Clonal evolution from B-cell acute lymphoblastic leukemia with BCR::ABL1 multilineage involvement to acute myeloid leukemia after multiple anti-CD19 chimeric antigen receptor T-cell therapy.

Not available.

Small-molecule modulators of tumor immune microenvironment.

In recent years, tumor immunotherapy, aimed at increasing the activity of immune cells and reducing immunosuppressive effects, has attracted wide attention. Among them, immune checkpoint blocking (ICB) is the most commonly explored therapeutic approach. All approved immune checkpoint inhibitors (ICIs) are clinically effective monoclonal antibodies (mAbs). Compared with biological agents, small-molecule drugs have many unique advantages in tumor immunotherapy. Therefore, they also play an important role. Immunosuppressive signals such as PD-L1, IDO1, and TGF-ß, etc. overexpressed in tumor cells form the tumor immunosuppressive microenvironment. In addition, the efficacy of multi-pathway combined immunotherapy has also been reported and verified. Here, we mainly reviewed the mechanism of tumor immunotherapy, analyzed the research status of small-molecule modulators, and discussed drug candidates' structure-activity relationship (SAR). It provides more opportunities for further research to design more immune small-molecule modulators with novel structures.

Nannochloropsis as an Emerging Algal Chassis for Light-Driven Synthesis of Lipids and High-Value Products.

In light of the escalating global energy crisis, microalgae have emerged as highly promising producers of biofuel and high-value products. Among these microalgae, Nannochloropsis has received significant attention due to its capacity to generate not only triacylglycerol (TAG) but also eicosapentaenoic acid (EPA) and valuable carotenoids. Recent advancements in genetic tools and the field of synthetic biology have revolutionized Nannochloropsis into a powerful biofactory. This comprehensive review provides an initial overview of the current state of cultivation and utilization of the Nannochloropsis genus. Subsequently, our review examines the metabolic pathways governing lipids and carotenoids, emphasizing strategies to enhance oil production and optimize carbon flux redirection toward target products. Additionally, we summarize the utilization of advanced genetic manipulation techniques in Nannochloropsis. Together, the insights presented in this review highlight the immense potential of Nannochloropsis as a valuable model for biofuels and synthetic biology. By effectively integrating genetic tools and metabolic engineering, the realization of this potential becomes increasingly feasible.

PDAT regulates PE as transient carbon sink alternative to triacylglycerol in Nannochloropsis.

Triacylglycerols (TAGs) are the main storage lipids in photosynthetic organisms under stress. In the oleaginous alga Nannochloropsis oceanica, while multiple acyl CoA:diacylglycerol (DAG) acyltransferases (NoDGATs) are involved in TAG production, the role of the unique phospholipid:DAG acyltransferase (NoPDAT) remains unknown. Here, we performed a functional complementation assay in TAG-deficient yeast (Saccharomyces cerevisiae) and an in vitro assay to probe the acyltransferase activity of NoPDAT. Subcellular localization, overexpression, and knockdown (KD) experiments were also conducted to elucidate the role of NoPDAT in N. oceanica. NoPDAT, residing at the outermost plastid membrane, does not phylogenetically fall into the clades of algae or plants and uses phosphatidylethanolamine (PE) and phosphatidylglycerol with 16:0, 16:1, and 18:1 at position sn-2 as acyl-donors in vivo. NoPDAT KD, not triggering any compensatory mechanism via DGATs, led to an ∼30% decrease of TAG content, accompanied by a vast accumulation of PEs rich in 16:0, 16:1, and 18:1 fatty acids (referred to as "LU-PE") that was positively associated with CO2 availability. We conclude that the NoPDAT pathway is parallel to and independent of the NoDGAT pathway for oil production. LU-PE can serve as an alternative carbon sink for photosynthetically assimilated carbon in N. oceanica when PDAT-mediated TAG biosynthesis is compromised or under stress in the presence of high CO2 levels.

Efficacy and safety-related factors of BTK inhibitors as a bridge to CAR-T therapy in R/R FL.

Although anti-CD19 chimeric antigen receptor (CAR) T cell therapy has achieved satisfactory results in relapsed/refractory (R/R) follicular lymphoma (FL), patients with R/R FL and high-risk disease characteristics, previous hematopoietic stem cell transplantation, bulky disease, and progression of disease within 2 years (POD24) had a low complete response (CR). Twenty-seven patients with R/R FL, later disease stages, higher tumor burden, or higher previous treatment lines who had received Bruton tyrosine kinase (BTK) inhibitors before anti-CD19 CAR T cell therapy, or received BTK inhibitors as combination therapy, were included in this study. The clinical response and adverse events (AEs) in anti-CD19 CAR T cell therapy were observed. All patients with R/R FL who received BTK inhibitors combined with anti-CD19-CAR T cell therapy had later disease stages, higher tumor burden, and higher treatment lines than those who did not receive BTK inhibitor combination therapy. However, no difference in the clinical response was found between the two groups. The clinical response in the POD24 group was lower than that in the non-POD24 group; however, no difference in the clinical response was found between the FL and transformed FL (tFL) groups, between the follicular lymphoma international prognostic index (FLIPI) 1 1-2 and FLIPI 1 3-5 groups, and between the FLIPI 2 1-2 and FLIPI 2 3-5 groups. The mean anti-CD19 CAR T cell peak was higher in the CAR-T group with BTK inhibitor than in the CAR-T group without BTK inhibitor. Meanwhile, a higher proportion of patients in the non-POD24 group, FL group, and PR group achieved CR after 2 months. No difference in cytokine secretion was found between the CAR-T group with and without BTK inhibitors. It was higher in the non-POD24 group, FLIPI 1 3-5 group, and FLIPI 2 3-5 group. No difference in cytokine release syndrome and immune effector cell-associated neurotoxic syndrome grades was found between the CAR-T groups with or without BTK inhibitors and between the other groups. Poor prognostic factors, other than POD24, did not affect the clinical response to BTK inhibitors in combination with anti-CD19 CAR T cell therapy in patients with R/R FL. Therefore, BTK inhibitors combined with anti-CD19 CAR-T therapy may be an effective and safe approach for patients with R/R FL and high-risk factors.Trial registration: The study was registered at http://www.chictr.org.cn/index.aspx as ChiCTR-ONN-16009862 and http://www.chictr.org.cn/index.aspx as ChiCTR1800019622.

Metabolic engineering of the oleaginous alga Nannochloropsis for enriching eicosapentaenoic acid in triacylglycerol by combined pulling and pushing strategies.

The marine alga Nannochloropsis oceanica has been considered as a promising photosynthetic cell factory for synthesizing eicosapentaenoic acid (EPA), yet the accumulation of EPA in triacylglycerol (TAG) is restricted to an extreme low level. Poor channeling of EPA to TAG was observed in N. oceanica under TAG induction conditions, likely due to the weak activity of endogenous diacylglycerol acyltransferases (DGATs) on EPA-CoA. Screening over thirty algal DGATs revealed potent enzymes acting on EPA-CoA. Whilst overexpressing endogenous DGATs had no or slight effect on EPA abundance in TAG, introducing selected DGATs with strong activity on EPA-CoA, particularly the Chlamydomonas-derived CrDGTT1, which resided at the outermost membrane of the chloroplast and provided a strong pulling power to divert EPA to TAG for storage and protection, led to drastic increases in EPA abundance in TAG and TAG-derived EPA level in N. oceanica. They were further promoted by additional overexpression of an elongase gene involved in EPA biosynthesis, reaching 5.9- and 12.3-fold greater than the control strain, respectively. Our results together demonstrate the concept of applying combined pulling and pushing strategies to enrich EPA in algal TAG and provide clues for the enrichment of other desired fatty acids in TAG as well.

Efficacy and follow-up of humanized anti-BCMA CAR-T cell therapy in relapsed/refractory multiple myeloma patients with extramedullary-extraosseous, extramedullary-bone related, and without extramedullary disease.

The prognosis of patients with multiple myeloma (MM) with extramedullary disease (EMD) remains poor. A high overall response rate (ORR) has been reported following anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR)-T cell therapy in relapsed/refractory (R/R) patients with MM; however, data on patients with EMD remain limited. Herein, we compared and analyzed the efficacy and long-term follow-up of anti-BCMA CAR-T cell therapy in R/R MM patients with extramedullary-extraosseous (EM-E), extramedullary-bone related (EM-B), and without extramedullary disease. No difference in the ORR was observed between the three groups. The long-term efficacy of anti-BCMA CAR-T cell therapy in the EM-E group was worse than that in patients without EMD and with EM-B. In the EM-E group, disease progression was the reappearance of extramedullary lesions without an increase in the MM cell percentage or M protein level. Although no difference in the proportion of CAR-T cells was detected among the three groups, the EM-E group might exhibit a relatively high grade of cytokine release syndrome following anti-BCMA CAR-T therapy. Interleukin-6 levels in the without EMD group were lower than those in the EM-E and EM-B groups. However, given the small number of cases in the three groups, statistical analysis was not performed.(ChiCTR1800017051 and ChiCTR2000033925).

A review on the assembly of multi-substituted pyridines via Co-catalyzed [2 + 2 + 2] cycloaddition with nitriles.

In recent years, many methods for the facile synthesis of pyridines and their derivatives have been developed. The [2 + 2 + 2] cycloaddition reaction of alkynes and nitriles catalyzed by transition metals has emerged as the most straightforward and efficient method to obtain pyridine derivatives. Recently, Earth-abundant cobalt has been employed as a versatile and economical catalyst for the synthesis of functionalized molecules, as compared to other transition metals. This review mainly focuses on the recent research and development of the Co-catalyzed intramolecular [2 + 2 + 2] cycloaddition of diynes-nitriles or intermolecular [2 + 2 + 2] cycloaddition reaction of alkynes or diynes with nitriles for the construction of chiral or achiral multi-substituted pyridines. Meanwhile, brief mechanistic insights are also discussed here to explain the observed regioselectivity.

Ibrutinib improves the efficacy of anti-CD19-CAR T-cell therapy in patients with refractory non-Hodgkin lymphoma.

The efficacy and side effects of the second-time humanized CD19 chimeric antigen receptor (CD19-CAR) T-cell therapy after unsuccessful first-time anti-CD19-CAR T-cell therapy and subsequent ibrutinib salvage treatment were observed in patients with refractory B-cell lymphoma. In our study, 3 patients with refractory mantle cell lymphoma (MCL) and 4 patients with refractory follicular lymphoma (FL) reached stable disease (SD), partial remission (PR), or progression of disease (PD) after first-time humanized anti-CD19-CAR T-cell therapy. They received ibrutinib as a salvage treatment and kept an SD in the following 7-16 mo, but their disease progressed again during ibrutinib salvage treatment. All 7 patients received a second-time humanized anti-CD19-CAR T-cell therapy, which was the same as their first-time anti-CD19-CAR T-cell therapy. In total, 3 MCL patients and 3 FL patients reached complete response (CR) with the second-time anti-CD19-CAR T-cell therapy combined with ibrutinib, whereas 1 FL patient reached PR. There were no differences in the transduction efficiency and proliferation between the 2 instances of anti-CD19-CAR T-cell therapy. However, the second-time anti-CD19-CAR T-cell therapy led to higher peaks of anti-CD19-CAR T cells and anti-CD19-CAR gene copies, but also to higher grades of cytokine release syndrome (CRS) and more serious hematological toxicity. The successful outcome of the second-time anti-CD19-CAR T-cell therapy might suggest that the previous ibrutinib treatment improved the activities of anti-CD19-CAR T cells.

Impact of COVID-19 lockdown on activity patterns and weight status among youths in China: the COVID-19 Impact on Lifestyle Change Survey (COINLICS).

Lockdown measures including school closures due to COVID-19 may affect youths' activity patterns and obesity status. This will be for the first time examined in China in this study on the basis of a large national sample from the COVID-19 Impact on Lifestyle Change Survey (COINLICS). Through an online questionnaire, 10,082 participants from high schools, colleges, and graduate schools, aged 19.8 ± 2.3 years, voluntarily reported their lifestyles and weight status before (January 2020) and after lockdown (April-May 2020). The significance of these changes was assessed between sexes and across education levels. We found that the youths' average body mass index significantly increased from 21.8 to 22.1 kg/m2, with the prevalences of overweight/obesity and obesity increasing from 21.4% to 24.6% and from 10.5% to 12.6%, respectively. Also, significant decreases were seen in the frequency of engaging in active transport, moderate-/vigorous-intensity housework, leisure-time moderate-/vigorous-intensity physical activity, and leisure-time walking, while significant increases were observed in the average sedentary time during workdays and weekends, the average sleeping time during workdays and weekends, and screen time. Our findings would serve as important evidence for shaping global strategies to counteract or reverse the lockdown effects on youths' obesity.

Urban-rural differences in the association between long-term exposure to ambient air pollution and obesity in China.

INTRODUCTION: Ambient air pollution might increase the risk of obesity; however, the evidence regarding the relationship between air pollution and obesity in comparable urban and rural areas is limited. Therefore, our aim was to contrast the effect estimates of varying air pollution particulate matter on obesity between urban and rural areas. METHODS: Four obesity indicators were evaluated in this study, namely, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Exposure to ambient air pollution (e.g., particulate matter with aerodynamic diameters 1.0 µm [PM1], PM2.5, and PM10) was estimated using satellite-based random forest models. Linear regression and logistic regression models were used to assess the associations between air pollution particulate matter and obesity. Furthermore, the effect estimates of different air pollution particulates were contrasted between urban and rural areas. RESULTS: A total of 36,998 participants in urban areas and 31, 256 in rural areas were included. We found positive associations between long-term exposure to PM1, PM2.5, and PM10 and obesity. Of these air pollutants, PM2.5 had the strongest association. The results showed that the odds ratios (ORs) for general obesity were 1.8 (95% CI, 1.64 to 1.98) per interquartile range (IQR) µg/m3 increase in PM1, 1.89 (95% CI, 1.71 to 2.1) per IQR µg/m3 increase in PM2.5, and 1.74 (95% CI, 1.58 to 1.9) per IQR µg/m3 increase in PM10. The concentrations of air pollutants were lower in rural areas, but the effects of air pollution on obesity of rural residents were higher than those of urban residents. CONCLUSION: Long-term (3 years average) exposure to ambient air pollution was associated with an increased risk of obesity. We observed regional disparities in the effects of particulate matter exposure from air pollution on the risk of obesity, with higher effect estimates found in rural areas. Air quality interventions should be prioritized not only in urban areas but also in rural areas to reduce the risk of obesity.

Association of Daytime Napping with chronic diseases among Tibetan people in China: a cross-sectional study.

BACKGROUND: Obesity, diabetes, and hypertension, as three of the most prevalent chronic diseases, remain a daunting health challenge. However, to our knowledge, no study has made a thorough examination of the association between the three chronic diseases and daytime napping, a widely accepted behavior in many countries. This is especially necessary among Tibetan populations, whose lifestyles and health outcomes may be unique, yet patterns of chronic diseases and napping are under-examined. Thus, we sought to explore the aforementioned association in the Tibetan population of China. METHODS: A total of 2902 participants aged 45-79 in 2019 were included. Multivariate logistic regressions were conducted in 2020. The sex disparity was examined through interaction and stratified analyses. RESULTS: Hypertension (40.7%) was more prevalent than obesity (20.2%) and diabetes (21.6%). Comparing to non-nappers, those who napped were more likely to have any conditions (OR = 1.30, 95% CI = 1.04-1.62 for 1-59 min/day group and OR = 1.40, 95% CI = 1.10-1.80 for ≥60 min/day group). Participants who had 1-59 min/day of napping were more likely to develop obesity (OR = 1.37, 95% CI = 1.07-1.75), and ≥ 60 min/day of napping was associated with diabetes (OR = 1.33, 95% CI = 1.01-1.74). The interactions between napping and sex were not statistically significant in the models. CONCLUSIONS: The study revealed napping was unfavorably associated with obesity, diabetes, and any conditions in Tibetan people living on the Tibetan Plateau. Future interventions regarding the three chronic diseases may pay more attention to napping. TRIAL REGISTRATION: Not applicable.

Zebrafish microRNA miR-210-5p inhibits primitive myelopoiesis by silencing foxj1b and slc3a2a mRNAs downstream of gata4/5/6 transcription factor genes.

Zebrafish gata4/5/6 genes encode transcription factors that lie on the apex of the regulatory hierarchy in primitive myelopoiesis. However, little is known about the roles of microRNAs in gata4/5/6-regulated processes. Performing RNA-Seq deep sequencing analysis of the expression changes of microRNAs in gata4/5/6-knockdown embryos, we identified miR-210-5p as a regulator of zebrafish primitive myelopoiesis. Knocking down gata4/5/6 (generating gata5/6 morphants) significantly increased miR-210-5p expression, whereas gata4/5/6 overexpression greatly reduced its expression. Consistent with inhibited primitive myelopoiesis in the gata5/6 morphants, miR-210-5p overexpression repressed primitive myelopoiesis, indicated by reduced numbers of granulocytes and macrophages. Moreover, knocking out miR-210 partially rescued the defective primitive myelopoiesis in zebrafish gata4/5/6-knockdown embryos. Furthermore, we show that the restrictive role of miR-210-5p in zebrafish primitive myelopoiesis is due to impaired differentiation of hemangioblast into myeloid progenitor cells. By comparing the set of genes with reduced expression levels in the gata5/6 morphants to the predicted target genes of miR-210-5p, we found that foxj1b and slc3a2a, encoding a forkhead box transcription factor and a solute carrier family 3 protein, respectively, are two direct downstream targets of miR-210-5p that mediate its inhibitory roles in zebrafish primitive myelopoiesis. In summary, our results reveal that miR-210-5p has an important role in the genetic network controlling zebrafish primitive myelopoiesis.

Synergistic effect of ibrutinib and CD19 CAR-T cells on Raji cells in vivo and in vitro.

Ibrutinib might improve the efficacy of anti-CD19 chimeric antigen receptor (CD19 CAR) T-cell therapy in chronic lymphocytic leukemia (CLL). We studied the possibility and mechanism of the synergistic effect of ibrutinib and CAR-T cells in other types of lymphoma. In this study, we selected the CD19 CAR-T cells of a patient with lymphoma who failed in his CD19 CAR-T-cell therapy and a dose of 8 mg/kg/d ibrutinib. Subcutaneous and tail vein tumorigenic mice were established with Raji cells. The differences in the synergistic effect between these 2 models were compared by bioluminescence imaging (BLI) monitoring and flow cytometry (FCM). The expression of the STAT-3 signaling pathway was assessed by western blot analysis. There was no synergistic effect of ibrutinib and CD19 CAR-T cells in vitro. Programmed cell death-ligand 1 (PD-L1) was expressed in 0.23 ± 0.06% of Raji cells. In the subcutaneous tumorigenic model, the luciferase signal was reduced significantly in the group receiving ibrutinib combined with CD19 CAR-T cells. Moreover, the proportion of CD19 CAR-T cells was higher in the polytherapy group than in the CAR-T-cell monotherapy group. However, we did not get an analogous synergistic effect in the tail vein tumorigenic model. STAT-3 signaling pathway expression in the residual tumor cells did not differ between those with and those without ibrutinib, suggesting that the IL-10/STAT-3/PD-L1 pathway was not involved in the synergistic effect. Therefore, some other mechanism might be a target for ibrutinib. Our results provide evidence for the use of ibrutinib in polytherapy for other types of B-cell lymphoma.

Genetic transmission networks of HIV-1 CRF07_BC strain among HIV-1 infections with virologic failure of ART in a minority area of China: a population-based study.

BACKGROUND: The drug resistance and the virologic failure of antiretroviral therapy (ART) are quite severe in Liangshan. A better understanding of the virologic failure of ART and the HIV-1 transmission network dynamics is essential for the surveillance and prevention of HIV. Here, we analyzed the HIV-1 CRF07_BC strain genetic transmission networks and their associated factors among people living with HIV-1 (PLWH) who had virologic failure of ART by using close genetic links. METHODS: The drug-resistant mutations were determined using the Stanford University HIV Drug Resistance Database. HIV-1 pol genes sequences were used for phylogenetic and genotypic drug resistance analysis. The genetic transmission networks were performed by comparing sequences, constructing the phylogenetic tree, calculating the pairwise distance, and visualizing the network. RESULTS: A total of 1050 PLWH with CRF07_BC pol sequences were finally identified and included in the genetic transmission network analysis from 2016 to 2017. Of the 1050 CRF07_BC pol sequences, 346 (32.95%) fell into clusters at a genetic distance of 0.006, resulting in 137 clusters ranging in size from 2 to 40 individuals. Subjects who were widowed or divorced were less likely to form a genetic transmission network (adjusted OR: 0.50), while subjects who had shared a needle ≥ five times were more likely to form a network (adjusted OR: 1.88). CONCLUSIONS: The genetic transmission networks revealed the complex transmission pattern, highlighting the urgent need for transmission monitoring of virologic failure of ART and selection of more effective therapeutic regimens to promote viral suppression.

Prevalence and determinants of virological failure, genetic diversity and drug resistance among people living with HIV in a minority area in China: a population-based study.

BACKGROUND: Liangshan Yi Autonomous Prefecture is one of the areas that most severely affected by human immunodeficiency virus (HIV) in China, and virological failure on antiretroviral therapy (ART) is serious in this area. Analyses of prevalence and determinants of ART failure, the genetic diversity and drug resistance among people living with HIV (PLWH) helps improve HIV treatment efficiency and prevent HIV transmission. METHODS: A total of 5157 PLWH were recruited from 2016 to 2017. The venous blood samples were subjected to RT-PCR, followed by sequencing of the HIV-1 pol gene, targeting the protease and reverse transcriptase fragments. HIV-1 diversity was analyzed using the DNAStar software and drug resistance mutations were analyzed using the Stanford University HIV Drug Resistance Database. RESULTS: A total of 2156 (41.81%) PLWH showed virological failure on ART. Males (ORm = 1.25), heterosexual behaviors and drug injection (ORm = 1.44) and mother to child transmission routes (ORm = 1.58), the clinical stage of AIDS (ORm = 1.35), having used illicit drugs and shared the needles (1-4 times: ORm = 1.34; more than 5 times: ORm = 1.52), having ever replaced ART regimen (ORm = 1.48) increased the risk of virological failure among PLWH, while higher education lever (ORm = 0.77) and ≥ 12 months on ART (12 ~ 36 months: ORm = 0.72; ≥36 months: ORm = 0.66) was associated with lower likelihood of virological failure. The data revealed that CRF07_BC (1508, 95.62%) were the most common strains, and the drug-resistant rate was 32.10% among PLWH with virological failure in this area. The high frequencies of drug resistance were found in EFV and NVP of NNRTIs, ABC, FTC and 3TC of NRTIs, and TPV/r in PIs. The most common mutations in NNRTIs, NRTIs and PIs were K103N/KN (64.69%), M184V/MV/I (36.29%) and Q58E/QE (4.93%), respectively. CONCLUSION: We concluded that surveillance of virological failure, HIV-1 subtypes, and drug resistance to understand HIV-1 epidemiology and guide modification of ART guidelines, and target prevention and control strategies should be formatted to reduce the virological failure and drug resistance to promote viral suppression and prevent HIV-1 transmission.

Cross-cultural adaptation and validation of the 3D-CAM Chinese version in surgical ICU patients.

BACKGROUND: Accurate diagnosis of delirium is very important for prevention and treatment. Present study was designed to validate the 3-Minute Diagnostic Interview for CAM-defined Delirium Chinese version (3D-CAM-CN) in surgical ICU patients. METHODS: In this prospective diagnostic study, the 3D-CAM was translated into Chinese with culture adaption. Two interviewers (Roles A and B) independently administrated 3D-CAM-CN assessment in adult patients from postoperative days 1 to day 3. At the meantime, a panel of psychiatrists diagnosed delirium according to the Diagnostic and Statistical Manual of Mental Disorders-fifth edition as the reference standard. The sensitivity and specificity were calculated to analyze the diagnostic character of the 3D-CAM-CN. Kappa coefficient was used to evaluate interrater reliability. RESULTS: Two hundred forty-five adult patients were assessed for at least 2 days, resulting a total of 647 paired-assessments. When compared with the reference standard, the sensitivity and specificity of the 3D-CAM-CN assessment were 87.2 and 96.7%, respectively, by Role A and 84.6 and 97.4%, respectively, by Role B, with good interrater reliability (Kappa coefficient = 0.82, P < 0.001). It also performed well in patients with mild cognitive impairment, with the sensitivity from 85.7 to 100% and the specificity from 95.7 to 96.4%. CONCLUSION: Our results showed that the 3D-CAM-CN can be used as a reliable and accurate instrument for delirium assessment in surgical patients. TRIAL REGISTRATION: This trail was approved by the Clinical Research Ethic Committee of Peking University First Hospital (No. 2017-1321) and registered on Chinese clinical trial registry on July 6, 2017 (ChiCTR-OOC-17011887).

The transcription factor Foxc1a in zebrafish directly regulates expression of nkx2.5, encoding a transcriptional regulator of cardiac progenitor cells.

Cardiogenesis is a tightly controlled biological process required for formation of a functional heart. The transcription factor Foxc1 not only plays a crucial role in outflow tract development in mice, but is also involved in cardiac structure formation and normal function in humans. However, the molecular mechanisms by which Foxc1 controls cardiac development remain poorly understood. Previously, we reported that zebrafish embryos deficient in foxc1a, an ortholog of mammalian Foxc1, display pericardial edemas and die 9-10 days postfertilization. To further investigate Foxc1a's role in zebrafish cardiogenesis and identify its downstream target genes during early heart development, we comprehensively analyzed the cardiovascular phenotype of foxc1a-null zebrafish embryos. Our results confirmed that foxc1a-null mutants exhibit disrupted cardiac morphology, structure, and function. Performing transcriptome analysis on the foxc1a mutants, we found that the expression of the cardiac progenitor marker gene nkx2.5 was significantly decreased, but the expression of germ layer-patterning genes was unaffected. Dual-fluorescence in situ hybridization assays revealed that foxc1a and nkx2.5 are co-expressed in the anterior lateral plate mesoderm at the somite stage. Chromatin immunoprecipitation and promoter truncation assays disclosed that Foxc1a regulates nkx2.5 expression via direct binding to two noncanonical binding sites in the proximal nkx2.5 promoter. Moreover, functional rescue experiments revealed that developmental stage-specific nkx2.5 overexpression partially rescues the cardiac defects of the foxc1a-null embryos. Taken together, our results indicate that during zebrafish cardiogenesis, Foxc1a is active directly upstream of nkx2.5.

A Dose-Dependent Spatiotemporal Response of Angiogenesis Elicited by Zn Biodegradation during the Initial Stage of Bone Regeneration.

Zinc (Zn) plays a crucial role in bone metabolism and imbues biodegradable Zn-based materials with the ability to promote bone regeneration in bone trauma. However, the impact of Zn biodegradation on bone repair, particularly its influence on angiogenesis, remains unexplored. This study reveals that Zn biodegradation induces a consistent dose-dependent spatiotemporal response in angiogenesis,both in vivo and in vitro. In a critical bone defect model, an increase in Zn release intensity from day 3 to 10 post-surgery is observed. By day 10, the CD31-positive area around the Zn implant significantly surpasses that of the Ti implant, indicating enhanced angiogenesis. Furthermore,angiogenesis exhibits a distance-dependent pattern closely mirroring the distribution of Zn signals from the implant. In vitro experiments demonstrate that Zn extraction fosters the proliferation and migration of human umbilical vein endothelial cells and upregulates the key genes associated with tube formation, such as HIF-1α and VEGF-A, peaking at a concentration of 22.5 µM. Additionally, Zn concentrations within the range of 11.25-45 µM promote the polarization of M0-type macrophages toward the M2-type, while inhibiting polarization toward the M1-type. These findings provide essential insights into the biological effects of Zn on bone repair, shedding light on its potential applications.