👤 N D Greene

Drought and water scarcity, exacerbated by global warming, are enormous threats to global food sustainability and security. Poultry, in particular, are highly impacted by adverse environmental stressors. As nutrient absorption and intestinal integrity are critical for growth and performance, understanding the impact on the broiler gastrointestinal tract is highly relevant. Here, we examined the effect of chronic cyclic heat stress (HS) on the jejunal expression profile of tight-junction, gap-junction, adherens, and desmosome genes in the 4th generation of broiler lines divergently selected for low (LWE)- and high-water efficiency (HWE). Male HWE and LWE broilers (n = 240/line) were allotted to 12 environmental chambers (2 floor pens/chamber, 6 chambers/line, 20 birds/pen) and were exposed to cyclic HS (36°C for 9h/day from 9:00 am to 6:00 pm) or thermoneutral conditions (25°C) from day 29 to 49 of age in a 2 × 2 factorial design. Growth performance and mortality were recorded. At day 49, jejunal tissues were collected for molecular analyses using real-time quantitative PCR and immunoblot. Jejunal gene expression of multiple gut integrity factors were higher (P < 0.05) in the HWE as compared to the LWE lines, including claudin 22 (CLDN22), -34, occluding (OCDN), zona-occludin-2 (ZO-2), gap junction alpha1 (GJA1), GJA3, GJC1, and cadherin 1 (CDH1). CLDN8, -20, -25, -4, GJC2, and GJD2 were also greater (P < 0.05) in HWE, but were additionally downregulated (P < 0.05) during HS. Conversely PALS1-associated tight junction protein (PATJ) and desmocollin 1 (DSC1) mRNAs were significantly downregulated in the HWE as compared to the LWE broilers. Significant interactions between the line and environment were seen in CLDN1, where the expression was decreased in the LWE but increased in the HWE in HS. Additionally, CLDN15 and -16 genes were greatest in the HWE under TN conditions, while catenin alpha 2 (CTNNA2) was highest in the HWE during HS. Overall, the jejunal expression profile of key genes associated with intestinal barrier integrity likely contributes to the water efficiency phenotype and the response of these birds to HS. Show less

Heat stress (HS) has long posed a significant challenge to the poultry industry due to its adverse effects, such as depressed feed intake, decreased growth performance, and increased water consumption. Water efficiency (WE, conversion of water intake into body weight gain), although often neglected, is a key economic and production trait that is significantly affected by HS. Recently, we selected two broiler lines for high WE (HWE) and low WE (LWE) and showed a differential hypothalamic expression of genes involved in water homeostasis regulation. As the gut also plays a significant role in water absorption, the present study aimed to determine the effect of chronic HS on duodenal barrier integrity in LWE and HWE broilers. Male HWE and LWE chicks (240 chicks/line) were individually wing-banded for line identification, weighed, and placed in 12 controlled environmental chambers (2 pens/chambers). On day 29, birds were subjected to thermoneutral conditions (TN, 25 °C) or cyclic HS conditions (HS, 36 °C for 9 h/day from 9:00 a.m. to 6:00 p.m.) (120 birds/line/environment) for 3 weeks. On day 49, duodenal tissues were collected for histological, biochemical, and molecular analyses. Hematoxylin and eosin (H&E) staining revealed that HS significantly reduced villus height in the duodenum. Further analysis using qPCR showed that the mRNA expressions of intestinal barrier integrity-related genes, including claudins (CLDN1, 4, 5, 8, 16, and 22), PALS1-associated tight junction protein ( Show less

Heat stress (HS) is a global serious issue in the poultry industry with numerous adverse effects, including increased stress, depressed feed intake (FI), poor growth performance and higher mortality. Herbal adaptogens, plant extracts considered as stress response modifiers, are metabolic regulators that improve an organism's ability to adapt to and minimize damage from environmental stresses. Previously, we showed that herbal adaptogen supplementation increased FI and body weight (BW) of broiler (meat-type) chickens reared under HS conditions. Therefore, we hypothesized that these effects may be mediated through modulation of hypothalamic feeding-related neuropeptides. Male Cobb 500 chicks were reared in 12 environmental chambers with three diets: a corn-soybean-based diet (C) and two herbal adaptogen-supplemented diets at 500 g/1000 kg (NR-PHY-500) and 1 kg/1000 kg (NR-PHY-1000). Broilers in 9 chambers were exposed to chronic cyclic HS (35 °C for 8 h/day) from d29 to d42, while 3 chambers were maintained at 24 °C (thermoneutral, TN) for all 42 days. Hypothalamic samples were collected on d42 from each group, both before the onset of HS (Pre-HS) that day and after 3 h of HS (post-HS). Hypothalamic expressions of neuropeptide Y (NPY) receptors Y4 and Y7, Corticotropin-releasing hormone (CRH), orexin receptor 1 (ORXR1), melanocortin receptors (MC1R, MC4R, and MC5R), visfatin and neurosecretory protein GL (NPGL) genes were significantly upregulated by adaptogen supplementation. The hypothalamic expression of MC2R was affect by period, with a significant upregulation during post-HS phase. There was a significant period by treatment interaction for hypothalamic orexin and adiponectin expression. The hypothalamic expression of NPY, Y1, Y2, Y5, Y6, proopiomelanocortin (POMC), cocaine and amphetamine regulated transcript (CART), agouti-related peptide (AgRP), ORXR2, AdipR1/2, MC3R, and ghrelin was not affected by diet supplementation nor by HS exposure. In conclusion, these findings suggest that in-feed supplementation of adaptogen might improve FI and growth via modulation of hypothalamic feeding-related neuropeptides in heat-stressed broilers. Show less

Paracrine activation of pro-fibrotic hedgehog (HH) signaling in pancreatic ductal adenocarcinoma (PDAC) results in stromal amplification that compromises tumor drug delivery, efficacy, and patient survival. Interdiction of HH-mediated tumor-stroma crosstalk with smoothened (SMO) inhibitors (SHHi) "primes" PDAC patient-derived xenograft (PDX) tumors for increased drug delivery by transiently increasing vascular patency/permeability, and thereby macromolecule delivery. However, patient tumor isolates vary in their responsiveness, and responders show co-induction of epithelial-mesenchymal transition (EMT). We aimed to identify the signal derangements responsible for EMT induction and reverse them and devise approaches to stratify SHHi-responsive tumors noninvasively based on clinically-quantifiable parameters. Animals underwent diffusion-weighted magnetic resonance (DW-MR) imaging for measurement of intratumor diffusivity. In parallel, tissue-level deposition of nanoparticle probes was quantified as a marker of vascular permeability/perfusion. Transcriptomic and bioinformatic analysis was employed to investigate SHHi-induced gene reprogramming and identify key "nodes" responsible for EMT induction. Multiple patient tumor isolates responded to short-term SHH inhibitor exposure with increased vascular patency and permeability, with proportionate increases in tumor diffusivity. Nonresponding PDXs did not. SHHi-treated tumors showed elevated FGF drive and distinctly higher nuclear localization of fibroblast growth factor receptor (FGFR1) in EMT-polarized tumor cells. Pan-FGFR inhibitor NVP-BGJ398 (Infigratinib) reversed the SHHi-induced EMT marker expression and nuclear FGFR1 accumulation without compromising the enhanced permeability effect. This dual-hit strategy of SMO and FGFR inhibition provides a clinically-translatable approach to compromise the profound impermeability of PDAC tumors. Furthermore, clinical deployment of DW-MR imaging could fulfill the essential clinical-translational requirement for patient stratification. Show less

Closed spinal dysraphisms are poorly understood malformations classified as neural tube (NT) defects. Several, including terminal myelocystocele, affect the distal spine. We have previously identified a NT closure-initiating point, Closure 5, in the distal spine of mice. Here, we document equivalent morphology of the caudal-most closing posterior neuropore (PNP) in mice and humans. Closure 5 forms in a region of active FGF signalling, and pharmacological FGF receptor blockade impairs its formation in cultured mouse embryos. Conditional genetic deletion of Fgfr1 in caudal embryonic tissues with Cdx2Cre diminishes neuroepithelial proliferation, impairs Closure 5 formation and delays PNP closure. After closure, the distal NT of Fgfr1-disrupted embryos dilates to form a fluid-filled sac overlying ventrally flattened spinal cord. This phenotype resembles terminal myelocystocele. Histological analysis reveals regional and progressive loss of SHH- and FOXA2-positive ventral NT domains, resulting in OLIG2 labelling of the ventral-most NT. The OLIG2 domain is also subsequently lost, eventually producing a NT that is entirely positive for the dorsal marker PAX3. Thus, a terminal myelocystocele-like phenotype can arise after completion of NT closure with localised spinal mis-patterning caused by disruption of FGFR1 signalling. Show less

The IL-6 cytokine family signals through the common signal transduction molecule gp130 combined with a cytokine-specific receptor. Gp130 signaling on CD4 T cells is vital in controlling chronic infection of mice with lymphocytic choriomeningitis virus clone 13 (LCMV Cl13), but the precise role of individual members of the IL-6 cytokine family is not fully understood. Transcriptional analysis highlighted the importance of gp130 signaling in promoting key processes in CD4 T cells after LCMV Cl13 infection, particularly genes associated with T follicular helper (Tfh) cell differentiation and IL-21 production. Further, Show less

Gestational diabetes mellitus (GDM) was associated with greater autism risk in epidemiological studies. Disrupted leptin signaling may contribute to their coincidence, as it is found in both disorders. Given this we examined leptin receptor (Lepr) deficient (BKS.Cg-Dock7 Show less

Resistance to oncogene-targeted therapies involves discrete drug-tolerant persister cells, originally discovered through in vitro assays. Whether a similar phenomenon limits efficacy of programmed cell death 1 (PD-1) blockade is poorly understood. Here, we performed dynamic single-cell RNA-Seq of murine organotypic tumor spheroids undergoing PD-1 blockade, identifying a discrete subpopulation of immunotherapy persister cells (IPCs) that resisted CD8+ T cell-mediated killing. These cells expressed Snai1 and stem cell antigen 1 (Sca-1) and exhibited hybrid epithelial-mesenchymal features characteristic of a stem cell-like state. IPCs were expanded by IL-6 but were vulnerable to TNF-α-induced cytotoxicity, relying on baculoviral IAP repeat-containing protein 2 (Birc2) and Birc3 as survival factors. Combining PD-1 blockade with Birc2/3 antagonism in mice reduced IPCs and enhanced tumor cell killing in vivo, resulting in durable responsiveness that matched TNF cytotoxicity thresholds in vitro. Together, these data demonstrate the power of high-resolution functional ex vivo profiling to uncover fundamental mechanisms of immune escape from durable anti-PD-1 responses, while identifying IPCs as a cancer cell subpopulation targetable by specific therapeutic combinations. Show less

High environmental temperature has strong adverse effects on poultry production, welfare, and sustainability and, thereby, constitutes one of the most challenging stressors. Although colossal information has been published on the effects of heat stress on poultry productivity and gut health, the fundamemntal mechanisms associated with heat stress responses and intestinal barrier function are still not well defined. The aim of the present study was, therefore, to determine the effects of acute (2 h) heat stress on growth performance, gut integrity, and intestinal expression of heat shock and tight junction proteins in slow- (broilers of the 1950's, ACRB), moderate- (broilers of 1990's, 95RAN), rapid-(modern broilers, MRB) growing birds, and their ancestor wild jungle fowl (JF). Heat stress exposure significantly increased the core body temperature of 95RAN and MRB chickens by ~0.5-1°C, but not that of JF and ACRB compared to their counterparts maintained at thermoneutral conditions. Heat stress also depressed feed intake and increased serum fluorescein isothiocyanate-dextran (FITC-D) levels ( Show less

Genome-wide association studies (GWAS) have contributed significantly to the understanding of complex disease genetics. However, GWAS only report association signals and do not necessarily identify culprit genes. As most signals occur in non-coding regions of the genome, it is often challenging to assign genomic variants to the underlying causal mechanism(s). Topologically associating domains (TADs) are primarily cell-type-independent genomic regions that define interactome boundaries and can aid in the designation of limits within which an association most likely impacts gene function. We describe and validate a computational method that uses the genic content of TADs to prioritize candidate genes. Our method, called 'TAD_Pathways', performs a Gene Ontology (GO) analysis over genes that reside within TAD boundaries corresponding to GWAS signals for a given trait or disease. Applying our pipeline to the bone mineral density (BMD) GWAS catalog, we identify 'Skeletal System Development' (Benjamini-Hochberg adjusted P=1.02x10 Show less

Dual specificity phosphatase 6 (DUSP6) functions as a feedback attenuator of fibroblast growth factor signaling during development. In vitro high throughput chemical screening attempts to discover DUSP6 inhibitors have yielded limited success. However, in vivo whole-organism screens of zebrafish identified compound 1 (BCI) as an allosteric inhibitor of DUSP6. Here we designed and synthesized a panel of analogues to define the structure-activity relationship (SAR) of DUSP6 inhibition. In vivo high-content analysis in transgenic zebrafish, coupled with cell-based chemical complementation assays, identified structural features of the pharmacophore of 1 that were essential for biological activity. In vitro assays of DUSP hyperactivation corroborated the results from in vivo and cellular SAR. The results reinforce the notion that DUSPs are druggable through allosteric mechanisms and illustrate the utility of zebrafish as a model organism for in vivo SAR analyses. Show less

Juvenile neuronal ceroid-lipofuscinosis (JNCL) or Batten/Spielmeyer-Vogt-Sjogren disease (OMIM #204200) is one of a group of nine clinically related inherited neurodegenerative disorders (CLN1-9). JNCL results from mutations in CLN3 on chromosome 16p12.1. The neuronal loss in Batten disease has been shown to be due to a combination of apoptosis and autophagy suggesting that CLN3P, the defective protein, may have an anti-neuronal death function. PANDER (PANcreatic-DERived factor) is a novel cytokine that was recently cloned from pancreatic islet cells. PANDER is specifically expressed in the pancreatic islets, small intestine, testis, prostate, and neurons of the central nervous system, and has been demonstrated to induce apoptosis. In this study, we over-expressed CLN3P in SH-SY5Y neuroblastoma cells and monitored the effects on PANDER-induced apoptosis. CLN3P significantly increased the survival rate of the SH-SY5Y cells in this system. This study provides additional evidence that the function of CLN3P is related to preventing neuronal apoptosis. Show less

Batten disease or JNCL, is the juvenile form of Neuronal Ceroid Lipofuscinosis (NCL) an autosomal recessive neurodegenerative disorder. Since retinal degeneration is an early consequence of Batten disease, we examined the eyes of Cln3 knockout mice (1-20 months of age), along with heterozygotes and appropriate controls, to determine whether or not the Cln3 defect would lead to characteristic retinal degeneration and visual loss. Accumulation of autofluorescent material and intracellular inclusions were markedly increased in Cln3 knockout retinal ganglion cells, as well as most other nuclear layers. Nerve fiber density was also significantly decreased in Cln3 knockout retinae. Apoptosis was observed in the photoreceptor layer of Cln3 knockout. However, the degree of retinal degeneration up to age 20 months was not extensive. Fundus examinations of Cln3 knockout mice showed no significant abnormalities, while electroretinograms remained robust through 11 months of age. In summary, it appears that accumulation of autofluorescent material, carbohydrate storage material, as well as apoptotic cell death are retinal manifestations of the Cln3 defect that do not appear to extinguish retinal function in this mouse model of Batten disease. Show less

A transactivation motif has been identified in the neurodegenerative disease protein, CLN3. The C-terminal domain (residues 394-438) of CLN3 can function as a transcriptional activator when fused to the DNA binding domain, LexA. A series of deletion and substitution constructs have been generated to identify the essential region for transactivation. A similar motif is also present in the POU domain transcription factor, nubbin. However, this domain alone does not activate transcription, allowing further localisation of the critical residues in CLN3 required for activity. Show less

Juvenile neuronal ceroid lipofuscinosis (Batten disease) is a childhood neurodegenerative disease that is caused by mutations in the CLN3 gene. The protein encoded by CLN3 has no homology with any proteins of known function and its cellular role remains elusive. In order to investigate the role played by the CLN3 protein we aimed to identify interacting proteins. Here, we describe the yeast two-hybrid system as the approach taken to investigate such protein-protein interactions. CLN3 was expressed as a fusion protein with a DNA-binding domain and used to screen a library of human fetal brain cDNAs fused to a transcriptional activation domain. Owing to low level expression of the full length CLN3 fusion protein, truncated regions corresponding to the predicted hydrophilic regions were also tested. No proteins that interact with CLN3 were detected, nor was there any evidence for CLN3-CLN3 interactions. Potential interaction of CLN3 with subunit c of mitochondrial ATP synthase, the major component of the storage material that accumulates in Batten disease patients, was also tested. No interaction was detected suggesting that the accumulation of subunit c does not result from loss of a process that requires a direct interaction with CLN3. We conclude that either CLN3 does not interact with other proteins or such interactions cannot be detected using the two-hybrid system. Show less

Batten disease, the juvenile-onset form of neuronal ceroid lipofuscinosis (NCL), is a progressive neurodegenerative disorder of childhood with an age of onset of 5-10 years of age. JNCL is caused by mutations in the CLN3 gene which encodes a membrane protein of unknown function. Magnetic resonance imaging of the brain of juvenile NCL patients has revealed changes in signal intensity and tissue atrophy, predominantly in the cortex and cerebellum. A mouse model for Batten disease was created by targeted disruption of the murine Cln3 gene in order to further understanding of the pathophysiology of Batten disease and to evaluate potential therapeutic approaches. Several features of the disease are displayed by Cln3 mice including accumulation of characteristic storage material in neurons. The aim of this work was to investigate neurodegeneration in the Cln3 mouse model using high resolution magnetic resonance imaging to measure signal intensity ratios in selected regions of interest. Global changes were observed in the brains of 12-month-old mutant mice that mirror those seen in juvenile NCL patients. There is a decrease in signal intensity ratio in grey matter regions including cortex, hippocampus and cerebellum, tissues where neuronal storage accumulation and cell loss have been seen in the mouse model. The alterations seen in Cln3 mutant mice support the validity of further imaging studies and suggest that this method will have application in assessment of therapeutic approaches in the study of mutant mouse models of NCL including the Cln3 mouse. Show less

The proto-oncogene Raf is a major regulator of growth and differentiation. Previous studies from a number of laboratories indicate that Raf activates a signaling pathway that is independent of the classic MEK1,2-ERK1,2 cascade. However, no other signaling cascade downstream of Raf has been identified. We describe a new member of the mitogen-activated protein kinase family, p97, an ERK5-related kinase that is activated and Raf associated when cells are stimulated by Raf. Furthermore, p97 is selectively responsive to different growth factors, providing a mechanism for specificity in cellular signaling. Thus, p97 is activated by the neurogenic factor fibroblast growth factor (FGF) but not the mitogenic factor epidermal growth factor (EGF) in neuronal cells. Conversely, the related kinase ERK5 is activated by EGF but not FGF. p97 phosphorylates transcription factors such as Elk-1 and Ets-2 but not MEF2C at transactivating sites, whereas ERK5 phosphorylates MEF2C but not Elk-1 or Ets-2. Finally, p97 is expressed in a number of cell types including primary neural and NIH 3T3 cells. Taken together, these results identify a new signaling pathway that is distinct from the classic Raf-MEK1,2-ERK1,2 kinase cascade and can be selectively stimulated by growth factors that produce discrete biological outcomes. Show less

Batten disease, a degenerative neurological disorder with juvenile onset, is the most common form of the neuronal ceroid lipofuscinoses. Mutations in the CLN3 gene cause Batten disease. To facilitate studies of Batten disease pathogenesis and treatment, a murine model was created by targeted disruption of the Cln3 gene. Mice homozygous for the disrupted Cln3 allele had a neuronal storage disorder resembling that seen in Batten disease patients: there was widespread and progressive intracellular accumulation of autofluorescent material that by EM displayed a multilamellar rectilinear/fingerprint appearance. Inclusions contained subunit c of mitochondrial ATP synthase. Mutant animals also showed neuropathological abnormalities with loss of certain cortical interneurons and hypertrophy of many interneuron populations in the hippocampus. Finally, as is true in Batten disease patients, there was increased activity in the brain of the lysosomal protease Cln2/TPP-1. Our findings are evidence that the Cln3-deficient mouse provides a valuable model for studying Batten disease. Show less

JNCL is a neurodegenerative disease of childhood caused by mutations in the CLN3 gene. A mouse model for JNCL was created by disrupting exons 1-6 of Cln3, resulting in a null allele. Cln3 null mice appear clinically normal at 5 months of age; however, like JNCL patients, they exhibit intracellular accumulation of autofluorescent material. A second approach will generate mice in which exons 7 and 8 of Cln3 are deleted, mimicking the common mutation in JNCL patients. Show less