3D Chromatin Structures of Mature Gametes and Structural Reprogramming during Mammalian Embryogenesis.

High-order chromatin structure plays important roles in gene expression regulation. Knowledge of the dynamics of 3D chromatin structures during mammalian embryo development remains limited. We report the 3D chromatin architecture of mouse gametes and early embryos using an optimized Hi-C method with low-cell samples. We find that mature oocytes at the metaphase II stage do not have topologically associated domains (TADs). In sperm, extra-long-range interactions (>4 Mb) and interchromosomal interactions occur frequently. The high-order structures of both the paternal and maternal genomes in zygotes and two-cell embryos are obscure but are gradually re-established through development. The establishment of the TAD structure requires DNA replication but not zygotic genome activation. Furthermore, unmethylated CpGs are enriched in A compartment, and methylation levels are decreased to a greater extent in A compartment than in B compartment in embryos. In summary, the global reprogramming of chromatin architecture occurs during early mammalian development.

The transcription factor c-Myb regulates CD8+ T cell stemness and antitumor immunity.

Stem cells are maintained by transcriptional programs that promote self-renewal and repress differentiation. Here, we found that the transcription factor c-Myb was essential for generating and maintaining stem cells in the CD8+ T cell memory compartment. Following viral infection, CD8+ T cells lacking Myb underwent terminal differentiation and generated fewer stem cell-like central memory cells than did Myb-sufficient T cells. c-Myb acted both as a transcriptional activator of Tcf7 (which encodes the transcription factor Tcf1) to enhance memory development and as a repressor of Zeb2 (which encodes the transcription factor Zeb2) to hinder effector differentiation. Domain-mutagenesis experiments revealed that the transactivation domain of c-Myb was necessary for restraining differentiation, whereas its negative regulatory domain was critical for cell survival. Myb overexpression enhanced CD8+ T cell memory formation, polyfunctionality and recall responses that promoted curative antitumor immunity after adoptive transfer. These findings identify c-Myb as a pivotal regulator of CD8+ T cell stemness and highlight its therapeutic potential.

Cytoplasmic SIRT6-mediated ACSL5 deacetylation impedes nonalcoholic fatty liver disease by facilitating hepatic fatty acid oxidation.

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive hepatic lipid accumulation, which can progress to nonalcoholic steatohepatitis (NASH). Histone deacetylase Sirtuin 6 (SIRT6) regulates NAFLD by regulating metabolism-related gene expression, but an extrachromosomal role for SIRT6 in NAFLD development remains elusive. We investigated whether SIRT6 functions on NAFLD in the cytoplasm. We found that SIRT6 binds saturated fatty acids, especially palmitic acid. This binding leads to its nuclear export, where it deacetylates long-chain acyl-CoA synthase 5 (ACSL5), thereby facilitating fatty acid oxidation. High-fat diet-induced NAFLD is suppressed by ACSL5 hepatic overexpression but is exacerbated by its depletion. As confirmation, overexpression of a deacetylated ACSL5 mimic attenuated NAFLD in Sirt6 liver-specific knockout mice. Moreover, NASH-hepatic tissues from both patients and diet-fed mice exhibited significantly reduced cytoplasmic SIRT6 levels and increased ACSL5 acetylation. The SIRT6/ACSL5 signaling pathway has a critical role in NAFLD progression and might constitute an avenue for therapeutic intervention.

Programming and inheritance of parental DNA methylomes in mammals.

The reprogramming of parental methylomes is essential for embryonic development. In mammals, paternal 5-methylcytosines (5mCs) have been proposed to be actively converted to oxidized bases. These paternal oxidized bases and maternal 5mCs are believed to be passively diluted by cell divisions. By generating single-base resolution, allele-specific DNA methylomes from mouse gametes, early embryos, and primordial germ cell (PGC), as well as single-base-resolution maps of oxidized cytosine bases for early embryos, we report the existence of 5hmC and 5fC in both maternal and paternal genomes and find that 5mC or its oxidized derivatives, at the majority of demethylated CpGs, are converted to unmodified cytosines independent of passive dilution from gametes to four-cell embryos. Therefore, we conclude that paternal methylome and at least a significant proportion of maternal methylome go through active demethylation during embryonic development. Additionally, all the known imprinting control regions (ICRs) were classified into germ-line or somatic ICRs.

The GATAD2B-NuRD complex drives DNA:RNA hybrid-dependent chromatin boundary formation upon DNA damage.

Double-strand breaks (DSBs) are the most lethal form of DNA damage. Transcriptional activity at DSBs, as well as transcriptional repression around DSBs, are both required for efficient DNA repair. The chromatin landscape defines and coordinates these two opposing events. However, how the open and condensed chromatin architecture is regulated remains unclear. Here, we show that the GATAD2B-NuRD complex associates with DSBs in a transcription- and DNA:RNA hybrid-dependent manner, to promote histone deacetylation and chromatin condensation. This activity establishes a spatio-temporal boundary between open and closed chromatin, which is necessary for the correct termination of DNA end resection. The lack of the GATAD2B-NuRD complex leads to chromatin hyperrelaxation and extended DNA end resection, resulting in homologous recombination (HR) repair failure. Our results suggest that the GATAD2B-NuRD complex is a key coordinator of the dynamic interplay between transcription and the chromatin landscape, underscoring its biological significance in the RNA-dependent DNA damage response.

Reconstructed covalent organic frameworks.

Covalent organic frameworks (COFs) are distinguished from other organic polymers by their crystallinity1-3, but it remains challenging to obtain robust, highly crystalline COFs because the framework-forming reactions are poorly reversible4,5. More reversible chemistry can improve crystallinity6-9, but this typically yields COFs with poor physicochemical stability and limited application scope5. Here we report a general and scalable protocol to prepare robust, highly crystalline imine COFs, based on an unexpected framework reconstruction. In contrast to standard approaches in which monomers are initially randomly aligned, our method involves the pre-organization of monomers using a reversible and removable covalent tether, followed by confined polymerization. This reconstruction route produces reconstructed COFs with greatly enhanced crystallinity and much higher porosity by means of a simple vacuum-free synthetic procedure. The increased crystallinity in the reconstructed COFs improves charge carrier transport, leading to sacrificial photocatalytic hydrogen evolution rates of up to 27.98 mmol h-1 g-1. This nanoconfinement-assisted reconstruction strategy is a step towards programming function in organic materials through atomistic structural control.

C1QBP Promotes Homologous Recombination by Stabilizing MRE11 and Controlling the Assembly and Activation of MRE11/RAD50/NBS1 Complex.

MRE11 nuclease forms a trimeric complex (MRN) with RAD50 and NBS1 and plays a central role in preventing genomic instability. When DNA double-strand breaks (DSBs) occur, MRN is quickly recruited to the damage site and initiates DNA end resection; accordingly, MRE11 must be tightly regulated to avoid inefficient repair or nonspecific resection. Here, we show that MRE11 and RAD50 form a complex (MRC) with C1QBP, which stabilizes MRE11/RAD50, while inhibiting MRE11 nuclease activity by preventing its binding to DNA or chromatin. Upon DNA damage, ATM phosphorylates MRE11-S676/S678 to quickly dissociate the MRC complex. Either excess or insufficient C1QBP impedes the recruitment of MRE11 to DSBs and impairs the DNA damage response. C1QBP is highly expressed in breast cancer and positively correlates with MRE11 expression, and the inhibition of C1QBP enhances tumor regression with chemotherapy. By influencing MRE11 at multiple levels, C1QBP is, thus, an important player in the DNA damage response.

Acetylation of PHF5A Modulates Stress Responses and Colorectal Carcinogenesis through Alternative Splicing-Mediated Upregulation of KDM3A.

Alternative pre-mRNA-splicing-induced post-transcriptional gene expression regulation is one of the pathways for tumors maintaining proliferation rates accompanying the malignant phenotype under stress. Here, we uncover a list of hyperacetylated proteins in the context of acutely reduced Acetyl-CoA levels under nutrient starvation. PHF5A, a component of U2 snRNPs, can be acetylated at lysine 29 in response to multiple cellular stresses, which is dependent on p300. PHF5A acetylation strengthens the interaction among U2 snRNPs and affects global pre-mRNA splicing pattern and extensive gene expression. PHF5A hyperacetylation-induced alternative splicing stabilizes KDM3A mRNA and promotes its protein expression. Pathologically, PHF5A K29 hyperacetylation and KDM3A upregulation axis are correlated with poor prognosis of colon cancer. Our findings uncover a mechanism of an anti-stress pathway through which acetylation on PHF5A promotes the cancer cells' capacity for stress resistance and consequently contributes to colon carcinogenesis.

Improving normothermic machine perfusion and blood transfusion through biocompatible blood silicification.

The growing world population and increasing life expectancy are driving the need to improve the quality of blood transfusion, organ transplantation, and preservation. Here, to improve the ability of red blood cells (RBCs) for normothermic machine perfusion, a biocompatible blood silicification approach termed "shielding-augmenting RBC-in-nanoscale amorphous silica (SARNAS)" has been developed. The key to RBC surface engineering and structure augmentation is the precise control of the hydrolysis form of silicic acid to realize stabilization of RBC within conformal nanoscale silica-based exoskeletons. The formed silicified RBCs (Si-RBCs) maintain membrane/structural integrity, normal cellular functions (e.g., metabolism, oxygen-carrying capability), and enhance resistance to external stressors as well as tunable mechanical properties, resulting in nearly 100% RBC cryoprotection. In vivo experiments confirm their excellent biocompatibility. By shielding RBC surface antigens, the Si-RBCs provide universal blood compatibility, the ability for allogeneic mechanical perfusion, and more importantly, the possibility for cross-species transfusion. Being simple, reliable, and easily scalable, the SARNAS strategy holds great promise to revolutionize the use of engineered blood for future clinical applications.

DOT1L-mediated RAP80 methylation promotes BRCA1 recruitment to elicit DNA repair.

Breast Cancer Type 1 Susceptibility Protein (BRCA1) is a tumor-suppressor protein that regulates various cellular pathways, including those that are essential for preserving genome stability. One essential mechanism involves a BRCA1-A complex that is recruited to double-strand breaks (DSBs) by RAP80 before initiating DNA damage repair (DDR). How RAP80 itself is recruited to DNA damage sites, however, is unclear. Here, we demonstrate an intrinsic correlation between a methyltransferase DOT1L-mediated RAP80 methylation and BRCA1-A complex chromatin recruitment that occurs during cancer cell radiotherapy resistance. Mechanistically, DOT1L is quickly recruited onto chromatin and methylates RAP80 at multiple lysines in response to DNA damage. Methylated RAP80 is then indispensable for binding to ubiquitinated H2A and subsequently triggering BRCA1-A complex recruitment onto DSBs. Importantly, DOT1L-catalyzed RAP80 methylation and recruitment of BRCA1 have clinical relevance, as inhibition of DOT1L or RAP80 methylation seems to enhance the radiosensitivity of cancer cells both in vivo and in vitro. These data reveal a crucial role for DOT1L in DDR through initiating recruitment of RAP80 and BRCA1 onto chromatin and underscore a therapeutic strategy based on targeting DOT1L to overcome tumor radiotherapy resistance.

Rapid detection of IDH mutations in gliomas by intraoperative mass spectrometry.

The development and performance of two mass spectrometry (MS) workflows for the intraoperative diagnosis of isocitrate dehydrogenase (IDH) mutations in glioma is implemented by independent teams at Mayo Clinic, Jacksonville, and Huashan Hospital, Shanghai. The infiltrative nature of gliomas makes rapid diagnosis necessary to guide the extent of surgical resection of central nervous system (CNS) tumors. The combination of tissue biopsy and MS analysis used here satisfies this requirement. The key feature of both described methods is the use of tandem MS to measure the oncometabolite 2-hydroxyglutarate (2HG) relative to endogenous glutamate (Glu) to characterize the presence of mutant tumor. The experiments i) provide IDH mutation status for individual patients and ii) demonstrate a strong correlation of 2HG signals with tumor infiltration. The measured ratio of 2HG to Glu correlates with IDH-mutant (IDH-mut) glioma (P < 0.0001) in the tumor core data of both teams. Despite using different ionization methods and different mass spectrometers, comparable performance in determining IDH mutations from core tumor biopsies was achieved with sensitivities, specificities, and accuracies all at 100%. None of the 31 patients at Mayo Clinic or the 74 patients at Huashan Hospital were misclassified when analyzing tumor core biopsies. Robustness of the methodology was evaluated by postoperative re-examination of samples. Both teams noted the presence of high concentrations of 2HG at surgical margins, supporting future use of intraoperative MS to monitor for clean surgical margins. The power of MS diagnostics is shown in resolving contradictory clinical features, e.g., in distinguishing gliosis from IDH-mut glioma.

The evolution of hot Jupiters revealed by the age distribution of their host stars.

The unexpected discovery of hot Jupiters challenged the classical theory of planet formation inspired by our solar system. Until now, the origin and evolution of hot Jupiters are still uncertain. Determining their age distribution and temporal evolution can provide more clues into the mechanism of their formation and subsequent evolution. Using a sample of 383 giant planets around Sun-like stars collected from the kinematic catalogs of the Planets Across Space and Time project, we find that hot Jupiters are preferentially hosted by relatively younger stars in the Galactic thin disk. We subsequently find that the frequency of hot Jupiters declines with age as [Formula: see text]. In contrast, the frequency of warm/cold Jupiters shows no significant dependence on age. Such a trend is expected from the tidal evolution of hot Jupiters' orbits, and our result offers supporting evidence using a large sample. We also perform a joint analysis on the planet frequencies in the stellar age-metallicity plane. The result suggests that the frequencies of hot Jupiters and warm/cold Jupiters, after removing the age dependence are both correlated with stellar metallicities as [Formula: see text] and [Formula: see text], respectively. Moreover, we show that the above correlations can explain the bulk of the discrepancy in hot Jupiter frequencies inferred from the transit and radial velocity (RV) surveys, given that RV targets tend to be more metal-rich and younger than transits.

BRCA1 promotes repair of DNA damage in cochlear hair cells and prevents hearing loss.

Cochlear hair cells (HCs) sense sound waves and allow us to hear. Loss of HCs will cause irreversible sensorineural hearing loss. It is well known that DNA damage repair plays a critical role in protecting cells in many organs. However, how HCs respond to DNA damage and how defective DNA damage repair contributes to hearing loss remain elusive.In this study, we showed that cisplatin induced DNA damage in outer hair cells (OHCs) and promoted OHC loss, leading to hearing loss in mice of either sex. Cisplatin induced the expression of Brca1, a DNA damage repair factor, in OHCs. Deficiency of Brca1 induced OHC and hearing loss, and further promoted cisplatin-induced DNA damage in OHCs, accelerating OHC loss. This study provides the first in vivo evidence demonstrating that cisplatin mainly induces DNA damage in OHCs and that BRCA1 promotes repair of DNA damage in OHCs and prevents hearing loss. Our findings not only demonstrate that DNA-damage inducible agent generates DNA damage in postmitotic HCs, but also suggest that DNA repair factors, like BRCA1, protect postmitotic HCs from DNA-damage induced cell death and hearing loss.Significance statement Sensorineural hearing loss is the most severe hearing loss caused by irreversible loss of cochlear hair cells. Hair cells are vulnerable to aging and ototoxic drug. Though DNA damage repair plays a critical role in protecting cells in many organs, it is poorly understood how DNA damage is repaired in hair cells. This study provides the first in vivo evidence demonstrating that cisplatin mainly induces DNA damage in outer hair cells and that BRCA1 promotes repair of DNA damage in outer hair cells and prevents outer hair cell loss as well as hearing loss.

USP11 deubiquitinates E-cadherin and maintains luminal fate of mammary tumor cells to suppress breast cancer.

Basal-like breast cancer may originate from luminal epithelial or cancerous cells. Inadequately repaired DNA damage impairs luminal differentiation and promotes aberrant luminal to basal trans-differentiation in mammary epithelial cells (MECs). Ubiquitin-specific peptidase 11 (USP11), a deubiquitinase, plays a critical role in DNA damage repair. The role of USP11 in controlling mammary cell differentiation and tumorigenesis remains poorly understood. We generated Usp11 knockout mice and breast cancer cell lines expressing wild-type (WT) and mutant form of USP11. By using these mutant mice, cell lines, and human USP11-deficient and -proficient breast cancer tissues, we tested how USP11 controls mammary cell fate. We generated Usp11 knock-out mice and found that deletion of Usp11 reduced the expression of E-cadherin and promoted DNA damage in MECs. Overexpression of WT USP11, but not a deubiquitinase-inactive mutant form of USP11, promoted luminal differentiation, enhanced DNA damage repair, and suppressed tumorigenesis in mice. Mechanistically, we found that USP11 enhanced the protein expression of E-cadherin dependent on its deubiquitinase activity, and that USP11 deubiquitinated E-cadherin at K738. We discovered that USP11 bound to E-cadherin through its C-terminal region. In human breast cancers, expression of USP11 was positively correlated with that of E-cadherin, and high USP11 predicted better recurrence-free survival. Our findings provide compelling genetic and biochemical evidence that USP11 not only promotes DNA damage repair but also deubiquitinates E-cadherin and maintains the luminal feature of mammary tumor cells, thereby suppressing luminal breast cancer.

Extracellular Matrix Disorganization Caused by ADAMTS16 Deficiency Leads to Bicuspid Aortic Valve With Raphe Formation.

BACKGROUND: A better understanding of the molecular mechanism of aortic valve development and bicuspid aortic valve (BAV) formation would significantly improve and optimize the therapeutic strategy for BAV treatment. Over the past decade, the genes involved in aortic valve development and BAV formation have been increasingly recognized. On the other hand, ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) gene family members have been reported to be able to modulate cardiovascular development and diseases. The present study aimed to further investigate the roles of ADAMTS family members in aortic valve development and BAV formation. METHODS: Morpholino-based ADAMTS family gene-targeted screening for zebrafish heart outflow tract phenotypes combined with DNA sequencing in a 304 cohort BAV patient registry study was initially carried out to identify potentially related genes. Both ADAMTS gene-specific fluorescence in situ hybridization assay and genetic tracing experiments were performed to evaluate the expression pattern in the aortic valve. Accordingly, related genetic mouse models (both knockout and knockin) were generated using the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) method to further study the roles of ADAMTS family genes. The lineage-tracing technique was used again to evaluate how the cellular activity of specific progenitor cells was regulated by ADAMTS genes. Bulk RNA sequencing was used to investigate the signaling pathways involved. Inducible pluripotent stem cells derived from both BAV patients and genetic mouse tissue were used to study the molecular mechanism of ADAMTS. Immunohistochemistry was performed to examine the phenotype of cardiac valve anomalies, especially in the extracellular matrix components. RESULTS: ADAMTS genes targeting and phenotype screening in zebrafish and targeted DNA sequencing on a cohort of patients with BAV identified ADAMTS16 (a disintegrin and metalloproteinase with thrombospondin motifs 16) as a BAV-causing gene and found the ADAMTS16 p. H357Q variant in an inherited BAV family. Both in situ hybridization and genetic tracing studies described a unique spatiotemporal pattern of ADAMTS16 expression during aortic valve development. Adamts16+/- and Adamts16+/H355Q mouse models both exhibited a right coronary cusp-noncoronary cusp fusion-type BAV phenotype, with progressive aortic valve thickening associated with raphe formation (fusion of the commissure). Further, ADAMTS16 deficiency in Tie2 lineage cells recapitulated the BAV phenotype. This was confirmed in lineage-tracing mouse models in which Adamts16 deficiency affected endothelial and second heart field cells, not the neural crest cells. Accordingly, the changes were mainly detected in the noncoronary and right coronary leaflets. Bulk RNA sequencing using inducible pluripotent stem cells-derived endothelial cells and genetic mouse embryonic heart tissue unveiled enhanced FAK (focal adhesion kinase) signaling, which was accompanied by elevated fibronectin levels. Both in vitro inducible pluripotent stem cells-derived endothelial cells culture and ex vivo embryonic outflow tract explant studies validated the altered FAK signaling. CONCLUSIONS: Our present study identified a novel BAV-causing ADAMTS16 p. H357Q variant. ADAMTS16 deficiency led to BAV formation.

Coordination of zygotic genome activation entry and exit by H3K4me3 and H3K27me3 in porcine early embryos.

Histone modifications are critical epigenetic indicators of chromatin state associated with gene expression. Although the reprogramming patterns of H3K4me3 and H3K27me3 have been elucidated in mouse and human preimplantation embryos, the relationship between these marks and zygotic genome activation (ZGA) remains poorly understood. By ultra-low-input native chromatin immunoprecipitation and sequencing, we profiled global H3K4me3 and H3K27me3 in porcine oocytes and in vitro fertilized (IVF) embryos. We found that promoters of ZGA genes occupied sharp H3K4me3 peaks in oocytes, and these peaks became broader after fertilization, and reshaped into sharp again during ZGA. By simultaneous depletion of H3K4me3 demethylase KDM5B and KDM5C, we determined that broad H3K4me3 domain maintenance impaired ZGA gene expression, suggesting its function to prevent premature ZGA entry. By contrast, broad H3K27me3 domains underwent global removal upon fertilization, followed by a re-establishment for H3K4me3/H3K27me3 bivalency in morulae. We also found that bivalent marks were deposited at promoters of ZGA genes, and inhibiting this deposition was correlated with the activation of ZGA genes. It suggests that promoter bivalency contributes to ZGA exit in porcine embryos. Moreover, we demonstrated that aberrant reprogramming of H3K4me3 and H3K27me3 triggered ZGA dysregulation in somatic cell nuclear transfer (SCNT) embryos, whereas H3K27me3-mediated imprinting did not exist in porcine IVF and SCNT embryos. Our findings highlight two previously unknown epigenetic reprogramming modes coordinated with ZGA in porcine preimplantation embryos. Finally, the similarities observed between porcine and human histone modification dynamics suggest that the porcine embryo may also be a useful model for human embryo research.

Transcriptional mechanism of E2F1/TFAP2C/NRF1 in regulating KANK2 gene in nephrotic syndrome.

The mortality rate linked with nephrotic syndrome (NS) is quite high. The renal tubular injury influences the response of NS patients to steroid treatment. KN motif and ankyrin repeat domains 2 (KANK2) regulates actin polymerization, which is required for renal tubular cells to maintain their function. In this study, we found that the levels of KANK2 in patients with NS were considerably lower than those in healthy controls, especially in NS patients with acute kidney injury (AKI). To get a deeper understanding of the KANK2 transcriptional control mechanism, the core promoter region of the KANK2 gene was identified. KANK2 was further found to be positively regulated by E2F Transcription Factor 1 (E2F1), Transcription Factor AP-2 Gamma (TFAP2C), and Nuclear Respiratory Factor 1 (NRF1), both at mRNA and protein levels. Knocking down E2F1, TFAP2C, or NRF1 deformed the cytoskeleton of renal tubular cells and reduced F-actin content. EMSA and ChIP assays confirmed that all three transcription factors could bind to the upstream promoter transcription site of KANK2 to transactivate KANK2 in renal tubular epithelial cells. Our study suggests that E2F1, TFAP2C, and NRF1 play essential roles in regulating the KANK2 transcription, therefore shedding fresh light on the development of putative therapeutic options for the treatment of NS patients.

Plasma homocysteine level, estradiol level, and brain atrophy: a Mendelian randomization study.

OBJECTIVES: Observational studies link elevated plasma homocysteine (Hcy) with vascular disease. Our aim was to assess the gender difference in the association between the plasma tHcy level and brain atrophy and identify the possible influencer. We employed Mendelian randomization (MR) to explore the causal relationship between plasma tHcy level, estradiol level, and brain atrophy. METHODS: A total of 687 patients with brain atrophy were included, and gender-specific subgroup analyses in association between tHcy and brain atrophy are conducted. From genome-wide association studies, we selected genetic variants (P < 5 × 10-8) for the plasma tHcy level and estradiol level. We investigated the degree of brain atrophy (including gray matter volume and total brain volume) in the UK biobank (n = 7,916). The inverse variance-weighted and several sensitivity MR regression analyses were carried out. RESULTS: The plasma tHcy level was significantly associated with brain atrophy for females, but not for males. An MR study showed that there was little evidence of the causal link between elevated plasma tHcy and brain atrophy. On the other hand, we found evidence to support causality for genetically decreased estradiol with higher risk of brain atrophy. Furthermore, genetic predisposition to elevated plasma tHcy was associated with a lower estradiol level. CONCLUSIONS: The influence of estradiol on the association between tHcy and brain atrophy deserves further investigation.

miR-148b-5p regulates hypercalciuria and calcium-containing nephrolithiasis.

Calcium-containing stones represent the most common form of kidney calculi, frequently linked to idiopathic hypercalciuria, though their precise pathogenesis remains elusive. This research aimed to elucidate the molecular mechanisms involved by employing urinary exosomal microRNAs as proxies for renal tissue analysis. Elevated miR-148b-5p levels were observed in exosomes derived from patients with kidney stones. Systemic administration of miR-148b-5p in rat models resulted in heightened urinary calcium excretion, whereas its inhibition reduced stone formation. RNA immunoprecipitation combined with deep sequencing identified miR-148b-5p as a suppressor of calcitonin receptor (Calcr) expression, thereby promoting urinary calcium excretion and stone formation. Mice deficient in Calcr in distal epithelial cells demonstrated elevated urinary calcium excretion and renal calcification. Mechanistically, miR-148b-5p regulated Calcr through the circRNA-83536/miR-24-3p signaling pathway. Human kidney tissue samples corroborated these results. In summary, miR-148b-5p regulates the formation of calcium-containing kidney stones via the circRNA-83536/miR-24-3p/Calcr axis, presenting a potential target for novel therapeutic interventions to prevent calcium nephrolithiasis.

The RNA-binding motif protein 14 regulates telomere integrity at the interface of TERRA and telomeric R-loops.

Telomeric repeat-containing RNA (TERRA) and its formation of RNA:DNA hybrids (or TERRA R-loops), influence telomere maintenance, particularly in human cancer cells that use homologous recombination-mediated alternative lengthening of telomeres. Here, we report that the RNA-binding motif protein 14 (RBM14) is associated with telomeres in human cancer cells. RBM14 negatively regulates TERRA expression. It also binds to TERRA and inhibits it from forming TERRA R-loops at telomeres. RBM14 depletion has several effects, including elevated TERRA levels, telomeric R-loops, telomere dysfunction-induced DNA damage foci formation, particularly in the presence of DNA replication stress, pRPA32 accumulation at telomeres and telomere signal-free ends. Thus, RBM14 protects telomere integrity via modulating TERRA levels and its R-loop formation at telomeres.