The rockefeller university

Suicide is a major public health concern, and the number of deaths by suicide has been increasing in recent years in the US. There are various biological risk factors for suicide, but causal molecular mechanisms remain unknown, suggesting that investigation of novel mechanisms and integrative approaches are necessary. Transfer (t)RNAs and their modifications, including cytosine methylation (m5C), have received little attention regarding their role in normal or diseased brain function, though they are dynamic mediators of protein synthesis. tRNA regulation is highly interconnected with proteomic and metabolomic outcomes, suggesting that investigating these multiple levels of molecular regulation together may elucidate more information on neural function and suicide risk. In the current study, we used an integrative 'omics' approach to probe tRNA dysregulation, including tRNA expression and tRNA m5C, proteomics, and amino acid metabolomics in prefrontal cortex from 98 subjects who died by suicide during an episode of major depressive disorder (MDD) and neurotypical controls. While no changes were detected in amino acid content, results showed increased tRNAGlyGCC expression in the suicide brain that is not driven by changes in m5C. Proteomics revealed increased expression of proteins with high glycine codon GGC content, demonstrating a strong association between isoacceptor-specific tRNA expression and proteomic outcomes in the suicide brain, which is in line with previous work linking tRNAGly with alterations in glycine-rich proteins in a translational rodent model of depression. Further, we confirmed using a rodent model that tRNAGlyGCC overexpression was sufficient to increase the expression of proteins with high glycine codon GGC content that were upregulated in the suicide brain. By characterizing the effects of MDD-suicide in human PFC tissue, we now begin to elucidate a novel molecular signature with downstream consequences for psychiatric outcomes.

Although cell-fate specification is generally attributed to transcriptional regulation, emerging data also indicate a role for molecules linked with intermediary metabolism. For example, alpha-ketoglutarate (alpha KG), which fuels energy production and biosynthetic pathways in the tricarboxylic acid (TCA) cycle, is also a co-factor for chromatin-modifying enzymes1, 2-3. Nevertheless, whether TCA-cycle metabolites regulate cell fate during tissue homeostasis and regeneration remains unclear. Here we show that TCA-cycle enzymes are expressed in the intestine in a heterogeneous manner, with components of the alpha KG dehydrogenase complex4, 5-6 upregulated in the absorptive lineage and downregulated in the secretory lineage. Using genetically modified mouse models and organoids, we reveal that 2-oxoglutarate dehydrogenase (OGDH), the enzymatic subunit of the alpha KG dehydrogenase complex, has a dual, lineage-specific role. In the absorptive lineage, OGDH is upregulated by HNF4 transcription factors to maintain the bioenergetic and biosynthetic needs of enterocytes. In the secretory lineage, OGDH is downregulated through a process that, when modelled, increases the levels of alpha KG and stimulates the differentiation of secretory cells. Consistent with this, in mouse models of colitis with impaired differentiation and maturation of secretory cells, inhibition of OGDH or supplementation with alpha KG reversed these impairments and promoted tissue healing. Hence, OGDH dependency is lineage-specific, and its regulation helps to direct cell fate, offering insights for targeted therapies in regenerative medicine.

In widefield fluorescence imaging of neurons, out-of-focus and scattered light from the bright cell body often obscures nearby dim fibers and degrades their contrast. Scanning techniques can solve this problem but are limited by reduced imaging speed and increased cost. In this study, stray light in widefield imaging is greatly reduced by modulating the illumination intensity to different structures. An iterative approach is used to identify fibers by real-time image processing and target illumination to fibers by a digital micromirror device add-on to a common widefield microscope. Bright cell bodies are illuminated with minimal light intensity, and in-focus fibers with high light intensity. This procedure minimizes the background and enhances the visibility of fibers while maintaining a fast imaging speed, low photobleaching rate, and low cost. By updating the targeting pattern, illumination is maintained on the structures of interest, even in moving samples. Using this targeted illumination approach, high contrast, optically sectioned imaging of complex neurons is demonstrated in anesthetized C. elegans, ex vivo mouse brain slice, and restrained zebrafish larva, as well as high-speed imaging of dynamic changes in C. elegans.

The human metabolic and excretion profile of zalunfiban, a novel glycoprotein IIb/IIIa inhibitor, was studied in a phase 1 clinical trial.C-14-zalunfiban was administered subcutaneously as a single fixed dose (9.5 mg with 5 mu Ci total radioactivity). Zalunfiban whole blood concentrations were measured using liquid chromatography-mass spectrometry. C-14-zalunfiban and metabolites were measured using liquid scintillation counting and accelerator mass spectrometry in whole blood, urine, and faeces. Eight participants were enrolled. Zalunfiban was well-tolerated. Following injection zalunfiban was detectable within 5 minutes and the last measurable concentration was observed within 4 hours. The median T-max was 0.25 hours and mean half-life was 0.96 hours. Zalunfiban accounted for 35.6% of total whole blood radioactivity AUC at 4 hours. The single major identified metabolite was des-gly-zalunfiban (M1), which has <1% of zalunfiban's antiplatelet activity. M1 was the primary urinary metabolite (52.98% of dose) with minor amounts of zalunfiban (1.31%) detected. M1 was also the major metabolite in faeces (2.87%). Total dose recovery reached >90% by 240 hours. Zalunfiban is rapidly metabolised to the nearly inactive M1 metabolite, which is excreted primarily in urine. Renal impairment, therefore, is unlikely to significantly prolong zalunfiban effects and dose adjustment in patients with reduced renal function may not be required.

Rationale: Pretargeted radioimmunotherapy (PRIT), which combines systemic antibody-based targeting with ionizing radiation, is promising for treating liver metastases in patients with colorectal cancer (CRC). Previously, we established a three-step DOTA-PRIT regimen to deliver DOTA radiometal payloads to CRC using an anti-tumor/anti-DOTA bispecific antibody (BsAb) targeting cell surface glycoprotein A33 (GPA33), a tumor antigen target expressed on over 95% of primary and metastatic CRC; a clearing agent; and a monovalent Lu-177 radiohapten called [Lu-177]Lu-ABD. More recently, we developed a bivalent Lu-177 radiohapten called [Lu-177]Lu-Gemini to enhance tumor uptake and radiohapten retention. Here, we aimed to compare the efficacy and safety of bivalent vs. monovalent three-step DOTA-PRIT regimens in orthotopic CRC liver metastasis models, to mimic a clinical path forward. Methods: We established two orthotopic CRC liver metastasis models by inoculating either SW1222-luc (GPA33high) or LoVo (GPA33low) human CRC cells in athymic nude mice under ultrasonographic guidance. Tumor targeting efficacy and dosimetry of the radiohaptens were compared using ex vivo biodistribution studies, SPECT/CT, and quantitative autoradiography. We also performed a DOTA-PRIT experiment to compare the efficacy and safety profiles of bivalent (single-cycle [Lu-177]Lu-Gemini, 48 h pretargeting interval) vs. monovalent (multicycle [Lu-177]Lu-ABD, 24 h pretargeting interval) three-step DOTA-PRIT regimens, each designed to deliver comparable total radiation doses to tumors (around 50 Gy). Results: Both radiohaptens demonstrated efficient SW1222-luc tumor targeting, with [Lu-177]Lu-Gemini showing superior targeting and tumor activity retention compared with [Lu-177]Lu-ABD. In LoVo tumors, [Lu-177]Lu-Gemini showed superior targeting, while [177Lu]Lu-ABD showed negligible targeting. Dosimetry estimates revealed higher SW1222-luc tumor mean absorbed doses for [Lu-177]Lu-Gemini (119.88 cGy/MBq, 48 h pretargeting interval) compared with [Lu-177]Lu-ABD (32.88 cGy/MBq, 24 h pretargeting interval), with more favorable blood and kidney therapeutic indices (50 and 9 for [Lu-177]Lu-Gemini, and 15 and 5 for [Lu-177]Lu-ABD, respectively). In the DOTA-PRIT experiment, both monovalent (injected activity: 3 x 44.4 MBq, 133.2 MBq total) and bivalent (injected activity: 44.4 MBq total) radiohapten regimens increased the median survival of treated mice compared with controls: 71 days for [Lu-177]Lu-ABD-treated mice, 81 days for [Lu-177]Lu-Gemini-treated mice, and 18 days for controls, without a statistical difference between treatment groups. Treatments were well tolerated, without significant weight loss or hematologic changes. Radiation-induced injuries were not identified histologically in the kidneys or bone marrow of mice submitted for necropsy. Conclusions: Our study demonstrates the exceptional benefit of a multivalent radiohapten strategy when treating an advanced model of CRC liver metastasis. Three-step GPA33 DOTA-PRIT with Lu-177-Gemini demonstrated that multivalency 1) improves PRIT therapeutic indices for blood and kidney and 2) has the potential to greatly reduce the administered activity without compromising the efficiency of the PRIT platform in clinically relevant models of target-rich and target-poor metastatic CRC.

IntroductionBiologic drug survival in psoriasis is variable. While clinical factors such as obesity and comorbidities contribute to early discontinuation, genetic predictors are less defined. The ZMIZ1/TGF-beta/STAT axis regulates immune-metabolic responses and represents a promising pharmacogenetic target.MethodsWe retrospectively analyzed 875 biologic treatment courses from 312 patients with moderate-to-severe psoriasis (NCT07041112). A pathway-based genetic score was derived from seven single nucleotide polymorphisms (SNPs) in the ZMIZ1/TGF-beta/STAT axis and dichotomized at the median. The primary outcome was time to biologic discontinuation, assessed with Kaplan-Meier curves and Cox proportional hazards models adjusted for demographic, clinical, and inflammatory covariates.ResultsPatients with a high genetic score had significantly longer drug survival (hazard ratio [HR] = 0.74; 95% confidence interval [CI]: 0.62-0.89; p = 0.0015), despite elevated baseline tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-15, and leptin. This indicates that genetic background simultaneously conditioned immune-metabolic activation and treatment persistence. Predictive value was strongest for anti-IL12/23 agents (HR = 0.44; 95% CI: 0.26-0.75; p = 0.002) and anti-TNF therapies (HR = 0.79; 95% CI: 0.62-0.99; p = 0.045), but absent for anti-IL17/IL-23 agents after adjustment. None of the circulating biomarkers independently predicted survival.ConclusionA functional genetic score in the ZMIZ1/TGF-beta/STAT pathway independently predicted long-term biologic persistence in psoriasis, particularly with anti-TNF and anti-IL12/23 therapies. Its association with immune-metabolic activation suggests that genetic background shapes both inflammatory status and treatment durability. Incorporating such profiling into predictive algorithms may improve treatment personalization and biologic retention.Trial RegistrationTrial Registration NCT07041112.

In mammalian cells, gene copy number is controlled to maintain gene expression and genome stability. However, a common molecular feature across cancer types is oncogene amplification, increasing the copy number and expression of tumor-promoting genes and thus promoting cancer progression. For example, in tyrosine kinase inhibitor (TKI)-resistant lung adenocarcinoma (LUAD), oncogene amplification is frequent. Despite the prevalence of oncogene amplification in TKI-resistant tumors, the underlying mechanisms are not fully understood. Here, we find that LUADs exhibit a unique chromatin signature demarcated by strong CTCF and cohesin deposition in drug-naive tumors, which correlates with the boundaries of oncogene amplicons in TKI-resistant LUAD cells. We identify a global chromatin-priming effect during the acquisition of TKI resistance, marked by a dynamic increase of H3K27Ac, cohesin loading and inter-TAD interactions, which occur before the onset of oncogene amplification. Furthermore, we show that METTL7A, reported to localize to the endoplasmic reticulum and inner nuclear membrane, has a chromatin regulatory function by binding to amplified loci and regulating cohesin recruitment and inter-TAD interactions. METTL7A appears to remodel the chromatin landscape prior to large-scale copy number gains. Although METTL7A depletion exerts little phenotypical effects on drug-naive cells, its depletion prevents the formation and maintenance of TKI resistant-clones, showcasing its role as cells become resistant. In summary, we unveil a mechanism required for the acquisition of TKI resistance regulated by an unexpected chromatin function of METTL7A.

Rapid molecular assays guiding treatment of methicillin-resistant Staphylococcus aureus detect SCCmec (Xpert) or the SCCmec-orfX junction (BCID2). Sequence variation in this region can disrupt primer binding, yielding false-negative results. Investigation of a missed bloodstream infection linked escape to a CRISPR-Cas-associated SCCmec variant, leading to identification of 64 variants from 45 patients-2% of 2432 screened. Misdiagnosis was restricted to clonal complex 5, a hospital-associated lineage; 11 of 40 SCCmec/junctions evaded detection by BCID2 or Xpert. Variants had mecA instability and circulated in healthcare settings. Our findings reveal a unique escape mechanism and underscore a threat to diagnostic accuracy. This study identifies methicillin-resistant Staphylococcus aureus clones carrying a CRISPR-Cas-linked SCCmec variant that escapes detection by rapid, point-of-care molecular diagnostics that are routinely used to guide antimicrobial therapy of bloodstream infections; the work has implications for clinical management.