Abstract Bone defects (BDs), a prevalent clinically refractory orthopaedic disease, presently have no effective treatments. Mesenchymal stem cells (MSCs) can differentiate into osteoblasts and serve as potential seed cells for bone tissue engineering for BD treatment. However, the feasibility of using MSCs as seed cells for bone tissue engineering remains unclear. As a result, the critical issue of large‐scale cell‐scaffold preparation remains unresolved. In this study, we demonstrated for the first time that human embryonic stem cell‐derived MSCs, also known as immunity‐and‐matrix‐regulatory cells (IMRCs), could be inoculated into microcarriers to create osteogenic micro‐tissues appropriate for scalable production in 250 mL bioreactor. IMRCs were generally smaller than umbilical cord‐derived MSCs (UCMSCs) and could attach, migrate, proliferate and differentiate within the porous microcarriers, whereas UCMSCs could only attach to the surface of microcarriers. Osteogenic micro‐tissues generated from IMRCs‐seeded microcarriers significantly increased osteocalcin levels after 21 days of differentiation in a bioreactor. Furthermore, the expression levels of osteogenic biomarker genes/proteins such as alkaline phosphatase (ALP), osteocalcin (OCN), runt‐related transcription factor 2 (RUNX2), osteopontin (OPN) and osterix (OSX) were significantly higher than osteogenic micro‐tissues derived from UCMSCs‐seeded microcarriers. Our findings imply that IMRCs could potentially serve as seed cells for the scalable production of osteogenic micro‐tissues for BD treatment.
Incorporating emerging ultrawide bandgap semiconductors with a metal-semiconductor-metal (MSM) architecture is highly desired for deep-ultraviolet (DUV) photodetection. However, synthesis-induced defects in semiconductors complicate the rational design of MSM DUV photodetectors due to their dual role as carrier donors and trap centers, leading to a commonly observed trade-off between responsivity and response time. Here, we demonstrate a simultaneous improvement of these two parameters in {\epsilon}-Ga2O3 MSM photodetectors by establishing a low-defect diffusion barrier for directional carrier transport. Specifically, using a micrometer thickness far exceeding its effective light absorption depth, the {\epsilon}-Ga2O3 MSM photodetector achieves over 18-fold enhancement of responsivity and simultaneous reduction of the response time, which exhibits a state-of-the-art photo-to-dark current ratio near 10^8, a superior responsivity of >1300 A/W, an ultrahigh detectivity of >10^16 Jones and a decay time of 123 ms. Combined depth-profile spectroscopic and microscopic analysis reveals the existence of a broad defective region near the lattice-mismatched interface followed by a more defect-free dark region, while the latter one serves as a diffusion barrier to assist frontward carrier transport for substantially enhancing the photodetector performance. This work reveals the critical role of the semiconductor defect profile in tuning carrier transport for fabricating high-performance MSM DUV photodetectors.
Retinal pigment epithelium (RPE) is a kind of monolayer cells situated between neural retina and choroid, and plays an important role in maintaining the functions of retina and photoreceptor. Its functions mainly include absorbing stray light, providing nutrients for neural retina and phagocytizing outer section of photoreceptor. Photoreceptor damage caused by dysfunctions, degeneration and loss of RPE is the main reason that leads to age-related macular degeneration (AMD) and retinitis pigmentosa (RP).
The pollen morphology of 54 species and one variety of seven genera in Polygonatae including Clintonia, Disporopsis, Disporum, Maianthemum, Polygonatum, Smilacina and Streptopus was observed and studied in detail; of these, nine species were reported for the first time. Our results showed that the surface ornamentation of pollen grains of the studied materials could be divided into seven types, namely gemmate, granulate-foveolate, perforate, reticulate, rugulate, rugulate-perforate and verrucate. In line with previous studies, we believe that (i) Smilacina ginfushanicum should be classified into the genus Heteropolygonatum rather than the genus Smilacina; (ii) Polygonatum should be divided into section Polygonatum and section Verticillata; (iii) Smilacina and Maianthemum should be combined as one genus, i.e. Maianthemum sensu lato; and (iv) Clintonia, Disporum and Streptopus should be separated from the tribe Polygonatae.
Mesenchymalstem cell (MSC)-based therapy is being increasingly explored in preclinical and clinical studies as a regenerative method for treating osteoarthritis (OA). However, the use of primary MSCs is hampered by a number of limitations, including donor heterogeneity and inconsistent cell quality. Here, we tested the therapeutic potential of embryonic stem cell-derived MSCs (ES-MSCs) in anOA rat model. ES-MSCs were generated and identified by morphology, trilineage differentiation and flow cytometry. Sprague Dawley rats were treated with either a single dose (106 cells/rat) of ES-MSCs or with three doses spaced one week apart for each dose, starting at four weeks after anterior cruciate ligament transectionto induce OA. Cartilage quality was evaluated at 6 and 10 weeks after treatment with behavioral analysis, macroscopic examination, and histology. At sixweeks after treatment, the groups treated with both single and repeated doses of ES-MSCs had significantly better modified Mankin scores and International Cartilage Repair Society (ICRS) macroscopic scores in the femoral condyle compared to the control group. At 10 weeks after treatment, the repeated doses group had a significantly better ICRS macroscopic scores in the femoral condyle compared to the single dose and control groups. Histological analysis also showed more proteoglycan and less cartilage loss, along with lower Mankin scores in the repeated doses group. In conclusion, treatment with multiple injections of ES-MSCs can ameliorate OA in a rat model. TheES-MSCs have potential to be considered as a regenerative therapy for OA, and can provide an infinite cellular source.
To the Editor, Acute lung injury (ALI) and the inflammatory cytokine storm cause considerable amount of deaths in the COVID-19 pandemic.1, 2 Currently, very limited therapeutic options are available for the COVID-19-induced ALI. In our preclinical experiments,3 we found that a single intravenous transfusion of immunity- and matrix-regulatory cells (IMRCs), derived from fully differentiated human embryonic stem cells, could safely treat ALI by rapidly modulating the inflammation induced by pulmonary cell death.3 Encouraged by this result, as part of an expanded access programme, we pilot-tested GMP-grade IMRC transfusion as a compassionate treatment in a severely ill COVID-19 patient who was diagnosed with ALI. A 44-year-old male patient from Wuhan was admitted on 23 January 2020, presenting with a 6-day history of fever and cough. The physical examination revealed a fever of 37.9°C, blood pressure of 120/61 mm Hg, pulse rate of 80 beats per minute, respiratory rate of 21 breaths per minute and blood oxygen saturation of 97.9%. Laboratory testing showed lymphocytopenia with a lymphocyte count of 0.65 × 109 cells per litre. Nasopharyngeal swab specimen was collected and tested positive for SARS-CoV-2 by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). He was briefly treated with Lianhua Qingwen (herbal flu drug) and the anti-retroviral cocktail lopinavir/ritonavir (Kaletra), but showed no improvement. By January 28, the fever had risen to 39°C, and he had shortness of breath under oxygen supplementation. CT scans showing multiple ground-glass opacities indicated the pneumonia had progressed to a severe stage (Figure 1A). On January 30, his resting blood oxygen saturation fell to 91%, and he was diagnosed as a severely ill patient with ALI. After the patient's consent, he was intravenously infused with 3 × 106 IMRCs per kilogram body weight the same day. He was given a second infusion of IMRCs with the same dose mentioned above with interval seven days. The patient's blood pressure rose from 127/76 mm Hg to 158/106 mm Hg after the first IMRC infusion, and he was given 10 mg nifedipine orally on infusion days 1, 4, 5 and 6. The patient showed no signs of discomfort except for transient high blood pressure. By February 2, the patient no longer had shortness of breath, and his resting blood oxygen saturation rose to 95%. By February 5 (first infusion day 7), the patient's throat swab tested negative for SARS-CoV-2 by qRT-PCR, which was reconfirmed on February 7. However, chest CT scans showed that the pneumonia was still in the advanced stage. On hospital day 15 (illness day 21, first infusion day 8), the patient still had lymphocytopenia with a lymphocyte count of 0.79 × 109 cells per litre. On hospital day 17 (illness day 23, first infusion day 10), the patient recovered from lymphocytopenia with a lymphocyte count of 1.02 × 109 cells per litre (Table S1). On hospital day 20 (illness day 26, first infusion day 13), after showing significant recovery by CT scans, the patient was recommended for discharge. On March 2 (first infusion day 33), one month after the first IMRC infusion, follow-up CT scans showed that the patient had completely recovered. Cytokines in the patient's plasma were measured on first infusion day 1, first infusion day 8 (second infusion day 1) and first infusion day 11 (second infusion day 4) (Table S2). Most pro-inflammatory cytokines showed a marked decrease, including G-CSF, M-CSF, GM-CSF, IL-1α, IL-1β, IL-5, IL-6, IL-7, IL-8, IL-15 IL-17E/IL-25, IL-27, IP10/CXCL10, MCP-1/CCL2, MCP-2/CCL7, MIG/CXCL9, MIP-1α/CCL3 and GRO-α/CXCL1 (Figure 1B). There was also an increase in immunomodulatory cytokines, such as IL-1RA, IL-12, IL-22 and MDC/CCL22 (Figure 1C). To the best of our knowledge, this is the first time that pure hESC-derived IMRCs have been intravenously infused into the human body. No severe adverse events were observed one month after IMRC infusion. Further work will determine whether this therapy can be replicated widely. This work was supported by National Emergency Project of the Ministry of Science and Technology of China (2020YFC0843900 and 2020YFC0841900), Beijing Municipal Science & Technology Commission (Z181100003818005), National Key Research and Development Program (2016YFA0101502), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA16030701, XDA16040502), and International Partnership Program of Chinese Academy of Sciences (152111KYSB20160004). The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. BH, RJ and JH conceived the project. ZL, TG and BG, provided the testing results of IMRCs. WH, FJ, HD and WL analysed clinical case. JW, ZH, LW and Y.T designed the research and wrote the manuscript with help from all of the authors. Drs. JW, ZH, LW and YT contributed equally to this case report. B. H., JH and R. J. are the corresponding authors of this case report. All authors read and approved the final manuscript. The study is approved by the Ethics Committee of Beijing Youan Hospital, Capital Medical University, Beijing, China. ClinicalTrials.gov Identifier: NCT04331613. https://www.clinicaltrials.gov/ct2/show/NCT04331613?term=Castem&draw=2&rank=1 The data that support the findings of this study are available from the corresponding author upon reasonable request. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Abstract Background Primary membranous nephropathy (MN) is a kidney-specific autoimmune disease. Human embryonic stem cells-derived immunity-and-matrix regulatory cells (hESC-IMRCs) have immunoregulatory functions. We hypothesized that hESC-IMRCs might have therapeutic effects on MN and be a potential treatment in clinical practice. Methods Rats of Heymann nephritis were set up by immunization with sheep anti-rat Fx1A serum. hESC-IMRCs were intravenously administrated upon the detection of proteinuria, with 6×10 6 cells (high-dose) or 3×10 6 cells (low-dose) in 1 ml every other day. Splenocytes and IMRCs were co-cultured at different times and ratios. Cell types and cytokines were detected by flow cytometry and enzyme-linked immunosorbent assay. Results Proteinuria of rats with Heymann nephritis was reduced remarkably to a level comparable to negative controls, in both low-dose (45.6 vs. 282.3 mg/d, P<0.001) and high-dose (35.2 vs. 282.3 mg/d, P<0.001) hESC-IMRC treatment groups. IgG and C3 deposit, glomerular basement membrane thickness (613.6 vs. 1014.3 nm, P=0.003) and foot process effacement (271.0 vs. 496.4 nm, P<0.001) was alleviated in the kidneys. The proportions of CD4+CD25+ T cells in circulation (7.2 vs. 3.4%, P=0.002) and in spleen (14.9 vs. 10.0%, P<0.001) were increased, the circulating level of IL-10 was increased (42.1 vs. 27.4 pg/ml, P<0.001), and the circulating level of complement C3 was decreased (464.2 vs. 872.7 ng/ml, P=0.010), after hESC-IMRC interventions. IL-10 increased remarkably in the co-culture supernatant of lymphocytes and IMRCs at 48 hours with ratio 10:1. Conclusions The intravenously delivered hESC-IMRCs alleviated proteinuria and kidney injuries of Heymann nephritis, by their immunosuppressive functions through regulatory T cells and IL-10. These pre-clinical results indicate that IMRCs worth careful consideration for human trials in the treatment of MN.
Abstract Recently, the protective effect of exosomes on ischemia/reperfusion (I/R) injury has become a research hotspot. The purpose of this study was to explore the therapeutic potential of microglia-derived exosomes on cerebral I/R injury. BV2 cell-derived exosomes (BV2-Exo) were extracted and characterized. The cerebral I/R model was constructed in vivo and intervened by using exosomes loaded with miR-302a-3p. The oxygen and glucose deprivation (OGD) model was constructed in vitro to simulate cerebral I/R injury. The binding sites of miR-302a-3p to Keap1 were analyzed by bioinformatics prediction and confirmed by dual-luciferase reporter assay. A study of whether exosomal miR-302a-3p affected cerebral I/R injury via the Keap1/Nrf2 axis was carried out by overexpression of keap1 (oe-keap1). Experimental results in vivo showed exosomal miR-302a-3p significantly repaired the cognitive impairment and suppressed the cell death of hippocampal neurons induced by cerebral I/R injury. Besides, exosomal miR-302a-3p inhibited the expression of ferroptosis-related proteins NCOA4, PTGS2, and p53 in cerebral I/R-treated mice. Bioinformatics prediction and double-luciferase reporter assay showed that Keap1 was the direct downstream target of miR-302a-3p. Experiment results in vitro showed that oe-Keap1 reversed the therapeutic effect of exosomal miR-302a-3p on cerebral I/R injury via the Keap1/Nrf2 axis, promoting the high expression of NCOA4, PTGS2, and p53 and the increase of Fe 2+ , MDA and ROS levels. These results demonstrated that microglia-exosomal miR-302a-3p suppressed ferroptosis to alleviate cerebral I/R injury by inhibiting neuronal ferritinophagy via regulating the Keap1/Nrf2 axis.
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