bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reprogramming cell fates by RNA binding proteins in stem cells and cancer
Authors: Ito Takahiro 
Published: April 2020

Stem cells and cancer share a characteristic potential of self‐renewal, which is essential for long‐term maintenance of both cell types in vivo. Similar to a hierarchy of stem and progenitor cells in normal tissues, many types of tumors are maintained by a small population of self‐renewing cancer cells while the bulk of the tumor is consisted of more differentiated cells with no or limited renewal activity. The self‐renewing cancer cells, or cancer stem cells, are often resistant to conventional therapies and thereby mediate tumor relapse. With the ability to self‐renew and propagate the tumor, cancer stem cells also contribute to metastasis and disease progression to a more aggressive, often fatal, disease phase. Therefore, regulatory mechanisms of stem cell fates have emerged as one of the promising areas for targeted cancer therapies. Recent studies have demonstrated that RNA binding proteins play major roles in both normal and malignant stem cells. We are particularly interested in how RNA binding proteins affect stem cell potentials and contribute to disease development in myeloid leukemia and would like to share our findings on their roles in the branched‐chain amino acid metabolism and stem cell maintenance.Support or Funding InformationSupported by the Research Scholar Grant from the American Cancer Society.
RNA, Chromatin, and the Coordinated Control of Gene Expression
Authors: Johnson Tracy 
Published: April 2020

RNA splicing is carried out by a large ribonucleoprotein machine, the spliceosome. Biochemical dissection of the splicing reaction has uncovered dynamic spliceosome rearrangements that are critical for proper recognition of splice sites and removal of introns. Recently, there has been growing evidence that assembly of the spliceosome onto pre‐mRNA occurs co‐transcriptionally, while the RNA polymerase is actively engaged with a chromatin template, which raises the question of how transcription, and more specifically, the state of the chromatin affects spliceosome assembly. Here we describe how conserved chromatin modifications influence spliceosome assembly to affect splicing outcomes and how changes in splicing allow cells to respond appropriately to their environment.Support or Funding InformationNIH/NIGMS RO1 GM085474 HHMI 52008140
Leukemia Inhibitory Factor Regulates the Post Stroke Immune Cell Infiltration in Aged Male and Female Rats
Authors: Appleton Malik 
Published: April 2020

Ischemic stroke is one of the leading causes of death in the world. There currently only two FDA approved treatments for ischemic stroke, tissue plasminogen activator (tPA), and mechanical thrombectomy. Leukemia inhibitory factor or LIF, has been shown to improve functional recovery in young rats put under ischemic stroke conditions, but neither the responses of older rats or the gendered rat differences in immune responses have yet been tested with LIF. The purpose of this study is to identify the differences in immune cell infiltration of aged male and female rats subjected to MCAO and treated with LIF. For his study, the rats were subjected to either MCAO surgery or sham surgery, and given an injection of either LIF or PBS at 6, 24, and 48 hour time points after surgery. At the 72h time point the rats had MRI scans done on their brains immediately before euthanisia, and brains, blood, and spleens of the rats were collected for flow cytometry analysis. The spleen, blood, and brain samples were stained and analyzed with a flow cytometer for counts of Macrophages and Monocytes, B cells, and CD4 and CD8 T cells, and the resulting data was compiled using FlowJo and visualized using GraphPad. Results show that while there are some potential differences in the immune cell infiltrations of male vs female rats and PBS vs LIF rats, the deviation in sample levels of immune cells is on high for statistically significant conclusions to be made. A larger sample size for each group (currently n≤4 per treatment group) would be needed in a future study to investigate his further.Support or Funding InformationKY‐WV Louis Stoke Alliance For Minority Participation (NSF #1826763), ASPET SURF Program at the University of Kentucky
Dual NMDAR signaling: flux‐independent pH sensor and flux‐dependent regulator of mitochondrial membrane potential (mΔψ) and cell membrane‐mitochondria bridging.
Authors: de Oca Pavel Montes , Hernandez-Cruz Arturo 
Published: April 2020

Glutamate N‐methyl‐D‐aspartate (NMDA) receptor (NMDAR) is critical for neurotransmission as a Ca2+ channel. Nonetheless, several reports have demonstrated also flux‐independent signaling. Astrocytes express NMDAR distinct from its neuronal counterpart, but cultured astrocytes have no electrophysiological response and controversial findings have questioned NMDAR function. We recently demonstrated that in cultured astrocytes NMDA at pH6 (NMDA/pH6) elicits flux‐independent Ca2+ release from the Endoplasmic Reticulum (ER) and depletes mitochondrial membrane potential (mΔψ). Here we show that flux‐independent Ca2+ release is mainly due to pH6 and NMDAR, whereas mΔψ depletion requires both pH6 and flux‐dependent NMDAR signaling. Immunofluorescence exhibited that plasma membrane (PM) NMDAR is apposed or surrounds ER and mitochondria. Moreover, NMDA/pH6 treatment generated ER stress, increased endocytosis, mitochondria‐ER and ‐nuclear contacts and strikingly, PM invaginations near mitochondria along with electrodense structures referred here as PM‐mitochondrial bridges (PM‐m‐br). Our data and earlier observations strongly suggest PM‐mitochondria communication, as a proof of concept of this notion, NMDA/pH6 provoked mitochondria labeling by the PM dye FM‐4‐64FX. Finally, we analyzed by WB NMDAR subunit GluN1 to explore putative causes of NMDAR dual function, we found fragments with M.W. consistent with previously identified cleavage sites. Accordingly, GluN1 intracellular and extracellular domains presented little colocalization. Our findings demonstrate that NMDAR plays a dual function: a flux‐independent pH sensor and a flux‐dependent regulator of mΔψ. More importantly, mΔψ depletion seems to be mediated by PM‐mitochondria communication. Finally, we found different GluN1 fragments that could be involved in NMDAR dual signaling, although causality awaits demonstration (submitted to JBC).Support or Funding InformationSupported by CONACyT project #132706 and PAPIIT‐UNAM AG200119.
Molecular Characterization of Fungi Associated with Pharmaceutical Products
Authors: Oyebanji Elizabeth Olawumi , Adekunle Adeyinka Adedotun 
Published: April 2020

Pharmaceuticals are medicinal products used in the prevention, treatment, and diagnosis of diseases. As such, the presence of microorganisms’ especially fungal toxins can reduce or eliminate the product’s therapeutic activity and constitute a potential danger to patient health.This study attempts to determine the fungal loads of liquid preparation used as medication in Lagos State and its environs and identify the fungal isolates. 252 different types of oral liquid drugs (200syrups and 52 suspensions) which included paracetamol syrup, cough syrup and antibiotics suspension manufactured in five different pharmaceutical industries in Nigeria were methodically sampled and analyzed for fungi contamination using standardized method. The isolated fungi were identified using morphological characterization as well as 16SrDNA sequencing. 13% of the sampled syrups were found to be contaminated with fungi where the colony forming units for paracetamol syrup, cough syrup and antibiotics suspension ranges from 2.0×101 – 9.6×104, 1.0×102–7.5×104 and 1.0×101–8.8×104cfu/ml respectively while 87% yielded no growth. Thirteen (13) morphologically different species of fungi were identified which included Aspergillus niger strains, A. tamari strains, A. japonicas, A. flavus, A. awamari, A. ellipticus, A. tubingensis, Meyerozyma caaribbica, Candida carpophila and Eurotiomycetes spp. The presence of microorganisms in oral liquid samples might explain the treatment complicacy of the diseased children. Therefore, microbiological quality of such drugs is thus suggested.
Evidence for Neurohormonal Triggers of Cardiomyocyte Polyploidization and Cardiac Regenerative Potential Loss During Endothermy Acquisition
Authors: Huang Guo 
Published: April 2020

Tissue regenerative potential displays striking divergence across phylogeny and ontogeny, but the underlying mechanisms remain enigmatic. Loss of mammalian cardiac regenerative potential correlates with cardiomyocyte cell‐cycle arrest and polyploidization as well as the development of postnatal endothermy. Genetic evidences in both mice and zebrafish support that cardiomyocyte polyploidization represents a major barrier limiting cardiac regenerative capacity. Through phylogenetic analyses of 41 vertebrate species, we uncover that certain monotreme, edentate, cetacean, chiropteran species have unusually high percentages of diploid cardiomyocytes in the adult heart. Furthermore, diploid cardiomyocyte abundance conforms to Kleiber’s law—the 3/4‐power law scaling of metabolism with bodyweight—and inversely correlates with standard metabolic rate, body temperature, and serum thyroxine level. Inactivation of thyroid hormone signaling reduces mouse cardiomyocyte polyploidization, delays cell‐cycle exit, and retains cardiac regenerative potential in adults. Conversely, exogenous thyroid hormones inhibit zebrafish heart regeneration. Notably, inhibition of thyroid hormone synthesis in mice after birth results in low body temperatures.Recently, we discover the nervous system as a secondary major regulator of mammalian cardiomyocyte polyploidization, cell cycle arrest, and body temperature increase. Moreover, inhibitions of neuronal activity and thyroid hormone signaling in neonates have additive effects, yielding mice with the highest percentage of diploid cardiomyocytes and lowest body temperature to our knowledge. Thus, our results support a model where loss of cardiomyocyte regenerative capacity, driven by increasing neurohormonal activities, may be a tradeoff for the acquisition of endothermy during animal evolution and postnatal development.Support or Funding InformationNIH
Effect of Levosimendan, an Inodilator, on Streptozotocin‐Induced Diabetic Nephropathy in Rats
Authors: Ali Badreldin H. , Al-Salam Suhail , Al Sulemani Yousuf M. , Abdelrahman Aly M. 
Published: April 2020

Levosimendan, an inodilator, was shown to have a renal protective effect in different models of kidney dysfunction in experimental animals and in patients with heart failure. The aim of this study was to examine the effect of levosimendan on streptozotocin‐induced early diabetic nephropathy. Male Sprague Dawley rats (n = 24, 320–400 g) were randomly distributed into four groups and treated for 6 weeks. Groups 1 and 3 received either vehicle or levosimendan (1 mg/kg/day) for the last three weeks, respectively. Groups 2 and 4 were rendered diabetic by a single i.p. injection of streptozotocin (60 mg/kg) and were treated as in groups 1 and 3, respectively. At the end of the experiment, rats were placed in metabolic cages and urine was collected for biochemical analysis. Rats were then anesthetized and blood samples collected for biochemical analysis. Kidneys were removed for histopathology. In the untreated diabetic group, there was a significant decrease in body weight, polyuria and increased relative kidney weight. There was increased urinary albumin/creatinine ratio (UACR), 24 hour (h) albumin level and N‐acetyl‐β‐D‐glucosaminidase (NAG)/creatinine ratio (UNCR). Streptozotocin did not cause a significant effect on creatinine clearance when adjusted to body weight. In addition, diabetes was associated with increased oxidative stress [reduced plasma total antioxidant capacity (TAC) and catalase activities]. Kidneys from streptozotocin‐treated rats showed focal clear renal tubular cells affecting proximal convoluted tubules and focal mild interstitial fibrosis at the cortico‐medullary junction. Levosimendan significantly attenuated the reduction in body weight, polyuria and the increase in relative kidney weight. In addition, it significantly attenuated the increase in UACR, urinary 24 h albumin level and UNCR in diabetic rats. It also significantly mitigated the decrease in plasma TAC and catalase activities in diabetic rats. Rats in the diabetic group treated with levosimendan showed less clear cell changes but similar interstitial fibrosis when compared with the untreated diabetic group. This study shows that levosimendan ameliorated some of the changes seen in streptozotocin‐induced early diabetic nephropathy in rats. This could be partly due to its antioxidative effects.Support or Funding InformationSupported by an internal grant from Sultan Qaboos University (IG/MED/PHAR/18/01)
Mesenchymal Stem Cell Derived Extracellular Vesicles Enhance Myelin Plasticity in Rhesus Monkeys
Authors: Go Veronica , Sarikaya Deniz , Zhao Yuxin , Bowley Bethany GE , Medalla Maria , Rosene Douglas L. , Buller Benjamin , Moore Tara L. 
Published: April 2020

Cortical injury, such as injury from stroke, results in a cascade of events that includes cell death, inflammation and disruption of myelin. To date, there are no highly effective treatments for reducing the deficits that occur after injury. Recently, we have demonstrated that extracellular vesicles (EVs) harvested from rhesus monkey bone marrow derived cells when given 1 day and 14 days following injury facilitate recovery of function in aged rhesus monkeys within the first 3–5 weeks after cortical injury. Based on these findings and current proteomic literature of MSC‐EVs, we hypothesized that MSC‐EVs enhance myelin plasticity by limiting damage to oligodendrocytes and stimulating remyelination.To assess general myelin integrity after injury, we used Spectral Confocal Reflectance Microscopy (SCoRe) to image myelinated axons and found an increase in the density of myelinated axons in the EV group (p < 0.05). To assess whether the difference was due to reduced damage or remyelination, in sublesional white matter we assessed immunohistochemical labeling of Olig2, a general oligodendrocyte marker, and 8OHdG, a marker for DNA damage. We found reduced densities of Olig2 colocalized with 8OHdG in the EV group (p<0.05). As a marker of active demyelination and myelin debris clearance, we measured Myelin Basic Protein (MBP) concentrations in CSF and found a longitudinal reduction in the EV animals. To assess remyelination, we measured expression of MBP, a gene for myelination in mature oligodendrocytes, Myelin Regulatory Factor (MyRF), a gene for oligodendrocyte differentiation and maintenance, and Breast Carcinoma Amplified Sequence 1 (BCAS1), a gene for newly myelinating oligodendrocytes. Interestingly, we found a 4 fold increase in MyRF expression, and a 1.5 fold increase in MBP and BCAS1 in the EV animals relative to the vehicle control animals in perilesional brain tissue. Consistent with these gene expression differences associated with re‐myelination, we found that the densities of newly‐myelinating oligodendrocytes immune‐labeled with BCAS1, as well as mature oligodendrocytes expressing CC1, exhibited a trend towards an increase in the EV group (p = 0.09). These results suggest that EV treatment reduces myelin damage, while also stimulating myelin repair. Finally, these results correlated with enhanced motor recovery, suggesting that EV‐mediated white matter plasticity is a critical component for recovery after cortical injury.Support or Funding InformationSupported by NIH grant R21NS102991‐02.
Zika virus infection induces endoplasmic reticulum stress and apoptosis in placental trophoblasts
Authors: Muthuraj Philma Glora , Kraus Madison N , Sahoo Prakash Kumar , Bruett Taylor , Pattnaik Aryamav , Annamalai Arun Saravanakumar , Pattnaik Asit , Byrareddy Siddappa , Natarajan Sathish Kumar 
Published: April 2020

Zika virus (ZIKV) infection in pregnant woman can be vertically transmitted to the fetus via the placenta leading to Congenital Zika syndrome (CZS). CZS is characterized by microcephaly, retinal defects and intrauterine growth retardation. ZIKV also causes placental pathology leading to severe compromise in the growth and development of the fetus. Further, the molecular mechanism behind ZIKV‐induced apoptosis in placental trophoblasts is unknown. We hypothesize that accumulation of viral proteins in the endoplasmic reticulum could lead to sustained endoplasmic reticulum stress (ER stress) and trigger apoptotic events.MethodsHTR‐8, a human normal immortalized trophoblast cell and human choriocarcinoma derived cell lines (JEG‐3 and JAR) were infected with 0.1–1MOI ZIKV. Apoptosis was assessed by characteristic nuclear morphology staining with DAPI and caspase 3/7 activity.ResultsWe observed an increase in the mRNA levels of CHOP and the spliced form of XBP1 gene, 16–24h post infection in trophoblast. We also observed an increase in the levels of ER stress markers such as p‐IRE1α, p‐eif2α, and activation of c‐Jun N‐terminal Kinase (JNK) and p38 mitogen‐activated protein kinase (MAPK) after 16–24h of ZIKV infection in
trophoblast. As prolonged ER stress can cause apoptosis, we observed a dramatic increase in trophoblast apoptosis 48h post infection. Mechanistically, inhibition of JNK by SP600125 or pan caspase by Z‐VAD‐FMK significantly blocked ZIKV‐induced apoptosis in trophoblast. In conclusion, the mechanism of ZIKV‐induced placental trophoblast apoptosis involves the activation of ER stress and MAPK activation.Support or Funding InformationNIH: P20GM104320, Layman Seed award, UNL, Food for Health Research Initiative, UNL
Roles of Mitochondrial Dysfunction in Maleic Acid‐induced Acute Kidney Injury
Authors: Lin Hugo You-Hsien , Liang Chan-Jung 
Published: April 2020

BackgroundAcute kidney injury (AKI) is a growing public health burden globally. Mitochondrial function plays the key role in the progress of AKI. Maleic acid (MA) has been proofed to induce various renal dysfunctions include AKI. In our previous study, there were MA affinity proteins, including ATP synthase subunits, mitochondrial glyceraldehydes‐3‐phosphate, been identified in human kidney proximal tubular cells (HK2 cells)
(1). The goal of this study is investigating mitochondria roles in AKI using our MA‐induced mitochondrial dysfunction AKI modelMethodsFor the in vitro study, HK2 cells were induced with MA with 2mM and 5mM for 24 hours separately. For the in vivo study, we induced AKI in c57BL/6 mice by intraperitoneal MA injection with 400mg/kg body weight and sacrificed after 24 hours of injection.ResultsWe found that the MA treatment induces HK2 cell death with dosage responsive in MA 2mM (p<0.01) and MA 5mM (p<0.001). Serum BUN and creatinine were all increased (p<0.05) in the MA‐treated mice when compared to the vehicle treated mice. The histological analysis showed increased tubule injury index Jablonski score (p<0.001), tubular dilatation areas (p<0.001) and greater casting area (p<0.001) in MA‐treated as compared to vehicle‐treated mice. AKI marker, Kidney Injury Molecule‐1 was increased (p<0.001) in MA‐treated as compared to vehicle‐treated mice. The flow cytometry analysis indicated increased apoptosis (p<0.001), cell reactive oxidative stress (ROS) (p<0.001), mitochondrial ROS (p<0.001), and decreased mitochondria membrane potential (p<0.001) in MA‐treated compared to vehicle‐treated in vitro. In O2 respiration, MA‐treated HK2 cells decreased the capacity of electro transfer system activity (p<0.001) and nonphosphorylating LEAK respiration (electron flow coupled to proton pumping to compensate for proton leaks) (p<0.001), compared to vehicle‐treated. There was also significantly decreased ATP production in MA‐treated compared to vehicle‐treated in vitro. In mitochondria structure, the cristae of mitochondria were lost in MA‐treated compared to vehicle‐treated under transmission electron miscroscope examination. The gene expression was confirmed with the significant lower of ATPase6 in MA‐treated compared to vehicle‐treated. Moreover, renal mitochondrial protein of ATP subunit C (p<0.05) were significantly decreased in MA‐treated compared to vehicle treated in vivo.ConclusionThere results demonstrated that MA‐induced AKI through targeting renal proximal tubular mitochondrial ATP Synthase. Mitochondria may represent a novel therapeutic target for MA‐induced AKI.Support or Funding Information
Unregulated mTORC1 activation in the liver: hepatic loss of Depdc5 and Tsc1 synergistically produces liver failure and injury
Authors: Lee Jun Hee , Cho Chun-Seok , Ho Allison , Namkoong Sim , Kim Myungjin 
Published: April 2020

mTORC1 is an important metabolic regulator that responds to insulin/growth factors, nutrients and cellular stresses. DEPDC5 in the GATOR1 complex suppresses mTORC1 in conditions of limited nutrients, while TSC1 in the TSC1/TSC2 complex inhibits mTORC1 during insulin/growth factor deprivation and energetic stresses. Genetic variations in the DEPDC5 gene are associated with increased severity of liver pathologies during chronic hepatitis B and C virus (HBV/HCV) infection, which downregulates TSC1/TSC2. Using mice with liver‐specific Depdc5 deficiency, we examined how Depdc5 affects liver homeostasis, pathophysiology, and its interaction with Tsc1. Depdc5‐deficient mice exhibited enlargement of zone 3 hepatocytes, which progressed into liver damage, inflammation and fibrosis at later age. Double deletion of both Tsc1 and Depdc5 (DKO) produced synergistic mTORC1 activation, which was much more than what was observed from single Tsc1 or Depdc5 knockout mice. DKO mice experienced pronounced and widespread hepatocyte damage, and exhibited externally visible liver failure phenotypes, such as jaundice and systemic growth defects. Through systemic transcriptome analysis, we identified superoxide accumulation and oxidative damage as the main pathogenetic features distinguishing these mice from other mTORC1 models. Indeed, mTORC1 inhibition, as well as superoxide reduction, were sufficient to eliminate most pathological phenotypes we observed in mTORC1‐hyperactivated liver tissues. The current findings provide the genetic evidence supporting that growth factor/insulin‐regulated (Tsc1) and nutrient‐regulated (Depdc5) pathways genetically interact to coordinate mTORC1 activation. In addition, this multi‐pathway method for mTORC1 hyperactivation explains how DEPDC5 perturbations in humans aggravate HBV/HCV pathologies, which inhibit TSC1 and activate mTORC1.Support or Funding InformationR01DK102850, R01DK111465 and R01DK114131 to JHL, F31DK117610 to AH, K01AG061236 to MK, T32AG000114, T32GM008322, P30AG024824, P30AR069620, P30DK034933, P30DK089503 and P30CA046592