Clonal hematopoiesis of indeterminate potential (CHIP) is linked to diverse aging-related diseases, including hematologic malignancy and atherosclerotic cardiovascular disease (ASCVD). While CHIP is common among older adults, the underlying factors driving its development are largely unknown. To address this, we performed whole-exome sequencing on 8,374 blood DNA samples collected from 4,187 Atherosclerosis Risk in Communities Study (ARIC) participants over a median follow-up of 21 years. During this period, 735 participants developed incident CHIP. Splicing factor genes (SF3B1, SRSF2, U2AF1, and ZRSR2) and TET2 CHIP grow significantly faster than DNMT3A non-R882 clones. We find that age at baseline and sex significantly influence the incidence of CHIP, while ASCVD and other traditional ASCVD risk factors do not exhibit such associations. Additionally, baseline synonymous passenger mutations are strongly associated with CHIP status and are predictive of new CHIP clone acquisition and clonal growth over extended follow-up, providing valuable insights into clonal dynamics of aging hematopoietic stem and progenitor cells. This study also reveals associations between germline genetic variants and incident CHIP. Our comprehensive longitudinal assessment yields insights into cell-intrinsic and -extrinsic factors contributing to the development and progression of CHIP clones in older adults.

A major next step in hematopoietic stem cell (HSC) biology is to enhance our quantitative understanding of cellular and evolutionary dynamics involved in undisturbed hematopoiesis. Mathematical models have been and continue to be key in this respect, and are most powerful when parameterized experimentally and containing sufficient biological complexity. In this paper, we use data from label propagation experiments in mice to parameterize a mathematical model of hematopoiesis that includes homeostatic control mechanisms as well as clonal evolution. We find that nonlinear feedback control can drastically change the interpretation of kinetic estimates at homeostasis. This suggests that short-term HSC and multipotent progenitors can dynamically adjust to sustain themselves temporarily in the absence of long-term HSCs, even if they differentiate more often than they self-renew in undisturbed homeostasis. Additionally, the presence of feedback control in the model renders the system resilient against mutant invasion. Invasion barriers, however, can be overcome by a combination of age-related changes in stem cell differentiation and evolutionary niche construction dynamics based on a mutant-associated inflammatory environment. This helps us understand the evolution of e.g., TET2 or DNMT3A mutants, and how to potentially reduce mutant burden.

Recent studies have highlighted the significant role of 5-hydroxymethylcytosine (5hmC) in carcinogenesis. However, the specific role of 5hmC in osteosarcoma (OS) remains largely unexplored. The-re-fore, this study aimed to investigate the function of 5hmC and TET3 in OS. In this study, we found a decreased total level of 5hmC in OS tissues. The expression of the TET3 protein was also decreased in OS. Importantly, the decreased levels of TET3 were associated with a decreased disease-free survival (DFS) rate in patients. To investigate the role of TET3 and 5hmC in OS, we manipulated the levels of TET3 in MG-63 cells. Silencing TET3 in these cells resulted in a twofold increase in proliferation. Additio-nally, the level of 5hmC decreased in these cells. Con-versely, over-expression of TET3 in MG-63 cells led to the expected inhibition of proliferation and invasion, accompanied by an increase in 5hmC levels. In conclusion, both 5hmC and TET3 protein levels were decreased in OS. Additionally, the over-expression of TET3 inhibited the proliferation of MG-63 cells, while the suppression of TET3 had the opposite effect. These findings suggest that decreased levels of 5hmC and TET3 may serve as potential markers for OS.

The inversion of substrate size specificity is an evolutionary roadblock for proteins. The Duf4243 dioxygenases GedK and BTG13 are known to catalyze the aromatic cleavage of bulky tricyclic hydroquinone. In this study, we discover a Duf4243 dioxygenase PaD that favors small monocyclic hydroquinones from the penicillic-acid biosynthetic pathway. Sequence alignments between PaD and GedK and BTG13 suggest PaD has three additional motifs, namely motifs 1-3, distributed at different positions in the protein sequence. X-ray crystal structures of PaD with the substrate at high resolution show motifs 1-3 determine three loops (loops 1-3). Most intriguing, loops 1-3 stack together at the top of the pocket, creating a lid-like tertiary structure with a narrow channel and a clearly constricted opening. This drastically changes the substrate specificity by determining the entry and binding of much smaller substrates. Further genome mining suggests Duf4243 dioxygenases with motifs 1-3 belong to an evolutionary branch that is extensively involved in the biosynthesis of natural products and has the ability to degrade diverse monocyclic hydroquinone pollutants. This study showcases how natural enzymes alter the substrate specificity fundamentally by incorporating new small motifs, with a fixed overall scaffold-architecture. It will also offer a theoretical foundation for the engineering of substrate specificity in enzymes and act as a guide for the identification of aromatic dioxygenases with distinct substrate specificities.

BACKGROUND: Cardiac surgery triggers sterile innate immune responses leading to postoperative complications. Clonal hematopoiesis (CH) is associated with short-term inflammation-mediated outcomes after cardiac surgery. The impact of CH on long-term postoperative outcomes remains unknown.
RESULTS: In this cohort study, patients undergoing elective cardiac surgery were included from January 2017 to September 2019. Patients were screened for CH using a predefined gene panel of 19 genes. Recorded clinical events were all-cause death, major adverse cardiac and cerebral events including cardiovascular death, myocardial infarction or nonscheduled coronary revascularization, stroke, and hospitalization for acute heart failure. The primary study outcome was time to a composite criterion including all-cause mortality and major adverse cardiac and cerebral events. Among 314 genotyped patients (median age: 67 years; interquartile range 59-74 years), 139 (44%) presented with CH, based on a variant allelic frequency ≥1%. Carriers of CH had a higher proportion of patients with a history of atrial fibrillation (26% for CH versus 17% for non-CH carriers, P=0.022). The most frequently mutated genes were DNMT3A, TET2, and ASXL1. After a median follow-up of 1203 [813-1435] days, the primary outcome occurred in 50 patients. After multivariable adjustment, CH was independently associated with a higher risk for the primary outcome (hazard ratio, 1.88 [95% CI, 1.05-3.41], P=0.035). Most adverse events occurred in patients carrying TET2 variants.
CONCLUSIONS: In patients undergoing cardiac surgery, CH is frequent and associated with a 2-fold increased long-term risk for major adverse clinical outcomes. CH is a novel risk factor for long-term postcardiac surgery complications and might be useful to personalize management decisions.
BACKGROUND: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03376165.

Tamoxifen, a selective estrogen receptor modulator (SERM), exhibits dual agonist or antagonist effects contingent upon its binding to either G-protein-coupled estrogen receptor (GPER) or estrogen nuclear receptor (ESR). Estrogen signaling plays a pivotal role in initiating epigenetic alterations and regulating estrogen-responsive genes in breast cancer. Employing three distinct breast cancer cell lines-MCF-7 (ESR+; GPER+), MDA-MB-231 (ESR-; GPER-), and SkBr3 (ESR-; GPER+)-this study subjected them to treatment with two tamoxifen derivatives: 4-hydroxytamoxifen (4-HT) and endoxifen (Endox). Through 2D high-performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS), varying levels of 5-methylcytosine (5-mC) were found, with MCF-7 displaying the highest levels. Furthermore, TET3 mRNA expression levels varied among the cell lines, with MCF-7 exhibiting the lowest expression. Notably, treatment with 4-HT induced significant changes in TET3 expression across all cell lines, with the most pronounced increase seen in MCF-7 and the least in MDA-MB-231. These findings underscore the influence of tamoxifen derivatives on DNA methylation patterns, particularly through modulating TET3 expression, which appears to be contingent on the presence of estrogen receptors. This study highlights the potential of targeting epigenetic modifications for personalized anti-cancer therapy, offering a novel avenue to improve treatment outcomes.

DNA methylation is extensively reconfigured during development, but the functional significance and cell type-specific dependencies of DNA demethylation in lineage specification remain poorly understood. Here, we demonstrate that developmental DNA demethylation, driven by ten-eleven translocation 1/2/3 (TET1/2/3) enzymes, is essential for establishment of neural stem cell (NSC) identity and gliogenic potential. We find that loss of all three TETs during NSC specification is dispensable for neural induction and neuronal differentiation but critical for astrocyte and oligodendrocyte formation, demonstrating a selective loss of glial competence. Mechanistically, TET-mediated demethylation was essential for commissioning neural-specific enhancers in proximity to master neurodevelopmental and glial transcription factor genes and for induction of these genes. Consistently, loss of all three TETs in embryonic NSCs in mice compromised glial gene expression and corticogenesis. Thus, TET-dependent developmental demethylation is an essential regulatory mechanism for neural enhancer commissioning during NSC specification and is a cell-intrinsic determinant of NSC identity and gliogenic potential.

Clonal hematopoiesis of indeterminate potential (CHIP) is defined by the presence of a cancer-associated somatic mutation in white blood cells in the absence of overt hematological malignancy. It arises most commonly from loss-of-function mutations in the epigenetic regulators DNMT3A and TET2. CHIP predisposes to both hematological malignancies and atherosclerotic cardiovascular disease in humans. Here we demonstrate that loss of Dnmt3a in myeloid cells increased murine atherosclerosis to a similar degree as previously seen with loss of Tet2. Loss of Dnmt3a enhanced inflammation in macrophages in vitro and generated a distinct adventitial macrophage population in vivo which merges a resident macrophage profile with an inflammatory cytokine signature. These changes surprisingly phenocopy the effect of loss of Tet2. Our results identify a common pathway promoting heightened innate immune cell activation with loss of either gene, providing a biological basis for the excess atherosclerotic disease burden in carriers of these two most prevalent CHIP mutations.

OBJECTIVE: To investigate the clinical characteristics and influence of co-mutated gene on acute myeloid leukemia patients (AML) with FMS-like tyrosine kinase-3 (FLT3) mutations.
METHODS: A total of 273 FLT3+ AML patients were enrolled, and the co-mutation gene data of the patients were collected to further analyze the prognosis of the patients. FLT3 and other common mutations were quantified by PCR amplification products direct sequencing and second-generation sequencing (NGS).
RESULTS: When patients were divided into FLT3- ITD +, FLT3- TKD +, FLT3- ITD ++TKD + and FLT3- ITD -+TKD - group according to the type of FLT3 mutations, it was found that the frequencies of TET2, GATA2, NRAS and ASXL1 mutation were significantly different among the 4 groups (all P < 0.05). When patients were divided into allelic ratio (AR) ≥0.5 and <0.5 group, it was found that the frequencies of FLT3- ITD +, FLT3 -ITD - +TKD -, NPM1, NRAS and C-kit were significantly different between the two groups (all P < 0.05). When patients were divided into normal and abnormal karyotype group, it was found that the frequencies of FLT3- ITD +, FLT3- TKD +, NPM1, GATA2 and C-kit were significantly different between the two groups (all P < 0.05). The median overall survival (OS) of AML patients with FLT3 -TKD + (including FLT3- ITD ++TKD +) was longer than that of patients with FLT3- ITD + alone (P < 0.05). The OS and relapse-free survival (RFS) of AML patients with FLT3++TET2+ were both shorter than those of patients with FLT3++TET2- (both P < 0.05).
CONCLUSIONS: The mutation frequencies of co-mutated genes are correlated with subtypes of FLT3, karyotype and AR. AML patients with FLT3 -TKD + have longer OS than patients with FLT3- ITD + alone, and patients with co-mutation of TET2 have shorter median OS and RFS.
UNASSIGNED: 伴FLT3突变的急性髓系白血病患者共突变基因的临床特征及与预后的关系.
UNASSIGNED: 探讨伴有FLT3突变的初诊急性髓系白血病（AML）患者共突变基因的临床特征及其对患者预后生存的影响。.
UNASSIGNED: 273例FLT3突变的AML患者纳入研究，收集患者的共突变基因资料，进一步对患者预后进行分析。FLT3等常见基因突变用PCR扩增产物直接测序和二代测序定量。.
UNASSIGNED: 按FLT3突变的类型进行分组，分为FLT3- ITD +、FLT3 -TKD +、FLT3- ITD ++TKD +和FLT3-ITD -+TKD -组，其中TET2、GATA2、NRAS和ASXL1在4组间突变频率不同（均P < 0.05）；按FLT3突变的等位基因比率（AR）分组，分为AR≥0.5和<0.5两组，其中FLT3- ITD +、FLT3- ITD -+TKD -、NPM1、NRAS和C-kit在两组间突变频率具有统计学差异（均P < 0.05）；按染色体核型进行分组，分为正常核型组和异常核型组，其中FLT3- ITD +、FLT3 -TKD +、NPM1、GATA2、C-kit在两组间突变频率不同（均P < 0.05）。伴有FLT3- TKD + AML患者（包括FLT3- ITD ++TKD +）的总生存期(OS)长于单独FLT3- ITD +的患者(P < 0.05)，FLT3++TET2+ AML患者的中位OS及无复发生存期(RFS)均短于FLT3++TET2-患者(均P < 0.05)。.
UNASSIGNED: 共突变基因的突变频率与FLT3亚型、核型和等位基因比例有关。伴有FLT3- TKD +AML患者的OS长于单独FLT3- ITD +患者，伴TET2共突变患者的中位OS和RFS较短。.

OBJECTIVE: To investigate the prognostic significance of DTA (DNMT3A, TET2, ASXL1 ) gene mutations in patients with non-M3 acute myeloid leukemia (AML).
METHODS: The clinical data of 180 newly diagnosed AML patients hospitalized in the First People\'s Hospital of Changzhou from January 2018 to April 2022 were retrospectively analyzed. Next-generation sequencing technology was used to detect 150 gene mutations in the patients, and log-rank tests and Cox regression models were used to analyze the prognostic factors.
RESULTS: DTA gene mutations were detected in 83 (46.1%) of 180 AML patients. Compared to patients without DTA mutations, patients with DTA mutations were significantly older (P < 0.001). The median overall survival (OS) time and disease-free survival (DFS) time in the DTA mutation group were significantly shorter than those in the group without DTA mutation (both P < 0.05). Multivariate analysis showed that age ≥ 60 years (P < 0.001), with DTA mutation (P =0.018), and intermediate-risk (relative to favorable-risk) (P =0.005) were independent risk factors for OS in AML patients.
CONCLUSIONS: AML patients with DTA mutations are relatively older, with shorter median OS time and DFS time, and poor prognosis.
UNASSIGNED: DTA突变在初诊急性髓系白血病患者中的预后价值.
UNASSIGNED: 探讨DTA（DNMT3A、TET2、ASXL1 ）突变在非M3型急性髓系白血病（AML）患者中的预后意义。.
UNASSIGNED: 回顾性分析2018年1月至2022年4月就诊于常州市第一人民医院的180例AML患者的临床资料，采用二代测序技术检测患者的150种基因突变情况，采用log-rank检验和Cox回归模型分析影响预后的因素。.
UNASSIGNED: 180例AML患者中，有83例（46.1%）患者检出DTA基因突变。与无DTA突变组相比，DTA突变组患者年龄更大（P < 0.001）。DTA突变型组较无DTA突变组的中位总生存时间（OS）及无病生存时间（DFS）均明显缩短（P < 0.05）。多因素分析结果显示，年龄≥60岁（P < 0.001）、伴DTA突变（P =0.018）、预后中等（相对于预后良好）（P =0.005）是影响患者OS的独立危险因素。.
UNASSIGNED: 伴DTA突变的AML患者年龄偏大，中位OS和中位DFS时间短，预后不佳。.