Chikungunya virus (CHIKV), which is primarily transmitted by Aedes aegypti and Ae. albopictus, has recently rapidly spread across the world, which poses a huge threat to public health. Chikungunya fever (CHIKF), caused by CHIKV infection, typically manifests as acute febrile illness with severe polyarthralgia that may persist for months to years. A few severe CHIKF cases may be accompanied by serious neurological complications, even resulting in death. The accelerating global expansion of CHIKV is closely associated with genetic variations of the virus, and mutated genes in CHIKV may augment the virus adaptability to Aedes vectors and transmission efficiency. Currently, the diagnosis of the CHIKV infection primarily relies on molecular and serological assays; however, there are still multiple challenges for early and differential diagnosis of CHIKV infections due to co-infections with arboviruses and nonspecific early symptoms. The first prophylactic vaccine for CHIKF has been recently approved in the United States; however, the large-scale application still awaits further validations. More importantly, there are no licensed antiviral therapies against CHIKV until now. This review describes the structure and pathogenesis of CHIKV, summarizes the latest epidemiology and advances in the diagnosis of CHIKV infections, and depicts the current status and prospects of antiviral agents and vaccine development, so as to inform evidence-based prevention and control strategies.

OBJECTIVE: To investigate the effects and underlying mechanism of ionizing radiation on the adipogenic of mesenchymal stem cells (MSCs). METHODS: Mouse MSCs were cultured in vitro and treated with 2 Gy and 6 Gy radiation with ⁶⁰Co, and the radiation dose rate was 0.98 Gy/min. Bulk RNA-seq was performed on control and irradiated MSCs. The changes of adipogenic differentiation and oxidative stress pathways of MSC were revealed by bioinformatics analysis. Oil Red O staining was used to detect the adipogenic differentiation ability of MSCs in vitro, and real-time fluorescence quantitative PCR (qPCR) was used to detect the expression differences of key regulatory factors Cebpa, Lpl and Pparg after radiation treatment. At the same time, qPCR and Western blot were used to detect the effect of inhibition of Nrf2, a key factor of antioxidant stress pathway, on the expression of key regulatory factors of adipogenesis. Moreover, the species conservation of the irradiation response of human bone marrow MSCs and mouse MSC was determined by qPCR. RESULTS: Bulk RNA-seq suggested that ionizing radiation promotes adipogenic differentiation of MSCs and up-regulation of oxidative stress-related genes and pathways. The results of Oil Red O staining and qPCR showed that ionizing radiation promoted the adipogenesis of MSCs, with high expression of Cebpa, Lpl and Pparg, as well as oxidative stress-related gene Nrf2. Nrf2 pathway inhibitors could further enhance the adipogenesis of MSCs in bone marrow after radiation. Notably, the similar regulation of oxidative pathways and enhanced adipogenesis post irradiation were observed in human bone marrow MSCs. In addition, irradiation exposure led to up-regulated mRNA expression of interleukin-6 and down-regulated mRNA expression of colony stimulating factor 2 in human bone marrow MSCs. CONCLUSION Ionizing radiation promotes adipogenesis of MSCs in mice, and oxidative stress pathway participates in this effect, blocking Nrf2 further promotes the adipogenesis of MSCs. Additionally, irradiation activates oxidative pathways and promotes adipogenic differentiation of human bone marrow MSCs.
Mesenchymal Stem Cells/cytology* ; Oxidative Stress/radiation effects* ; Animals ; Adipogenesis/radiation effects* ; Mice ; Radiation, Ionizing ; Cell Differentiation/radiation effects* ; Humans ; NF-E2-Related Factor 2/metabolism* ; PPAR gamma ; Cells, Cultured

OBJECTIVE: To establish an in vitro cell model simulating acute graft-versus-host disease (aGVHD) bone marrow microenvironment injury with the advantage of mouse serum of aGVHD model and explore the effect of serum of aGVHD mouse on the adipogenic differentiation ability of mesenchymal stem cells (MSCs). METHODS: The 6-8-week-old C57BL/6N female mice and BALB/c female mice were used as the donor and recipient mice of the aGVHD model, respectively. Bone marrow transplantation (BMT) mouse model (n=20) was established by being injected with bone marrow cells (1×10⁷ per mouse) from donor mice within 4-6 hours after receiving a lethal dose (8.0 Gy, 72.76 cGy/min) of γ ray general irradiation. A mouse model of aGVHD (n=20) was established by infusing a total of 0.4 ml of a mixture of donor mouse-derived bone marrow cells (1×10⁷ per mouse) and spleen lymphocytes (2×10⁶ per mouse). The blood was removed from the eyeballs and the mouse serum was aspirated on the 7^th day after modeling. Bone marrow-derived MSCs were isolated from 1-week-old C57BL/6N male mice and incubated with 2%, 5% and 10% BMT mouse serum and aGVHD mouse serum in the medium, respectively. The effect of serum in the two groups on the in vitro adipogenic differentiation ability of mouse MSCs was detected by Oil Red O staining. The expression levels of related proteins PPARγ and CEBPα were detected by Western blot. The expression differences of key adipogenic transcription factors including PPARγ, CEBPα, FABP4 and LPL were determined by real-time quantitative PCR (RT-qPCR). RESULTS: An in vitro cell model simulating the damage of bone marrow microenvironment in mice with aGVHD was successfully established. Oil Red O staining showed that the number of orange-red fatty droplets was significantly reduced and the adipogenic differentiation ability of MSC was impaired at aGVHD serum concentration of 10% compared with BMT serum. Western blot experiments showed that adipogenesis-related proteins PPARγ and CEBPα expressed in MSCs were down-regulated. Further RT-qPCR assay showed that the production of PPARγ, CEBPα, FABP4 and LPL, the key transcription factors for adipogenic differentiation of MSC, were significantly reduced. CONCLUSION The adipogenic differentiation capacity of MSCs is inhibited by aGVHD mouse serum.
Animals ; Mesenchymal Stem Cells/cytology* ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Adipogenesis ; Female ; Cell Differentiation ; Graft vs Host Disease/blood* ; Bone Marrow Cells/cytology* ; PPAR gamma/metabolism* ; Disease Models, Animal ; CCAAT-Enhancer-Binding Protein-alpha/metabolism*

OBJECTIVE: To prepare clinical-grade human umbilical cord-derived mesenchymal stem cells (hUC-MSC) with high expression of hematopoietic supporting factors and evaluate their stem cell characteristics. METHODS: Fetal umbilical cord tissues were collected from healthy postpartum women during full-term cesarean section. Wharton's jelly was mechanically separated and hUC-MSCs were obtained by explant culture method and enzyme digestion method in an animal serum-free culture system with addition of human platelet lysate. The phenotypic characteristics of hUC-MSCs obtained by two methods were detected by flow cytometry. The differences in proliferation ability between the two groups of hUC-MSCs were identified through CCK-8 assay and colony forming unit-fibroblast (CFU-F) assay. The differences in multilineage differentiation potential between the two groups of hUC-MSCs were identified through induction of adipogenic, osteogenic, and chondrogenic differentiation. The mRNA expression levels of hematopoietic supporting factors such as SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in the two groups of hUC-MSCs were identified by real-time fluorescence quantiative PCR(RT-qPCR). RESULTS: The results of flow cytometry showed that hUC-MSCs obtained by the two methods both expressed high levels of CD73, CD90 and CD105, while lowly expressed CD31, CD45 and HLA-DR. The results of CCK-8 and CFU-F assay showed that the proliferation ability of hUC-MSCs obtained by explant culture method was better than those obtained by enzyme digestion method. The results of the triple lineage differentiation experiment showed that there was no significant difference in multilineage differentiation potential between the two grous of hUC-MSCs. The results of RT-qPCR showed that the mRNA expression levels of hematopoietic supporting factors SCF, IL-3, CXCL12, VCAM1 and ANGPT1 in hUC-MSCs obtained by explant cultrue method were higher than those obtained by enzyme digestion method. CONCLUSION Clinical-grade hUC-MSCs with high expression levels of hematopoietic supporting factors were successfully cultured in an animal serum-free culture system.
Humans ; Mesenchymal Stem Cells/metabolism* ; Umbilical Cord/cytology* ; Cell Differentiation ; Female ; Cell Proliferation ; Cells, Cultured ; Chemokine CXCL12/metabolism* ; Angiopoietin-1/metabolism* ; Vascular Cell Adhesion Molecule-1/metabolism* ; Stem Cell Factor/metabolism* ; Flow Cytometry ; Pregnancy

Cervical spondylotic radiculopathy(CSR)is a condition caused by the degeneration of cervical intervertebral discs and facet joints,primarily manifesting as the pain,sensory abnormalities,and motor dysfunction in the cervical nerve innervation area of neck,shoulder,and upper limb.For the treatment of CSR,tendon-bone syndrome differentiation in traditional Chinese medicine often faces the issues of conceptual confusion and non-standard syndrome differentiation.Based on the traditional tendon-bone syndrome differentiation and by integrating modern anatomical insights,Professor LIN Ding-Kun,an esteemed scholar of Traditional Chinese Medicine,proposed a classification system for the cervical spine that includes the categories of tendons,joints,bones and marrow.This paper explored the thoughts of Professor LIN for the tendon-bone syndrome differentiation of CSR,summarized the targets of manual therapy,and proposed the four kinds of pathological changes such as tendon overstrain,joint dislocation,bone lesion,and marrow injury,as well as the four techniques of traditional Chinese medicine manipulations,i.e.relaxation of tendons,reduction of joints,protection of marrow,and treatment of bones.The aim is to improve the syndrome-differentiation and treatment for CSR with orthopedic and traumatologic manipulations,and to provide reference for clinical practice.

Objective:To establish a mesenchymal stem cell(MSC)-based in vitro cell model for the evaluation of mouse bone marrow acute graft-versus-host disease(aGVHD).Methods:Female C57BL/6N mice aged 6-8 weeks were used as bone marrow and lymphocyte donors,and female BALB/c mice aged 6-8 weeks were used as aGVHD recipients.The recipient mouse received a lethal dose(8.0 Gy,72.76 cGy/min)of total body γ irradiation,and injected with donor mouse derived bone marrow cells(1× 107/mouse)in 6-8 hours post irradiation to establish a bone marrow transplantation(BMT)mouse model(n=20).In addition,the recipient mice received a lethal dose(8.0 Gy,72.76 cGy/min)of total body γ irradiation,and injected with donor mouse derived bone marrow cells(1 × 107/mouse)and spleen lymphocytes(2 × 106/mouse)in 6-8 hours post irradiation to establish a mouse aGVHD model(n=20).On the day 7 after modeling,the recipient mice were anesthetized and the blood was harvested post eyeball enucleation.The serum was collected by centrifugation.Mouse MSCs were isolated and cultured with the addition of 2％,5％,and 10％recipient serum from BMT group or aGVHD group respectively.The colony-forming unit-fibroblast(CFU-F)experiment was performed to evaluate the potential effects of serums on the self-renewal ability of MSC.The expression of CD29 and CD105 of MSC was evaluated by immunofluorescence staining.In addition,the expression of self-renewal-related genes including Oct-4,Sox-2,and Nanog in MSC was detected by real-time fluorescence quantitative PCR(RT-qPCR).Results:We successfully established an in vitro cell model that could mimic the bone marrow microenvironment damage of the mouse with aGVHD.CFU-F assay showed that,on day 7 after the culture,compared with the BMT group,MSC colony formation ability of aGVHD serum concentrations groups of 2％and 5％was significantly reduced(P＜0.05);after the culture,at day 14,compared with the BMT group,MSC colony formation ability in different aGVHD serum concentration was significantly reduced(P＜0.05).The immunofluorescence staining showed that,compared with the BMT group,the proportion of MSC surface molecules CD29+and CD 105+cells was significantly dereased in the aGVHD serum concentration group(P＜0.05),the most significant difference was at a serum concentration of 10％(P＜0.001,P＜0.01).The results of RT-qPCR detection showed that the expression of the MSC self-renewal-related genes Oct-4,Sox-2,and Nanog was decreased,the most significant difference was observed at an aGVHD serum concentration of 10％(P＜0.01,P＜0.001,P＜0.001).Conclusion:By co-culturing different concentrations of mouse aGVHD serum and mouse MSC,we found that the addition of mouse aGVHD serum at different concentrations impaired the MSC self-renewal ability,which providing a new tool for the field of aGVHD bone marrow microenvironment damage.

Objective:To prepare mesenchymal stem cells with antioxidant capacity (AO-MSC ) from human umbilical cords and evaluate its cell biological properties.Methods:In control group,mesenchymal stem cells (MSC) were isolated by digesting human umbilical cord Wharton's Jelly tissues with 0.2％ collagenase Ⅱ,and the released cells were collected and cultured in an animal serum-free culture medium.In AO-MSC group,incompletely collagenase Ⅱ-digested tissue debris were allowed to adhere to flusk flat bottoms and the AO-MSC was harvested by adherent culture. The conventional digestion and culture method was used as control.MSC colony forming ability was evaluated by fibroblast colony forming assay (CFU-F).MSC proliferative capacity was evaluated by CCK-8 assay.The MSC surface markers were detected by using flow cytometry and immunofluorescence staining.The adipogenic and osteogenic capacity of MSC was evaluated by multi-differentiation in vitro,and the mRNA expression of genes that control adipogenic and osteogenic differentiation was detected by real-time fluorescence quantitative PCR (RT-qPCR );Moreover,the mRNA expression of antioxidant substances such as SOD-1,GSH,GAT,and NQO1 in MSC was also evaluated by RT-qPCR.Results:The AO-MSC isolated by this strategy reached a confluence of 80％-90％ at around 18 days and grew in a swirling pattern.Flow cytometry and immunofluorescence staining assays showed that CD73,CD29,CD105,CD90 were highly expressed and CD31,CD45,HLA-DR were scarcely expressed in AO-MSC.AO-MSC exhibited stronger self-renewal and differentiation ability compared to MSC.However,the in vitro adipogenic-osteogenic capacity of MSC in the control group was stronger than that of AO-MSC.RT-qPCR assay showed that AO-MSC expressed higher mRNA levels of antioxidant substances compared to MSC.Conclusion:Human AO-MSC is successfully prepared from human umbilical cord without animal serum.

Mesenchymal stem cells (MSC) possess unique immunomodulatory properties and have enormous potential in the treatment of graft-versus-host disease (GVHD). However,the low implantation and survival rates of MSC in vivo,coupled with their weak immunosuppressive functions,have resulted in unstable clinical efficacy in the treatment of GVHD. Preconditioning of MSC with hypoxia,active molecules and gene modification can enhance the function of MSC and improve the implantation rate,survival rate and therapeutic effect of MSC. This review summarized the strategies for enhancing the efficacy of MSC in the treatment of hematopoietic stem cell transplantation complicated with GVHD in recent years,aiming to provide new strategies for optimizing the application of MSC in the prevention and treatment of GVHD.

Objective To investigate the imaging features of intestinal schwannoma(IS)in order to improve the diagnostic ability of the disease.Methods The clinical and imaging data of 14 patients with surgically and pathologically confirmed IS were retrospectively analyzed,including the location,size,morphology,nature,growth pattern,CT density,MRI signal,PET/CT metabolism and other characteristics of the tumors.Results Of the 14 IS cases,the lesions of 3 cases were located in the duodenum,2 cases in the cecum,8 cases in the colon and 1 case in the rectum.The lesions were all round or oval,with an average maximum diameter of(2.4±1.1)cm.The lesions were solid in 13 cases,extraluminal growth in 10 cases,cystic degeneration in 1 case and myxoid degeneration in 1 case.Chronic inflammatory lymph nodes were seen around the diseased intestines in 9 cases,and the short diameter of lymph nodes was greater than 5 mm in 6 cases.All 14 cases of IS showed low attenuation on plain CT scan,and progressive enhancement after contrast injection,including 1 case of mild enhancement,2 cases of moderate enhancement,and 11 cases of obvious enhancement.Two cases of IS showed low signal intensity on T1WI,slightly high signal intensity on T2WI,significantly high signal intensity on DWI,and obvious progressive enhancement after contrast injection on MRI.Two cases of IS showed high metabolism on 18F-FDG-PET/CT,and the SUVmax was 9.4 and 8.8,respectively.Conclusion The imaging findings of IS were characteristic to a certain extent.They mainly manifested as solid nodules or masses derived from the intestinal submucosa,with uniform attenuation or signal intensity,obvious progressive enhancement after contrast injection,obvious hypermetabolism on 18F-FDG-PET/CT,and slightly larger homogeneous lymph nodes were common around the lesions.

Objective: To evaluate the bone repair effect of 3D-printed magnesium (Mg)-loaded polycaprolactone (PCL) scaffolds in a rat skull defect model. Methods: PCL scaffolds mixed with Mg microparticles were prepared by using 3D printing technology, as were pure PCL scaffolds. The surface morphologies of the two scaffolds were observed by scanning electron microscopy (SEM), and the surface elemental composition was analyzed via energy dispersive spectroscopy (EDS). The physical properties of the scaffolds were characterized through contact angle measurements and an electronic universal testing machine. This study has been reviewed and approved by the Ethics Committee. A critical size defect model was established in the skull of 15 Sprague-Dawley (SD) rats, which were divided into the PCL group, PCL-Mg group, and untreated group, with 5 rats in each group. Micro-CT scanning was performed to detect and analyze skull defect healing at 4 and 8 weeks after surgery, and samples from the skull defect area and major organs of the rats were obtained for histological staining at 8 weeks after surgery. Results: The scaffolds had a pore size of (480 ± 25) μm, a fiber diameter of (300 ± 25) μm, and a porosity of approximately 66%. The PCL-Mg scaffolds contained 1.0 At% Mg, indicating successful incorporation of Mg microparticles. The contact angle of the PCL-Mg scaffolds was 68.97° ± 1.39°, indicating improved wettability compared to that of pure PCL scaffolds. Additionally, compared with that of pure PCL scaffolds, the compressive modulus of the PCL-Mg scaffolds was (57.37 ± 8.33) MPa, demonstrating enhanced strength. The PCL-Mg group exhibited the best bone formation behavior in the skull defect area compared with the control group and PCL group at 4 and 8 weeks after surgery. Moreover, quantitative parameters, such as bone volume (BV), bone volume/total volume (BV/TV), bone surface (BS), bone surface/total volume (BS/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and bone mineral density (BMD), of skull defects were better than those in the other groups, indicating the best bone regeneration effect. H&E, Goldner, and VG staining revealed more mineralized new bone formation in the PCL-Mg group than in the other groups, and H&E staining of the major organs revealed good biosafety of the material. Conclusion PCL-Mg scaffolds can promote the repair of bone defects and have clinical potential as a new scaffold material for the repair of maxillofacial bone defects.