Phase separation-competent FBL promotes early pre-rRNA processing and translation in acute myeloid leukaemia.

RNA-binding proteins (RBPs) are pivotal in acute myeloid leukaemia (AML), a lethal disease. Although specific phase separation-competent RBPs are recognized in AML, the effect of their condensate formation on AML leukaemogenesis, and the therapeutic potential of inhibition of phase separation are underexplored. In our in vivo CRISPR RBP screen, fibrillarin (FBL) emerges as a crucial nucleolar protein that regulates AML cell survival, primarily through its phase separation domains rather than methyltransferase or acetylation domains. These phase separation domains, with specific features, coordinately drive nucleoli formation and early processing of pre-rRNA (including efflux, cleavage and methylation), eventually enhancing the translation of oncogenes such as MYC. Targeting the phase separation capability of FBL with CGX-635 leads to elimination of AML cells, suggesting an additional mechanism of action for CGX-635 that complements its established therapeutic effects. We highlight the potential of PS modulation of critical proteins as a possible therapeutic strategy for AML.

The ATF4-RPS19BP1 axis modulates ribosome biogenesis to promote erythropoiesis.

Hematopoietic differentiation is controlled by intrinsic regulators and the extrinsic hematopoietic niche. Activating transcription factor 4 (ATF4) plays a crucial role in the function of fetal and adult hematopoietic stem cell maintenance; however, the precise function of ATF4 in the bone marrow niche and the mechanism by which ATF4 regulates adult hematopoiesis remain largely unknown. Here, we employ four cell-type-specific mouse Cre lines to achieve conditional knockout of Atf4 in Cdh5+ endothelial cells, Prx1+ bone marrow stromal cells, Osx+ osteo-progenitor cells, and Mx1+ hematopoietic cells, and uncover the role of Atf4 in niche cells and hematopoiesis. Intriguingly, depletion of Atf4 in niche cells does not affect hematopoiesis; however, Atf4-deficient hematopoietic cells exhibit erythroid differentiation defects, leading to hypoplastic anemia. Mechanistically, ATF4 mediates direct regulation of Rps19bp1 transcription, which is, in turn, involved in 40S ribosomal subunit assembly to coordinate ribosome biogenesis and promote erythropoiesis. Finally, we demonstrate that under conditions of 5-fluorouracil-induced stress, Atf4 depletion impedes the recovery of hematopoietic lineages, which requires efficient ribosome biogenesis. Taken together, our findings highlight the indispensable role of the ATF4-RPS19BP1 axis in the regulation of erythropoiesis.

Microplastics dampen the self-renewal of hematopoietic stem cells by disrupting the gut microbiota-hypoxanthine-Wnt axis.

Microplastics (MPs) are contaminants ubiquitously found in the global biosphere that enter the body through inhalation or ingestion, posing significant risks to human health. Recent studies emerge that MPs are present in the bone marrow and damage the hematopoietic system. However, it remains largely elusive about the specific mechanisms by which MPs affect hematopoietic stem cells (HSCs) and their clinical relevance in HSC transplantation (HSCT). Here, we established a long-term MPs intake mouse model and found that MPs caused severe damage to the hematopoietic system. Oral gavage administration of MPs or fecal transplantation of microbiota from MPs-treated mice markedly undermined the self-renewal and reconstitution capacities of HSCs. Mechanistically, MPs did not directly kill HSCs but disrupted gut structure and permeability, which eventually ameliorated the abundance of Rikenellaceae and hypoxanthine in the intestine and inactivated the HPRT-Wnt signaling in bone marrow HSCs. Furthermore, administration of Rikenellaceae or hypoxanthine in mice as well as treatment of WNT10A in the culture system substantially rescued the MPs-induced HSC defects. Finally, we validated in a cohort of human patients receiving allogenic HSCT from healthy donors, and revealed that the survival time of patients was negatively correlated with levels of MPs, while positively with the abundance of Rikenellaceae, and hypoxanthine in the HSC donors' feces and blood. Overall, our study unleashes the detrimental roles and mechanisms of MPs in HSCs, which provides potential strategies to prevent hematopoietic damage from MPs and serves as a fundamental critique for selecting suitable donors for HSCT in clinical practice.

Inhibition of CD38 enzymatic activity enhances CAR-T cell immune-therapeutic efficacy by repressing glycolytic metabolism.

Chimeric antigen receptor (CAR)-T therapy has shown superior efficacy against hematopoietic malignancies. However, many patients failed to achieve sustainable tumor control partially due to CAR-T cell exhaustion and limited persistence. In this study, by performing single-cell multi-omics data analysis on patient-derived CAR-T cells, we identify CD38 as a potential hallmark of exhausted CAR-T cells, which is positively correlated with exhaustion-related transcription factors and further confirmed with in vitro exhaustion models. Moreover, inhibiting CD38 activity reverses tonic signaling- or tumor antigen-induced exhaustion independent of single-chain variable fragment design or costimulatory domain, resulting in improved CAR-T cell cytotoxicity and antitumor response. Mechanistically, CD38 inhibition synergizes the downregulation of CD38-cADPR -Ca2+ signaling and activation of the CD38-NAD+-SIRT1 axis to suppress glycolysis. Collectively, our findings shed light on the role of CD38 in CAR-T cell exhaustion and suggest potential clinical applications of CD38 inhibition in enhancing the efficacy and persistence of CAR-T cell therapy.

Mitochondrial isocitrate dehydrogenase impedes CAR T cell function by restraining antioxidant metabolism and histone acetylation.

The efficacy of chimeric antigen receptor (CAR) T cell therapy is hampered by relapse in hematologic malignancies and by hyporesponsiveness in solid tumors. Long-lived memory CAR T cells are critical for improving tumor clearance and long-term protection. However, during rapid ex vivo expansion or in vivo tumor eradication, metabolic shifts and inhibitory signals lead to terminal differentiation and exhaustion of CAR T cells. Through a mitochondria-related compound screening, we find that the FDA-approved isocitrate dehydrogenase 2 (IDH2) inhibitor enasidenib enhances memory CAR T cell formation and sustains anti-leukemic cytotoxicity in vivo. Mechanistically, IDH2 impedes metabolic fitness of CAR T cells by restraining glucose utilization via the pentose phosphate pathway, which alleviates oxidative stress, particularly in nutrient-restricted conditions. In addition, IDH2 limits cytosolic acetyl-CoA levels to prevent histone acetylation that promotes memory cell formation. In combination with pharmacological IDH2 inhibition, CAR T cell therapy is demonstrated to have superior efficacy in a pre-clinical model.

Single-cell RNA sequencing reveals the immunoregulatory roles of PegIFN-α in patients with chronic hepatitis B.

BACKGROUND AND AIMS: Chronic hepatitis B (CHB) is caused by HBV infection and affects the lives of millions of people worldwide by causing liver inflammation, cirrhosis, and liver cancer. Interferon-alpha (IFN-α) therapy is a conventional immunotherapy that has been widely used in CHB treatment and achieved promising therapeutic outcomes by activating viral sensors and interferon-stimulated genes (ISGs) suppressed by HBV. However, the longitudinal landscape of immune cells of CHB patients and the effect of IFN-α on the immune system are not fully understood. APPROACH AND RESULTS: Here, we applied single-cell RNA sequencing (scRNA-seq) to delineate the transcriptomic landscape of peripheral immune cells in CHB patients before and after PegIFN-α therapy. Notably, we identified three CHB-specific cell subsets, pro-inflammatory (Pro-infla) CD14+ monocytes, Pro-infla CD16+ monocytes and IFNG+ CX3CR1- NK cells, which highly expressed proinflammatory genes and positively correlated with HBsAg. Furthermore, PegIFN-α treatment attenuated percentages of hyperactivated monocytes, increased ratios of long-lived naive/memory T cells and enhanced effector T cell cytotoxicity. Finally, PegIFN-α treatment switched the transcriptional profiles of entire immune cells from TNF-driven to IFN-α-driven pattern and enhanced innate antiviral response, including virus sensing and antigen presentation. CONCLUSIONS: Collectively, our study expands the understanding of the pathological characteristics of CHB and the immunoregulatory roles of PegIFN-α, which provides a new powerful reference for the clinical diagnosis and treatment of CHB.

Novel nomograms to predict risk and prognosis in hospitalized patients with severe fever with thrombocytopenia syndrome.

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging and life-threatening infectious disease caused by SFTS virus. Although recent studies have reported the use of nomograms based on demographic and laboratory data to predict the prognosis of SFTS, no study has included viral load, which is an important factor that influences the prognosis, when compared with other risk factors. Therefore, this study aimed to develop a model that predicts SFTS prognosis before it reaches the critical illness stage and to compare the predictive ability of groups with and without viral load. Methods: Two hundred patients with SFTS were enrolled between June 2018 and August 2023. Data were sourced from the first laboratory results at admission, and two nomograms for mortality risk were developed using multivariate logistic regression to identify the risk variables for poor prognosis in these patients. We calculated the area under the receiver operating characteristic curve (AUC) for the two nomograms to assess their discrimination, and predictive abilities were compared using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Results: The multivariate logistic regression analysis identified four independent risk factors: age, bleeding manifestations, prolonged activated partial thromboplastin time, and viral load. Based on these factors, a final nomogram predicting mortality risk in patients with SFTS was constructed; in addition, a simplified nomogram was constructed excluding the viral load. The AUC [0.926, 95% confidence interval (CI): 0.882-0.970 vs. 0.882, 95% CI: 35 0.823-0.942], NRI (0.143, 95% CI, 0.036-0.285), and IDI (0.124, 95% CI, 0.061-0.186) were calculated and compared between the two models. The calibration curves of the two models showed excellent concordance, and decision curve analysis was used to quantify the net benefit at different threshold probabilities. Conclusion: Two critical risk nomograms were developed based on the indicators for early prediction of mortality risk in patients with SFTS, and enhanced predictive accuracy was observed in the model that incorporated the viral load. The models developed will provide frontline clinicians with a convenient tool for early identification of critically ill patients and initiation of a better personalized treatment in a timely manner.

Dlk1 maintains adult mice long-term HSCs by activating Notch signaling to restrict mitochondrial metabolism.

BACKGROUND: Adult hematopoietic stem cells (HSCs) homeostasis is critically important in maintaining lifelong hematopoiesis. However, how adult HSCs orchestrate its homeostasis remains not fully understood. Imprinted gene Dlk1 has been shown to play critical role in mouse embryonic hematopoiesis and in regulation of stem cells, but its physiological roles in adult HSCs are unknown. METHODS: We performed gene expression analysis of Dlk1, and constructed conditional Dlk1 knockout (KO) mice by crossing Mx1 cre mice with Dlkflox/flox mice. Western blot and quantitative PCR were used to detect Dlk1 KO efficiency. Flow cytometry was performed to investigate the effects of Dlk1 KO on HSCs, progenitors and linage cells in primary mice. Competitive HSCs transplantation and secondary transplantation was used to examine the effects of Dlk1 KO on long-term hematopoietic repopulation potential of HSCs. RNA-Seq and cell metabolism assays was used to determine the underlying mechanisms. RESULTS: Dlk1 was highly expressed in adult mice long-term HSCs (LT-HSCs) relative to progenitors and mature lineage cells. Dlk1 KO in adult mice HSCs drove HSCs enter active cell cycle, and expanded phenotypical LT-HSCs, but undermined its long-term hematopoietic repopulation potential. Dlk1 KO resulted in an increase in HSCs' metabolic activity, including glucose uptake, ribosomal translation, mitochondrial metabolism and ROS production, which impaired HSCs function. Further, Dlk1 KO in adult mice HSCs attenuated Notch signaling, and re-activation of Notch signaling under Dlk1 KO decreased the mitochondrial activity and ROS production, and rescued the changes in frequency and absolute number of HSCs. Scavenging ROS by antioxidant N-acetylcysteine could inhibit mitochondrial metabolic activity, and rescue the changes in HSCs caused by Dlk1 KO. CONCLUSION: Our study showed that Dlk1 played an essential role in maintaining HSC homeostasis, which is realized by governing cell cycle and restricting mitochondrial metabolic activity.

The biogeography and co-occurrence network patterns of bacteria and microeukaryotes in the estuarine and coastal waters.

Community and diversity shifts of bacteria and microeukaryotes with strong environmental and spatial variations have been unveiled in the Pearl River Estuary (PRE) and northern coastal part of South China Sea (SCS). However, it is not clear what the determining factors shape the microbial community and how the biotic interactions respond to the estuarine and oceanic environment. Here, we established the multiple regression models (MRM) and co-occurrence networks on microbial communities in PRE and SCS habitats. The results showed that there were significant differences of the abiotic factors affecting the bacterial and microeukaryotic communities between PRE and SCS habitats. Salinity explained the largest variations to the microbial community dissimilarities in PRE. Whereas spatial and environmental factors determined the microbial community dissimilarities in SCS. Positive relations between parasitic lineages (e.g. Perkinsea and Cercozoa) and algal taxa (Dinophyceae, Cryptophyta, Chlorophyta and Ochrophyta) dominated in the PRE network. While parasites Syndiniales positively correlated with other Syndiniales and protists in SCS. Strong positive associations among autotrophic and heterotrophic groups were revealed in both niches. Therefore, the biotic interactions are also important and may be responsible for the unexplained variations of the abiotic factors from MRM models. Microbial network in the PRE estuarine water had weakened resistance to environmental disturbances, while the SCS network had greater capacity to maintain network stability. This study shed light on the different mechanisms of abiotic and biotic factors in shaping the compositions of bacteria and microeukaryotes between PRE and SCS niches, and highlights the weakening effect of environmental disturbances on the microbial network stability.

Single-cell ATAC-seq maps the comprehensive and dynamic chromatin accessibility landscape of CAR-T cell dysfunction.

Chimeric antigen receptor T cells (CAR-T) therapy has achieved remarkable therapeutic success in treating a variety of hematopoietic malignancies. However, the high relapse rate and poor in vivo persistence, partially caused by CAR-T cell exhaustion, are still important barriers against CAR-T therapy. It remains largely elusive on the mechanisms of CAR-T exhaustion and how to attenuate exhaustion to achieve better therapeutic efficacy. In this study, we initially observed that CAR-T cells showed rapid differentiation and increased exhaustion after co-culture with tumor cells in vitro, and then performed single-cell ATAC-seq to depict the comprehensive and dynamic landscape of chromatin accessibility of CAR-T cells during tumor cell stimulation. Analyses of differential chromatin accessible regions and motif accessibility revealed that TFs were distinct in each cell type and reconstituted a coordinated regulatory network to drive CAR-T exhaustion. Furthermore, we performed scATAC-seq in patient-derived CAR-T cells and identified BATF and IRF4 as pivotal regulators in CAR-T cell exhaustion. Finally, knockdown of BATF or IRF4 enhanced the killing ability, inhibited exhaustion, and prolonged the persistence of CAR-T cells in vivo. Together, our study unraveled the epigenetic regulatory mechanisms of CAR-T exhaustion and provided new insights into CAR-T engineering to achieve better clinical treatment benefits.

Small but strong: Pivotal roles and potential applications of snoRNAs in hematopoietic malignancies.

Small nucleolar RNAs (snoRNAs) belong to a family of noncoding RNAs that are 60-300 nucleotides in length, and they are classified into two classes according to their structure and function: C/D box snoRNAs, playing an essential role in 2'-O-methylation modification on ribosomal RNA; H/ACA box snoRNAs, involved in the pseudouridylation of rRNA. SnoRNAs with unclear functions, no predictable targets, and unusual subcellular locations are called orphan snoRNAs. Recent studies have revealed abnormal expression and demonstrated the pivotal roles of snoRNAs and their host genes in various types of hematological malignancies. This review discusses recent discoveries concerning snoRNAs in a variety of hematological malignancies, including multiple myeloma, lymphoma and leukemia, and sheds light on the application of snoRNAs as diagnostic and prognostic markers as well as therapeutic targets of hematological malignancies in the future.

Clinical features of severe fever with thrombocytopenia syndrome and analysis of risk factors for mortality.

BACKGROUND: To understand the clinical characteristics of and explore the risk factors for mortality in patients with severe fever with thrombocytopenia syndrome (SFTS). METHODS: Data from SFTS patients diagnosed by laboratory examination at Chaohu Hospital affiliated with Anhui Medical University from June 2017 to January 2021 were retrospectively analysed. According to the clinical results, all confirmed patients were divided into the surviving group (80 patients) and non-surviving group (20 patients). The two groups were compared in terms of general characteristics, clinical symptoms and signs, laboratory indicators and other aspects. The independent risk factors for mortality in SFTS patients were analysed by multivariate binary logistic regression. RESULTS: Univariate analysis showed a significant difference in age and the incidence of consciousness disturbance, respiratory failure, haemorrhagic manifestations, renal dysfunction, shock, aspartate aminotransferase (AST) ≥400 U/L, creatine kinase (CK)≥1000 U/L, creatine kinase isoenzymes (CK-MB) ≥100 U/L, lactate dehydrogenase (LDH) ≥1000 U/L, serum creatinine ≥100 mmol/L, blood urea nitrogen ≥7.5 mmol/L and C-reactive protein ≥8 mg/L between the two groups (P < 0.05). CONCLUSIONS: Consciousness disorder, haemorrhagic manifestations, renal dysfunction, AST ≥ 400 U/L, and LDH ≥ 1000 U/L are independent risk factors for mortality in SFTS patients and merit close attention in clinical treatment to avoid fatal consequences.

Effects of algal blooms on selenium species dynamics: A case study in the Changjiang Estuary, China.

The selenium cycle in the marine environment is sensitive to biological activity, but knowledge of dissolved Se species dynamics during coastal algal blooms is limited. Selenium species dynamics during diatom blooms in the Changjiang Estuary were investigated in a survey of dissolved inorganic and organic Se. Dissolved inorganic Se (Se(IV) + Se(VI)) was the predominant species in river-dominanated areas, while dissolved organic selenide (DOSe) was predominant in ocean-dominanated areas. Relationships between DOSe and chromophoric dissolved organic matter involved both humic- and protein-like components, suggesting distinct sources of DOSe in river- and ocean-dominance areas, respectively. A three-endmember-mixing model was used to describe biological processes in ocean-dominanated surface waters. In diatom-bloom areas, the co-occurrence of depletion of Se(IV) and Se(VI) (of ~90% and 30%, respectively) and a 44% increase in production of DOSe indicates that phytoplankton act as vectors for Se species transformation. A Se(IV)*P indicator was developed to quantify limiting concentrations of Se(IV) in water relative to that of phosphorus. Negative Se(IV)*P concentrations indicate that Se(IV) is limited due to biological utilization of dissolved inorganic phosphorus by diatoms, resulting in secondary uptake of Se(VI) in the Changjiang Estuary.

Mitochondrial Protein PINK1 Positively Regulates RLR Signaling.

The serine/threonine kinase phosphatase and tensin homolog (PTEN)-induced putative kinase 1(PINK1) controls mitochondrial quality and plays a vital role in the pathogenesis of early-onset Parkinson's disease. However, whether PINK1 has functions in innate antiviral immunity is largely unknown. Here, we report that viral infection down regulates PINK1 expression in macrophages. PINK1 knockdown results in decreased cytokine production and attenuated IRF3 and NF-κB activation upon viral infection. PINK1 promotes the retinoic-acid-inducible gene I (RIG-I)-like receptors (RLR)-triggered immune responses in a kinase domain-dependent manner. Furthermore, PINK1 associates with TRAF3 via the kinase domain and inhibits Parkin-mediated TRAF3 K48-linked proteasomal degradation. In addition, PINK1 interacts with Yes-associated protein 1 (YAP1) upon viral infection and impairs YAP1/IRF3 complex formation. Collectively, our results demonstrate that PINK1 positively regulates RIG-I triggered innate immune responses by inhibiting TRAF3 degradation and relieving YAP-mediated inhibition of the cellular antiviral response.

Correction to: TAOK1 negatively regulates IL-17-mediated signaling and inflammation.

In this article, published online 5 February 2018, the second primer of mouse actin, il-6, il-1ß, TNFα, cxcl1, cxcl2, and ccl20 in Table 2 should be marked as "reverse primer" instead of "forward primer". Corrected Table 2 is shown below. The authors regret the errors.

TAOK1 negatively regulates IL-17-mediated signaling and inflammation.

Interleukin 17 (IL-17) is an important cytokine that can induce tissue inflammation and is involved in the pathogenesis of numerous autoimmune diseases. However, the regulation of its signaling transduction has not been well described. In this study, we report that thousand and one kinase 1 (TAOK1) functions as a negative regulator of IL-17-mediated signal transduction and inflammation. TAOK1 knockdown promotes IL-17-induced cytokine and chemokine expression and the activation of mitogen-activated protein kinases and nuclear factor-κB. We further demonstrate that TAOK1 interacts with IL-17 receptor A (IL-17RA) independent of its kinase activity, and TAOK1 dose-dependently prevents the formation of the IL-17R-Act1 (nuclear factor activator 1, also known as tumor necrosis factor receptor-associated factor 3 interacting protein 2) complex. Consistent with this, TAOK1 deficiency exacerbates colitis in the 2,4,6-trinitrobenzenesulfonic acid)-induced experimental model of inflammatory bowel disease, likely by its promotion of the IL-17-mediated signaling pathway. TAOK1 expression is decreased in the colons of ulcerative colitis patients. In conclusion, these findings suggest that TAOK1 is involved in the development of IL-17-related autoimmune disorders.

[The profile of antibiotic resistantpathogens isolated from ascites fluid patients in intensive care unit during past 12 years.

Objective: To investigate the profile and antibiotic resistance of bacteria in patients with ascites infection in intensive care unit (ICU) patients in order to provide a reference for rational clinical use of antibiotics. Methods: A retrospective analysis was conducted. The bacteria isolated from ascetic fluid patients admitted from January 1st, 2004 to October 31st, 2015 to ICU of the First Affiliated Hospital of Anhui Medical University were identified, and their susceptibility to antibiotics was analyzed. Patients, who were admitted from January 1st, 2004 to December 31st, 2009 were assigned to group A, and patients admitted afterwards were assigned to group B. Results: A total of 637 specimens of ascetic fluid were examined, with 185 positive culture (29.0%) during the 12 years, and 203 strains of bacteria were found. Among them 126 strains (62.1%) of gram-negative bacteria (G-), 54 (26.6%) of gram-positive bacteria (G+) and 23 (11.3%) strains of fungi were found. Compared the result of group B with that of group A, the proportion of G- bacteria was increased [71.2% (99/139) vs. 44.2% (27/64)], and that of G+ decreased [17.3% (24/139) vs. 46.9% (30/64)] in group B. The difference was statistically significant (χ2 = 20.34, P = 0.001). The main pathogenic bacteria were G-, and Enterobacteriaceae was the most common pathogenic bacteria in intra-abdominal infection of ICU patients. The isolation rate of Escherichia coli and Klebsiella pneumoniae(35.7%, 10.3%) ranked in the first and third in G- bacteria, respectively. The resistant rate of Escherichia coli against penicillin and third generation cephalosporin were > 95.0% and > 73.3%, and it showed a sensitive rate of 70% to ß-lactam/inhibitor, amikacin and minocycline, and a higher sensitivity to carbapenems and tigecycline (11.1%, 0). Forty-eight strains of non-fermentation bacteria were found with a rate of 23.7%. The positive rates of Acinetobacter baumannii in groups A and B were 7.8% (5/64) and 23.7% (33/139), respectively, and they ranked first among non-fermentation bacteria. Twenty strains (62.5%) multidrug-resistant Acinetobacter baumannii were found. Acinetobacter baumannii showed a resistance rate of 84.6% to cefoperazone/sulbactam, 35.3% to minocycline, and 53.3% to tigecycline. Candida albicans was the most commonly isolated fungus in intra-abdominal infections (87.5%). No strains resistant to common antifungal drugs were isolated. Conclusions: G- bacteria was the main pathogen in intra-abdominal infection in patients with ascites. Non-fermenters showed an increasing trend of producing infection, and the proportion of multidrug-resistant Acinetobacter baumannii infection increased year by year, and more attention should be taken by attending doctors.