H. L. Snyder Medical Foundation

Despite viral suppression, many people with HIV (PWH) experience persistent cognitive difficulties. We previously demonstrated that cerebrospinal fluid (CSF) N-acetyl-aspartyl-glutamate (NAAG) was associated with spatial attention and working memory. Here, we report that CSF NAAG also correlates with an inflammatory signature (M-CSF, IL-15, MCP-1, sCD40L, IL-18, MMP-9) that relates to spatial attention and working memory. These results suggest that CSF NAAG may serve as an immunomodulatory biomarker relevant to cognition in PWH.

Streptomyces gilvosporeus F607 governs natamycin biosynthesis via a modular polyketide synthase (PKS) system, which includes an atypical loading module (SgnS0) featuring unique functional domains: a carboxylic acid-CoA ligase (CoL), an acyl carrier protein (ACPL1), a ketosynthase (KS) domain, an acyltransferase (AT) domain, and an ACPL2 configuration (CoL-ACPL1-KSS-AT-ACPL2). Here, we resolve the catalytic logic of this initiation module and leverage its architectural features for the efficient synthesis of natamycin. An sgnS0 knockout strain S. gilvosporeus F607/ΔsgnS0 produces undetectable natamycin, suggesting that sgnS0 is indispensable for natamycin biosynthesis. We employed a combination of site-directed mutagenesis targeting the KSS and AT domains of SgnS0, demonstrating that the AT domain specifically loads a malonyl group onto the ACP domain, followed by KSS-mediated decarboxylation to generate acetyl-ACP intermediates. The SgnS0 enzyme presented a transacylation catalytic efficiency (kcat/Km = 0.59 ± 0.02 μM–1·min–1), while the CoL-deletion mutant SgnS0-AKAA showed a 30.5% reduction in transacylation catalytic efficiency (0.41 ± 0.01 μM–1·min–1). This indicates that, nonessential for core catalysis, the CoL domain acts as a structural modulator optimizing catalytic efficiency. Additionally, in vivo mutagenesis and in vitro enzymatic analysis identified both ACPL1 and ACPL2 as essential for biosynthetic function with dual inactivation abolishing natamycin production. Guided by these findings, we engineered the SgnS0 module incorporating tandem ACP architectures in vitro and in S. gilvosporeus F607. Systematic insertion of one or two ACPL2 copies downstream of the native ACPL2 domain of SgnS0 in vitro revealed that a three-ACP construct significantly enhanced the transacylation catalytic efficiency, achieving a 2.64-fold increase in kcat/Km. Furthermore, dual ACPL2 insertions occurring in S. gilvosporeus F607 yielded a natamycin titer of 9.5 g L–1─representing a 160% improvement over the wild-type strain S. gilvosporeus F607. These findings provide a mechanistic basis for the ACP domain function in modular PKSs and highlight tandem ACP engineering as a powerful strategy to boost secondary metabolite production.

SynGAP is a potent regulator of biochemical signaling in neurons and plays critical roles in neuronal function. It was first identified in 1998, and has since been extensively characterized as a mediator of synaptic plasticity. Because of its involvement in synaptic plasticity, SynGAP has emerged as a critical protein for normal cognitive function. In recent years, mutations in the SYNGAP1 gene have been shown to cause intellectual disability in humans and have been linked to other neurodevelopmental disorders, such as autism spectrum disorders and schizophrenia. While the structure and biochemical function of SynGAP have been well characterized, a unified understanding of the various roles of SynGAP at the synapse and its contributions to neuronal function remains to be achieved. In this review, we summarize and discuss the current understanding of the multifactorial role of SynGAP in regulating neuronal function gathered over the last two decades.

Neglected tropical disease such as urinary schistosomiasis have had devastating effects on the renal system, which has been extensively studied but its effect on the liver and liver proteins still remain largely unknown despite schistosoma haematobium spending a major part of its lifecycle in the veins surrounding the liver and hepatic portal system. In this experiment, we assessed the prevalence and effect of schistosoma haematobium on the human liver among the dwellers of Papa village, Osun state Nigeria. We utilize 60 test samples consisting mainly of the dwellers from Papa village and 60 control samples collected from Osogbo urban city in Osun state Nigeria, which were screened for schistosoma haematobium eggs to establish prevalence of the parasite. Also, both the test sample and control sample were subjected to coagulation and biochemical analysis to ascertain the severity of schistosoma haematobium on the liver. The result showed the presence of an average of 440 eggs of schistosoma haematobium per 10 mls in the test population and no schistosoma haematobium egg in the control population. There was a significant difference in the value of total protein, globulin, albumin, erythrocyte sedimentation rate, prothrombin time and partial thromboplastin time with kaolin when the test population was compared to the control population. These blood parameters were indicative of the severity of schistosoma haematobium infection on the liver. Combination strategies such as Intensive health education, vector control and early treatment should be recommended in combating the presence of schistosoma haematobium and prevent egg migration in visceral organs of the body, including the liver.

Inositol hexakisphosphate kinases (IP6Ks) regulate various biological processes. Among pyrophosphates generated by IP6Ks, diphosphoinositol pentakisphosphate (IP7), and bis-diphosphoinositol tetrakisphosphate have been extensively characterized. IP7 is produced in mammals by a family of inositol hexakisphosphate kinases, IP6K1, IP6K2, and IP6K3, which have distinct biological functions. We report that IP6K2 binds protein 4.1.N with high affinity and specificity. Nuclear translocation of 4.1N, which is required for its principal functions, is dependent on IP6K2. Both of these proteins are highly expressed in granule cells of the cerebellum where their interaction regulates Purkinje cell morphology and cerebellar synapses. The deletion of IP6K2 in male/female mice elicits substantial defects in synaptic influences of granule cells upon Purkinje cells as well as notable impairment of locomotor function. Moreover, the disruption of IP6K2-4.1N interactions impairs cell viability. Thus, IP6K2 and its interaction with 4.1N appear to be major determinants of cerebellar disposition and psychomotor behavior.SIGNIFICANCE STATEMENT Inositol phosphates are produced by a family of inositol hexakisphosphate kinases (IP6Ks)-IP6K1, IP6K2, and IP6K3. Of these, the physiological roles of IP6K2 in the brain have been least characterized. In the present study, we report that IP6K2 binds selectively to the neuronal protein 4.1N. Both of these proteins are highly expressed in granule cells of the cerebellum. Using IP6K2 knock-out (KO) mice, we establish that IP6K2-4.1N interactions in granule cells regulate Purkinje cell morphology, the viability of cerebellar neurons, and psychomotor behavior.

Abstract A key component to overcoming the reproducibility crisis in biomedical research is the development of readily available, rigorously validated and renewable protein affinity reagents. As part of the NIH Protein Capture Reagents Program (PCRP), we have generated a collection of 1406 highly validated, immunoprecipitation (IP) and/or immunoblotting (IB) grade, mouse monoclonal antibodies (mAbs) to 736 human transcription factors. We used HuProt™ human protein microarrays to identify mAbs that recognize their cognate targets with exceptional specificity. Using an integrated production and validation pipeline, we validated these mAbs in multiple experimental applications, and have distributed them to the Developmental Studies Hybridoma Bank (DSHB) and several commercial suppliers. This study allowed us to perform a meta-analysis that identified critical variables that contribute to the generation of high quality mAbs. We find that using full-length antigens for immunization, in combination with HuProt™ analysis, provides the highest overall success rates. The efficiencies built into this pipeline ensure substantial cost savings compared to current standard practices.

Introduction: Invasive measurement of cardiac power (CP) and stroke work (SW) during exercise are robust indices of cardiac function and relate to syndrome severity and prognosis in heart failure patients with preserved (HFpEF) or reduced (HFrEF) ejection fraction. Because invasive measurement via catheterization laboratories are not always readily available, non-invasive cardiopulmonary exercise testing to estimate cardiac function is routinely performed in the clinical evaluation of HFpEF and HFrEF. However, it is unknown how VO 2 relates with CP and SW in HFpEF vs HFrEF. We compared relationships between CP and SW with VO 2 at rest and peak exercise in HFpEF vs HFrEF. Methods: 30 HFpEF and 32 HFrEF (EF: 62±2 vs 22±1%; males: 17 vs 30; age: 70±2 vs 55±2 yrs; BMI: 34±1 vs 28±1 kg/m 2 ; wt: 98±4 vs 86±3 kg (all p<0.05)) participated in exercise testing during right heart catheterization. Oxygen consumption (VO 2 ) was measured continuously from rest to peak work. Invasive measures at rest and peak work included mean radial arterial pressure (MAP), right atrial pressure (RAP), and pulmonary capillary wedge pressure (PCWP). We calculated CP=(MAP–RAP) x Q I x 2.22х10 -3 and SW=(MAP–PCWP) x SV I x 0.133. Results: At rest, R 2 between VO 2 and CP or SW were not different between HFpEF (CP=0.41, SW=0.30) and HFrEF (CP=0.39, SW=0.15). Slopes did not differ significantly between HFpEF (CP=0.13, SW=0.01) and HFrEF (CP=0.16, SW=0.01) for regressions between VO 2 and CP or SW; but, fitted intercepts of the regression showed significantly higher intercepts in HFrEF (CP=0.89, SW=1.16) vs HFpEF (CP=0.05, SW=0.27) for VO 2 vs CP and SW, respectively. At peak exercise, R 2 between VO 2 and CP or SW were not different between HFpEF (CP=0.48, SW=0.64) and HFrEF (CP=0.70, SW=0.67). Slopes did not differ between HFpEF (CP=0.18, SW=0.02) and HFrEF (CP=0.15, SW=0.02) for regressions between VO 2 and CP or SW, whereas the fitted intercepts the slope of the regression were significantly higher in HFrEF (CP=5.1, SW=4.4) vs HFpEF (CP=3.2, SW=2.0) for VO 2 vs CP and SW, respectively. Conclusion: Our data suggest that despite lower VO 2 relative to CP and SW in HFpEF, both the strength of relationship and rate of increase in VO 2 relative to CP and SW are similar between HFpEF and HFrEF at rest and peak exercise.

We report a 12-week outcome study in which nine persons with long-term chronic aphasia received individual and group speech-language teletherapy services, and also used on-line language exercises to practice from home between therapy sessions. Participants were assessed at study initiation and completion using the Western Aphasia Battery, a portion of the Communicative Effectiveness Index, ASHA National Outcome Measurement System, and RIC Communication Confidence Rating Scale for Aphasia; additionally participants were polled regarding satisfaction at discharge. Pretreatment and post-treatment means were calculated and compared, and matched t-tests were used to determine significance of improvements following treatment, with patterns of independent on-line activity analyzed. Analysis of scores shows that means improved on most measures following treatment, generally significantly: the WAB AQ improved +3.5 (p = .057); the CETI Overall (of items administered) — +17.8 (p = .01), and CCRSA Overall — + 10.4 (p = .0004). Independent work increased with time, and user satisfaction following participation was high.

The inositol pyrophosphates, molecular messengers containing an energetic pyrophosphate bond, impact a wide range of biologic processes. They are generated primarily by a family of three inositol hexakisphosphate kinases (IP6Ks), the principal product of which is diphosphoinositol pentakisphosphate (IP7). We report that IP6K2, via IP7 synthesis, is a major mediator of cancer cell migration and tumor metastasis in cell culture and in intact mice. IP6K2 acts by enhancing cell-matrix adhesion and decreasing cell-cell adhesion. This action is mediated by IP7-elicited nuclear sequestration and inactivation of the tumor suppressor liver kinase B1 (LKB1). Accordingly, inhibitors of IP6K2 offer promise in cancer therapy.