses the growth of small cell lung cancer by modulating GLS1 splicing.

The mRNA precursor 3'-end modification factor NUDT21 is a major regulator of 3'UTR shortening and an important component of pre-mRNA cleavage and polyadenylation. However, its role in pathologic progress of small cell lung cancer (SCLC) remains unclear. In this study, we observed that NUDT21 expression is downregulated in SCLC tissues. Hypoxia-induced down-regulation of NUDT21 through HIF-1α. NUDT21 shRNA transduction promotes proliferation and inhibits apoptosis of A549 cells. NUDT21 inhibition also promotes tumor growth in a mouse xenograft model. Furthermore, we clarified that HIF-1α mediated NUDT21 downregulation which altered the expression patterns of two isoforms of GLS1, GAC and KGA. These results link the hypoxic tumor environments to aberrant glutamine metabolism which is important for cellular energy in SCLC cells. Therefore, NUDT21 could be considered as a potential target for the treatment of SCLC.

Skeletal stem cell-mediated suppression on inflammatory osteoclastogenesis occurs via concerted action of cell adhesion molecules and osteoprotegerin.

In the current study, we investigated how skeletal stem cells (SSCs) modulate inflammatory osteoclast (OC) formation and bone resorption. Notably, we found that intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and osteoprotegerin (OPG) play a synergistic role in SSC-mediated suppression of inflammatory osteoclastogenesis. The effect of SSCs on inflammatory osteoclastogenesis was investigated using a lipopolysaccharide-induced mouse osteolysis model in vivo and human osteoarthritis synovial fluid (OASF) in vitro. OC formation was determined by tartrate-resistant acid phosphatase staining. Bone resorption was evaluated by microcomputerized tomography, serum C-terminal telopeptide assay, and pit formation assay. The expression of ICAM-1, VCAM-1, and OPG in SSCs and their contribution to the suppression of osteoclastogenesis were determined by flow cytometry or enzyme linked immunosorbent assay. Gene modification, neutralization antibodies, and tumor necrosis factor-α knockout mice were used to further explore the mechanism. The results demonstrated that SSCs remarkably inhibited inflammatory osteoclastogenesis in vivo and in vitro. Mechanistically, inflammatory OASF stimulated ICAM-1 and VCAM-1 expression as well as OPG secretion by SSCs. In addition, ICAM-1 and VCAM-1 recruited CD11b+ OC progenitors to proximity with SSCs, which strengthened the inhibitory effects of SSC-derived OPG on osteoclastogenesis. Furthermore, it was revealed that tumor necrosis factor α is closely involved in the suppressive effects. In summary, SSCs express a higher level of ICAM-1 and VCAM-1 and produce more OPG in inflammatory microenvironments, which are sufficient to inhibit osteoclastogenesis in a "capture and educate" manner. These results may represent a synergistic mechanism to prevent bone erosion during joint inflammation by SSCs.

Intercellular adhesion molecule-1 enhances the therapeutic effects of MSCs in a dextran sulfate sodium-induced colitis models by promoting MSCs homing to murine colons and spleens.

BACKGROUND: To investigate the therapeutic effect of intercellular adhesion molecule (ICAM)-1-modified mesenchymal stem cells (MSCs) in a mouse model of inflammatory bowel disease (IBD) induced by dextran sulfate sodium. METHODS: Primary MSCs and ICAM-1-overexpressing MSCs (C3 cells) were generated in vitro. The IBD mouse model was induced with drinking water containing dextran sulfate sodium for 7 days. For stem cell therapy, mice were randomly assigned to six experimental groups: the control group, IBD group, primary MSC group, C3 group, C3-vector group, and C3-ICAM-1 group. Mice were given a single injection of 1 × 106 primary MSCs or gene-modified MSCs via the tail vein on day 3 of DDS administration. The general conditions of the mice in each group were observed. Additionally, the pathological changes in the colon were observed and scored. Primary MSCs and gene-modified MSCs were stained with the fluorescent dye CM-DIL before injection into the tail vein of mice. The distribution of infused cells in IBD mice was observed in frozen sections. Mechanistically, the polarization of Th1, Th2, Th17, and regulatory T cells (Tregs) in the spleen was determined by flow cytometry. Moreover, the mRNA expression levels of IBD-related immune factors in splenocytes were measured by quantitative PCR. RESULTS: A single injection of MSCs promoted general recovery and reduced pathological damage in IBD mice. Additionally, ICAM-1-overexpressing MSCs had stronger therapeutic effects than ICAM-1low MSCs. Furthermore, the in vivo distribution analysis results indicated that a higher number of ICAM-1-overexpressing MSCs homed to the colon and spleen of IBD mice. Moreover, the delivery of ICAM-1 overexpressing MSCs decreased the numbers of Th1 and Th17 cells but increased the number of Tregs in the spleen of IBD mice. The quantitative PCR analysis results revealed that an infusion of ICAM-1-overexpressing MSCs influenced the expression of spleen-derived immune factors by remarkably reducing the mRNA levels of IFN-γ and IL-17A and increasing the mRNA level of Foxp3. CONCLUSIONS: Our results demonstrate that ICAM-1-modified mesenchymal stem cells (MSCs) remarkably alleviate inflammatory damage in IBD mice by promoting MSC homing to the target and immune organs. The findings suggest that ICAM-1 is required to maintain the therapeutic effects of MSCs in IBD treatment and identified a novel role of ICAM-1 in inflammatory diseases.

miRNA-17-92 protects endothelial cells from erastin-induced ferroptosis through targeting the A20-ACSL4 axis.

Endothelial cell death is linked to vascular diseases such as atherosclerosis and tissue ischemia. miRNA-17-92 (miR-17-92) is a multiple functional oncogenic miRNA cluster which plays vital roles in tumor angiogenesis and tissue development. However, its role in regulation of endothelial cell ferroptosis remains unclear. In this study, we revealed that miR-17-92 protects endothelial HUVEC cells from erastin-induced ferroptosis. miR-17-92 overexpression significantly reduced erastin-induced growth inhibition and ROS generation of HUVEC cells. Furthermore, Zinc lipoprotein A20, a validated target of miR-17-92, was identified as a novel regulator of endothelial cell ferroptosis. Lentivirus mediated A20 overexpression increased ROS generation and enhanced erastin-induced ferroptosis, whereas A20 knockdown inhibited erastin-induced ferroptosis. Mechanistic studies revealed that erastin-induced ferroptosis is associated with GPX4 downregulation and ACSL4 upregulation. miR-17-92 overexpression or A20 inhibition increased the ACSL4 expression in HUVEC cells. A20 was identified to directly with and regulate ACSL4 expression by immunoprecipitation. It suggests that the A20-ACSL4 axis plays important roles in erastin-induced endothelial ferroptosis. In conclusion, this study revealed a novel mechanism through which miR-17-92 protects endothelial cells from erastin-induced ferroptosis by targeting the A20-ACSL4 axis.

TEM8 functions as a receptor for uPA and mediates uPA-stimulated EGFR phosphorylation.

BACKGROUND: TEM8 is a cell membrane protein predominantly expressed in tumor endothelium, which serves as a receptor for the protective antigen (PA) of anthrax toxin. However, the physiological ligands for TEM8 remain unknown. RESULTS: Here we identified uPA as an interacting partner of TEM8. Binding of uPA stimulated the phosphorylation of TEM8 and augmented phosphorylation of EGFR and ERK1/2. Finally, TEM8-Fc, a recombinant fusion protein comprising the extracellular domain of human TEM8 linked to the Fc portion of human IgG1, efficiently abrogated the interaction between uPA and TEM8, blocked uPA-induced migration of HepG2 cells in vitro and inhibited the growth and metastasis of human MCF-7 xenografts in vivo. uPA, TEM8 and EGFR overexpression and ERK1/2 phosphorylation were found co-located on frozen cancer tissue sections. CONCLUSIONS: Taken together, our data provide evidence that TEM8 is a novel receptor for uPA, which may play a significant role in the regulation of tumor growth and metastasis.

A novel AXL chimeric antigen receptor endows T cells with anti-tumor effects against triple negative breast cancers.

Identifying targets for chimeric antigen receptor-modulated T lymphocyte (CAR-T) therapy against solid tumors is an urgent problem to solve. In this study, we showed for the first time that the receptor tyrosine kinase, AXL, is overexpressed in various tumor cell lines and patient tumor tissues including triple negative breast cancer (TNBC) cell lines and patient samples, making AXL a potent novel target for cancer therapy, specifically for TNBC treatment. We also engineered T cells with a CAR consisting of a novel single-chain variable fragment against AXL and revealed its antigen-specific cytotoxicity and ability to release cytokines in a TNBC cell line and other AXL-positive tumors in vitro. Furthermore, AXL-CAR-T cells displayed a significant anti-tumor effect and in vivo persistence in a TNBC xenograft model. Taken together, our findings indicate that AXL-CAR-T cells can represent a promising therapeutic strategy against TNBC.