Germinal center responses to SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals.

Vaccine-mediated immunity often relies on the generation of protective antibodies and memory B cells, which commonly stem from germinal center (GC) reactions. An in-depth comparison of the GC responses elicited by SARS-CoV-2 mRNA vaccines in healthy and immunocompromised individuals has not yet been performed due to the challenge of directly probing human lymph nodes. Herein, through a fine-needle aspiration-based approach, we profiled the immune responses to SARS-CoV-2 mRNA vaccines in lymph nodes of healthy individuals and kidney transplant recipients (KTXs). We found that, unlike healthy subjects, KTXs presented deeply blunted SARS-CoV-2-specific GC B cell responses coupled with severely hindered T follicular helper cell, SARS-CoV-2 receptor binding domain-specific memory B cell, and neutralizing antibody responses. KTXs also displayed reduced SARS-CoV-2-specific CD4 and CD8 T cell frequencies. Broadly, these data indicate impaired GC-derived immunity in immunocompromised individuals and suggest a GC origin for certain humoral and memory B cell responses following mRNA vaccination.

Tuning sterol extraction kinetics yields a renal-sparing polyene antifungal.

Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model1. Recently, the clinically vital but also highly renal-toxic small-molecule natural product amphotericin B was instead found to kill fungi primarily by forming extramembraneous sponge-like aggregates that extract ergosterol from lipid bilayers2-6. Here we show that rapid and selective extraction of fungal ergosterol can yield potent and renal-sparing polyene antifungals. Cholesterol extraction was found to drive the toxicity of amphotericin B to human renal cells. Our examination of high-resolution structures of amphotericin B sponges in sterol-free and sterol-bound states guided us to a promising structural derivative that does not bind cholesterol and is thus renal sparing. This derivative was also less potent because it extracts ergosterol more slowly. Selective acceleration of ergosterol extraction with a second structural modification yielded a new polyene, AM-2-19, that is renal sparing in mice and primary human renal cells, potent against hundreds of pathogenic fungal strains, resistance evasive following serial passage in vitro and highly efficacious in animal models of invasive fungal infections. Thus, rational tuning of the dynamics of interactions between small molecules may lead to better treatments for fungal infections that still kill millions of people annually7,8 and potentially other resistance-evasive antimicrobials, including those that have recently been shown to operate through supramolecular structures that target specific lipids9.

CCNE1 amplification is synthetic lethal with PKMYT1 kinase inhibition.

Amplification of the CCNE1 locus on chromosome 19q12 is prevalent in multiple tumour types, particularly in high-grade serous ovarian cancer, uterine tumours and gastro-oesophageal cancers, where high cyclin E levels are associated with genome instability, whole-genome doubling and resistance to cytotoxic and targeted therapies1-4. To uncover therapeutic targets for tumours with CCNE1 amplification, we undertook genome-scale CRISPR-Cas9-based synthetic lethality screens in cellular models of CCNE1 amplification. Here we report that increasing CCNE1 dosage engenders a vulnerability to the inhibition of the PKMYT1 kinase, a negative regulator of CDK1. To inhibit PKMYT1, we developed RP-6306, an orally bioavailable and selective inhibitor that shows single-agent activity and durable tumour regressions when combined with gemcitabine in models of CCNE1 amplification. RP-6306 treatment causes unscheduled activation of CDK1 selectively in CCNE1-overexpressing cells, promoting early mitosis in cells undergoing DNA synthesis. CCNE1 overexpression disrupts CDK1 homeostasis at least in part through an early activation of the MMB-FOXM1 mitotic transcriptional program. We conclude that PKMYT1 inhibition is a promising therapeutic strategy for CCNE1-amplified cancers.

Endogenous DNA 3' Blocks Are Vulnerabilities for BRCA1 and BRCA2 Deficiency and Are Reversed by the APE2 Nuclease.

The APEX2 gene encodes APE2, a nuclease related to APE1, the apurinic/apyrimidinic endonuclease acting in base excision repair. Loss of APE2 is lethal in cells with mutated BRCA1 or BRCA2, making APE2 a prime target for homologous recombination-defective cancers. However, because the function of APE2 in DNA repair is poorly understood, it is unclear why BRCA-deficient cells require APE2 for viability. Here we present the genetic interaction profiles of APE2, APE1, and TDP1 deficiency coupled to biochemical and structural dissection of APE2. We conclude that the main role of APE2 is to reverse blocked 3' DNA ends, problematic lesions that preclude DNA synthesis. Our work also suggests that TOP1 processing of genomic ribonucleotides is the main source of 3'-blocking lesions relevant to APEX2-BRCA1/2 synthetic lethality. The exquisite sensitivity of BRCA-deficient cells to 3' blocks indicates that they represent a tractable vulnerability in homologous recombination-deficient tumor cells.

Poleward and weakened westerlies during Pliocene warmth.

The prevailing mid-latitude westerly winds, known as the westerlies, are a fundamental component of the climate system because they have a crucial role in driving surface ocean circulation1 and modulating air-sea heat, momentum and carbon exchange1-3. Recent work suggests that westerly wind belts are migrating polewards in response to anthropogenic forcing4,5. Reconstructing the westerlies during past warm periods such as the Pliocene epoch, in which atmospheric carbon dioxide (CO2) was about 350 to 450 parts per million6 and temperatures were about 2 to 4 degrees Celsius higher than today7, can improve our understanding of changes in the position and strength of these wind systems as the climate continues to warm. Here we show that the westerlies were weaker and more poleward during the warm Pliocene than during glacial periods after the intensification of Northern Hemisphere glaciation (iNHG), which occurred around 2.73 million years ago8. Our results, which are based on dust and export productivity reconstructions, indicate that major ice sheet development during the iNHG was accompanied by substantial increases in dust fluxes in the mid-latitude North Pacific Ocean, especially compared to those in the subarctic North Pacific. Following this shift, changes in dust and productivity largely track the glacial-interglacial cycles of the late Pliocene and early Pleistocene epochs. On the basis of this pattern, we infer that shifts in the westerlies were primarily driven by variations in Plio-Pleistocene thermal gradients and ice volume. By combining this relationship with other dust records9-11 and climate modelling results12, we find that the proposed changes in the westerlies were globally synchronous. If the Pliocene is predictive of future warming, we posit that continued poleward movement and weakening of the present-day westerlies in both hemispheres can be expected.

CD4 T Cell-Derived IL-21 Is Critical for Sustaining Plasmodium Infection-Induced Germinal Center Responses and Promoting the Selection of Memory B Cells with Recall Potential.

Development of Plasmodium-specific humoral immunity is critically dependent on CD4 Th cell responses and germinal center (GC) reactions during blood-stage Plasmodium infection. IL-21, a cytokine primarily produced by CD4 T cells, is an essential regulator of affinity maturation, isotype class-switching, B cell differentiation, and maintenance of GC reactions in response to many infection and immunization models. In models of experimental malaria, mice deficient in IL-21 or its receptor IL-21R fail to develop memory B cell populations and are not protected against secondary infection. However, whether sustained IL-21 signaling in ongoing GCs is required for maintaining GC magnitude, organization, and output is unclear. In this study, we report that CD4+ Th cells maintain IL-21 expression after resolution of primary Plasmodium yoelii infection. We generated an inducible knockout mouse model that enabled cell type-specific and timed deletion of IL-21 in peripheral, mature CD4 T cells. We found that persistence of IL-21 signaling in active GCs had no impact on the magnitude of GC reactions or their capacity to produce memory B cell populations. However, the memory B cells generated in the absence of IL-21 exhibited reduced recall function upon challenge. Our data support that IL-21 prevents premature cellular dissolution within the GC and promotes stringency of selective pressures during B cell fate determination required to produce high-quality Plasmodium-specific memory B cells. These data are additionally consistent with a temporal requirement for IL-21 in fine-tuning humoral immune memory responses during experimental malaria.

Dual thermal ecotypes coexist within a nearly genetically identical population of the unicellular marine cyanobacterium Synechococcus.

The extent and ecological significance of intraspecific functional diversity within marine microbial populations is still poorly understood, and it remains unclear if such strain-level microdiversity will affect fitness and persistence in a rapidly changing ocean environment. In this study, we cultured 11 sympatric strains of the ubiquitous marine picocyanobacterium Synechococcus isolated from a Narragansett Bay (RI) phytoplankton community thermal selection experiment. Thermal performance curves revealed selection at cool and warm temperatures had subdivided the initial population into thermotypes with pronounced differences in maximum growth temperatures. Curiously, the genomes of all 11 isolates were almost identical (average nucleotide identities of >99.99%, with >99% of the genome aligning) and no differences in gene content or single nucleotide variants were associated with either cool or warm temperature phenotypes. Despite a very high level of genomic similarity, sequenced epigenomes for two strains showed differences in methylation on genes associated with photosynthesis. These corresponded to measured differences in photophysiology, suggesting a potential pathway for future mechanistic research into thermal microdiversity. Our study demonstrates that present-day marine microbial populations can harbor cryptic but environmentally relevant thermotypes which may increase their resilience to future rising temperatures.

Trade-offs between bycatch and target catches in static versus dynamic fishery closures.

While there have been recent improvements in reducing bycatch in many fisheries, bycatch remains a threat for numerous species around the globe. Static spatial and temporal closures are used in many places as a tool to reduce bycatch. However, their effectiveness in achieving this goal is uncertain, particularly for highly mobile species. We evaluated evidence for the effects of temporal, static, and dynamic area closures on the bycatch and target catch of 15 fisheries around the world. Assuming perfect knowledge of where the catch and bycatch occurs and a closure of 30% of the fishing area, we found that dynamic area closures could reduce bycatch by an average of 57% without sacrificing catch of target species, compared to 16% reductions in bycatch achievable by static closures. The degree of bycatch reduction achievable for a certain quantity of target catch was related to the correlation in space and time between target and bycatch species. If the correlation was high, it was harder to find an area to reduce bycatch without sacrificing catch of target species. If the goal of spatial closures is to reduce bycatch, our results suggest that dynamic management provides substantially better outcomes than classic static marine area closures. The use of dynamic ocean management might be difficult to implement and enforce in many regions. Nevertheless, dynamic approaches will be increasingly valuable as climate change drives species and fisheries into new habitats or extended ranges, altering species-fishery interactions and underscoring the need for more responsive and flexible regulatory mechanisms.

Mitochondrial double-stranded RNA triggers induction of the antiviral DNA deaminase APOBEC3A and nuclear DNA damage.

APOBEC3A is an antiviral DNA deaminase often induced by virus infection. APOBEC3A is also a source of cancer mutation in viral and nonviral tumor types. It is therefore critical to identify factors responsible for APOBEC3A upregulation. Here, we test the hypothesis that leaked mitochondrial (mt) double-stranded (ds)RNA is recognized as foreign nucleic acid, which triggers innate immune signaling, APOBEC3A upregulation, and DNA damage. Knockdown of an enzyme responsible for degrading mtdsRNA, the exoribonuclease polynucleotide phosphorylase, results in mtdsRNA leakage into the cytosol and induction of APOBEC3A expression. APOBEC3A upregulation by cytoplasmic mtdsRNA requires RIG-I, MAVS, and STAT2 and is likely part of a broader type I interferon response. Importantly, although mtdsRNA-induced APOBEC3A appears cytoplasmic by subcellular fractionation experiments, its induction triggers an overt DNA damage response characterized by elevated nuclear γ-H2AX staining. Thus, mtdsRNA dysregulation may induce APOBEC3A and contribute to observed genomic instability and mutation signatures in cancer.

Capmatinib is an effective treatment for MET-fusion driven pediatric high-grade glioma and synergizes with radiotherapy.

BACKGROUND: Pediatric-type diffuse high-grade glioma (pHGG) is the most frequent malignant brain tumor in children and can be subclassified into multiple entities. Fusion genes activating the MET receptor tyrosine kinase often occur in infant-type hemispheric glioma (IHG) but also in other pHGG and are associated with devastating morbidity and mortality. METHODS: To identify new treatment options, we established and characterized two novel orthotopic mouse models harboring distinct MET fusions. These included an immunocompetent, murine allograft model and patient-derived orthotopic xenografts (PDOX) from a MET-fusion IHG patient who failed conventional therapy and targeted therapy with cabozantinib. With these models, we analyzed the efficacy and pharmacokinetic properties of three MET inhibitors, capmatinib, crizotinib and cabozantinib, alone or combined with radiotherapy. RESULTS: Capmatinib showed superior brain pharmacokinetic properties and greater in vitro and in vivo efficacy than cabozantinib or crizotinib in both models. The PDOX models recapitulated the poor efficacy of cabozantinib experienced by the patient. In contrast, capmatinib extended survival and induced long-term progression-free survival when combined with radiotherapy in two complementary mouse models. Capmatinib treatment increased radiation-induced DNA double-strand breaks and delayed their repair. CONCLUSIONS: We comprehensively investigated the combination of MET inhibition and radiotherapy as a novel treatment option for MET-driven pHGG. Our seminal preclinical data package includes pharmacokinetic characterization, recapitulation of clinical outcomes, coinciding results from multiple complementing in vivo studies, and insights into molecular mechanism underlying increased efficacy. Taken together, we demonstrate the groundbreaking efficacy of capmatinib and radiation as a highly promising concept for future clinical trials.

Oncohistones and disrupted development in pediatric-type diffuse high-grade glioma.

Recurrent, clonal somatic mutations in histone H3 are molecular hallmarks that distinguish the genetic mechanisms underlying pediatric and adult high-grade glioma (HGG), define biological subgroups of diffuse glioma, and highlight connections between cancer, development, and epigenetics. These oncogenic mutations in histones, now termed "oncohistones", were discovered through genome-wide sequencing of pediatric diffuse high-grade glioma. Up to 80% of diffuse midline glioma (DMG), including diffuse intrinsic pontine glioma (DIPG) and diffuse glioma arising in other midline structures including thalamus or spinal cord, contain histone H3 lysine 27 to methionine (K27M) mutations or, rarely, other alterations that result in a depletion of H3K27me3 similar to that induced by H3 K27M. This subgroup of glioma is now defined as diffuse midline glioma, H3K27-altered. In contrast, histone H3 Gly34Arg/Val (G34R/V) mutations are found in approximately 30% of diffuse glioma arising in the cerebral hemispheres of older adolescents and young adults, now classified as diffuse hemispheric glioma, H3G34-mutant. Here, we review how oncohistones modulate the epigenome and discuss the mutational landscape and invasive properties of histone mutant HGGs of childhood. The distinct mechanisms through which oncohistones and other mutations rewrite the epigenetic landscape provide novel insights into development and tumorigenesis and may present unique vulnerabilities for pHGGs. Lessons learned from these rare incurable brain tumors of childhood may have broader implications for cancer, as additional high- and low-frequency oncohistone mutations have been identified in other tumor types.

A retrospective cohort study of socioeconomic deprivation and post-liver transplant survival in adults.

The Area Deprivation Index is a granular measure of neighborhood socioeconomic deprivation. The relationship between neighborhood socioeconomic deprivation and recipient survival following liver transplantation (LT) is unclear. To investigate this, the authors performed a retrospective cohort study of adults who underwent LT at the University of Washington Medical Center from January 1, 2004, to December 31, 2020. The primary exposure was a degree of neighborhood socioeconomic deprivation as determined by the Area Deprivation Index score. The primary outcome was posttransplant recipient mortality. In a multivariable Cox proportional analysis, LT recipients from high-deprivation areas had a higher risk of mortality than those from low-deprivation areas (HR: 1.81; 95% CI: 1.03-3.18, p =0.04). Notably, the difference in mortality between area deprivation groups did not become statistically significant until 6 years after transplantation. In summary, LT recipients experiencing high socioeconomic deprivation tended to have worse posttransplant survival. Further research is needed to elucidate the extent to which neighborhood socioeconomic deprivation contributes to mortality risk and identify effective measures to improve survival in more socioeconomically disadvantaged LT recipients.

Engineering of Rieske dioxygenase variants with improved cis-dihydroxylation activity for benzoates.

Rieske dioxygenases have a long history of being utilized as green chemical tools in the organic synthesis of high-value compounds, due to their capacity to perform the cis-dihydroxylation of a wide variety of aromatic substrates. The practical utility of these enzymes has been hampered however by steric and electronic constraints on their substrate scopes, resulting in limited reactivity with certain substrate classes. Herein, we report the engineering of a widely used member of the Rieske dioxygenase class of enzymes, toluene dioxygenase (TDO), to produce improved variants with greatly increased activity for the cis-dihydroxylation of benzoates. Through rational mutagenesis and screening, TDO variants with substantially improved activity over the wild-type enzyme were identified. Homology modeling, docking studies, molecular dynamics simulations, and substrate tunnel analysis were applied in an effort to elucidate how the identified mutations resulted in improved activity for this polar substrate class. These analyses revealed modification of the substrate tunnel as the likely cause of the improved activity observed with the best-performing enzyme variants.

Perioperative daptomycin for prophylaxis of vancomycin-resistant Enterococcus infection in colonized liver transplant recipients.

BACKGROUND: Infection with vancomycin-resistant Enterococcus (VRE) in liver transplant recipients (LTR) has been associated with extended hospital stays, increased readmission rates, graft failure, and death. A tailored perioperative surgical prophylaxis regimen targeting VRE may reduce postoperative infections in VRE-colonized patients. This study investigated the outcomes of perioperative daptomycin in this patient population. METHODS: This retrospective, single-center cohort study included LTR ≥ 18 years old who were VRE-colonized from June 2018 to November 2022. VRE colonization was identified by a VRE rectal swab screen or a positive VRE culture prior to transplant. Two groups were analyzed: daptomycin versus no daptomycin. All LTR received perioperative piperacillin-tazobactam for 24 h. If VRE-colonized, one dose of daptomycin (6 mg/kg) was given pre- and postoperatively. Demographics, clinical characteristics, risk factors for VRE infection, and daptomycin dose were collected. The primary outcome was VRE infection at 14 days and 90 days post-transplant. RESULTS: There were 36 VRE-colonized LTR; 19 received daptomycin and 17 did not. Baseline characteristics and risk factors for VRE infection were similar between groups. More VRE infections occurred in the no daptomycin group within 14 days post-transplant (24% vs. 0%, p = .04), but at 90 days posttransplant there was no significant difference (29% vs. 16%, p = .43). The average daptomycin dose was 7.1 mg/kg. CONCLUSION: Perioperative daptomycin reduced the rate of VRE infections in VRE-colonized LTR within 14 days posttransplant but not at 90 days. Future studies should evaluate if higher doses and/or longer duration of perioperative daptomycin can reduce VRE infections beyond 14 days post-transplant.

Erythema dyschromicum perstans-like eruptions induced by epidermal growth factor receptor inhibitors in patients with lung cancer.

INTRODUCTION: Cutaneous adverse reactions to epidermal growth factor receptor inhibitors (EGFRi) are some of the most common side effects that patients experience. However, cutaneous adverse reactions that cause dyspigmentation in patients have been rarely reported. Erythema dyschromicum perstans (EDP) is a rare pigmentary condition that causes ashy-grey hyperpigmented macules and patches, with a few cases reported from EGFRi in the literature. The disfiguration caused by this condition may negatively impact patients' quality of life. Our study aimed to describe the clinical characteristics of EDP induced by EGFRi to better recognize and manage the condition. METHODS: We conducted a multicenter retrospective review at three academic institutions to identify patients with EDP induced by EGFRi from 2017 to 2023 and included sixteen patients in our study. RESULTS: The median age of patients was 66 years old, with 63% female and 37% male (Table 1). The majority of our patients were Asian (88%). All patients had non-small cell lung cancer and most patients received osimertinib. Median time to EDP was 6 months. The most common areas of distribution were the head/neck region, lower extremities, and upper extremities. Various topical ointments were trialed; however, approximately less than half had improvement in their disease and most patients had persistent EDP with no resolution. All patients desired treatment except one with EDP on the tongue, and there was no cancer treatment discontinuation or interruption due to EDP. Table 1 Patient demographics and clinical characteristics of 16 patients with EDP induced by EGFRi Case no Demographics: age, race, and sex Fitzpatrick skin type Cancer type EGFR therapy Concomitant photosensitive drug(s) Time to EDP (months) Clinical features Distribution Symptoms Treatments and clinical course EDP status from most recent follow up 1 47 y/o Asian male III Stage IV NSCLC Erlotinib None Unknown Brown-blue-gray hyperpigmented patches Bilateral shins Left thigh Xerosis Pruritus Triamcinolone 0.1% ointment for 4 months, improvement of blue discoloration Tacrolimus 0.1% BID for 9 months, improvement but no resolution Ongoing 2 62 y/o Asian female IV Stage IV NSCLC Osimertinib None 4 Gray-brown hyperpigmented patches Bilateral arms Back Forehead Neck Right shin None Tacrolimus 0.1% ointment for 1 year with minor improvement Ongoing 3 69 y/o Asian female IV Stage IV NSCLC Osimertinib None 4 Gray-brown macules and patches Chest Face Forehead Bilateral legs None Tacrolimus 0.1% ointment for 10 months, no improvement Ongoing 4 79 y/o White male II Stage IV NSCLC Osimertinib None 15 Mottled grey-blue hyperpigmented patches and plaques with mild scaling Bilateral arms Back Forehead Neck None Photoprotection, no improvement Ongoing 5 69 y/o Asian female III Stage IV NSCLC Osimertinib Ibuprofen 4 Blue-grey hyperpigmented macules and patches Abdomen Bilateral arms None Tacrolimus 0.1% ointment for 7 months, no improvement Ongoing 6 65 y/o Asian male III Stage IV NSCLC Osimertinib None 20 Hyperpigmented blue gray macules and patches Helix Bilateral shins None Photoprotection, no improvement Ongoing 7 66 y/o Asian female IV Stage IV NSCLC Erlotinib TMP-SMX 6 Ashy grey-brown thin plaques Back Forehead None 2.5% hydrocortisone ointment for 8 months, resolved Resolved 8 82 y/o Asian male III Stage III NSCLC Erlotinib Simvastatin 20 Ash-grey hyperpigmented patches Dorsal feet Forehead Scalp None Photoprotection Ongoing 9 57 y/o Asian female III Stage II NSCLC Erlotinib None 1 Bue-grey discoloration Tongue None No intervention Ongoing 10 51 y/o Asian female III Stage IV NSCLC Osimertinib None 9 Blue-grey hyperpigmented macules and patches Bilateral arms Axillae Groin Neck Trunk None 2.5% hydrocortisone ointment, triamcinolone 0.1% ointment, photoprotection with mild improvement Ongoing 11 67 y/o Asian male III Stage IV NSCLC Osimertinib None 7 Gray-blue macules and patches with mild background erythema and scaling Bilateral arms Ears Face Bilateral shins None Triamcinolone 0.1% ointment, protection for 6 months with mild improvement Ongoing 12 75 y/o Asian female IV Stage III NSCLC Osimertinib TMP-SMX 3 Gray-blue hyperpigmented patches Bilateral arms Abdomen Back Face Bilateral shins Pruritus Triamcinolone 0.1% and betamethasone 0.01% with relief of pruritus, lesions unchanged Triluma cream 6 months, mild improvement Ongoing 13 42 y/o Asian male IV Stage IV NSCLC Afatinib TMP-SMX 24 Grey-brown hyperpigmented patches Back Face None Hydroquinone 4% cream for 2 years with mild improvement Ongoing 14 74 y/o White female III Stage II NSCLC Osimertinib Atorvastatin 4 Grey-brown hyperpigmented patches Bilateral legs Trunk None Photoprotection Ongoing 15 64 y/o Asian female IV Stage IV NSCLC Osimertinib None 3 Gray-brown hyperpigmentation Abdomen Bilateral arms Back Bilateral legs Pruritus Triamcinolone 0.1% cream; No change, minimal concern to patient Ongoing 16 52 y/o Asian female IV Stage IV NSCLC Osimertinib None 42 Gray hyperpigmented patches with digitate shape Abdomen Bilateral flanks None Triamcinolone 0.1% cream Ongoing NSCLC, non-small cell lung cancer, TMP-SMX, Trimethoprim/Sulfamethoxazole CONCLUSIONS: We highlight the largest case series describing EDP from EGFR inhibitors, which mostly affected Asian patients with lung malignancy and on EGFR tyrosine kinase inhibitors. Clinicians should be able to recognize this condition in their patients and assess how it is affecting their quality of life, and refer to dermatology to help with management.

HELB Is a Feedback Inhibitor of DNA End Resection.

DNA double-strand break repair by homologous recombination is initiated by the formation of 3' single-stranded DNA (ssDNA) overhangs by a process termed end resection. Although much focus has been given to the decision to initiate resection, little is known of the mechanisms that regulate the ongoing formation of ssDNA tails. Here we report that DNA helicase B (HELB) underpins a feedback inhibition mechanism that curtails resection. HELB is recruited to ssDNA by interacting with RPA and uses its 5'-3' ssDNA translocase activity to inhibit EXO1 and BLM-DNA2, the nucleases catalyzing resection. HELB acts independently of 53BP1 and is exported from the nucleus as cells approach S phase, concomitant with the upregulation of resection. Consistent with its role as a resection antagonist, loss of HELB results in PARP inhibitor resistance in BRCA1-deficient tumor cells. We conclude that mammalian DNA end resection triggers its own inhibition via the recruitment of HELB.

Epigenetics to clinicopathological features: a bibliometric analysis of H3 G34-mutant diffuse hemispheric glioma literature.

PURPOSE: Pediatric-type diffuse high-grade gliomas are the leading cause of cancer-related morbidity and mortality in children. More than 30% of diffuse hemispheric gliomas (DHG) in adolescents harbor histone H3 G34 mutations and are recognized by the World Health Organization as a distinct tumor entity. By reporting bibliometric characteristics of the most cited publications on H3 G34-mutant DHG (H3 G34 DHG), we provide an overview of emerging literature and speculate where future research efforts may lead. METHODS: One hundred fourteen publications discussing H3 G34 DHG were identified, categorized as basic science (BSc), clinical (CL), or review (R), and ranked by citation number. Various bibliometric parameters were summarized, and a comparison between article types was performed. RESULTS: Articles within this study represent principal investigators from 15 countries and were published across 63 journals between 2012 and 2024, with 36.84% of articles originating in the United States. Overall median values were as follows: citation count, 20 (range, 0-2591), number of authors, 9 (range, 2-78), and year of publication, 2020 (range, 2012-2024). Among the top ten most cited articles, BSc articles accounted for all ten reports. Compared to CL and R articles, BSc articles were published in journals with higher impact factors. CONCLUSION: We establish variability in bibliometric parameters for the most cited publications on H3 G34 DHG. Our findings demonstrate a paucity of high-impact and highly cited CL reports and acknowledge an unmet need to intersect basic mechanism with clinical data to inform novel therapeutic approaches.

Eccentricity forcing of East Asian monsoonal systems over the past 3 million years.

The East Asian summer monsoon and the precipitation it brings are relevant for millions of people. Because of the monsoon's importance, there has been a substantial amount of work attempting to describe the driving mechanisms behind its past variability. However, discrepancies exist, with speleothem-based East Asian monsoon reconstructions differing from those based on loess records from the Chinese Loess Plateau during the late Quaternary. The periodicity of wet and dry phases experienced by desert areas that lie on the periphery of the East Asian monsoon's influence offer another independent view of monsoonal variability. Here, we provide environmental records based on magnetic parameters for the last 3 million years from the Tengger Desert, China, one such marginal arid region. Our results reveal wet-dry cycles at a dominant frequency of 405 kiloyears, with drier intervals corresponding to eccentricity minima. These findings are consistent with previous reconstructions of East Asian summer and North African summer monsoon precipitation variability. Our records emphasize the dominant role of eccentricity in forcing East Asian monsoonal precipitation as well as monsoonal-derived environmental fluctuations experienced in peripheral desert areas. These results challenge the traditional view that high-latitude ice sheets are the primary driver of East Asian monsoon precipitation during the Quaternary based on Chinese loess records.

Structure of autoinhibited Akt1 reveals mechanism of PIP3-mediated activation.

The protein kinase Akt is one of the primary effectors of growth factor signaling in the cell. Akt responds specifically to the lipid second messengers phosphatidylinositol-3,4,5-trisphosphate [PI(3,4,5)P3] and phosphatidylinositol-3,4-bisphosphate [PI(3,4)P2] via its PH domain, leading to phosphorylation of its activation loop and the hydrophobic motif of its kinase domain, which are critical for activity. We have now determined the crystal structure of Akt1, revealing an autoinhibitory interface between the PH and kinase domains that is often mutated in cancer and overgrowth disorders. This interface persists even after stoichiometric phosphorylation, thereby restricting maximum Akt activity to PI(3,4,5)P3- or PI(3,4)P2-containing membranes. Our work helps to resolve the roles of lipids and phosphorylation in the activation of Akt and has wide implications for the spatiotemporal control of Akt and potentially lipid-activated kinase signaling in general.

Analysis of reasons for failure to return to sport after Latarjet surgery: a systematic review.

BACKGROUND: The purpose of this study was to perform a systematic review of the literature to identify Shoulder Instability Return to Sport after Injury (SIRSI) scores in athletes who underwent open Latarjet surgery, determine the reasons why athletes failed to return to play (RTP) after Latarjet surgery, and compare SIRSI scores of those who did vs. did not RTP. METHODS: According to PRISMA guidelines, the PubMed, SportDiscus, and Ovid MEDLINE databases were queried to identify studies evaluating return to sport after Latarjet surgery. Study quality was assessed using the MINORS criteria. Studies were included if RTP after Latarjet surgery and a psychological factor were evaluated, with potential psychological factors including readiness to RTP and reasons for failure to RTP. RESULTS: Fourteen studies, 10 of level III evidence and 4 of level IV evidence, with 1034 patients were included. A total of 978 athletes were eligible to RTP. Of these, 792 (79%) successfully returned to play and 447 (56.4%) returned to play at their previous level of play. Mean RTP time was 6.2 months. Postoperative SIRSI scores averaged 71.2 ± 8.8 at a mean of 21 months' follow-up. Postoperative SIRSI scores for those able to RTP was 73.2, whereas athletes unable to RTP scored an average of 41.5. Mean postoperative SIRSI scores for those in contact sports was 71.4, whereas those in noncontact sports was 86.5. There were 31 athletes with a documented reason why they did not RTP, with postoperative shoulder injury being the most common reason (54.5%). Fear of reinjury and feeling "not psychologically confident" each represented 6.5% of the total. CONCLUSION: Athletes who RTP have higher average SIRSI scores than those who are unable to RTP. Of the athletes who documented why they did not RTP, more than half cited a shoulder injury as their reason for not returning to play, whereas fear of reinjury and lack of psychological readiness were other common reasons.