Comparative analysis of pressure ulcer development in stroke patients within and outside healthcare facilities: A systematic review and meta-analysis.

The risk of pressure ulcers in stroke patients is a significant concern, impacting their recovery and quality of life. This systematic review and meta-analysis investigate the prevalence and risk factors of pressure ulcers in stroke patients, comparing those in healthcare facilities with those in home-based or non-clinical environments. The study aims to elucidate how different care settings affect the development of pressure ulcers, serving as a crucial indicator of patient care quality and management across diverse healthcare contexts. Following PRISMA guidelines, a comprehensive search was conducted across PubMed, Embase, Web of Science and the Cochrane Library. Inclusion criteria encompassed studies on stroke patients in various settings, reporting on the incidence or prevalence of pressure ulcers. Exclusion criteria included non-stroke patients, non-original research and studies with incomplete data. The Newcastle-Ottawa scale was used for quality assessment, and statistical analyses involved both fixed-effect and random-effects models, depending on the heterogeneity observed. A total of 1542 articles were initially identified, with 11 studies meeting the inclusion criteria. The studies exhibited significant heterogeneity, necessitating the use of a random-effects model. The pooled prevalence of pressure injuries was 9.53% in patients without family medical services and 2.64% in patients with medical services. Sensitivity analysis confirmed the stability of these results, and no significant publication bias was detected through funnel plot analysis and Egger's linear regression test. The meta-analysis underscores the heightened risk of pressure injuries in stroke patients, especially post-discharge. It calls for concerted efforts among healthcare providers, policymakers and caregivers to implement targeted strategies tailored to the specific needs of different care environments. Future research should focus on developing and evaluating interventions to effectively integrate into routine care and reduce the incidence of pressure injuries in stroke patients.

Risk assessment and pathogen profile of surgical site infections in traumatic brain injury patients undergoing emergency craniotomy: A retrospective study.

Emergency craniotomy in patients with traumatic brain injury poses a significant risk for surgical site infections (SSIs). Understanding the risk factors and pathogenic characteristics of SSIs in this context is crucial for improving outcomes. This comprehensive retrospective analysis spanned from February 2020 to February 2023 at our institution. We included 25 patients with SSIs post-emergency craniotomy and a control group of 50 patients without SSIs. Data on various potential risk factors were collected, including demographic information, preoperative conditions, and intraoperative details. The BACT/ALERT3D Automated Bacterial Culture and Detection System was utilized for rapid bacterial pathogen identification. Statistical analyses included univariate and multivariate logistic regression to identify significant risk factors for SSIs. The study identified Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus as the most prevalent pathogens in SSIs. Significant risk factors for SSIs included the lack of preoperative antibiotic use, postoperative drainage tube placement, diabetes mellitus, and the incorporation of invasive procedures, all of which showed a significant association with SSIs in the univariate analysis. The multivariate analysis further highlighted the protective effect of preoperative antibiotics and the increased risks associated with anaemia, diabetes mellitus, postoperative drainage tube placement, and the incorporation of invasive procedures. Our research underscores the critical role of factors like insufficient preoperative antibiotics, postoperative drainage, invasive techniques, anaemia, and diabetes mellitus in elevating the risk of surgical site infections in traumatic brain injury patients undergoing emergency craniotomy. Enhanced focus on these areas is essential for improving surgical outcomes.

CEA cell adhesion molecule 5 enriches functional human hematopoietic stem cells capable of long-term multi-lineage engraftment.

Hematopoietic stem cell (HSC) surface markers improve the understanding of cell identity and function. Here, we report that human HSCs can be distinguished by their expression of the CEA Cell Adhesion Molecule 5 (CEACAM5, CD66e), which serves as a marker and a regulator of HSC function. CD66e+ cells exhibited a 5.5-fold enrichment for functional long term HSCs compared to CD66e- cells. CD66e+CD34+CD90+CD45RA- cells displayed robust multi-lineage repopulation and serial reconstitution ability in immunodeficient mice compared to CD66e-CD34+CD90+CD45RA-cells. CD66e expression also identified almost all repopulating HSCs within the CD34+CD90+CD45RA- population. Together, these results indicated that CEACAM5 is a marker that enriches functional human hematopoietic stem cells capable of long-term multi-lineage engraftment.

Interlukin-4 weakens resistance to stress injury and megakaryocytic differentiation of hematopoietic stem cells by inhibiting Psmd13 expression.

Thrombocytopenia is a major and fatal complication in patients with acute myeloid leukemia (AML), which results from disrupted megakaryopoiesis by leukemic niche and blasts. Our previous research revealed that elevated interleukin-4 (IL-4) in AML bone marrow had adverse impact on multiple stages throughout megakaryopoiesis including hematopoietic stem cells (HSCs), but the specific mechanism remains unknown. In the present study, we performed single-cell transcriptome analysis and discovered activated oxidative stress pathway and apoptosis pathway in IL-4Rαhigh versus IL-4Rαlow HSCs. IL-4 stimulation in vitro led to apoptosis of HSCs and down-regulation of megakaryocyte-associated transcription factors. Functional assays displayed higher susceptibility of IL-4Rαhigh HSCs to tunicamycin and irradiation-induced apoptosis, demonstrating their vulnerability to endoplasmic reticulum (ER) stress injury. To clarify the downstream signaling of IL-4, we analyzed the transcriptomes of HSCs from AML bone marrow and found a remarkable down-regulation of the proteasome component Psmd13, whose expression was required for megakaryocytic-erythroid development but could be inhibited by IL-4 in vitro. We knocked down Psmd13 by shRNA in HSCs, and found their repopulating capacity and megakaryocytic differentiation were severely compromised, with increased apoptosis in vivo. In summary, our study uncovered a previous unrecognized regulatory role of IL-4-Psmd13 signaling in anti-stress and megakaryocytic differentiation capability of HSCs.

Single-cell dissection of human hematopoietic reconstitution after allogeneic hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation is an effective regenerative therapy for many malignant, inherited, or autoimmune diseases. However, our understanding of reconstituted hematopoiesis in transplant patients remains limited. Here, we uncover the reconstitution dynamics of human allogeneic hematopoietic stem and progenitor cells (HSPCs) at single-cell resolution after transplantation. Transplanted HSPCs underwent rapid and measurable changes during the first 30 days after transplantation, characterized by a strong proliferative response on the first day. Transcriptomic analysis of HSPCs enabled us to observe that immunoregulatory neutrophil progenitors expressing high levels of the S100A gene family were enriched in granulocyte colony-stimulating factor-mobilized peripheral blood stem cells. Transplant recipients who developed acute graft-versus-host disease (aGVHD) infused fewer S100Ahigh immunoregulatory neutrophil progenitors, immunophenotyped as Lin-CD34+CD66b+CD177+, than those who did not develop aGVHD. Therefore, our study provides insights into the regenerative process of transplanted HSPCs in human patients and identifies a potential criterion for identifying patients at high risk for developing aGVHD early after transplant.

Temporal molecular program of human hematopoietic stem and progenitor cells after birth.

Hematopoietic stem and progenitor cells (HSPCs) give rise to the blood system and maintain hematopoiesis throughout the human lifespan. Here, we report a transcriptional census of human bone-marrow-derived HSPCs from the neonate, infant, child, adult, and aging stages, showing two subpopulations of multipotent progenitors separated by CD52 expression. From birth to the adult stage, stem and multipotent progenitors shared similar transcriptional alterations, and erythroid potential was enhanced after the infant stage. By integrating transcriptome, chromatin accessibility, and functional data, we further showed that aging hematopoietic stem cells (HSCs) exhibited a bias toward megakaryocytic differentiation. Finally, in comparison with the HSCs from the cord blood, neonate bone-marrow-derived HSCs were more quiescent and had higher long-term regeneration capability and durable self-renewal. Taken together, this work provides an integral transcriptome landscape of HSPCs and identifies their dynamics in post-natal steady-state hemopoiesis, thereby helping explore hematopoiesis in development and diseases.

Loss of Nupr1 promotes engraftment by tuning the quiescence threshold of hematopoietic stem cell repository via regulating p53-checkpoint pathway.

Hematopoietic stem cells (HSCs) are dominantly quiescent under homeostasis, which is a key mechanism of maintaining the HSC pool for life-long hematopoiesis. Dormant HSCs poise to be immediately activated on urgent conditions and can return to quiescence after regaining homeostasis. To date, the molecular networks of regulating the threshold of HSC dormancy, if exist, remain largely unknown. Here, we unveiled that deletion of Nupr1, a gene preferentially expressed in HSCs, activated the quiescence HSCs under homeostatic status, which conferred engraftment competitive advantage on HSCs without compromising their stemness and multi-lineage differentiation abilities in serial transplantation settings. Following an expansion protocol, the Nupr1-/- HSCs proliferate more robustly than their wild type counterparts in vitro. Nupr1 inhibits the expression of p53 and the rescue of which offsets the engraftment advantage. Our data unveil the de novo role of Nupr1 as an HSC quiescence-regulator, which provides insights into accelerating the engraftment efficacy of HSC transplantation by targeting the HSC quiescence-controlling network.

Single-cell transcriptomic landscape of human blood cells.

High throughput single-cell RNA-seq has been successfully implemented to dissect the cellular and molecular features underlying hematopoiesis. However, an elaborate and comprehensive transcriptome reference of the whole blood system is lacking. Here, we profiled the transcriptomes of 7551 human blood cells representing 32 immunophenotypic cell types, including hematopoietic stem cells, progenitors and mature blood cells derived from 21 healthy donors. With high sequencing depth and coverage, we constructed a single-cell transcriptional atlas of blood cells (ABC) on the basis of both protein-coding genes and long noncoding RNAs (lncRNAs), and showed a high consistence between them. Notably, putative lncRNAs and transcription factors regulating hematopoietic cell differentiation were identified. While common transcription factor regulatory networks were activated in neutrophils and monocytes, lymphoid cells dramatically changed their regulatory networks during differentiation. Furthermore, we showed a subset of nucleated erythrocytes actively expressing immune signals, suggesting the existence of erythroid precursors with immune functions. Finally, a web portal offering transcriptome browsing and blood cell type prediction has been established. Thus, our work provides a transcriptional map of human blood cells at single-cell resolution, thereby offering a comprehensive reference for the exploration of physiological and pathological hematopoiesis.

A comprehensive RNA editome reveals that edited Azin1 partners with DDX1 to enable hematopoietic stem cell differentiation.

Adenosine-to-inosine RNA editing and the catalyzing enzyme adenosine deaminase are both essential for hematopoietic development and differentiation. However, the RNA editome during hematopoiesis and the underlying mechanisms are poorly defined. Here, we sorted 12 murine adult hematopoietic cell populations at different stages and identified 30 796 editing sites through RNA sequencing. The dynamic landscape of the RNA editome comprises stage- and group-specific and stable editing patterns, but undergoes significant changes during lineage commitment. Notably, we found that antizyme inhibitor 1 (Azin1) was highly edited in hematopoietic stem and progenitor cells (HSPCs). Azin1 editing results in an amino acid change to induce Azin1 protein (AZI) translocation to the nucleus, enhanced AZI binding affinity for DEAD box polypeptide 1 to alter the chromatin distribution of the latter, and altered expression of multiple hematopoietic regulators that ultimately promote HSPC differentiation. Our findings have delineated an essential role for Azin1 RNA editing in hematopoietic cells, and our data set is a valuable resource for studying RNA editing on a more general basis.

Radiation-induced bystander effects impair transplanted human hematopoietic stem cells via oxidative DNA damage.

Total body irradiation (TBI) is commonly used in host conditioning regimens for human hematopoietic stem cell (HSC) transplantation to treat various hematological disorders. Exposure to TBI not only induces acute myelosuppression and immunosuppression, but also injures the various components of the HSC niche in recipients. Our previous study demonstrated that radiation-induced bystander effects (RIBE) of irradiated recipients decreased the long-term repopulating ability of transplanted mouse HSCs. However, RIBE on transplanted human HSCs have not been studied. Here, we report that RIBE impaired the long-term hematopoietic reconstitution of human HSCs as well as the colony-forming ability of human hematopoietic progenitor cells (HPCs). Our further analyses revealed that the RIBE-affected human hematopoietic cells showed enhanced DNA damage responses, cell-cycle arrest, and p53-dependent apoptosis, mainly because of oxidative stress. Moreover, multiple antioxidants could mitigate these bystander effects, though at different efficacies in vitro and in vivo. Taken together, these findings suggest that RIBE impair human HSCs and HPCs by oxidative DNA damage. This study provides definitive evidence for RIBE on transplanted human HSCs and further justifies the necessity of conducting clinical trials to evaluate different antioxidants to improve the efficacy of HSC transplantation for the patients with hematological or nonhematological disorders.

Single-cell transcriptomes of peripheral blood cells indicate and elucidate severity of COVID-19.

The blood and immune system of coronavirus disease 2019 (COVID-19) infected patients are dysfunctional, and numerous studies have been conducted to resolve their characteristics and pathogenic mechanisms. Nevertheless, the variations of immune responses along with disease severity have not been comprehensively documented. Here, we profiled the single-cell transcriptomes of 96,313 peripheral blood mononuclear cells (PBMCs) derived from 12 COVID-19 patients (including four moderate, four severe and four critical cases) and three healthy donors. We showed that proliferative CD8 effector T cells with declined immune functions and cytotoxicity accumulated in the critical stage. By contrast, the quantity of natural killer (NK) cells was significantly reduced, while they exhibited enhanced immune activities. Notably, a gradually attenuated responseto COVID-19 along with disease severity was observed in monocytes, in terms of cellular composition, transcriptional discrepancy and transcription factor regulatory network. Furthermore, we identified immune cell-type dependent cytokine signatures distinguishing the severity of COVID-19 patients. In addition, cell interactions between CD8 effector T/NK cells and monocytes mediated by inflammatory cytokines were enhanced in moderate and severe stages, but weakened in critical cases. Collectively, our work uncovers the cellular and molecular players underlying the disordered and heterogeneous immune responses associated with COVID-19 severity, which could provide valuable insights for the treatment of critical COVID-19 patients.

lncRNA TTN­AS1 upregulates RUNX1 to enhance glioma progression via sponging miR­27b­3p.

Long non­coding RNAs (lncRNAs) contribute to the tumorigeneses of numerous types of cancer, including glioma. The present study was designed to unveil a novel lncRNA functioning in glioma and explore the underlying mechanisms. lncRNA titin­antisense RNA1 (TTN­AS1), miR­27b­3p and Runt­related transcription factor 1 (RUNX1) expression in glioma tissues and cell lines was estimated by RT­qPCR. Si­TTN­AS1 was transfected into glioma cell lines (U251 and LN229), and CCK­8 assay, flow cytometry, wound healing and Transwell assays were applied to estimate the function of TTN­AS1 in glioma cells. miR­27b­3p inhibitor was used to explore the mechanisms. The results revealed that TTN­AS1 was highly expressed in glioma specimens and cell lines. Downregulation of TTN­AS1 inhibited the proliferation, migration and invasion of the glioma cells, as well as increased the rate of apoptosis. In vivo, the tumor growth was also inhibited by TTN­AS1 depletion in nude mice. Furthermore, we revealed that TTN­AS1 exerted oncogenic effects via sponging miR­27b­3p and thereby positively regulating RUNX1 expression. In conclusion, the present study supported that TTN­AS1 acts as an oncogene in glioma by targeting miR­27b­3p to release RUNX1. This finding may contribute to gene therapy of glioma.

Differentiation of transplanted haematopoietic stem cells tracked by single-cell transcriptomic analysis.

How transplanted haematopoietic stem cells (HSCs) behave soon after they reside in a preconditioned host has not been studied due to technical limitations. Here, using single-cell RNA sequencing, we first obtained the transcriptome-based classifications of 28 haematopoietic cell types. We then applied them in conjunction with functional assays to track the dynamic changes of immunophenotypically purified HSCs in irradiated recipients within the first week after transplantation. Based on our transcriptional classifications, most homed HSCs in bone marrow and spleen became multipotent progenitors and, occasionally, some HSCs gave rise to megakaryocytic-erythroid or myeloid precursors. Parallel in vitro and in vivo functional experiments supported the paradigm of robust differentiation without substantial HSC expansion during the first week. Therefore, this study uncovers the previously inaccessible kinetics and fate choices of transplanted HSCs in myeloablated recipients at early stage, with implications for clinical applications of HSCs and other stem cells.

Mesenchymal stem cells suppress leukemia via macrophage-mediated functional restoration of bone marrow microenvironment.

Bone marrow (BM) mesenchymal stem cells (MSCs) are critical components of the BM microenvironment and play an essential role in supporting hematopoiesis. Dysfunction of MSCs is associated with the impaired BM microenvironment that promotes leukemia development. However, whether and how restoration of the impaired BM microenvironment can inhibit leukemia development remain unknown. Using an established leukemia model and the RNA-Seq analysis, we discovered functional degeneration of MSCs during leukemia progression. Importantly, intra-BM instead of systemic transfusion of donor healthy MSCs restored the BM microenvironment, demonstrated by functional recovery of host MSCs, improvement of thrombopoiesis, and rebalance of myelopoiesis. Consequently, intra-BM MSC treatment reduced tumor burden and prolonged survival of the leukemia-bearing mice. Mechanistically, donor MSC treatment restored the function of host MSCs and reprogrammed host macrophages into arginase 1 positive phenotype with tissue-repair features. Transfusion of MSC-reprogrammed macrophages largely recapitulated the therapeutic effects of MSCs. Taken together, our study reveals that donor MSCs reprogram host macrophages to restore the BM microenvironment and inhibit leukemia development.

Correction: PDGFB-expressing mesenchymal stem cells improve human hematopoietic stem cell engraftment in immunodeficient mice.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Potential benefits, mechanisms, and uncertainties of convalescent plasma therapy for COVID-19.

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in China led to a public health emergency of international concern, putting all health organizations on high alert in the beginning of 2020. Corona virus disease 2019 (COVID-19) is highly infectious and has resulted in thousands of deaths which exceeded that of the SARS coronavirus (SARS-CoV) outbreak back in 2002 and 2003 in China. Besides, the number of diagnosed patients, patients who are suspected to have contracted the disease, and deaths are increasing worldwide. Unfortunately, effective drugs and vaccines to combat SARS-CoV-2 are still lacking. Convalescent plasma, a seemingly successful treatment for COVID-19 patients, proved to be of huge value in terms of saving severely ill patients. This review introduces the reported effects, potential mechanisms, and future uncertainties of convalescent plasma therapy in the treatment of COVID-19 patients, in the hopes that it will provide useful information for relevant physicians and researchers.

PDGFB-expressing mesenchymal stem cells improve human hematopoietic stem cell engraftment in immunodeficient mice.

The bone marrow (BM) niche regulates multiple hematopoietic stem cell (HSC) processes. Clinical treatment for hematological malignancies by HSC transplantation often requires preconditioning via total body irradiation, which severely and irreversibly impairs the BM niche and HSC regeneration. Novel strategies are needed to enhance HSC regeneration in irradiated BM. We compared the effects of EGF, FGF2, and PDGFB on HSC regeneration using human mesenchymal stem cells (MSCs) that were transduced with these factors via lentiviral vectors. Among the above niche factors tested, MSCs transduced with PDGFB (PDGFB-MSCs) most significantly improved human HSC engraftment in immunodeficient mice. PDGFB-MSC-treated BM enhanced transplanted human HSC self-renewal in secondary transplantations more efficiently than GFP-transduced MSCs (GFP-MSCs). Gene set enrichment analysis showed increased antiapoptotic signaling in PDGFB-MSCs compared with GFP-MSCs. PDGFB-MSCs exhibited enhanced survival and expansion after transplantation, resulting in an enlarged humanized niche cell pool that provide a better humanized microenvironment to facilitate superior engraftment and proliferation of human hematopoietic cells. Our studies demonstrate the efficacy of PDGFB-MSCs in supporting human HSC engraftment.

Targeting of apoptosis gene loci by reprogramming factors leads to selective eradication of leukemia cells.

Applying somatic cell reprogramming strategies in cancer cell biology is a powerful approach to analyze mechanisms of malignancy and develop new therapeutics. Here, we test whether leukemia cells can be reprogrammed in vivo using the canonical reprogramming transcription factors-Oct4, Sox2, Klf4, and c-Myc (termed as OSKM). Unexpectedly, we discover that OSKM can eradicate leukemia cells and dramatically improve survival of leukemia-bearing mice. By contrast, OSKM minimally impact normal hematopoietic cells. Using ATAC-seq, we find OSKM induce chromatin accessibility near genes encoding apoptotic regulators in leukemia cells. Moreover, this selective effect also involves downregulation of H3K9me3 as an early event. Dissection of the functional effects of OSKM shows that Klf4 and Sox2 play dominant roles compared to c-Myc and Oct4 in elimination of leukemia cells. These results reveal an intriguing paradigm by which OSKM-initiated reprogramming induction can be leveraged and diverged to develop novel anti-cancer strategies.

[Dynamics of Proliferation and Differentiation after Transplantation of Hematopoietic Cells in Mouse].

OBJECTIVE: To observe the dynamic changes of hematopoietic reconstitution and multiple lineages differentiation at early phase after transplantation. METHODS: Whole bone marrow mononuclear cells (wBMMNC, 5×106) and enriched c-Kit+ hematopoietic stem/progenitor cells (HSPC, 3×105) from the BM of B6-Ly5.1 mice were transplanted into lethally irradiated B6-Ly5.2 mice, the frequencies and absolute numbers of donor-derived cells (including LKS- and LKS+) were detected by flow cytometry. The multiple lineages differentiation of donor-derived cells was also monitored by flow cytometry. The homing and early phase proliferations of donor-derived cells were observed by two-photon microscope. RESULTS: The donor-derived cells started to proliferation from 5-7 days after transplantation and reached the peak value at 2-3 weeks after wBMMNC transplantation. The donor-derived cells proliferated from 1-2 weeks and maintained until 4 weeks after c-kit+HSPC transplantation. At 1 week after transplantation, the donor-derived cells mainly differentiated into myeloid cells with a few lymphoid cells production (B cells) but the production of T cells was not observed at most in wBMMNC transplanted group, while myeloid cells occupied the majority of donor-derived cells at 2-4 weeks; donor-derived cells almost totally differentiated into myeloid cells at 1-3 weeks after transplantation in c-Kit+ transplanted group and donor-derived B cells appeared at 4 weeks. The absolute number of donor-derived LKS- and LKS+ cells in the BM of c-Kit+ transplanted group were much higher than that of wBMMNC group (P＜0.001) at 2 weeks respectively. The clustering proliferation of cKit+ cells at 4-5 days after transplantation was observed by two photon microscope. CONCLUSION: The dynamical rate of proliferation and reconstitution of donor-derived cells are much earlier and quicker in c-Kit+ group than those of wBMMNC group. c-Kit+ cells mainly differentiate into myeloid cells within 1-3 weeks and the lymphoid cell differentiation starts at 4 weeks after transplantation. The immediate proliferation and differentiation of c-Kit+ cells within 1 week maybe due to the urgent needs of hematopoietic regeneration under the myeloablated hosts.

Bone marrow endothelial cell-derived interleukin-4 contributes to thrombocytopenia in acute myeloid leukemia.

Normal hematopoiesis can be disrupted by the leukemic bone marrow microenvironment, which leads to cytopenia-associated symptoms including anemia, hemorrhage and infection. Thrombocytopenia is a major and sometimes fatal complication in patients with acute leukemia. However, the mechanisms underlying defective thrombopoiesis in leukemia have not been fully elucidated. In the steady state, platelets are continuously produced by megakaryocytes. Using an MLL-AF9-induced acute myeloid leukemia mouse model, we demonstrated a preserved number and proportion of megakaryocyte-primed hematopoietic stem cell subsets, but weakened megakaryocytic differentiation via both canonical and non-canonical routes. This primarily accounted for the dramatic reduction of megakaryocytic progenitors observed in acute myeloid leukemia bone marrow and a severe disruption of the maturation of megakaryocytes. Additionally, we discovered overproduction of interleukin-4 from bone marrow endothelial cells in acute myeloid leukemia and observed inhibitory effects of interleukin-4 throughout the process of megakaryopoiesis in vivo Furthermore, we observed that inhibition of interleukin-4 in combination with induction chemotherapy not only promoted recovery of platelet counts, but also prolonged the duration of remission in our acute myeloid leukemia mouse model. Our study elucidates a new link between interleukin-4 signaling and defective megakaryopoiesis in acute myeloid leukemia bone marrow, thereby offering a potential therapeutic target in acute myeloid leukemia.