Deciphering molecular heterogeneity and dynamics of human hippocampal neural stem cells at different ages and injury states.

While accumulated publications support the existence of neurogenesis in the adult human hippocampus, the homeostasis and developmental potentials of neural stem cells (NSCs) under different contexts remain unclear. Based on our generated single-nucleus atlas of the human hippocampus across neonatal, adult, aging, and injury, we dissected the molecular heterogeneity and transcriptional dynamics of human hippocampal NSCs under different contexts. We further identified new specific neurogenic lineage markers that overcome the lack of specificity found in some well-known markers. Based on developmental trajectory and molecular signatures, we found that a subset of NSCs exhibit quiescent properties after birth, and most NSCs become deep quiescence during aging. Furthermore, certain deep quiescent NSCs are reactivated following stroke injury. Together, our findings provide valuable insights into the development, aging, and reactivation of the human hippocampal NSCs, and help to explain why adult hippocampal neurogenesis is infrequently observed in humans.

3D-printed guides versus computer navigation for pedicle screw placement in the surgical treatment of congenital scoliosis deformities.

BACKGROUND: To compare the safety and clinical outcomes of 3D-printed guides versus computer navigation for pedicle screw placement in the correction of congenital scoliosis deformities. METHODS: The study was a single-centre retrospective controlled study and was approved by the hospital ethics committee for the analysis all patients under the age of 18 years with at least 2 years of follow-up. Sixty-three patients who underwent surgical correction for congenital scoliosis deformities in our hospital from January 2015 to December 2020 were divided into two groups based on the decision following preoperative doctor‒patient communication. Among them, 43 patients had pedicle screws placed with 3D-printed guider plates, while the remaining 20 patients had screws inserted with the assistance of computer navigation. The perioperative period, follow-up results and imaging data were compared between the groups. RESULTS: The operation was completed successfully for patients in both groups. The 3D-printed guide-assisted screw placement technique proved to be significantly superior to the computer navigation technique in terms of operation time, screw placement time, and intraoperative blood loss (p < .05), although the former had more frequent intraoperative fluoroscopies than the latter (p < .05). The mean follow-up time was 41.4 months, and the SRS-22 scores significantly improved in both groups over time postoperatively (p < .05). The 3D-printing group had better SRS-22 scores than the navigation group 6 months after surgery and at the last follow-up (p < .05). Compared with preoperative values, the coronal Cobb angle, local kyphotic Cobb angle, C7-S1 coronal deviation (C7PL-CSVL), and sagittal deviation (SVA) were significantly improved in both groups after surgery (p < .05). CONCLUSION: Both techniques achieve the purpose of precise screw placement and proper correction of the deformities. In contrast, the 3D-printed guide-assisted screw placement technique showed advantages in terms of operation time, screw placement time, intraoperative blood loss and patient satisfaction with outcomes.

Introduction of hospital-based health technology assessment in China: experiences from seven pilot hospitals.

OBJECTIVES: This study aimed to introduce a pilot program for hospital-based health technology assessment (HB-HTA) in China and present the participants' experiences based on seven case studies from seven tertiary hospitals. METHODS: One-year pilot projects were initiated at the beginning of 2018. Seven pilot hospitals were closely followed from the beginning until the completion of their pilot HTA project. Regular interviews were conducted with the hospital managers leading the HB-HTA projects and key members of the special HTA teams. Observations were made based on field trips and written HTA reports. RESULTS: Three pilot projects evaluated the use of medical consumables, three evaluated the use of surgical or medical interventions, and one evaluated an innovative management model for ventilators. Real-world data were collected from all the pilot projects to assist with the assessments. Most HB-HTA pilot projects achieved remarkable results such as improvements in economic efficiency; however, there were also obvious deficiencies such as the lack of a necessary cost-effectiveness analysis. CONCLUSIONS: The results varied among the seven HB-HTA pilot projects. The HB-HTA pilot program was implemented to promote the use of HB-HTA in hospital decision making in China. At the same time, HB-HTA in China faces challenges. We have made some policy recommendations based on the findings of the pilot projects.

Human neural stem cells.

'Human neural stem cells' jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research, is the first guideline for human neural stem cells (hNSCs) in China. This standard specifies the technical requirements, test methods, test regulations, instructions for use, labelling requirements, packaging requirements, storage requirements, transportation requirements and waste disposal requirements for hNSCs, which is applicable to the quality control for hNSCs. It was originally released by the China Society for Cell Biology on 30 August 2022. We hope that publication of the guideline will facilitate institutional establishment, acceptance and execution of proper protocols, and accelerate the international standardization of hNSCs for clinical development and therapeutic applications.

Human midbrain dopaminergic progenitors.

Human midbrain dopaminergic progenitors (mDAPs) are one of the most representative cell types in both basic research and clinical applications. However, there are still many challenges for the preparation and quality control of mDAPs, such as the lack of standards. Therefore, the establishment of critical quality attributes and technical specifications for mDAPs is largely needed. "Human midbrain dopaminergic progenitor" jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research, is the first guideline for human mDAPs in China. This standard specifies the technical requirements, test methods, inspection rules, instructions for usage, labelling requirements, packaging requirements, storage requirements, transportation requirements and waste disposal requirements for human mDAPs, which is applicable to the quality control for human mDAPs. It was originally released by the China Society for Cell Biology on 30 August 2022. We hope that the publication of this guideline will facilitate the institutional establishment, acceptance and execution of proper protocols, and accelerate the international standardization of human mDAPs for clinical development and therapeutic applications.

PD-L1 expression levels in mesenchymal stromal cells predict their therapeutic values for autoimmune hepatitis.

BACKGROUND: Autoimmune hepatitis is a chronic inflammatory hepatic disorder with no effective treatment. Mesenchymal stromal cells (MSCs) have emerged as a promising treatment owing to their unique advantages. However, their heterogeneity is hampering use in clinical applications. METHODS: Wharton's jelly derived MSCs (WJ-MSCs) were isolated from 58 human donors using current good manufacturing practice conditions. Gene expression profiles of the WJ-MSCs were analyzed by transcriptome and single-cell RNA-sequencing (scRNA-seq), and subsequent functional differences were assessed. Expression levels of programmed death-ligand 1 (PD-L1) were used as an indicator to screen WJ-MSCs with varied immunomodulation activities and assessed their corresponding therapeutic effects in a mouse model of concanavalin A-induced autoimmune hepatitis. RESULTS: The 58 different donor-derived WJ-MSCs were grouped into six gene expression profile clusters. The gene in different clusters displayed obvious variations in cell proliferation, differentiation bias, trophic factor secretion, and immunoregulation. Data of scRNA-seq revealed four distinct WJ-MSCs subpopulations. Notably, the different immunosuppression capacities of WJ-MSCs were positively correlated with PD-L1 expression. WJ-MSCs with high expression of PD-L1 were therapeutically superior to WJ-MSCs with low PD-L1 expression in treating autoimmune hepatitis. CONCLUSION: PD-L1 expression levels of WJ-MSCs could be regarded as an indicator to choose optimal MSCs for treating autoimmune disease. These findings provided novel insights into the quality control of MSCs and will inform improvements in the therapeutic benefits of MSCs.

Diabetes-related Screw Loosening: The Distinction of Surgical Sites and the Relationship among Diabetes, Implant Stabilization and Clinical Outcomes.

OBJECTIVES: Diabetes mellitus (DM) is correlated with poor clinical outcomes in spinal surgery. However, the effect of it on screw stabilization has not been investigated. The aim of this study was to evaluate the screw loosening rate and postoperative outcomes in diabetic patients and to identify potential risk factors associated with loosening. METHODS: This was a retrospective study. Two hundred and forty-three patients who received cervical or lumbar internal fixation between 2015 and 2019 were enrolled. Screw loosening was assessed on radiography, and clinical outcomes were evaluated by the improvement of visual analogue scale (VAS), Oswestry disability index (ODI) or Japanese Orthopaedic Association (JOA) scores. The relationship of DM, screw loosening and clinical outcomes were analyzed with chi-square tests and regression analyses. RESULTS: One hundred and twenty-two patients (50.2%) with diabetes were included in this study. Diabetes led to the increase of the rate of screw loosening in the lumbar spine, while the loosening rate did not vary significantly in the cervical spine. The occurrence of screw loosening in the lumbar spine was more likely to be associated with clinical outcomes for motor performance including walking and sitting. However, no significant effect on JOA and VAS scores in the cervical spine of screw loosening was found. Moreover, the history of DM affected the outcomes of the patients who underwent spinal surgery. CONCLUSION: DM had an adverse effect on screw stabilization. The impaired improvement of clinical outcomes in diabetics after spinal surgery was related to screw loosening. In addition to the direct effects on operative wounds and neural function, the impact on the screws due to DM was also worth noting.

Generation of Human Endometrial Assembloids with a Luminal Epithelium using Air-Liquid Interface Culture Methods.

The endometrial lining of the uterus is essential for women's reproductive health and consists of several different types of epithelial and stromal cells. Although models such as gland-like structures (GLSs) and endometrial assembloids (EnAos) are successfully established, they lack an intact luminal epithelium, which makes it difficult to recapitulate endometrial receptivity. Here, a novel EnAo model (ALI-EnAo) is developed by combining endometrial epithelial cells (EnECs) and stromal cells (EnSCs) and using an improved matrix and air-liquid interface (ALI) culture method. ALI-EnAos exhibit intact EnSCs and glandular and luminal epithelia, which recapitulates human endometrium anatomy, cell composition, hormone-induced menstrual cycle changes, gene expression profiles, and dynamic ciliogenesis. The model suggests that EnSCs, together with the extracellular matrix and ALI culture conditions, contribute to EnAo phenotypes and characteristics reflective of the endometrial menstrual cycle. This enables to transcriptionally define endometrial cell subpopulations. It anticipates that ALI-EnAos will facilitate studies on embryo implantation, and endometrial growth, differentiation, and disease.

Dissecting peri-implantation development using cultured human embryos and embryo-like assembloids.

Studies of cultured embryos have provided insights into human peri-implantation development. However, detailed knowledge of peri-implantation lineage development as well as underlying mechanisms remains obscure. Using 3D-cultured human embryos, herein we report a complete cell atlas of the early post-implantation lineages and decipher cellular composition and gene signatures of the epiblast and hypoblast derivatives. In addition, we develop an embryo-like assembloid (E-assembloid) by assembling naive hESCs and extraembryonic cells. Using human embryos and E-assembloids, we reveal that WNT, BMP and Nodal signaling pathways synergistically, but functionally differently, orchestrate human peri-implantation lineage development. Specially, we dissect mechanisms underlying extraembryonic mesoderm and extraembryonic endoderm specifications. Finally, an improved E-assembloid is developed to recapitulate the epiblast and hypoblast development and tissue architectures in the pre-gastrulation human embryo. Our findings provide insights into human peri-implantation development, and the E-assembloid offers a useful model to disentangle cellular behaviors and signaling interactions that drive human embryogenesis.

Clinical efficacy of different open approaches in the surgical treatment of thoracolumbar tuberculosis: a single-center retrospective comparative study.

OBJECTIVE: To assess the clinical efficacy of three different surgical approaches in the treatment of thoracolumbar tuberculosis. METHODS: A total of 138 patients with thoracolumbar tuberculosis treated by open surgery were retrospectively analyzed. The surgical methods were divided into anterior, posterior and anterior-posterior combined. The hospital stays, amount of bleeding, operative time, preoperative, postoperative and last follow-up ESR, CRP, Frankel score, ODI, VAS, correction and loss rate of kyphosis, fusion rate and complications were recorded and analyzed. RESULTS: The average follow-up was 66 months. The average hospital stay, operative time and amount of bleeding of the anterior-posterior combined group were higher than other groups (P < 0.05). ESR and CRP of all patients were reduced postoperatively (P < 0.05). No significant difference among the three groups was found in the postoperative correction angle of kyphosis (P < 0.05), while the pre- and postoperative Cobb angle as well as correction rate had significant differences. The posterior approach could achieve better correction, and the loss of correction was more in the anterior group, 40.9 percent of patients performed correction loss. The Frankel score, VAS and ODI were significantly reduced among the three groups, and the incidence rate of complications of the anterior approach was lower than the other groups, with a significant difference (P < 0.05). CONCLUSION: The anterior approach has more advantages and fewer complications, which is supposed to give preference to and could not be replaced by the posterior and anterior-posterior combined approach.

Improved 3D Markerless Mouse Pose Estimation Using Temporal Semi-Supervision.

Three-dimensional markerless pose estimation from multi-view video is emerging as an exciting method for quantifying the behavior of freely moving animals. Nevertheless, scientifically precise 3D animal pose estimation remains challenging, primarily due to a lack of large training and benchmark datasets and the immaturity of algorithms tailored to the demands of animal experiments and body plans. Existing techniques employ fully supervised convolutional neural networks (CNNs) trained to predict body keypoints in individual video frames, but this demands a large collection of labeled training samples to achieve desirable 3D tracking performance. Here, we introduce a semi-supervised learning strategy that incorporates unlabeled video frames via a simple temporal constraint applied during training. In freely moving mice, our new approach improves the current state-of-the-art performance of multi-view volumetric 3D pose estimation and further enhances the temporal stability and skeletal consistency of 3D tracking.

Human Pre-gastrulation Embryo Culture in 3D Condition.

The development process of human embryo until blastocyst is well understood during the past 30 years, however, embryogenesis from blastocyst to pre-gastrulation was still remained a "black box". Limited by research materials and culture technologies, the "black box" is still unopened. We recently established an extended three-dimensional (3D) culture system of human blastocysts (Xiang et al., Nature 577(7791):537-542, 2020). The 3D embryo culture system could enable human blastocyst growing up to early primitive streak anlage stage in vitro. Here, we introduce the detail protocol and notes of culturing human 3D embryos.

Genetically engineered mesenchymal stem cells with dopamine synthesis for Parkinson's disease in animal models.

Although striatal delivery of three critical genes for dopamine synthesis by viruses is a potential clinical approach for treating Parkinson's disease (PD), the approach makes it difficult to finely control dopamine secretion amounts and brings safety concerns. Here, we generate genetically engineered mesenchymal stem cells encoding three critical genes for dopamine synthesis (DOPA-MSCs). DOPA-MSCs retain their MSC identity and stable ability to secrete dopamine during passaging. Following transplantation, DOPA-MSCs reinstate striatal dopamine levels and correct motor function in PD rats. Importantly, after grafting into the caudate and putamen, DOPA-MSCs provide homotopic reconstruction of midbrain dopamine pathways by restoring striatal dopamine levels, and safely and long-term (up to 51 months) correct motor disorders and nonmotor deficits in acute and chronic PD rhesus monkey models of PD even with advanced PD symptoms. The long-term benefits and safety results support the idea that the development of dopamine-synthesized engineered cell transplantation is an important strategy for treating PD.

Capital Formation, Green Innovation, Renewable Energy Consumption and Environmental Quality: Do Environmental Regulations Matter?

The world economy continues to witness a steady rise in carbon emissions, which makes it challenging to fulfill the terms of the Paris agreement on reducing greenhouse gas emissions. In this context, countries worldwide enact environmental regulations to curtail environmental pollution to promote sustainable development. However, the importance of environmental regulations has not been fully validated in the previous literature. In addition, the concurrent roles of capital formation, green innovation, and renewability cannot be overlooked. Against this backdrop, this study selects data from G7 countries from 1994 to 2019 to explore the effect of environmental regulations, capital formation, green innovation, and renewable energy consumption on CO2 emissions. In order to achieve the above research objectives, we employ the Method of Moments Quantile Regression (MM-QR) for empirical analysis. The results reveal that capital formation significantly enhances environmental quality by reducing CO2 emissions across all quantiles (10th-90th). Environmental regulations show a significant and negative impact on CO2 emission mainly at the middle and higher emissions quantiles, while the effect is insignificant at lower quantiles (10th). Moreover, green innovation and renewable energy consumption mitigate CO2 emissions across all quantiles (10th-90th), while economic growth deteriorates environmental quality in G7 countries. The panel granger causality results indicate the unidirectional causality running from capital formation, environmental regulations, and renewable energy towards CO2 emissions, which implies that any policy related to these variables will Granger cause CO2 emissions but not the other way round. Based on the findings, important policy implications are proposed to promote sustainable development in G7 countries.

Single-cell analysis of embryoids reveals lineage diversification roadmaps of early human development.

Despite its clinical and fundamental importance, our understanding of early human development remains limited. Stem cell-derived, embryo-like structures (or embryoids) allowing studies of early development without using natural embryos can potentially help fill the knowledge gap of human development. Herein, transcriptome at the single-cell level of a human embryoid model was profiled at different time points. Molecular maps of lineage diversifications from the pluripotent human epiblast toward the amniotic ectoderm, primitive streak/mesoderm, and primordial germ cells were constructed and compared with in vivo primate data. The comparative transcriptome analyses reveal a critical role of NODAL signaling in human mesoderm and primordial germ cell specification, which is further functionally validated. Through comparative transcriptome analyses and validations with human blastocysts and in vitro cultured cynomolgus embryos, we further proposed stringent criteria for distinguishing between human blastocyst trophectoderm and early amniotic ectoderm cells.

Deconstructing human peri-implantation embryogenesis based on embryos and embryoids†.

The peri-implantation period from blastula to gastrula is one of the crucial stages of human embryo and stem cell development. During development, human embryos undergo many crucial events, such as embryonic lineage differentiation and development, structural self-assembly, pluripotency state transition, cell communication between lineages, and crosstalk between the embryo and uterus. Abnormalities in these developmental events will result in implantation failure or pregnancy loss. However, because of ethical and technical limits, the developmental dynamics of human peri-implantation embryos and the underlying mechanisms of abnormal development remain in a "black box." In this review, we summarize recent progress made toward our understanding of human peri-implantation embryogenesis based on extended in vitro cultured embryos and stem cell-based embryoids. These findings lay an important foundation for understanding early life, promoting research into human stem cells and their application, and preventing and treating infertility. We also propose key scientific issues regarding peri-implantation embryogenesis and provide an outlook on future study directions. Finally, we sum up China's contribution to the field and future opportunities.

Leaving flatland: Advances in 3D behavioral measurement.

Animals move in three dimensions (3D). Thus, 3D measurement is necessary to report the true kinematics of animal movement. Existing 3D measurement techniques draw on specialized hardware, such as motion capture or depth cameras, as well as deep multi-view and monocular computer vision. Continued advances at the intersection of deep learning and computer vision will facilitate 3D tracking across more anatomical features, with less training data, in additional species, and within more natural, occlusive environments. 3D behavioral measurement enables unique applications in phenotyping, investigating the neural basis of behavior, and designing artificial agents capable of imitating animal behavior.

BRN2 as a key gene drives the early primate telencephalon development.

Evolutionary mutations in primate-specific genes drove primate cortex expansion. However, whether conserved genes with previously unidentified functions also play a key role in primate brain expansion remains unknown. Here, we focus on BRN2 (POU3F2), a gene encoding a neural transcription factor commonly expressed in both primates and mice. Compared to the limited effects on mouse brain development, BRN2 biallelic knockout in cynomolgus monkeys (Macaca fascicularis) is lethal before midgestation. Histology analysis and single-cell transcriptome show that BRN2 deficiency decreases RGC expansion, induces precocious differentiation, and alters the trajectory of neurogenesis in the telencephalon. BRN2, serving as an upstream factor, controls specification and differentiation of ganglionic eminences. In addition, we identified the conserved function of BRN2 in cynomolgus monkeys to human RGCs. BRN2 may function by directly regulating SOX2 and STAT3 and maintaining HOPX. Our findings reveal a previously unknown mechanism that BRN2, a conserved gene, drives early primate telencephalon development by gaining novel mechanistic functions.