bluuebunny/crossref_metadata_2025 huggingface dataset:
ISOFLURANE‐INDUCED IMPAIRMENTS IN RODENTS EXPOSED TO A NOVEL OBJECT RECOGNITION TASK
Authors: Lopez-Astacio Robert A. , Jimenez Esther , Hernandez Anixa , Colon Pablo , Perez Emily , Puig Hector , Valentin Dennis , Thompson Kenira
Published: June 2021

Previous work has shown that general anesthesia results in post‐surgical cognitive deficits. In addition, previous work has shown that isoflurane increases inflammatory cytokine expression and causes cell injury in the hippocampus, which may contribute to isoflurane‐induced cognitive impairment in rats. Others found that a single isoflurane exposure does not affect Morris Water Maze performance in mice. Although the possible role of isoflurane on hippocampal plasticity has been previously assessed, the role of an acute exposure of isoflurane on novel object recognition has not been described. Here, we will compare the acute effects of isoflurane anesthesia and ketamine anesthesia in a rodent model of hippocampal learning known as the Novel Object Recognition (NOR) Task. Male Sprague Dawley rats (3 mo. old) were exposed to either isoflurane anesthesia (1–3%) or ketamine anesthesia (100 mg/kg) 14 days prior to training on NOR. Our results clearly indicate that animals anesthestized with ketamine display typical learning of the novel object recognition task whereas isoflurane administered animals display distinct impairments (p < 0.05). Our results support the notion that an acute administration of isoflurane anesthesia results in hippocampal‐dependent spatial memory impairments. Future work should be aimed at developing neuroprotectants to diminish isoflurane‐mediated learning deficits in the hippocampus in surgical patients.
High salt intake increases ETB receptor function in the renal medulla of rats
Authors: Jin Chunhua , Pollock David M.
Published: June 2021

The present study was conducted to test the hypothesis that high salt intake would increase the diuretic and natriuretic effects of renal medullary ETB receptor stimulation in vivo. Two groups of male Sprague Dawley (SD) rats were compared; after being fed normal (0.3%) and high salt (4%) diet for 7 days. Rats were anesthetized and a catheter implanted in the renal medulla for interstitial infusion along with a ureteral catheter for urine collection. An adjustable occluder was placed around the aorta proximal to the left renal artery to maintain renal perfusion pressure throughout the protocol. After equilibration and two 20 min control periods, the urine flow (UV) and sodium excretion (UNaV) responses to medullary infusion of a low dose of the ETB receptor agonist sarafotoxin S6c (0.15 μg/kg/h) were determined over an 80 min infusion period. Intramedullary infusion of a relatively low dose of S6c (0.15 μg/kg/h) markedly increased the urine flow and sodium excretion in the high salt treated rats (UV: 5.6±0.7 to 30.7±3.1 μl/min; UNaV: 1.1±0.2 to 2.2±0.3 μmol/min; n=9), but not in the normal salt treated rats (UV: 8.6±2 to 11.6±1.9 μl/min; UNaV 0.5±0.1 to 0.5±0.1 μmol/min; n=8). We conclude that high salt intake enhances the diuretic and natriuretic effects of ETB receptor stimulation in vivo consistent with a role for the ETB receptor in maintaining fluid‐electrolyte balance.
Sex differences in response to chronic administration of Tacrolimus in spontaneously hypertensive rats
Authors: Moulana Mohadetheh , Wallace Kedra , Lima Roberta , Zhang Huimin , Mathbout Mohammad , LaMarca Babbette , Reckelhoff Jane
Published: June 2021

Hypertension in male spontaneously hypertensive rats (SHR) is thought to be mediated in part by enhanced immune function. Tacrolimus (FK‐506) is a potent immunosuppressive used to decrease occurrence of allograft rejection. The present study tested the hypothesis that there are sex differences in response to tacrolimus in SHR. Young male (YM, age 3 mos; n= 6) and young female (YF, aged 3 mos; n= 4–5) SHR received tacrolimus (0.25 mg/kg/day i.p.) for 14 d. Rats were implanted with radiotelemeters and mean arterial pressure (MAP) was measured chronically. Tacrolimus increased MAP in males (Control: 143 ±3 mmHg vs. Tacrolimus‐treated: 163 ±4 mmHg, p=S), but had no effect in females (Control: 132 ±3 mmHg vs. Tacrolimus‐treated: 133 ±2 mmHg). After the experiment, blood was taken and the numbers of CD4+ and CD8+ T cells in peripheral blood leukocytes (PBL) were measured by flow cytometry. The number of CD4+ T cells decreased by similar percentage in females (Control: 42 ±7 vs. Treated: 30 ±4% gated) and males (Control: 49 ±2 vs. Treated: 32 ±3% gated) treated with tacrolimus. However, tacrolimus treatment decreased the number of CD8+ by 72% in females (Control: 18 ±6 vs. Treated: 5 ±2% gated) and 40% in males (Control: 33 ±2 vs. Treated: 20 ±1% gated). The data show that in spite of similar reductions in CD4+ cells and greater reduction in CD8+ T cells, tacrolimus had no effect on MAP in females. In males, tacrolimus increased MAP despite decline in CD4+ and CD8+ T cells. Thus the contribution of CD4+ and CD8+ T cells in mediating the hypertension in male and female SHR is not clear.
Sex differences in antioxidant capacity contributes to hypertension in adult intrauterine growth restricted offspring
Authors: Hennington Bettye Sue , Ojeda Norma B. , Williamson Danielle T , Hill Melanie L , Betson Nicole E.E. , Alexander Barbara T.
Published: June 2021

Oxidative stress plays a more definitive role in mediating hypertension (HT) in males than in females. Intrauterine growth‐restriction (IUGR) programs HT in adult male IUGR offspring; yet, female IUGR offspring are normotensive. The mechanisms mediating sex differences in blood pressure in adult IUGR are not clear. Previously we reported that HT in male IUGR offspring (P<0.05) is associated with a marked increase in renal superoxide production (P<0.05). Chronic treatment with the antioxidant tempol has no effect on BP in male control offspring, but it normalizes BP (P<0.05) and renal superoxide production (P<0.05) in male IUGR. Renal superoxide production is not elevated in adult female IUGR offspring. This study tested the hypothesis that sex differences in renal antioxidant status contributes to differential programming of BP in adult IUGR offspring. Renal protein expression and activity of the antioxidants catalase (CAT), glutathione peroxidase and Cu‐Zn‐SOD did not differ in male control versus IUGR. However, renal CAT protein expression and activity were significantly elevated in female IUGR (P<0.05). Thus, these data suggest that compensatory up‐regulation of antioxidant capacity may contribute to normalization of BP in adult female IUGR and contribute to sex differences in HT programmed by IUGR. NIH HL074927 and HL51971, NIH 5P20MD002725‐05, 5P20RR016476‐11, 8P20GM103476‐11, NSF‐DBI‐0957421.
Down‐Regulation of Replication Factor C‐40 (RFC40) causes chromosomal missegregation in neonatal and hypertrophic adult rat cardiac myocytes
Authors: Ata Hirotaka , Shrestha Deepa , Oka Masahiko , Ochi Rikuo , Jong Chian Ju , Gebb Sarah , Benjamin John , Schaffer Stephen , Hobart Holly , Downey James , McMurtry Ivan , Gupte Rakhee
Published: June 2021

Background

Adult mammalian cardiac myocytes (CMs) are generally assumed to be terminally differentiated, nonetheless, a small fraction of CMs have been shown to replicate during ventricular remodeling. However, the expression of Replication Factor C (RFC; RFC140/40/38/37/36) protein that is required for DNA synthesis, in the adult normal and hypertrophied hearts has rarely been studied.

Methods

We performed qRT‐PCR, Western blot analysis and immunohistochemical analysis to determine the levels of RFC message and protein in adult normal and pulmonary arterial hypertension induced right ventricular hypertrophied hearts. We determined chromosomal missegregation using Fluorescent in situ hybridization (FISH) for rat chromosome 12.

Results

RFC40 message and protein increased marginally in the hypertrophied hearts as compared to the fetal hearts. Immunohistochemical analyses revealed RFC40, cyclin A, phospho‐Aurora A/B/C kinase and phosphohistone 3 positive right ventricular CMs. FISH analyses demonstrated chromosomal missegregation in these hearts. Knock‐down of RFC40 caused chromosomal missegregation and decrease in the rat neonatal CM numbers.

Conclusion

Our novel findings suggest that insufficient re‐expression of RFC40 may be responsible for causing chromosomal missegregation in CMs during right ventricular hypertrophy.
Structural basis for the interaction between E. coli RNase HI and SSB
Authors: Petzold Christine , Marceau Aimee H. , Miller Katherine H. , Marqusee Susan , Keck James L.
Published: June 2021

Single‐strand (ss) DNA binding proteins (SSBs) interact with over a dozen different DNA replication, recombination, and repair proteins in bacterial cells. These interactions help drive genome maintenance processes by recruiting diverse enzymatic activities to their cellular sites of action. We have identified a new interaction between SSB and Ribonuclease HI (RNase HI) from E. coli that we hypothesize is important for targeting the nuclease to the RNA primers on the lagging strand during DNA replication. SSB stimulates RNase HI activity (hydrolysis of RNA in RNA/DNA hybrids) in vitro, possibly through recruitment of the enzyme to hybrids that are adjacent to SSB/ssDNA. We have shown that RNase HI binds to the C‐terminus of SSB (SSB‐Ct), which is a mode of interaction that is shared among all SSB interaction partners examined to date. Crystallographic and NMR studies coupled with isothermal titration calorimetry have mapped the SSB‐binding site on RNase HI. Future work is aimed at testing the hypothesis that the SSB/RNase HI interaction targets RNase HI to the lagging strand in vivo. Research supported by GM068061.
PCNA trimer stability and its impact on mutagenesis
Authors: Washington M. Todd , Dieckman Lynne , Kondratick Christine
Published: June 2021

Mutagenesis drives carcinogenesis by activating proto‐oncogenes and inactivating tumor suppressor genes. To develop novel strategies to reduce mutagenesis, we are studying several PCNA mutant proteins that are unable to support translesion synthesis, the error‐prone replication of damaged DNA. PCNA is a key replication accessory factor that forms a trimer that encircles DNA and confers high processivity to classical DNA polymerases. The X‐ray crystal structures of these PCNA mutant proteins show that they have disruptions in the anti‐parallel beta sheet constituting the PCNA subunit interface. As a result, these mutant proteins have moderately reduced trimer stabilities. Moreover, kinetic studies with both classical and non‐classical DNA polymerases in the presence of these mutant PCNA proteins show that the ability of both types of DNA polymerases to carry out translesion synthesis is impaired. This has lead us to a new model by which decreased PCNA trimer stability prevents the replicative bypass of DNA lesions by all DNA polymerases. This suggests that one may be able to reduce mutagenesis by decreasing PCNA trimer stability. The project described was supported by Award Number GM081433 from the National Institute of General Medical Sciences to M.T.W.
CDK1 differentially regulates G‐overhang generation at leading and lagging telomeres
Authors: Dai Xueyu , Huang Chenhui , Chai Weihang
Published: June 2021

Mammalian telomeres contain a single‐stranded 3′ overhang (G‐overhang) that functions in telomere end protection and telomerase action. Previously we have demonstrated that G‐overhang length undergoes cell cycle‐regulated dynamics that is controlled by multiple steps involving C‐strand end resection, telomerase elongation, and C‐strand fill‐in. The objective of this study is to understand the mechanism regulating these steps. Here we report that in both telomerase positive and negative cells, C‐strand fill‐in takes place at lagging daughter telomeres but not at leading daughter telomeres. We also identified a second end resection step in the G2 phase at leading daughter telomeres. Using inhibitors and RNAi, we show that Cdk1 functions in G‐overhang generation. Further study reveals that CDK1 controls both C‐strand fill‐in and end resection. In addition, we find that DNA polymerase alpha (Polα) association with telomeres is elevated upon CDK1 inhibition, suggesting that CDK1 may modulate the synthesis activity of Polα rather than control the loading of Polα to telomeres. Stn1, a subunit of the Ctc1/Stn1/Ten1 complex that plays a role in telomere protection, functions in the same pathway with CDK1 during fill‐in. In summary, we propose that there are different steps for G‐overhang generation at leading and lagging telomeres, and CDK1 regulates these steps.

Supported by “NIH R15GM099008”
Is There Any Relationship Between CASP‐8 D302H Gene Variation and Colorectal Cancer Risk
Authors: Pence Sadrettin , Cacina Canan , Arikan Soykan , Turan Saime , Pence Esad , Genc Feyza , Yaylim Ilhan
Published: June 2021

Caspase‐8(CASP‐8) is a key regulator of apoptosis, an essential defense mechanism against hyperproliferation and tumorigenesis. Polymorphisms in CASP8 gene have been reported to influence cancer risk. The present study was designed to investigate the role of CASP‐8 D302H gene polymorphism in the colorectal cancer development. CASP‐8 D302H genotypes were determined by using polymerase chain reaction‐restriction fragment lenght polymorphism (PCR‐RFLP) analysis. A total of 80 patients with colorectal cancer and 127 control individuals were enrolled in the current study. There were no significant differences in the distribution of CASP‐8 D302H genotypes between colorectal cancer patients and controls The carrying of CASP‐8 D302H GG/CC homozygous genotypes were increased in patients compared to control group and this difference was statistically significant (p:0.023; 1.303(1.045–1.626). These results suggest that D302H polymorphism in CASP‐8 gene may be associated with increased risk of colorectal cancer.
Metabolite Predictors of HOMA in At‐Risk for Mobility Disability Elderly Subjects
Authors: Lustgarten Michael S. , Fielding Roger A.
Published: June 2021

The aim of this study was to evaluate the relationship between fasting serum levels of analytes and metabolites with the homeostasis model assessment of insulin resistance (HOMA), in at‐risk for mobility disability elderly subjects (avg. SPPB, 8.5). 73 participants (30 males, 43 females; avg. age, 78y) participated in the study. Serum analytes and metabolites were measured with use of the traditional chemistry screen and untargeted mass spectrometry‐based metabolomics, respectively. HOMA was calculated based on measurements of serum glucose and insulin. Sex and age‐adjusted linear regression was used to identify covariates significantly associated with HOMA (p≤0.05, q≤0.30), followed by stepwise multivariable linear regression on all significant covariates. BMI, eleven metabolites and two analytes were found to contain significant associations with HOMA. Sex and age‐adjusted stepwise regression identified the combination of BMI, four metabolites and one analyte to explain 51.6% of the variability inherent in HOMA. The evidence presented in the current study is the first attempt to identify baseline serum predictors of HOMA in at‐risk for mobility disability elderly subjects.
COMP‐Ang1 preserves vasculature and prevents vision loss in diabetic retinopathy
Authors: Cahoon Judd Michael , Olson Paul Robert , Zhang Xiao Hui , Flood Maggie Marie , Archer Bonnie , Ambati Balamurali Krishna
Published: June 2021

Diabetic retinopathy (DR) is the most common cause of blindness in the working‐age population. Vascular dysfunction is a hallmark of DR. Prolonged hyperglycemia results in loss of pericytes, the support cells that surround the capillary. An important pericyte derived trophic factor is angiopoietin‐1 (Ang‐1), which binds to the endothelial Tie2 receptor. Loss of pericytes and decreased Ang1 has been described as an early event in diabetic retinopathy. Here we show that vascular normalization with cartilage oligo matrix protein angiopoietin 1 (COMP‐Ang1) prevents endothelial dropout and the critical sequelae of ischemia and hyperpermeability in a mouse model of DR. COMP‐Ang1 increased VE‐cadherin expression and decreased VEGF‐A expression in the diabetic mouse retina. COMP‐Ang1 preserved vascular network area comparable to non‐diabetic control levels, despite persistent pericyte dropout. Additionally, COMP‐Ang1 decreased retinal inflammation, as noted by decreased leukocyte adhesion and infiltration. Furthermore, AAV2.COMP‐Ang1 therapy prevented retinal thinning and ganglion cell layer dropout. Most importantly, diabetic mice treated with COMP‐Ang1 retained near‐normal visual acuity and electroretinographic response. COMP‐Ang1 may be useful in promoting vascular normalization by reducing ischemia and hyperpermeability in diabetic retinopathy.
Thiol‐based Antioxidants Trigger Transient Mitochondrial Oxidation
Authors: Beaudoin Jessica Nicole , Kolossov Vladimir L. , Hanafin William , DiLiberto Stephen , Kenis P. G. , Gaskins H. R.
Published: June 2021

Perturbation of redox homeostasis has been associated with tumorigenisis, however, the underlying mechanisms are poorly understood due to analytical limitations. In this regard, we have used a ratiometric, redox‐sensitive green fluorescent protein attached to glutaredoxin to monitor real time redox potentials of the glutathione pool in the cytosol and mitochondrial matrix of colonic adenocarcinoma (HCT116), glioblastoma (GL261), and isogenic tumorigenic and normal porcine fibroblast (PF161) cell lines. Intriguingly, this wide array of cell types consistently exhibited mitochondrial oxidation following exposure to the antioxidants N‐acetylcysteine and glutathione ethyl ester. These chemotherapeutic drugs immediately triggered full oxidation of the mitochondrial sensor, followed by rapid recovery. This effect was observed exclusively in mitochondria, leading us to hypothesize involvement of the electron transport chain (ETC), the main source of reactive oxygen species. By systematically inhibiting respiratory complexes of the ETC, we identified complex III to be responsible for this short‐lived mitochondrial oxidation. The discovery that antioxidants initiate mitochondrial stress may provide insight into the efficacy of antioxidants in conjunction with chemotherapy. Our current focus is to determine if or how this mechanism may contribute to neoplastic transformation. Support granted by NIH R33 CA137719
Palm Fruit Juice phenolics reduce the number of mutations caused by 3′‐Azido‐3′‐deoxythymidine treatment in a cultured human cell line
Authors: Osborne Adam , Stopa Arielle , Solomon Martha , Wangh Lawrence , Hayes Kenneth C
Published: June 2021

3′‐Azido‐3′‐deoxythymidine (AZT), used to treat HIV/AIDS, has been shown to cause mitochondrial dysfunction over time. How this dysfunction develops and its relation to long‐term adverse side effects of treatment, that include diabetes and Alzheimer's disease, is not known. One hypothesis is that AZT causes mutations in mitochondrial DNA (mtDNA) that build up over time, and that these mutations lead to mitochondrial dysfunction and disease. A broadly applicable approach to detect mutations without sequencing was developed using a LATE‐PCR Lights‐On/Lights‐ Off multiplex assay. The study objective tested whether AZT increases mitochondrial DNA mutations over time and whether palm fruit juice (PFJ) would reduce this damage. PFJ contains phenolics that might act to reduce the amount of reactive oxygen species, which are mutagenic to mtDNA. Three gene targets, HV2, CO2, and ND1, from the mitochondria of HepG2 cells were studied to assess AZT‐induced mutations in cell culture. Initial results revealed that AZT treatment for 30 days induced up to a 9‐ fold increase in mutations in all three target genes compared to normal culture media. When palm fruit juice was added with AZT, mutations decreased by 35% versus AZT alone. These results provide insight into how AZT damages mtDNA and suggest a possible way to ameliorate AZT effects in patients.

This work was supported by a grant from the Malaysian Palm Oil Board.
Inhibitory effects of Alaria fistulosa uronan on tyrosinase activity and melanin synthesis
Authors: Lee Yong Hwan , Yoon Byung Han , Ku Mi Jeong
Published: June 2021

The aim of this study was to assess the inhibitory effects of Alaria fistulosa uronan on melanin synthesis and tyrosinase activity and their mechanisms. B16F1 cells were treated with A. fistulosa uronan (0, 0.1, 1 and 10 μg/mL, respectively) and α‐melanocyte stimulating hormone (α‐MSH), simultaneously. Content of melanin synthesis and tyrosinase activity were determined. The expressions of mitogen activated protein kinases (ERK, AKT, and p38) were measured by western blotting. Treatment with 0.1, 1 and 10 μg/mL significantly decreased tyrosinase activity by 5.7%, 9.4%, and 17.4%, respectively, compared to control (p<0.05). Treatment with 1 and 10 μg/mL A. fistulosa uronan and 200 nM α‐MSH significantly decreased melanin synthesis by 18.8% and 32.5%, respectively, compared to control (p<0.05). Phosphorylation of ERK and AKT were activated by treatment with A. fistulosa uronan for 30 min to 180 min. A. fistulosa uronan decreased tyrosinase activity by inhibition of microphthalmia‐associated transcription factor expression through the activation of ERK and AKT in B16F1 melanoma cells.
Synergistic Effects of Digitoxin Analogues in Combination with Chemotherapeutic Drugs
Authors: Hinds John William , McKenna Sean
Published: June 2021

Digitoxin is a cardiotonic agent that has traditionally been used as a treatment of congestive heart failure. Recently, it has been acknowledged for its potential in cancer treatment.[1–3] We have characterized a digitoxin‐glycoside, which is believed to express its cytotoxic effect through inhibition of the Na+/K+‐ATPase pump. This inhibition of Na+/K+ exchange by digitoxin is believed to induce apoptosis or programmed cell death selectively in cancer cells via Src‐tyrosine kinase.[4]

In previous studies we have synthesized various digitoxin analogues focusing on the stereochemical effects of the C3′/C4′ stereocenters. From this research we identified our lead analogue, α‐L‐rhamno 1.[5] In this study we aim to further the scientific understanding of α‐L‐rhamno 1 and its synergistic effects with other chemotherapeutic agents. The study was conducted on several cancer cell lines using MTT assays to measure cytotoxic effect and to generate dose‐response curves. The drugs chosen to be tested for synergistic or antagonistic effects were selected based on their widely varying mechanisms of action, and conventional use in chemotherapy. These drugs include camptothecin, doxorubicin, oxaliplatin, and 5‐fluorouracil.
Identification of key signaling molecules downstream of cAMP that regulate insulin secretion
Authors: Neuman Joshua C , Truchan Nathan A , Pasker Renee L , Kimple Michelle E
Published: June 2021

In the pancreatic islet, the unique heterotrimeric G protein α‐subunit, Gαz, inhibits adenylate cyclase, reducing cyclic adenosine monophosphate (cAMP) levels. cAMP is an important potentiator of glucose‐stimulated insulin secretion (GSIS) and Gαz‐null islets have enhanced GSIS. To further delineate the mechanisms downstream of cAMP that impact GSIS, an exon array analysis was performed in islets isolated from 10‐week‐old male Gαz‐null and control mice. Candidate genes were flagged as being differentially expressed in Gαz‐null islets. To further test the mechanism for gene regulation, highly glucose‐and cAMP‐responsive Ins‐1 832/3 insulinoma cells were treated with various stable cAMP analogs. PGC‐1α was induced greater than 4‐fold with increasing 8‐CPT‐cAMP dose and 8‐fold with increasing 8‐CPT‐cAMP treatment time. 8‐CPT‐cAMP activates both the Epac and PKA pathways. Treatment with an Epac‐specific cAMP analog, 8‐CPT‐2′‐O‐Me‐cAMP, had no effect on PGC‐1α suggesting PKA as the specific activator downstream of cAMP. Thus, PGC‐1α may play an important role in cAMP dependent insulin secretion and further functional characterization of PGC‐1α in the β‐cell may help explain the phenotype of increased GSIS in Gαz‐null islets. This work was funded by JDRF grant 17–2011‐608 (to M.E.K).
PAR‐1 is a novel mechano‐sensor transducing laminar flow‐mediated endothelial signaling
Authors: Kim Suji , Nam Daehwan , Han Junghwa , Woo Chang‐Hoon
Published: June 2021

Laminar blood flow acts mainly on vascular endothelial cells(ECs) which modulates atheroprotective functions. ECs express laminar flow‐mediating molecules of the mechano‐sensor including G proteins, integrin, and growth factor receptor. However, flow‐mediated signaling pathway of G protein and GPCR is not well established. Recent studies have indicated that PAR‐1 Known as GPCR which involves cytoprotective and anti‐inflammatory responses in endothelial cells. Here, we addressed whether the PAR‐1 is involved by laminar flow‐mediated atheroprotective signaling. In present study, depletion of PAR‐1 with siRNA against human PAR‐1 inhibited flow‐mediated KLF2‐and Nrf2‐dependent gene expression in ECs. In addition, confocal analysis showed that PAR‐1 was internalized into early endosome in response to laminar flow suggesting that PAR‐1 is activated by laminar blood flow. We identified HDAC5 as a downstream target molecule of PAR‐1. Furthermore depletion of PAR‐1 reversed the flow‐mediated anti‐inflammatory response for TNFa‐induced VCAM‐1 expression and monocyte adhesiveness. Taken together, these results provide that flow‐induced PAR‐1 activation exerts atheroprotective signaling pathway in ECs.
Calcium‐induced structural changes of the CaM–KCNQ complex
Authors: Lvov Anatoli , Mruk Karen , Kobertz William R
Published: June 2021

Association with ubiquitous calcium‐binding protein calmodulin (CaM) endows KCNQ (Kv7) potassium channels with sensitivity to intracellular calcium levels. While it is generally known that CaM binds to the cytoplasmic C‐termini of these channels, conformational changes underlying CaM‐dependent KCNQ modulation remain poorly understood. Previously, we used an intracellular tethered blocker approach in a combination with whole cell recordings to generate a quaternary structural model of CaM bound to a functioning KCNQ2/KCNQ3 channel. This structure positions CaM adjacent to the KCNQ activation gate. Here, we tested the hypothesis that calcium binding induces a repositioning of the CaM lobes bound to the channels. Comparison of the radial distances for fully calcified CaM to two different mutants that prevent calcium binding to either N‐ or C‐lobe (CaM1–2 or CaM3–4, respectively) demonstrated significant conformational changes in KCNQ/CaM1–2 (but not CaM3–4) complexes. These findings support the notion that calcification of the N‐lobe of Ca‐M results in conformational changes in CaMKCNQ complex, which underlie its sensitivity to intracellular calcium.
Genistein activates BMP‐Smad signaling pathway in MC3T3‐E1 cells
Authors: Katsuyama Hironobu , Fushimi Shigeko , Yamane Kunikazu , Hinenoya Hajime , Akiyama Yuji , Tomita Masafumi , Okuyama Toshiko , Watanabe Yoko , Katsuyama Midori , Saijoh Kiyofumi
Published: June 2021

Many epidemiological studies show that genistein intake is effective to maintain bone mineral density (BMD), so that the mechanisms underlying the effects of genistein on osteoblastic MC3T3‐E1 cells were investigated. Increase of osteoblastic MC3T3‐E1 cells were observed after administration of genistein. However, this increase was inhibited by ICI 182,780, inhibitor of estrogen. MC3T3‐E1 cells showed high alkaline phosphatase (ALP) activity after administration of genistein, indicating that genistein promoted estrogenic differentiation of MC3T3‐E1 cells. Production of osteoprotegerin (OPG), which is expressed by MC3T3‐E1 cells, was higher than control after administration of genistein by ELISA. Since OPG production was inhibited by noggin, inhibitor of BMP‐4, we investigated the BMP‐Smad signaling pathway. Genistein induced gene expression of BMP‐4. Moreover, immunofluorescence staining showed that genistein induced phosphorylation of Smad 1/5, a downstream molecule of BMP‐4, and noggin inhibited the phosphorylation of Smad 1/5. These results indicated that genistein might regulate osteoblastic function through BMP‐Smad signaling pathway as well as estrogen receptor pathway. This study was supported in part by a Research Project Grant (no. 21–204) from Kawasaki Medical School.
Persistent food insecurity is associated with active coping strategies among low‐income pregnant Latinas
Authors: Hromi‐Fiedler Amber , Bermúdez‐Millán Angela , Leon Joanne , Segura‐Pérez Sofia , Pérez‐Escamilla Rafael
Published: June 2021

The objective of this study was to evaluate the relationship of persistent food insecurity during pregnancy with coping strategies among low income pregnant Latinas (N=92). Persistent food insecurity was assessed using a modified version of the U.S. Household Food Security Scale across two time periods during pregnancy. Coping strategies were assessed using an adapted version (consisting of eleven subscales) of the Brief COPE. Preliminary results showed that persistent food insecurity was associated with higher levels of 4 coping subscales: self‐distraction, planning, acceptance, use of religion. Factor analyses of the 11 subscales suggested three overall coping strategies: active coping, negative emotion coping, and avoidant coping. Findings from unadjusted logistic regression analyses showed that women who experienced persistent food insecurity during pregnancy were 3.5 times more likely to use active coping strategies (consisting of humor, positive reframing, religion, planning, acceptance subscales) than those who experienced intermittent food insecurity or who were food secure. These findings suggest that active coping strategies may be more effective for Latinas experiencing persistent food insecurity during pregnancy than other coping strategies. Funded by Connecticut NIH EXPORT Center of Excellence for Eliminating Health Disparities among Latinos (NIH‐NCMHD Grant # P20MD0017650).
Household Food Insecurity is Positively Associated with Perceived Discrimination among Cambodian Pregnant Women in Massachusetts
Authors: Chen Shanshan , Peterman JN , Mouth Ronnie , Cordeiro Lorraine
Published: June 2021

Food insecurity is a growing concern in the US. For pregnant women, food insecurity may increase the risk of maternal morbidity and impair the growth and development of fetus. Discrimination is an important determinant of health inequalities. This cross‐sectional study investigated the associations between food insecurity and perceived discrimination among a group of pregnant Cambodian women (n=75) in Massachusetts. Demographics, acculturation, discrimination, and food security data were collected. The association between food insecurity and perceived discrimination were tested using logistic regression, adjusted for age, education, country of birth, and acculturation. The prevalence of household food insecurity was 48%. 54.5% of the participants reported discrimination due to ethnicity, skin color, and language. Higher rate of perceived discrimination was associated with higher risk of household food insecurity (OR=2.13, p<0.05). These findings suggest that perceived discrimination may constitute a significant risk factor for household food insecurity among Cambodian pregnant women in Massachusetts. Longitudinal studies examining these associations as well as identification of the underlying causes of the discrimination are needed.
Associations between nutritional status of micronutrients and the growth, body composition and biomarkers of metabolic risk in Chilean children
Authors: de Romana Daniel Lopez , Corvalan Camila , Uauy Ricardo , Cediel Gustavo , Duran Gabriela , Palomino Ana Maria
Published: June 2021

Introduction

The associations between micronutrients and obesity and/or chronic diseases are not consistent.

Methods

Cross‐sectional study of 300, 8–11 y children. The following measurements were obtained: 1) Anthropometry: weight (wt), height (ht), zBMI; 2) Body composition: % body fat; 3) Biomarkers metabolic risk: insulin, glucose, serum lipids, adiponectin, leptin; 4) Micronutrient indicators: hemoglobin (hb), serum ferritin (SF), serum transferrin receptors (TfR), hepcidin, plasma zinc (ZnPl) and serum VD concentrations (25OHD).

Results

26% of children were overweight and 29% obese. None of the children were anemic or Zn deficient. 4% were Fe deficient and 28% VD deficient. No associations were found between FS or 25OHD and either wt, ht, % fat or metabolic risk indicators. A significant direct association was observed between TfR and Wt (r 0.24), ht (r 0.14), zBMI (r 0.25), % body fat (r 0.22). Significant correlations were found between hepcidin and both wt (r −0.12) and zBMI (r −0.12). ZnPl correlated with % body fat (r 0.12) and insulin (r −0.20). No significant differences in Hb, SF, hepcidin or 25OHD were found between obese (Ob) and non‐obese children. Both TfR and ZnPl were significantly higher in Ob children.

Conclusions

Vitamin D status is not associated to Ht, % body fat or biomarkers of metabolic risk. Ob children had higher ZnPl and TfR concentrations than N children.

Source of funding: FONDECYT research grants 1090252, 1100206 and 1110085.
Effectiveness of ¡Pilas!, a community‐based pilot intervention for chronic disease prevention in Guatemalan school‐age children
Authors: Chacon Ana Violeta , Letona Paola , Ramirez‐Zea Manuel , Gittelsohn Joel , Caballero Benjamin
Published: June 2021

Background

Childhood obesity is increasing in Guatemala. Culturally appropriate interventions to promote healthy lifestyles in school‐age children are needed to prevent future chronic disease.

Objective

To assess short‐term effectiveness of a school and community‐based intervention ¡Pilas! that promotes healthy eating, physical activity (PA), and discourages alcohol and tobacco use in Guatemalan children.

Methods

This was a pre/post‐test, single sample study involving 119 children (aged 10–12 yrs) in two public schools in a poor urban area. The 17 week intervention had three components: school, food kiosk, and community. We measured knowledge, attitudes, self‐efficacy, dietary intake (24‐h food list measuring average times/day) and PA (steps/day and min/d at of moderate‐vigorous PA).

Results

Children increased their knowledge and self‐efficacy for healthy eating (p<0.01). PA knowledge, attitudes and self‐efficacy (p<0.01) also increased. Sweet‐beverage (from 0.74 to 0.64, p<0.01) and processed food intake (from 2.71 to 2.64, p=0.04) decreased. Self‐efficacy for avoiding alcohol and tobacco use increased (p<0.01). The intervention did not increase PA.

Conclusions

The intervention may improve psychosocial factors related to healthy eating, PA, alcohol and tobacco use in children. A randomized controlled trial is needed to assess a longer intervention with stronger PA strategies.

Grant Funding Source: NHLBI‐HHSN 268200900028C
A case study: Nutrition and Physical Activity Environments of Public Childcare Centers in Korea, Sweden, and US
Authors: Kim Juhee , Jackson Natalie , Elinder Liselotte Schäfer , Singhru Deepa , Olsson Linnea , Bremberg Sven , Kim Keunsei
Published: June 2021

Objectives

To compare nutrition and physical activity environments in public childcare centers across nations; we conducted a case study in Korea, Sweden, and US.

Methods

The Nutrition and Physical Activity Self‐Assessment for Child Care questionnaire was filled out by a childcare director from conveniently sampled public childcare centers from high‐ and low‐income areas in each nation (2 sites per nation).

Results

A greater variability was seen in physical activity than in nutrition in all three nations. All nations need to improve the “Education for Staff’ in nutrition and physical activity. Overall, Sweden's low‐income site received the lowest total score at 43.0; whilst the US's high‐income site scored the highest at 53.1. The US showed the largest disparity between the low‐and high income (43.7 and 53.1); whereas Korean sites showed similar scores (47.5 and 47.6).

Conclusion

The findings have limited interpretations because of a convenient sampling; however, there are areas to improve nutrition and physical activity‐related practices and policies, regardless of nations. Further, this study demonstrated feasibility to conduct an international comparison study. (Funding: National Research Foundation of Korea Grant (NRF‐2011–330‐B00190), European Union Center Grant & INSPIRE Grant at University of Illinois.)
Increased Gut Microbiome Diversity Following a High Fiber Mediterranean Style Diet
Authors: Steinle Nanette , Cirimotch Shana , Ryan Kathy , Fraser Claire , Shuldiner Alan , Mongodin Emmanuel
Published: June 2021

We investigated the effects of a Mediterranean style diet on the composition of the gut microbiome, and on fasting lipids. Nine men and women age 50–65 years with BMIs 25–35 kg/m2 and with impaired fasting glucose collected fecal samples during a 2‐week run‐in period, and after the 2‐week calorically‐neutral diet intervention, and provided blood for the analysis of fasting lipids. Bacterial RNA was extracted from pre and post intervention fecal samples, and 454 pyrosequencing of 16S rRNA transcripts (as cDNA) was performed. We sequenced 391,870 high‐quality 16S reads. There was a mean 14% decrease in triglyceride levels (180.8 mg/dl vs 156.8 mg/dl; SD = ± 57.5, p= 0.25), and a mean 12% decrease in LDL cholesterol levels (157.8 mg/dl vs 139.2 mg/dl; SD = ± 16.4, p= 0.009). We observed clustering of individuals’ microbial profiles; (e.g. each microbiome appears to be unique, and within each individual cluster, pre‐diet datapoints cluster separately from post diet datapoints). The number of species‐level operational taxonomic units increased following the diet intervention (+9.64% on average); richness as calculated by the Chao1 (+8.22%) and Ace estimates (+6.37%) increased, as well as the Simpson diversity index (+34%). Ongoing studies focus on identifying which specific group of microbes is responsible for this increase in diversity and their associations with metabolic and inflammatory markers.

Grant Funding Source: P30 DK072488 and the Dry Bean Health Research Program
Moderate hyperglycemia and a blunted anabolic response to perioperative parenteral amino acids in type 2 diabetes mellitus patients undergoing colorectal cancer surgery
Authors: Manjrekar Anagha , Nitschmann Evan , Lattermann Ralph , Schricker Thomas , Wykes Linda
Published: June 2021

Insulin resistance of type 2 diabetes mellitus (T2DM) is accentuated by surgical stress. Hyperglycemia can also be exacerbated by nutrition support; so a balance of anabolic and euglycemic strategies is essential. Patients with T2DM (n=7) or without (ND, n=11) undergoing colorectal cancer surgery received parenteral nutrition (PN) based on 20% of resting energy expenditure as amino acids (AAs, from 20h preop). Glucose, protein kinetics and fractional synthesis rate (FSR) of hepatic secretory proteins were measured with D‐[6,6‐2H2] glucose, L‐[1‐13C]leucine and L‐[ring‐2H5]phenylalanine while fasting preop, and again while receiving PN two days postop. In fasted state preop, subjects were in negative leucine balance, with T2DM being more negative than ND (p<0.027). PN improved leucine balance (p=0.008), but balance was more negative in T2DM. Surgery invoked an acute phase response with increased fibrinogen (p<0.0001) and its FSR (p<0.0007). Albumin FSR was maintained to a similar extent postop. Plasma glucose was similar preop, but higher postop in T2DM (p<0.005), possibly resulting from a tendency for higher endogenous production (p<0.10) and lower clearance (p<0.13). Plasma AAs showed changes typical of surgery attenuated increases in branched chains (p=0.035) and essentials (p=0.026) in T2DM. PN with AAs supports acute phase response in T2DM but with moderate hyperglycemia and a blunted anabolic response. Higher AA doses or combined AA and low glucose are suggested achieve anabolic response in T2DM.(Canadian Institutes of Health Research)
Inrauterine growth retardation results in altered metabolism and elevated preadipocyte proliferation in pigs
Authors: Ajuwon Kolapo M
Published: June 2021

The pig is a natural animal model for the study of intrauterine growth retardation because it is a polytocous animal. Being born small for gestational age (SGA) is associated with higher susceptibility to obesity development later in life. The biological explanation for this increased risk for obesity in SGA animals is not well defined. We determined the proliferative capacity of preadipocytes isolated from the subcutaneous adipose tissue of SGA or control neonatal pigs (less than 1 week old). Higher (approx. 70% increase) preadipocyte proliferation was observed in the SGA vs. control (P<0.05). Adipose tissue and preadipocytes from SGA pigs also have reduced PPARγand UCP‐2 expression. Preadipocytes from SGA animals have limited capacity for differentiation vs. control animals. Reduced UCP‐2 expression in SGA animals also suggest impaired fatty acid oxidation compared to control animals. The reduced capacity for differentiation in SGA animals may be linked to their reduced capacity to oxidize lipids. Strategies that upregulate fatty acid oxidation may help reduce preadipocyte proliferation and prevent future obesity development in SGA animals.
Predictors of vitamin D status in subjects that consume a vitamin D supplement
Authors: Levy Mark A , Dern Adam , Barker Tyler , Schneider Erik , McKinnon Toni , Robertson Jeff , Cuomo John , Wood Tim , Dixon Brian M
Published: June 2021

Recent evidence suggests that circulating vitamin D levels above the current RDA (20ng/ml) may be associated with better health outcomes. However, many factors impact vitamin D status, but their influence on serum levels of 25(OH)D remains unclear. In this retrospective, cross‐sectional study, we sought to identify predictor variables of vitamin D status in free living subjects. Serum levels of 25(OH)D were measured, and the variables gender, ethnicity, height, weight, age, geographic location, duration of daily sun exposure, use of sunscreen and sun‐obscuring clothing, dietary intake, supplement usage, latitude of residence and BMI were used to predict vitamin D status in a summer and winter cohort of subjects. Supplemental vitamin D3 intake was the most significant positive predictor ‐ whereas BMI was the most significant negative predictor ‐ of vitamin D status in both the summer and winter cohort. Additional positive predictors were fortified beverage consumption in the summer, and dairy consumption in the winter. Negative predictors were African American and Asian ethnicity in the summer, while latitude of residence >;36°N and Asian ethnicity were negative predictors in the winter. These results indicate that vitamin D supplementation is the most significant positive predictor of vitamin D status, and point to the practicality of utilizing vitamin D supplements to reduce hypovitaminosis D.
Vitamin D status, sun exposure and lipid profile among adolescents living in São Paulo, Brazil
Authors: Giudici Kelly Virecoulon , de Pádua Lopes Mariana Agostinho , Marchioni Dirce Maria Lobo , Fisberg Regina Mara , Martini Lígia Araújo
Published: June 2021

To evaluate the association between vitamin D (VD) status, lipid profile and sun exposure among adolescents living in Brazil. A total of 140 subjects (55.3% male), mean age 16.1 years (SD = 1.5) were included. A blood sample was collected after a 12‐hour fasting to determine VD, total cholesterol (TC), HDL‐c, LDL‐c and VLDL‐c concentrations. Height and weight were measured. Sun exposure data were obtained through a standardized questionnaire. Student T and Pearson's Chi‐Square tests were performed. Mean body mass index (BMI) was 21.6 kg/m2 (SD = 4.7), and 29.0% were overweight. Mean VD concentration was 28.8 ng/mL (SD = 11.6), and boys presented higher VD insufficiency than girls (70.3% vs 46.9%; p = 0.012). The adolescents classified in the highest tertile of VD presented lower BMI than those in the second tertile (20.4 kg/m2, SD = 3.3 vs 23.0 kg/m2, SD = 5.4; p = 0,041). The majority (85.6%) reported having the habit of getting exposed to the sun for more than 30 minutes, but 69.7% rarely or never apply sunscreen. The prevalence of low HDL‐c concentration was 17.1%, also higher among boys (25.6% vs 6.5%; p = 0.003). TC and LDL‐c concentrations were considered inadequate in 7.9% and 5.0% of the sample, respectively. Although the studied population lives in a sunny country and refers the habit of sunning, the prevalence of VD insufficiency was high, especially among boys, who also presented high HDL‐c inadequacy. FAPESP.
Korean Middle School Students’ Dietary Habits and Degree of Satisfaction with School Meals
Authors: Kim YoungA , Kim Hyo Young
Published: June 2021

The purpose of this study was to examine the dietary habits of middle school students and the effects of school meals on their dietary habits. 422 middle school students (212 boys and 210 girls) were cross‐sectional surveyed in Incheon, one of 5 major cities in Korea, using a questionnaire. Data were analyzed with SPSS 18.0 program.

The average Body Mass Index (BMI) of male and female students were 19.9 kg/m2 and 19.4 kg/m2, respectively in the normal weight range. There was a significant difference in the ratio of eating breakfast every day between male (64.6%) and female (50.0%) students (p<.01). In the aggregate, 73.9% of students had unbalanced eating habits and there were significant differences according to gender and BMI (p<.05). The biggest factor to affect their dietary habits was the dietary habits of their family's (p<.01). As for the degree of satisfaction with school meals, 83.1% of students were satisfied usually, while there was a significant difference according to gender and age (p<.01). Two major reasons for dissatisfaction with school meals were ‘poor taste’ (33.8%) and ‘small quantity’ (32.4%). Students expected the menu of school meals to be more diverse, new (49.1%), and to be composed with one‐dish meal more often (24.6%). It was found that school meals had partial impacts on students to eat vegetables more often and experience various food materials. Furthermore, unbalanced eating habits were corrected by school meals for a meaningful portion of students (31.3%). Therefore school meals and nutrition education are important because it matters on students’ dietary habits and their nutritional qualities.

Grant Funding Source: Inha University
Food Choices for 2–5 Year Old Children in California Childcare: Comparing 2008 and 2012
Authors: Sharma Sushma , Yoshida Sallie , Braff‐Guajardo Ellen , Ritchie Lorrene D
Published: June 2021

Nearly two million children regularly spend time in childcare in California. However, not much was known about the nutrition environments of these settings. In 2008, we conducted a statewide study (n=429 childcare sites) to investigate food and beverages options provided. This study was used to inform the Healthy Beverage law implemented in January 2012 to regulate beverages in licensed childcare in California. In 2012, we repeated the study with an aim to compare the major food categories provided to 2–5 year old children in 435 childcare sites (serving ~32,000 children) in California between 2008 and 2012.

Compared to 2008, in 2012 we found that 10% more sites reported serving whole grains servings, whereas 4% fewer sites served white grains. In 2012, 2% more sites served fresh fruits, whereas 7% fewer sites served canned fruit. Similarly, more sites served legumes (9%), vegetarian meat substitute (13%) and baked/broiled chicken/fish (15%) in 2012. However, increases (5–10%) were also observed for sugary items, fried potatoes, and potato chips.

From 2008 to 2012 an increased percentage of childcare sites provided foods that tend to positively impact the diet quality of young children. More efforts are required to bring positive changes for foods that tend to negatively impact diet quality, and contribute excess calories, such as sugary and savory snacks and fried potatoes.