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At least 1,063 records · Page 59

Loss of trefoil factor 1 inhibits biliary regeneration but accelerates the hepatic differentiation of progenitor cells in mice

Highlights: • In models of hepatic injury, the effect of TFF1-deficiency is investigated. • The TFF1-deficiency result in the impaired regeneration of the bile duct. • On the other hand, the differentiation of HPCs into hepatocytes is accelerated. • Hepatic and biliary regeneration depends on the TFF1 protein in injured liver. Although the regeneration of the adult liver depends on hepatic progenitor cells (HPCs), many uncertainties regarding hepatic regeneration in the injured liver remain. Trefoil factor family 1 (TFF1), a secretory protein predominantly expressed in the gastrointestinal tract, is responsible for mucosal restitution. Here, we investigated the role of TFF1 in liver regeneration using a mouse model of hepatic injury (choline-deficient ethionine-supplemented diet and carbon tetrachloride administration) and genetically engineered mice (TFF1 knockout (TFF1−/−)). Immunohistochemistry analysis of human liver samples revealed TFF1 expression in the hepatocytes close to ductular reaction and the regenerating biliary epithelium in injured liver. The number of cytokeratin 19 (CK19)-positive bile ducts was significantly decreased in the TFF1−/− mice after liver injury. Notch pathway in the TFF1−/− mice was also downregulated. HPCs in the control mice differentiated into biliary cells (CK19{sup +}/SRY HMG box 9 (SOX9){sup +}) more frequently. In contrast, HPCs in the TFF1−/− mice more frequently differentiated into a hepatic lineage (alpha fetoprotein{sup +}/SOX9{sup +}) after acute liver damage. Hepatocyte proliferation was upregulated, and the liver weight was increased in TFF1−/− mice in response to chronic liver damage. Thus, TFF1 is responsible for liver regeneration after liver injury by promoting HPC differentiation into a biliary lineage and inhibiting HPC differentiation into a hepatic lineage.

60 APPLIED LIFE SCIENCES↗

The relationship between Aquaporin-2 protein levels in amniotic fluid and the fetal kidney in humans

Aquaporin-2 (AQP2) is an important water channel protein that is expressed in the renal collecting duct and plays a key role in urine concentration and body water homeostasis. It has been demonstrated that the urinary excretion of AQP2 correlates strongly with its expression in the kidney in adult humans and rats. However, there have been no studies on the urinary excretion of AQP2 in human fetuses during development. Fetal urine is the main source of the amniotic fluid; we speculate that the level of AQP2 in the amniotic fluid could reflect the expression level of the AQP2 protein in the fetal kidney. The purpose of the present study was to explore the relationship between AQP2 in the amniotic fluid and that in the fetal kidney.

60 APPLIED LIFE SCIENCES↗

Evolutionary conservation of transferrin genomic organization and expression characterization in seven freshwater turtles

Highlights: • Transferrin have evolutionary conservation in genomic organization in freshwater turtles. • Transferrin have evolutionary conservation in expression characterization in freshwater turtles. • 12 positive selected sites were detected in freshwater turtles which were mainly located on the surface of Tf proteins. Serum transferrin (tf), encoding an iron-binding glycoprotein, has been revealed to play important roles in iron transportation and immune response, and it also has been demonstrated to be valuable for phylogenetic analysis in vertebrates. However, the evolutionary conservation, expression profiles and positive selection of transferrin genes among freshwater turtle species remain largely unclear. Here, the genomic DNA and coding sequences of transferrin genes were cloned and characterized in seven freshwater turtles including Mauremys mutica, Mauremys sinensis, Cyclemys dentate, Mauremyssi reevesi, Heosemys grandis, Trachemys scripta and Chrysemys picta. The isolated coding sequences of turtles' tf genes were 2118 bp or 2121 bp, encoding 706 or 707 amino acids. The predicted Tf proteins of turtles share high identities with M. mutica Tf, up to 91%–98% and the M. mutica Tf has the highest identity (91%) in amino acid with the Chelomia mydas Tf, the moderate with other reptiles' Tfs (65%–59%), chicken (58%), and Human Tf (∼55%), and the lowest with zebrafish Tf (41%). Additionally, tf genes were consistently composed of 17 exons and 16 introns with the same splicing sites in introns in all the turtles examined. Moreover, 12 positive selected sites were detected in these turtles’ Tf and mainly distributed on the surface of transferrin protein. Importantly, it was found that transferrin genes in all turtles examined were predominantly expressed in adult liver via real-time quantitative PCR. The molecular characterizations and expression profiles of transferrin would shed new insights into understanding the conversations and divergences of transferrin genes in turtles, even in vertebrates.

60 APPLIED LIFE SCIENCES↗

Compound D159687, a phosphodiesterase 4D inhibitor, induces weight and fat mass loss in aged mice without changing lean mass, physical and cognitive function

Highlights: • Seven weeks of Compound D159687 (D159687) induces weight loss in aged mice. • D159687 causes a selective loss of fat mass while preserving lean mass. • The weight loss in D159687 treated mice occurred despite increased food intake. Therapies that recapitulate the health benefits of caloric restriction in older adults are needed. Phosphodiesterase 4 inhibitors demonstrate such promise. We examined their effects on body weight and composition, physical and cognitive function in aged mice using Compound D159687 (D159687).

60 APPLIED LIFE SCIENCES↗

KATNAL1 is a more active and stable isoform of katanin, and is expressed dominantly in neurons

Highlights: • Neurons predominantly express KATNAL1 compared with KATNA1. • When introduced in cells, KATNAL1 showed higher microtubule-severing activity. • Cycloheximide chase analysis revealed that KATNAL1 is more stable in cells. • Knockdown of KATNAL1 but not KATANA1 resulted in enhancement of process elongation. Microtubule severing is essential for reorganization of microtubules during neuronal migration and process elongation. Katanin is a microtubule-severing enzyme, of which the major catalytic subunits are katanin A1 (KATNA1) and katanin A-like 1 (KATNAL1). The domain organization of the two subunits are almost the same; however, little is known about their functional difference. Here, we compared the expression pattern, microtubule-severing activity, intracellular degradation and knockdown phenotype in cultured cells of the two subunits. While KATNA1 was expressed ubiquitously among tissues of young adult mice, KATNAL1 was highly expressed in the brain and the testis. Neurons expressed almost only KATNAL1. When introduced into Neuro2a cells, KATNAL1 showed higher microtubule-severing activity. Cycloheximide chase analysis revealed that KATNAL1 is more stable in cells. To elucidate which part of the molecules are responsible for these characteristics, we generated chimeric molecules by swapping the amino-terminal and carboxyl-terminal halves between the two subunits. Experiments using these chimeras revealed that the amino-terminal half region is the determinant for their characteristics. Furthermore, KATNAL1 knockdown in Neuro2a cells resulted in enhancement of process elongation, while KATNA1 knockdown showed no effect. These data suggest that more active and more stable katanin subunit, KATNAL1, plays more important role in process elongation.

60 APPLIED LIFE SCIENCES↗

Endangered winter-run Chinook salmon rely on diverse rearing habitats in a highly altered landscape

Protecting habitats for imperiled species is central to conservation efforts. However, for migratory species, identifying juvenile habitats that confer success requires tracking individuals to reproduction. Here in this paper, we used otolith strontium isotope ratios ( 87 Sr/ 86 Sr) to reconstruct juvenile habitat use by endangered Sacramento River winter-run Chinook salmon that survived to adulthood. The isotope data revealed that 44–65% of surviving adults reared in non-natal habitats, most of which is not designated as critical habitat under the Endangered Species Act. Juveniles entered these non-natal habitats at small sizes, yet left freshwater at a similar size to those that reared in the mainstem Sacramento River, suggesting these alternate rearing habitats provide suitable growth conditions. These findings indicate Sacramento River winter-run Chinook salmon rely on rearing habitats across a broader geographic region than previously known, potentially opening up greater restoration and conservation opportunities for species recovery.

54 ENVIRONMENTAL SCIENCES↗

Chronic kidney disease and aging differentially diminish bone material and microarchitecture in C57Bl/6 mice

Chronic kidney disease (CKD) is a common disease of aging and increases fracture risk over advanced age alone. Aging and CKD differently impair bone turnover and mineralization. We thus hypothesize that the loss of bone quality would be greatest with the combination of advanced age and CKD. We evaluated bone from young adult (6 mo.), middle-age (18 mo.), and old (24 mo.) male C57Bl/6 mice three months following either 5/6th nephrectomy, to induce CKD, or Sham procedures. CKD exacerbated losses of cortical and trabecular microarchitecture associated with aging. Aging and CKD each resulted in thinner, more porous cortices and fewer and thinner trabeculae. Bone material quality was also reduced with CKD, and these changes to bone material were distinct from those due to age. Aging reduced whole-bone flexural strength and modulus, micrometer-scale nanoindentation modulus, and nanometer-scale tissue and collagen strain (small-angle x-ray scattering [SAXS]. By contrast, CKD reduced work to fracture and variation in bone tissue modulus and composition (Raman spectroscopy), and increased percent collagen strain. The increased collagen strain burden was associated with loss of toughness in CKD. In addition, osteocyte lacunae became smaller, sparser, and more disordered with age for Sham mice, yet these age-related changes were not clearly observed in CKD. However, for CKD, larger lacunae positively correlated with increased serum phosphate levels, suggesting that osteocytes play a role in systemic mineral homeostasis. This work demonstrates that CKD reduces bone quality, including microarchitecture and bone material properties, and that loss of bone quality with age is compounded by CKD. Finally, these findings may help reconcile why bone mass does not consistently predict fracture in the CKD population, as well as why older individuals with CKD are at high risk of fragility.

60 APPLIED LIFE SCIENCES↗

Effects of non-invasive brain stimulation on associative memory

Associative memory refers to remembering the association between two items, such as a face and a name. It is a crucial part of daily life, but it is also one of the first aspects of memory performance that is impacted by aging and by Alzheimer’s disease. Evidence suggests that transcranial direct current stimulation (tDCS) can improve memory performance, but few tDCS studies have investigated its impact on associative memory. In addition, no prior study of the effects of tDCS on memory performance has systematically evaluated the impact of tDCS on different types of memory assessments, such as recognition and recall tests. In this study, we measured the effects of tDCS on associative memory performance in healthy adults, using both recognition and recall tests. Participants studied face-name pairs while receiving either active (30 minutes, 2 mA) or sham (30 minutes, 0.1 mA) stimulation with the anode placed at F9 and the cathode placed on the contralateral upper arm. Participants in the active stimulation group performed significantly better on the recall test than participants in the sham group, recalling 50% more names, on average, and making fewer recall errors. However, the two groups did not differ significantly in terms of their performance on the recognition memory test. This investigation provides evidence that stimulation at the time of study improves associative memory encoding, but that this memory benefit is evident only under certain retrieval conditions.

60 APPLIED LIFE SCIENCES↗

Clozapine increased c-Fos protein expression in several brain subregions of socially isolated rats

Chronic social stress and/or pharmacological treatments differentially modulate the expression of c-Fos, a marker of neuronal activity, in subregions of the rat brain. Here, we examined the effect of the atypical antipsychotic Clozapine (Clz) (20 mg/kg/day for 3 weeks) on the neuronal activation pattern of c-Fos protein expression in stress-relevant brain subregions of adult male Wistar rats exposed to chronic social isolation (CSIS: 3 weeks), an animal model of depression and schizophrenia, and controls. The protein expression of c-Fos was also used to map neuronal populations in brain subregions activated by CSIS alone. Subregions which showed significantly increased c-Fos protein expression following CSIS included the retrosplenial cortex (RSC), (subregions:RSC granular cortex, c region (RSGc) and dysgranular (RSD)), dentate gyrus, dorsal (DGd), paraventricular thalamic nucleus, posterior part (PVP), lateral (LA)/basolateral (BL) complex of amygdala, caudate putamen (CPu) and accumbens nucleus, shell (AcbSh). Increases in c-Fos protein expression in the RSGc, RSD, DGd, PVP, LA/BL complex of amygdala and striatum (CPu, Acb Core (AcbC) and AcbSh) following Clz treatment in controls were found. Clz applied simultaneously with CSIS modulated neuronal activity in CPu, AcbC and AcbSh subregions compared to CSIS alone, increasing c-Fos protein expression. Furthermore, Clz revealed synergistic effects with CSIS in the CA1d and PVP. These identified neural circuits reflect brain subregions activated following CSIS and/or Clz administration. These data further contribute to the understanding of the effectiveness of Clz in the modulation of brain subregion activation in response to CSIS. © 2019.

60 APPLIED LIFE SCIENCES↗

The Gut Microbiota of Rural Papua New Guineans: Composition, Diversity Patterns, and Ecological Processes

Comparisons between the fecal microbiota of humans from industrialized and non-industrialized communities indicate a pronounced impact of westernization on the diversity and composition of the human gut microbiota. However, the exact consequences of westernization on community characteristics are still insufficiently understood, and the ecological processes that drive differences have not been elucidated. Here we have compared the fecal microbiota of adults from two non-industrialized regions in Papua New Guinea (PNG) with that of United States (US) residents. Papua New Guineans harbor communities with greater bacterial diversity but lower inter-individual variation. Although the fecal microbiota in PNG and US was largely dominated by shared bacterial lineages, the relative abundance of 25 families, 45 genera, and 230 species-level OTUs differed, and 47 core OTUs in PNG were undetectable in US residents. To gain insight into the ecological mechanisms that cause the observed differences, we quantified community assembly processes in PNG and US microbiomes using a null modeling approach. This analysis demonstrated a significant higher rate of bacterial dispersal in PNG and divergent selective environments in the US. Interestingly, equivalent findings were obtained for other datasets comparing industrialized and non-industrialized microbiomes. Overall, the findings demonstrate a dominant role for microbial dispersal in shaping the human gut microbiota in non-industrialized societies, and point to differential selection pressures across individuals as a major factor shaping microbiomes associated with modern lifestyle.

59 BASIC BIOLOGICAL SCIENCES↗

Identification and characterization of a class of MALAT1 -like genomic loci

The MALAT1 (Metastasis-Associated Lung Adenocarcinoma Transcript 1) gene encodes a noncoding RNA that is processed into a long nuclear retained transcript ( MALAT1 ) and a small cytoplasmic tRNA-like transcript (mascRNA). Using an RNA sequence- and structure-based covariance model, we identified more than 130 genomic loci in vertebrate genomes containing the MALAT1 3' end triple-helix structure and its immediate downstream tRNA-like structure, including 44 in the green lizard Anolis carolinensis . Structural and computational analyses revealed a co-occurrence of components of the 3' end module. MALAT1 -like genes in Anolis carolinensis are highly expressed in adult testis, thus we named them testis-abundant long noncoding RNAs (tancRNAs). MALAT1 -like loci also produce multiple small RNA species, including PIWI-interacting RNAs (piRNAs), from the antisense strand. The 3' ends of tancRNAs serve as potential targets for the PIWI-piRNA complex. Furthermore, we have identified an evolutionarily conserved class of long noncoding RNAs (lncRNAs) with similar structural constraints, post-transcriptional processing, and subcellular localization and a distinct function in spermatocytes.

59 BASIC BIOLOGICAL SCIENCES↗

Genome-wide fetalization of enhancer architecture in heart disease

Heart disease is associated with re-expression of key transcription factors normally active only during prenatal development of the heart. However, the impact of this reactivation on the regulatory landscape in heart disease is unclear. Here, we use RNA-seq and ChIP-seq targeting a histone modification associated with active transcriptional enhancers to generate genome-wide enhancer maps from left ventricle tissue from up to 26 healthy controls, 18 individuals with idiopathic dilated cardiomyopathy (DCM), and five fetal hearts. Healthy individuals have a highly reproducible epigenomic landscape, consisting of more than 33,000 predicted heart enhancers. In contrast, we observe reproducible disease-associated changes in activity at 6,850 predicted heart enhancers. Combined analysis of adult and fetal samples reveals that the heart disease epigenome and transcriptome both acquire fetal-like characteristics, with 3,400 individual enhancers sharing fetal regulatory properties. We also provide a comprehensive data resource (http://heart.lbl.gov) for the mechanistic exploration of DCM etiology.

60 APPLIED LIFE SCIENCES↗

The Long Noncoding RNA Paupar Modulates PAX6 Regulatory Activities to Promote Alpha Cell Development and Function

Many studies have highlighted the role of dysregulated glucagon secretion in the etiology of hyperglycemia and diabetes. Accordingly, understanding the mechanisms underlying pancreatic islet ? cell development and function has important implications for the discovery of new therapies for diabetes. In this study, comparative transcriptome analyses between embryonic mouse pancreas and adult mouse islets identified several pancreatic lncRNAs that lie in close proximity to essential pancreatic transcription factors, including the Pax6-associated lncRNA Paupar. We demonstrate that Paupar is enriched in glucagon-producing ? cells where it promotes the alternative splicing of Pax6 to an isoform required for activation of essential ??cell genes. Consistently, deletion of Paupar in mice resulted in dysregulation of PAX6 ? cell target genes and corresponding ? cell dysfunction, including blunted glucagon secretion. These findings illustrate a distinct mechanism by which a pancreatic lncRNA can coordinate glucose homeostasis by cell-specific regulation of a broadly expressed transcription factor.

diabetes, pancreatic islets, glucagon, alpha cells↗

Effects of PFOS on the behavior, growth, emergence, and predation susceptibility of larval mosquitoes ( Culex quinquefasciatus )

Per-/polyfluoroalkyl substances (PFAS) have been commonly used over several decades for a variety of products and are very persistent in the environment. However, not much is known about their direct effects on aquatic invertebrates and their ecosystems. We examined the survival, behavior, development, and predation susceptibility of mosquito larvae Culex quinquefasciatus exposed to concentrations of perfluorooctanesulfonic acid (PFOS) ranging from 0.02 to 453.7 µg/L. PFOS exposure resulted in reduced larval survival, with a 48 hour LC50 (concentration with 50 % mortality) of 255.99 µg/L. PFOS exposure also resulted in reduced developmental success and slower maturation to adulthood (and thus slower emergence from the water) compared to control larvae. PFOS also resulted in delays in reaction to prodding stimuli, which were meant to simulate a predator attack, and longer reactions to prodding. Larvae exposed to PFOS also spent more time at the bottom of the water column, rather than at the surface where respiration takes place. Effects of larval mosquito PFOS exposure on predation by unexposed damselfly naiads (genus Ischnura) were not detected. Overall, this research suggests that PFOS impacts mosquito larvae survival, behavior, development, and adult emergence, which could have important implications for food webs or public health given the role of mosquitos as disease vectors.

Food web dynamics↗

Early affective changes and increased connectivity in preclinical Alzheimer's disease

Abstract Introduction Affective changes precede cognitive decline in mild Alzheimer's disease and may relate to increased connectivity in a “salience network” attuned to emotionally significant stimuli. The trajectory of affective changes in preclinical Alzheimer's disease, and its relationship to this network, is unknown. Methods One hundred one cognitively normal older adults received longitudinal assessments of affective symptoms, then amyloid‐PET. We hypothesized amyloid‐positive individuals would show enhanced emotional reactivity associated with salience network connectivity. We tested whether increased global connectivity in key regions significantly related to affective changes. Results In participants later found to be amyloid positive, emotional reactivity increased with age, and interpersonal warmth declined in women. These individuals showed higher global connectivity within the right insula and superior temporal sulcus; higher superior temporal sulcus connectivity predicted increasing emotional reactivity and decreasing interpersonal warmth. Conclusions Affective changes should be considered an early preclinical feature of Alzheimer's disease. These changes may relate to higher functional connectivity in regions critical for social‐emotional processing.

Fredericks, Carolyn A.↗

24-hour human urine and serum profiles of Bisphenol A following ingestion in soup: Individual pharmacokinetic data and emographics

Here we present data to evaluate potential absorption of Bisphenol A through non-metabolizing tissues of the upper digestive tract. Concurrent serum and urine concentrations of d6-BPA, and its glucuronide and sulfate conjugates, were measured over a 24 h period in 10 adult male volunteers following ingestion of 30 μg d6-BPA/kg body weight in soup. The pharmacokinetic behavior of BPA and its metabolites in this cohort (rapid absorption, complete elimination, evidence against sublingual absorption) was reported. This Data in Brief article contains the corresponding individual pharmacokinetic data, reports the demographics of the cohort and provides additional details related to the analytical methods employed and is related to [4].

59 BASIC BIOLOGICAL SCIENCES↗

Over or under? Autonomous Sensor Fish reveals why overshot weirs may be safer than undershot weirs for fish passage

Many riverine fish species disperse downstream as eggs, juveniles, or adults, which can expose them to injury and death at hydro-structures. Low-head weirs are one example of a structure that can kill fish, and this impact has been shown to be substantially higher for undershot weirs when compared to overshot weirs. In this study, autonomous sensor devices were released at an overshot and undershot weir under similar discharges to assess what stressors maybe contributing to differences in the survival rates of fish. Although the undershot weir was more likely to expose fish to rapid decompression, the intensity of decompression was mild and it is more likely that higher levels of fluid shear at the undershot are more damaging to early life stage and small-bodied fish. Both weirs showed potential for strike, but this could be managed through improvements in design.

Pflugrath, Brett D.↗