Prediction of large-for-gestational-age infant by fetal growth charts and hemoglobin A1c level in pregnancy complicated by pregestational diabetes.

OBJECTIVES: To compare the ability of three fetal growth charts (Fetal Medicine Foundation (FMF), Hadlock and National Institutes of Child Health and Human Development (NICHD) race/ethnicity-specific) to predict large-for-gestational age (LGA) at birth in pregnant individuals with pregestational diabetes, and to determine whether inclusion of hemoglobin A1c (HbA1c) level improves the predictive performance of the growth charts. METHODS: This was a retrospective analysis of individuals with Type-1 or Type-2 diabetes with a singleton pregnancy that resulted in a non-anomalous live birth. Fetal biometry was performed between 28 + 0 and 36 + 6 weeks of gestation. The primary exposure was suspected LGA, defined as estimated fetal weight ≥ 90th percentile using the Hadlock (Formula C), FMF and NICHD growth charts. The primary outcome was LGA at birth, defined as birth weight ≥ 90th percentile, using 2017 USA natality reference data. The performance of the three growth charts to predict LGA at birth, alone and in combination with HbA1c as a continuous measure, was assessed using the area under the receiver-operating-characteristics curve (AUC), sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: Of 358 assessed pregnant individuals with pregestational diabetes (34% with Type 1 and 66% with Type 2), 147 (41%) had a LGA infant at birth. Suspected LGA was identified in 123 (34.4%) by the Hadlock, 152 (42.5%) by the FMF and 152 (42.5%) by the NICHD growth chart. The FMF growth chart had the highest sensitivity (77% vs 69% (NICHD) vs 63% (Hadlock)) and the Hadlock growth chart had the highest specificity (86% vs 76% (NICHD) and 82% (FMF)) for predicting LGA at birth. The FMF growth chart had a significantly higher AUC (0.79 (95% CI, 0.74-0.84)) for LGA at birth compared with the NICHD (AUC, 0.72 (95% CI, 0.68-0.77); P < 0.001) and Hadlock (AUC, 0.75 (95% CI, 0.70-0.79); P < 0.01) growth charts. Prediction of LGA improved for all three growth charts with the inclusion of HbA1c measurement in comparison to each growth chart alone (P < 0.001 for all); the FMF growth chart remained more predictive of LGA at birth (AUC, 0.85 (95% CI, 0.81-0.90)) compared with the NICHD (AUC, 0.79 (95% CI, 0.73-0.84)) and Hadlock (AUC, 0.81 (95% CI, 0.76-0.86)) growth charts. CONCLUSIONS: The FMF fetal growth chart had the best predictive performance for LGA at birth in comparison with the Hadlock and NICHD race/ethnicity-specific growth charts in pregnant individuals with pregestational diabetes. Inclusion of HbA1c improved further the prediction of LGA for all three charts. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Postmeal optogenetic inhibition of dorsal hippocampal principal neurons increases future intake in a time-dependent manner.

Research involving human participants indicates that memories of recently eaten meals limit how much is eaten during subsequent eating episodes; yet, the brain regions that mediate the inhibitory effects of ingestion-related memory on future intake are largely unknown. We hypothesize that dorsal hippocampal (dHC) neurons, which are critical for episodic memories of personal experiences, mediate the inhibitory effects of ingestion-related memory on future intake. Our research program aimed at testing this hypothesis has been influenced in large part by our mentor James McGaugh and his research on posttraining manipulations. In the present study, we used an activity-guided optogenetic approach to test the prediction that if dHC glutamatergic neurons limit future intake through a process that requires memory consolidation, then inhibition should increase subsequent intake when given soon after the end of a meal but delayed inhibition should have no effect. Viral vectors containing CaMKIIα-eArchT3.0-eYFP and fiber optic probes were placed in the dHC of male Sprague-Dawley rats. Compared to intake on a day when no inhibition was given, postmeal inhibition of dHC glutamatergic neurons given for 10 min after the end of a saccharin meal increased the likelihood that rats would consume a second meal 90 min later and significantly increased the amount of saccharin solution consumed during that next meal when the neurons were no longer inhibited. Importantly, delayed inhibition given 80 min after the end of the saccharin meal did not affect subsequent intake of saccharin. Given that saccharin has minimal postingestive gastric consequences, these effects are not likely due to the timing of interoceptive visceral cues generated by the meal. These data show that dHC glutamatergic neural activity is necessary during the early postprandial period for limiting future intake and suggest that these neurons inhibit future intake by consolidating the memory of the preceding meal.

Combinatorial metabolism drives the naive to primed pluripotent chromatin landscape.

Since epigenetic modifications are a key driver for cellular differentiation, the regulation of these modifications is tightly controlled. Interestingly, recent studies have revealed metabolic regulation for epigenetic modifications in pluripotent cells. As metabolic differences are prominent between naive (pre-implantation) and primed (post-implantation) pluripotent cells, the epigenetic changes regulated by metabolites has become an interesting topic of analysis. In this review we discuss how combinatorial metabolic activities drive the developmental progression through early pluripotent stages.

Folliculin regulates mTORC1/2 and WNT pathways in early human pluripotency.

To reveal how cells exit human pluripotency, we designed a CRISPR-Cas9 screen exploiting the metabolic and epigenetic differences between naïve and primed pluripotent cells. We identify the tumor suppressor, Folliculin(FLCN) as a critical gene required for the exit from human pluripotency. Here we show that FLCN Knock-out (KO) hESCs maintain the naïve pluripotent state but cannot exit the state since the critical transcription factor TFE3 remains active in the nucleus. TFE3 targets up-regulated in FLCN KO exit assay are members of Wnt pathway and ESRRB. Treatment of FLCN KO hESC with a Wnt inhibitor, but not ESRRB/FLCN double mutant, rescues the cells, allowing the exit from the naïve state. Using co-immunoprecipitation and mass spectrometry analysis we identify unique FLCN binding partners. The interactions of FLCN with components of the mTOR pathway (mTORC1 and mTORC2) reveal a mechanism of FLCN function during exit from naïve pluripotency.

Pharmacogenetic neuronal stimulation increases human tau pathology and trans-synaptic spread of tau to distal brain regions in mice.

In Alzheimer's Disease (AD), tau pathology has a spatiotemporally distinct pattern of progressive spread along anatomically connected neural pathways. Extracellular tau in the brain interstitial space increases in response to neuronal activity suggesting that neural activity may also drive pathogenic tau spread. Here we tested the hypothesis that neuronal activity drives human Tau (hTau) release and trans-synaptic spread to neuroanatomically connected regions. We used AAV to overexpress wild type full-length hTau and an excitatory DREADD (Designer Receptors Exclusively Activated by a Designer Drug) in mouse primary hippocampal cultures and determined that excitatory stimulation with the DREADD ligand clozapine N-oxide (CNO) promoted extracellular hTau release. We translated this approach to an in vivo model and used AAV to express hTau and the excitatory DREADD in the ventral hippocampus of wild type mice, P301L hTau-expressing mice, or tau knockout mice. Six to eight weeks following AAV injection, we determined that CNO treatment in DREADD-expressing mice resulted in increased hTau pathology and hTau spread to distal brain regions compared to unstimulated controls (CNO in non-DREADD mice, or vehicle in DREADD mice). The results highlight a potentially disease relevant exacerbation of tau pathology in response to elevated neuronal activity. This model underscores the propensity of non-mutant hTau to undergo neuronal spreading, as seen in AD. The model can translate to other preclinical species and can be used to evaluate modes of tau transmission and test the efficacy of therapeutic approaches that target tau or hyperexcitability.

Edwardsiella ictaluri infection in Pangasius catfish imported from West Bengal into the Southern Caribbean.

In response to a mortality event, seven Pangasius catfish (Pangasianodon hypophthalmus) were submitted to the University of the West Indies, School of Veterinary Medicine, Trinidad and Tobago, for diagnostic evaluation. These fish were part of a consignment that arrived from Kolkata two weeks earlier. Fish presented with perianal haemorrhage and blister-like swellings on the skin which ruptured to leave ulcers. Edwardsiella ictaluri was consistently recovered from the brain and skin. Repetitive sequence-mediated PCR analysis revealed genetic fingerprints consistent with E. ictaluri isolates from farm-raised channel catfish in Mississippi, USA. Plasmid analysis of the case isolates identified two unique plasmids that differ slightly in conformation and content from the pEI1 and pEI2 plasmids described for E. ictaluri from other fish hosts. The case isolates were also PCR negative for several E. ictaluri virulence factors. The biological implications of these genetic differences are unclear and warrant further study. This is the first report and documentation of E. ictaluri infection in Trinidad and Tobago, suggesting the pathogen may have been introduced concurrently with the importation of fish. This report emphasizes the importance of adequate health screenings of imported lots to minimize the threat of introducing E. ictaluri to non-endemic areas.

Comparison of Edwardsiella ictaluri isolates from different hosts and geographic origins.

The intraspecific variability of E. ictaluri isolates from different origins was investigated. Isolates were recovered from farm-raised catfish (Ictalurus punctatus) in Mississippi, USA, tilapia (Oreochromis niloticus) cultured in the Western Hemisphere and zebrafish (Danio rerio) propagated in Florida, USA. These isolates were phenotypically homologous and antimicrobial profiles were largely similar. Genetically, isolates possessed differences that could be exploited by repetitive-sequence-mediated PCR and gyrB sequence, which identified three distinct E. ictaluri genotypes: one associated with catfish, one from tilapia and a third from zebrafish. Plasmid profiles were also group specific and correlated with rep-PCR and gyrB sequences. The catfish isolates possessed profiles typical of those described for E. ictaluri isolates; however, plasmids from the zebrafish and tilapia isolates differed in both composition and arrangement. Furthermore, some zebrafish and tilapia isolates were PCR negative for several E. ictaluri virulence factors. Isolates were serologically heterogenous, as serum from a channel catfish exposed to a catfish isolate had reduced antibody activity to tilapia and zebrafish isolates. This work identifies three genetically distinct strains of E. ictaluri from different origins using rep-PCR, 16S, gyrB and plasmid sequencing, in addition to antimicrobial and serological profiling.

Transcriptional repression of IFNß1 by ATF2 confers melanoma resistance to therapy.

The resistance of melanoma to current treatment modalities represents a major obstacle for durable therapeutic response, and thus the elucidation of mechanisms of resistance is urgently needed. The crucial functions of activating transcription factor-2 (ATF2) in the development and therapeutic resistance of melanoma have been previously reported, although the precise underlying mechanisms remain unclear. Here, we report a protein kinase C-ɛ (PKCɛ)- and ATF2-mediated mechanism that facilitates resistance by transcriptionally repressing the expression of interferon-ß1 (IFNß1) and downstream type-I IFN signaling that is otherwise induced upon exposure to chemotherapy. Treatment of early-stage melanomas expressing low levels of PKCɛ with chemotherapies relieves ATF2-mediated transcriptional repression of IFNß1, resulting in impaired S-phase progression, a senescence-like phenotype and increased cell death. This response is lost in late-stage metastatic melanomas expressing high levels of PKCɛ. Notably, nuclear ATF2 and low expression of IFNß1 in melanoma tumor samples correlates with poor patient responsiveness to biochemotherapy or neoadjuvant IFN-α2a. Conversely, cytosolic ATF2 and induction of IFNß1 coincides with therapeutic responsiveness. Collectively, we identify an IFNß1-dependent, cell-autonomous mechanism that contributes to the therapeutic resistance of melanoma via the PKCɛ-ATF2 regulatory axis.

Gamma-secretase inhibitors target tumor-initiating cells in a mouse model of ERBB2 breast cancer.

Human breast tumors comprise a minor sub-population of tumor-initiating cells (TICs), commonly termed cancer stem cells. TICs are thought to sustain tumor growth and to confer resistance to current anticancer therapies. Hence, targeting TIC may be essential to achieving durable cancer cures. To identify molecular targets in breast TIC, we employed a transgenic mouse model of ERBB2 breast cancer; tumors arising in this model comprise a very high frequency of TIC, which is maintained in tumor cell populations propagated in vitro as non-adherent tumorspheres. The Notch pathway is dysregulated in human breast tumors and overexpression of constitutively active Notch proteins induces mammary tumors in mice. The Notch pathway has also been implicated in stem cell processes including those of mammary epithelial stem cells. Hence, we investigated the potential that the Notch pathway is required for TIC activity. We found that an antagonist of Notch signaling, a gamma (γ)-secretase inhibitor termed MRK-003, inhibited the survival of tumorsphere-derived cells in vitro and eliminated TIC as assessed by cell transplantation into syngeneic mice. Whereas MRK-003 also inhibited the self-renewal and/or proliferation of mammosphere-resident cells, this effect of the inhibitor was reversible thus suggesting that it did not compromise the survival of these cells. MRK-003 administration to tumor-bearing mice eliminated tumor-resident TIC and resulted in rapid and durable tumor regression. MRK-003 inhibited the proliferation of tumor cells, and induced their apoptosis and differentiation. These findings suggest that MRK-003 targets breast TIC and illustrate that eradicating these cells in breast tumors ensures long-term, recurrence-free survival.

CD161 DEFINES EFFECTOR T CELLS THAT EXPRESS LIGHT AND RESPOND TO TL1A-DR3 SIGNALING.

Expression of NK cell markers identifies pro-inflammatory T cell subsets in the liver and intestinal immune compartments. Specifically, CD161 is expressed on Th17 cells which play an important role in the regulation of mucosal inflammation. In this study, we characterized human peripheral blood CD161+ T cells as an effector population partially resembling a gut T cell phenotype. CD161+ CD4+ T cells express the gut-associated TNF family member, LIGHT, and respond to crosslinking of DR3, a receptor to another gut-associated cytokine, TL1A. Robust IFN-γ production in response to DR3 signaling correlated with enhanced expression of surface DR3 on CD161+ T cells and co-stimulation with IL12 and IL18. CD161+ T cell effector function was directly demonstrated by activation of responder monocytes in co-culture leading to CD40 upregulation and CD14 downregulation. CD161+ T cells reciprocally responded to activated monocytes, inducing expression of activation marker, CD69, and production of IL2 and IFN-γ, further demonstrating effective CD161+ T cell cross-talk with monocytes. Finally, CD161 defined a subset of T cells that co-express CD56, a second NK marker. Our findings implicate human CD161+ T cells in gut-associated signaling mechanisms, and suggest a monocyte mediated effector function in mucosal inflammation.

Down-regulation of the Notch pathway mediated by a gamma-secretase inhibitor induces anti-tumour effects in mouse models of T-cell leukaemia.

BACKGROUND AND PURPOSE: gamma-Secretase inhibitors (GSIs) block NOTCH receptor cleavage and pathway activation and have been under clinical evaluation for the treatment of malignancies such as T-cell acute lymphoblastic leukaemia (T-ALL). The ability of GSIs to decrease T-ALL cell viability in vitro is a slow process requiring >8 days, however, such treatment durations are not well tolerated in vivo. Here we study GSI's effect on tumour and normal cellular processes to optimize dosing regimens for anti-tumour efficacy. EXPERIMENTAL APPROACH: Inhibition of the Notch pathway in mouse intestinal epithelium was used to evaluate the effect of GSIs and guide the design of dosing regimens for xenograft models. Serum Abeta(40) and Notch target gene modulation in tumours were used to evaluate the degree and duration of target inhibition. Pharmacokinetic and pharmacodynamic correlations with biochemical, immunohistochemical and profiling data were used to demonstrate GSI mechanism of action in xenograft tumours. KEY RESULTS: Three days of >70% Notch pathway inhibition was sufficient to provide an anti-tumour effect and was well tolerated. GSI-induced conversion of mouse epithelial cells to a secretory lineage was time- and dose-dependent. Anti-tumour efficacy was associated with cell cycle arrest and apoptosis that was in part due to Notch-dependent regulation of mitochondrial homeostasis. CONCLUSIONS AND IMPLICATIONS: Intermittent but potent inhibition of Notch signalling is sufficient for anti-tumour efficacy in these T-ALL models. These findings provide support for the use of GSI in Notch-dependent malignancies and that clinical benefits may be derived from transient but potent inhibition of Notch.

A simple method to 'point count' silt using scanning electron microscopy aided by image analysis.

This study presents a simple method to 'point count' silt-sized grains using backscattered scanning electron microscopy together with image analysis. The work materialized out of the need to determine the heavy mineral abundance within silt obtained from coastal dunes to aid in the interpretation of dune weathering. This technique allows two broad mineral groups to be quantified according to their modal abundance. The groups are characterized by their dominant atomic elements present; atomic numbers >20 are classified as 'high' (metal oxides, zircon, monazite, carbonates, pyroxenes and amphiboles) and those <20 as 'low' (quartz, feldspars and organics). As a check on this technique, X-ray fluorescence was used. This showed a strong positive correlation (r2=0.85) with the developed point counting technique.

A secretin i.v. infusion activates gene expression in the central amygdala of rats.

For the last 100 years secretin has been extensively studied for its hormonal effects on digestion. Recent observations that the deficits in social reciprocity skills seen in young (3-4-year-old) autistic children are improved after secretin infusions suggest an additional influence on neuronal activity. We show here that i.v. administration of secretin in rats induces Fos protein expression in the neurons of the central amygdala as well as the area postrema, bed nucleus of the stria terminalis, external lateral parabrachial nucleus and supraoptic nucleus. However, secretin infusion did not induce Fos expression in the solitary tract nucleus or paraventricular nucleus, regions normally activated by related peptides such as cholecystokinin. The peak blood levels of secretin that induce Fos protein expression in rat brain are similar to the peak blood levels observed during i.v. treatment with secretin in humans. The amygdala is known to be critical for developing reciprocal social interaction skills and abnormalities in this brain region have been demonstrated in autistic children.

Generation of genetically altered mouse models for aging studies.

A number of mouse models have been identified and are being used for aging and age-associated disease research. However, the use of the genetically manipulated mouse model is still a relatively untapped resource for the study of the biology of aging. Genetically altered mice can be powerful tools for biology of aging research because gene expression can be controlled and correlated with established biomarkers. Standard transgene overexpression and gene targeting techniques were modified and used to generate 30 mouse lines during a 4-year period. These lines include models of Werner's syndrome (premature aging or progeria), Alzheimer's disease, other neurodegenerative condition, atherosclerosis, diabetes, immune dysfunction, musculoskeletal disorders, and oxidative stress. These new mouse models are providing additional insights into aging processes and will be useful for developing intervention strategies and collaborative interactions.

Deficient neurogenesis in forebrain-specific presenilin-1 knockout mice is associated with reduced clearance of hippocampal memory traces.

To examine the in vivo function of presenilin-1 (PS1), we selectively deleted the PS1 gene in excitatory neurons of the adult mouse forebrain. These conditional knockout mice were viable and grew normally, but they exhibited a pronounced deficiency in enrichment-induced neurogenesis in the dentate gyrus. This reduction in neurogenesis did not result in appreciable learning deficits, indicating that addition of new neurons is not required for memory formation. However, our postlearning enrichment experiments lead us to postulate that adult dentate neurogenesis may play a role in the periodic clearance of outdated hippocampal memory traces after cortical memory consolidation, thereby ensuring that the hippocampus is continuously available to process new memories. A chronic, abnormal clearance process in the hippocampus may conceivably lead to memory disorders in the mammalian brain.

Constitutive expression of LIGHT on T cells leads to lymphocyte activation, inflammation, and tissue destruction.

LIGHT, a member of the TNF family of cytokines (homologous to lymphotoxin, exhibits inducible expression and competes with HSV glycoprotein D for herpesvirus entry mediator, a receptor expressed on T cells), is induced on activated T cells and mediates costimulatory and antitumor activity in vitro. Relatively little information is available on the in vivo effects of LIGHT expression, particularly within the T cell compartment. In this work, we describe transgenic mice that express human LIGHT under the control of the CD2 promoter, resulting in constitutive transgene expression in cells of the T lymphocyte lineage. LIGHT-transgenic animals exhibit abnormalities in both lymphoid tissue architecture and the distribution of lymphocyte subsets. They also show signs of inflammation that are most severe in the intestine, along with tissue destruction of the reproductive organs. These LIGHT-mediated effects were recapitulated when immune-deficient mice were reconstituted with bone marrow from LIGHT-transgenic donor mice. T cells in the LIGHT-transgenic mice have an activated phenotype and mucosal T cells exhibit enhanced Th1 cytokine activity. The results indicate that LIGHT may function as an important regulator of T cell activation, and implicate LIGHT signaling pathways in inflammation focused on mucosal tissues.

Polyglutamine-expanded ataxin-7 antagonizes CRX function and induces cone-rod dystrophy in a mouse model of SCA7.

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder caused by a CAG repeat expansion. To determine the mechanism of neurotoxicity, we produced transgenic mice and observed a cone-rod dystrophy. Nuclear inclusions were present, suggesting that the disease pathway involves the nucleus. When yeast two-hybrid assays indicated that cone-rod homeobox protein (CRX) interacts with ataxin-7, we performed further studies to assess this interaction. We found that ataxin-7 and CRX colocalize and coimmunoprecipitate. We observed that polyglutamine-expanded ataxin-7 can dramatically suppress CRX transactivation. In SCA7 transgenic mice, electrophoretic mobility shift assays indicated reduced CRX binding activity, while RT-PCR analysis detected reductions in CRX-regulated genes. Our results suggest that CRX transcription interference accounts for the retinal degeneration in SCA7 and thus may provide an explanation for how cell-type specificity is achieved in this polyglutamine repeat disease.

Virus targeting of the tumor necrosis factor superfamily.

Herpesviruses appear to peacefully coexist with their natural hosts, with infection typically manifested as a benign, but lifelong process. However, coexistence depends on active resistance by innate and specific immune defenses as revealed in the striking virulence of herpesviruses when immunity fails. This pattern of infection is characteristic of a viral pathogen, such as cytomegalovirus, that has evolved efficient strategies targeted at host defense systems. Targeting members of the tumor necrosis factor (TNF)/lymphotoxin (LT) superfamily of cytokines is a strategy found in all herpesviruses, which suggests the existence of an intimate evolutionary link in their host-parasite relationship. Here we examine some of the strategies used by herpesvirus that target members of the TNF superfamily and discuss a recent study that revealed a novel mechanism that links LT-related ligands and interferons (IFN) to the establishment of coexistence between herpesvirus and its host cell.

Genomic characterization of LIGHT reveals linkage to an immune response locus on chromosome 19p13.3 and distinct isoforms generated by alternate splicing or proteolysis.

LIGHT is a member of the TNF cytokine superfamily that signals through the lymphotoxin (LT)beta receptor and the herpesvirus entry mediator. LIGHT may function as a costimulatory factor for the activation of lymphoid cells and as a deterrent to infection by herpesvirus, which may provide significant selective pressure shaping the evolution of LIGHT. Here, we define the molecular genetics of the human LIGHT locus, revealing its close linkage to the TNF superfamily members CD27 ligand and 4-1BB ligand, and the third complement protein (C3), which positions LIGHT within the MHC paralog on chromosome 19p13.3. An alternately spliced isoform of LIGHT mRNA that encodes a transmembrane-deleted form is detected in activated T cells and gives rise to a nonglycosylated protein that resides in the cytosol. Furthermore, membrane LIGHT is shed from the cell surface of human 293 T cells. These studies reveal new mechanisms involved in regulating the physical forms and cellular compartmentalization of LIGHT that may contribute to the regulation and biological function of this cytokine.