bluuebunny/crossref_metadata_2025 huggingface dataset:
Dried plums consumed twice daily increase antioxidant capacity after two weeks in adult women
Authors: Kaper Stacy , Howarth Leslie S , Petrisko Yumi , Furchner‐Evanson Allison , Nemoseck Tricia , Hong Mee Young , Kern Mark
Published: June 2021

Consumption of an antioxidant‐rich diet is associated with a lower incidence of heart disease and is thought to be involved with preventing cancer and other inflammatory diseases. The purpose of this study was to determine the effects of twice daily consumption of dried plums as snacks for two weeks on antioxidant capacity and C‐reactive protein in humans compared to cookie consumption. Twenty‐seven women aged 25–54 years were provided with twice daily 100 kcal servings of either dried plums or low‐fat cookies for separate two‐week feeding trials with a two‐week washout period. After an overnight fast, blood samples were collected prior to initiating each feeding trial and after two weeks of each trial. Serum C‐reactive protein was measured using an ELISA assay. The Trolox‐equivalent antioxidant capacity (TEAC) assay was used to measure antioxidant capacity. Two weeks intake of 100 kcal dried plums resulted in an increase in antioxidant capacity (P<0.05) compared to two weeks intake of 100 kcal cookies. Antioxidant capacity was increased after two weeks of dried plum snack (P=0.039) but decreased with cookie snacks (P=0.018). C‐reactive protein levels did not differ significantly between the two feeding trials. These results suggest that choice of snack may impact health by influencing antioxidant status.

This study was supported by the California Dried Plum Board.
RGS7 Protein Suppression of Gao Protein‐Mediated α2A‐Adrenergic Receptor Inhibition of Mouse Hippocampal CA3 Epileptiform Activity
Authors: Nelson Brian William , Goldenstein Brianna , Xu Ke , Luger Elizabeth , Wald Jenna , O'shea Lorraine , Weinshenker David , Sjogren Benita , Charbeneau Raelene , Huang Xinyan , Neubig Richard , Doze Van
Published: June 2021

G‐protein coupled α2 adrenergic receptor (AR) activation by epinephrine (EPI) inhibits epileptiform activity in the mouse hippocampal CA3 region. The mechanism underlying this action is unclear. This study investigated which subtypes of α2ARs, G‐proteins (Gαo or Gαi), and RGS proteins were involved in this response using recordings of hippocampal CA3 epileptiform bursts in mouse brain slices. First, we determined that this effect was mediated by the α2AAR subtype as the inhibitory action of EPI on epileptiform burst frequency was abolished in slices from α2AAR, but not α2CAR, knockout mice. Next, using transgenic mice with the G184S Gnai2 allele (knock‐ins) which interrupts G‐protein α unit binding to regulators of G‐protein signaling (RGS), we found that the α2AAR antiepileptic effects of EPI were enhanced in hippocampal slices from mutant Gαo mice but not Gαi2 mice. Finally, hypomorph mice with very low RGS7 protein levels were found to have increased α2AAR‐mediated hippocampal antiepileptic actions compared to their littermate controls. These results indicate that the EPI‐mediated inhibition of mouse hippocampal CA3 epileptiform burst activity is through an α2AAR/Gαo‐mediated pathway under strong inhibitory control by proteins of the RGS7 family. This suggests a possible role for selective α2AAR agonists or RGS7 inhibitors as a novel antiepileptic drug therapy.
S1P1 receptor activation is insufficient to mimic S1P‐mediated effects on aqueous humor outflow physiology
Authors: Sumida Grant , Stamer W. Daniel
Published: June 2021

Previously, sphingosine‐1‐phosphate (S1P) had been shown to decrease outflow facility in human eye organ‐culture models. The aim of this study is to determine the contribution of the S1P1 receptor in the tissues of the aqueous humor outflow pathway in mediating S1P's effect on outflow facility in humans.

Post‐mortem human eyes in organ culture were perfused at 8 mmHg constant pressure to obtain a baseline outflow facility. Normalized facilities following the exchange of anterior chamber contents with 5 μM SEW2871 (S1P1 agonist) or vehicle were 1.01 ± 0.10 and 1.05 ± 0.10, respectively (mean normalized facility ± SD; p=0.65). As a control, all eyes responded with a decreased facility following S1P exchange at the end of each experiment. In primary lines of trabecular meshwork and Schlemm's canal cells, the cell types located at the site of outflow resistance, SEW2871 failed to promote MLC phosphorylation (MLC‐P). Interestingly, W146 (S1P1 antagonist) enhanced S1P‐mediated MLC‐P.

SEW2871 does not replicate the S1P‐induced decrease in outflow facility, nor does it promote MLC‐P in cell culture models; suggesting other S1P receptor subtypes, alone or in combination with S1P1, are responsible for S1P's action on the outflow pathway.

Support: NEI (EY17007) and Research to Prevent Blindness Foundation
WAVE proteins mediate ENaC activity
Authors: Karpushev Alexey V , Levchenko Vladislav , Staruschenko Alexander
Published: June 2021

The epithelial Na+ channel (ENaC) is an essential channel responsible for Na+ reabsorption. Similar to other ion channels, ENaC activity is regulated, in part, by cortical cytoskeleton. Members of the Wiskott‐Aldrich syndrome protein (WASP)/WAVE family (N‐WASP, WASP, and WAVE1, −2, −3 isoforms) activate Arp2/3‐mediated actin polymerization, leading to distinct downstream effects. N‐WASP inducibly binds Arp2/3 in response to Cdc42, whereas WAVE proteins constitutively interact with Arp2/3 and are effectors of Rac1 activity. Coexpression of Rac1 with ENaC markedly increased channel activity, whereas coexpression of Cdc42 failed to change ENaC activity. N‐WASP and all three isoforms of WAVE significantly increase ENaC activity when coexpressed in CHO cells. However, wiskostatin, an inhibitor of N‐WASP did not effect ENaC activity in cells expressing the channel alone and coexpressed with either N‐WASP or WAVE1. Similarly, wiskostatin had no effect on Na+ reabsorption across mpkCCDc14 principal cell monolayers. Immunoblotting demonstrated the presence of WAVE1 and WAVE2 and absence of N‐WASP and WAVE3 in mpkCCDc14 and M‐1 cells. Immunohistochemistry analysis also revealed localization of only WAVE isoforms in the cortical collecting duct in Sprague‐Dawley rat kidneys in vivo. Thus, our findings suggest that WAVE proteins mediate ENaC activity via interaction with Rac1.

Supported by AHA and ASN.
Sex‐specific effects of atorvastatin on the blood pressure response to exercise
Authors: Dostaler Edward G , Thompson Paul D , Axtell Robert S , Latchman Peter , Parker Beth A
Published: June 2021

Purpose

To examine the effect of statin therapy on the blood pressure response to exercise in healthy adults.

Methods

Sixty eight adults (n=34 men (M) and women (W); ages 23–67) were randomized to atorvastatin 80 mg (A) daily or placebo (P) in a double blind fashion. Systolic, diastolic and mean arterial blood pressure (SBP, DBP and MAP, respectively) were measured every 3 minutes during a graded maximal exercise test with concurrent assessment of oxygen uptake (VO2) pre‐ and post‐6 months of treatment. The slope of the blood pressure response to exercise was calculated as Δ SBP, DBP or MAP/Δ VO2 (as % of VO2max). A repeated‐measures ANOVA with between‐subject factors of gender and drug was used to investigate slopes across time.

Results

The time*drug* gender interaction was marginally significant (both p = 0.06) for both the SBP and MAP response to exercise. Specifically, A reduced the slope of the pressor response to exercise in W but not M relative to P groups.

These findings suggest that atorvastatin may reduce the pressor response to exercise in women but not men. Supported by 1R01HL081893‐03.
A Novel Algorithm for Quantifying Multiunit Sympathetic Nerve Activity
Authors: Brockway Marina , Guzman Pilar , Veitenheimer Britta , Kuroki Marcos , Osborn John W
Published: June 2021

Although methods for long‐term recording of sympathetic nerve activity (SNA) in conscious animals have become available, the poor signal‐to‐noise ratio (SNR) that is characteristic of SNA recordings has limited the use of SNA preparations in understanding the role of neural control of physiological function. A novel software algorithm Multi‐domain Filtering (MDF) for analysis, denoising, and quantification of SNA has been developed. The MDF technique removes nearly all noise and artifact from SNA recordings including myoelectric artifacts, thermal, electrical and other noises while preserving information regarding the underlying SNA. In addition to denoising, the technique includes a rigorous computation of integrated SNA that more accurately reflects neural spike activity and avoids the time lag inherent to commonly used analog filtering techniques. MDF technique has the potential to extend preparation life by substantially improving SNR, particularly at the end of preparation life. It also has the potential to greatly reduce the need for manual review of data to identify noise events and eliminate the need for interventions to assess baseline noise level. MDF technique has proven to be sufficiently robust and computationally efficient that it can be used to automatically post‐process or real‐time process SNA data in a typical laboratory setting.

Supported by NIH Grant HL076312 and VivaQuant ™
Follicle‐stimulating hormone (FSH), interleukin‐1 (IL‐1) and bone density in adult women
Authors: Cannon Joseph G. , Cortez‐Cooper Miriam , Meaders Eric , Stallings Judith , Haddow Sara , Kraj Barbara , Sloan Gloria , Mulloy Anthony
Published: June 2021

This study tested the hypothesis that FSH promotes bone loss by inducing secretion of bone‐resorbing cytokines or by altering their receptor expression. Thirty six women (20–50 years old) were assessed for bone mineral density (BMD), circulating FSH, cytokine and soluble receptor concentrations, and expression of cytokine receptors on monocytes. Isolated mononuclear cells were also incubated in vitro with FSH. The results indicated that BMD was inversely related to serum FSH (R: −0.36 to −0.52, P: 0.03 to 0.001, depending upon skeletal site), and also related to physical activity and body composition. FSH induced mononuclear cells to secrete IL‐1β in proportion to the expression of FSH receptors on the monocytes, and serum FSH correlated with plasma IL‐1β. The ratio of plasma IL‐1β to IL‐1 receptor antagonist (IL‐1Ra) was inversely related to BMD (R = −0.53, P = 0.002) in all but the most physically‐active women, who had lower IL‐1 type I receptor expression relative to type II (decoy receptors, P = 0.01). Physical activity correlated with soluble IL‐1 receptor secretion (R = 0.53, P = 0.003) and IL‐1Ra correlated with % body fat (R = 0.66, P < 0.0001). In conclusion, BMD is related to serum FSH, physical activity and body composition. Although these factors have direct effects on BMD, the present study suggests that each may also influence BMD by modulating the activity of IL‐1β. Supported by NIH grant AG027714.
The Effects of Exercise and Muscle Mass on Growth of the Proximal Femur of Wild‐Type and Dystrophin‐Deficient Mice
Authors: Plochocki Jeffrey H , Nye David J
Published: June 2021

Postnatal growth of limb joints is mechanically regulated via an adaptive tissue modeling mechanism that minimizes the risk of articular damage. However, the precise relationship between joint form and mechanical loading is unclear. Because muscle mass is proportional to tissue loads, it has been hypothesized that muscle mass is an important determinant of joint morphology. We evaluate the effects of mechanical loading and muscle mass on proximal femur growth in sedentary and exercise‐treated wild‐type (WT) and dystrophin‐deficient (Mdx) mice aged 11 weeks. Mdx mice have greater body mass due to greater muscle mass than WT mice, but weaker muscles because of extensive fibrosis. Our results show that exercised WT mice have significantly larger calcified cartilage zones than sedentary WT mice (P < 0.05) but similar cartilage tissue areas and femur head diameters. No differences were found between exercised and sedentary Mdx mice. Exercised WT mice have significantly greater femur head diameters, calcified and noncalcified cartilage thickness, and cartilage area than exercised Mdx mice (P < 0.05). Our findings suggest muscle force has a greater effect on joint growth than muscle mass alone.
Gas Cluster Ion Beam (GCIB) surface modification of titanium enhances osteoblast proliferation and bone formation in vitro
Authors: Khoury Joseph , Kirkpatrick Sean R , Kodali Guru Charan , Svrluga Richard C , Tarrant Laurence JB
Published: June 2021

Titanium implants are considered to be bioactive, but osseointegration is often slow. Many have increased surface area of the implant to which osteoblasts bind by etching or sandblasting, and applied additive coatings such as hydroxyapatite. We have altered the atomic‐level structure of the TiO2 surface without adding material onto the surface. GCIB utilizes high energy ionized gas clusters of inert argon atoms. Bombardment of TiO2 results in increased surface wettability and amorphization. Ti pieces were divided into 2 groups: untreated, or GCIB irradiated with 5×1014 Ar clusters/cm2. Osteoblasts were seeded at 2000 cells/cm2, allowed to attach and proliferate up to 10 days (n=3). Cell counts were measured by MTS assay. RNA was extracted over 10 days and amplified for alkaline phosphatase (ALPL). Protein was extracted at 4, 24, and 48h and probed for total and phosphorylated p42, as a marker for cell proliferation. GCIB‐treated TiO2 showed: increased proliferation by day 10 (12,213 ± 1,570 vs 6,880 ±700 cells p<0.05); ALPL upregulated by 3.4 ± 0.6 (p<0.01) fold by day 10, indicating bone formation; phosphorylation of p42 is seen at 4h and sustained at 24h on GCIB‐treated, and only 4h on non‐treated surfaces. Results suggest that osteoblasts adhere and proliferate better on GCIB‐treated TiO2. GCIB treatment of dental implants has potential to enhance bone formation and significantly decrease osseointegration time.
Neurochemical coding of enteric neurons in embryonic and adult zebrafish (Danio rerio)
Authors: Uyttebroek Leen , Dirckx Margo , Harrisson Fernand , Hubens Guy , Shepherd Iain T , Timmermans Jean‐Pierre , Van Nassauw Luc
Published: June 2021

While morphology and development of the zebrafish enteric nervous system (ENS) are known, neurochemical coding of enteric neurons is still incomplete. Using immunofluorescence, we aimed to unravel the neurochemical coding of zebrafish enteric neurons. Tyrosine hydroxylase (TH), VIP and PACAP were observed in nerve fibres, while other markers were detected in neuronal cell bodies. In embryos, all markers, except for choline acetyltransferase (ChAT) and TH, were present from 72 hpf on. Nitrergic neurons, which were evenly distributed and remained constant in time, constituted a major subpopulation. The neuronal proportions of the other markers increased during development. These results support previous data that the ENS is well‐developed before the onset of feeding. In the adult, all markers were expressed in the ENS. A major percentage of neurons displayed calbindin and calretinin, while serotonin was the only marker showing significant distribution differences in the three intestinal regions. Serotonin was not coexpressed with any of the other markers. At least five neuronal subpopulations were determined. A functional classification of the subpopulations has been suggested.
Pertubations in myocardial mitochondrial bioenergetics by the aqueous corm extract of Hypoxis hemerrocallidea [African Potato;APE] in a rat model of type I diabetes mellitus
Authors: Zungu Makhosazane , Jawuza Nelisiwe Mangazile
Published: June 2021

To study the effects of APE on myocardial mitochondrial bioenergetics, Type I diabetes mellitus was induced in male Sprague Dawley rats by a single streptozotocin (STZ) injection (60 mg/kg.bw; i.p). After 3 weeks rats were orally treated (every third day) with distilled water (3ml/kg.bw) or APE (30 mg/kg. bw) for 5 weeks. The vehicle group was given citrate buffer followed by APE treatment. Heart mitochondrial functional parameters were measured using a Clark‐type oxygen electrode and employing a combination of malate (M), palmitoyl‐L‐carnitine (CP), pyruvate (P) and succinate as oxidative substrates. ADP/O ratio was increased in the diabetic group in the presence of MCP and M+P. APE treatment reduced ADP/O ratio and rate of ADP phosphorylation (MCP and succinate as substrates). Treatment of the diabetic group with APE attenuated the ADP/O ratio (for all substrates used) and decreased ADP phosphorylation rate (MCP as substrates), while it increased oligomycin‐insensitive proton leak and state 4 respiration (succinate as substrate). Our results demonstrate that APE inhibits rat heart mitochondrial efficiency and uncouples oxidative phosphorylation in a substrate‐dependent fashion and may help explain observed cardiac dysfunction associated with usage of this medicinal plant. South African Medical Research Council, South African National Research Foundation.
Pyrrolidine Dithiocarbamate Inhibition of Luteolin‐Induced Cleavage of Bcl‐2 Family Members in Human Leukemia HL‐60 Cells
Authors: Lee Ming‐Fen , Cheng An‐Chin , Pan Min‐Hsiung
Published: June 2021

In our previous study the cleavage of the proapoptotic Bcl‐2 proteins, such as Bad, Bid and Bax to produce their truncated forms, and the cleavage of the antiapoptotic Bcl‐2 proteins, such as Bcl‐XL, into their potent pro‐apoptotic fragments were detected in luteolin‐treated HL‐60 cells. We also explored the modulatory effects and molecular mechanisms of Pyrrolidine dithiocarbamate (PDTC) on the cytotoxicity of luteolin to HL‐60 cells, and PDTC could interfere with luteolin's ability to cleave poly(ADP‐ribose)‐polymerase (PARP) and DNA fragmentation of factor‐45 (DFF‐45). In the current study, we investigated the effects of PDTC on the luteolin‐induced cleavage of Bcl‐2 family members in human leukemia HL‐60 cells. The results indicated that no cleavage product of Bid, Bad, Bax and Bcl‐XL was found when HL‐60 cells were pre‐treated with PDTC before luteolin treatment. Our results demonstrated that PDTC could inhibit luteolin‐induced cleavage of Bcl‐2 family members, and therefore devoted to the inhibition of luteolin‐induced apoptosis.
Long‐term in vitro fermentation of high amylose starch digestion residues by human fecal inocula
Authors: Li Li , Yum Man‐Yu , White Pamela , Campbell Mark , Hendrich Suzanne
Published: June 2021

A three‐week in vitro anaerobic human fecal incubation system was used to screen fermentability of resistant starch residues (SRV, SRVI, SRVII) after amylase digestion for short chain fatty acid (SCFA) production and shifts in bacterial composition. Fermentation capacity was compared between lean (18.5<BMI<25, n=15) and overweight (BMI>25, n=15) subjects. All three SRs significantly increased gas production and decreased pH compared to blank (P<0.05), with no difference among treatments. The molar proportions of butyrate were similar among three SRs at 45%, which was significantly higher than that of the blank (20%, P<0.05), measured by GC. Higher propionate production was found from SRV compared to blank (P<0.05), whereas there was no significant difference between blank and SRVI or SRVII in propionate production. No significant difference was found in the individual or total SCFA production between lean and overweight subjects. Bifidobacterium, Lachnospiraceae and Bacteroidaceae spp. were enriched by SRs, revealed by PCR‐DGGE. In conclusion, a stable in vitro fermentation system was established. All three SRs increased butyrate production, but SRV differed from SRVI and SRVII with higher propionate production. No significant difference in the fermentation capacity of SRs was seen between lean and overweight subjects. Supported by Plant Sciences Institute, ISU.
Dietary supplementation with L‐glutamine and AminoGut™ enhances protein synthesis in chicken skeletal muscle
Authors: Li Peng , Kim Sung Woo , Nakagawa Kazuki , Zhou Huaijun , Wu Guoyao
Published: June 2021

This study determined if dietary supplementation with 0% (Control), 1% L‐glutamine (Gln), 1% L‐glutamate (Glu), or 1% AminoGut™ (a mixture of Gln and Glu) on protein synthesis in chicken muscle. Within 8 h after hatching, 40 broiler chickens were assigned randomly to 4 dietary treatments (10 chicks per group): 0%, 1% Gln, 1% Glu, or 1% AminoGut™. All diets were made isonitrogenous by addition of L‐alanine. Chicks had free access to starter and grower diets between d 1–14 and d 15–35, respectively. On d 35, fractional rates of protein synthesis (FRPS) in tissues were measured using the 3H‐phenylalanine flooding dose technique. Compared with the control group, dietary supplementation with Gln or AminoGut™ did not affect (P>0.05) feed intake, but increased (P<0.05) Gln concentrations in plasma (26–28%). Gln and AminoGut™ supplementation enhanced (P<0.05) FRPS in breast muscle (33–37%) and leg muscle (28–32%), but did not affect (P>0.05) protein synthesis in liver or jejunum. Glu supplementation had no effect (P>0.05) on any of the measured parameters. These results indicate that dietary supplementation with Gln or AminoGut™ promotes chicken growth through stimulating muscle protein synthesis.
Glycine and Other Metabolic Enhancers (ME) to Fill Deficiencies
Authors: Hubbard Richard , Chambers Jeff
Published: June 2021

This is a continuing evaluation of analysis data from our 2009 study on the safety and efficacy of our supplement mixture as metabolic enhancers (ME) (Proc Soc, 23 B98 2009). This second report on our supplement use is emphasizing the supplemented glycine and arginine along with our other ME materials. As before, the subjects are from 58 to 83 years of age, as 10 male and 11 females, who were either on a self choice vegetarian (vegan) diet or omnivore diet as verified by dietary questionnaire and diet confirmed by urinary ratio of histidine/1‐methyl histidine (Hubbard, RW, J. Nutr. 1995;125:2333). First morning urines at the start of the 3 month supplement period, were analyzed for glycine, arginine 1‐methylhistidine and histidine (Hubbard RW et al. J. Chrom 1988;431:163) with random draw at one of three start times for each of the clinical subjects. There were no significant changes in arginine levels. Glycine differences after supplementation, pre and post for vegans had a p=0.138, and for omnivores p=0.73 change. Urinary histidine levels for vegans showed no significant change before and after supplementation, but omnivore histidine levels were significantly lower (p=0.02) both pre‐and post than the vegans indicating that omnivores secrete significantly less histidine, from our data, than omnivores (p=0.01).
Improved transplantation efficiency hepatocytes expressing Ser45‐mutated‐β‐catenin
Authors: Nejak‐Bowen Kari Nichole , Monga Satdarshan
Published: June 2021

Because healthy, non‐diseased donor livers for orthotopic liver transplantation are scarce, the development of alternative sources of functioning hepatocytes as a bridge to transplantation is critical. However, the availability of viable hepatocytes in numbers large enough for use in cell therapy is currently limited. Hepatocytes overexpressing a mutated form of β‐catenin may have a homing, growth, and regenerative advantage over wild‐type (WT) cells, thus decreasing the numbers of cells needed for transplantation. Our laboratory has previously shown that transgenic (TG) hepatocytes overexpressing Ser45‐mutated‐β‐catenin proliferate faster in culture than WT hepatocytes and show increased viability after 120 hours. However, the replicative capacity of these TG hepatocytes is unchanged from that of WT, as they senesce at approximately the same number of passages as WT hepatocytes in long‐term culture. Addtionally, expression of telomerase is equivalent in both WT and TG livers, indicating that TG hepatocytes containing mutated β‐catenin do not proliferate indefinitely. Preliminary results suggest that transplanted (Tx) WT hepatocytes can contribute to the livers of hepatectomized (PHx) β‐catenin KO livers (a model of delayed regeneration), but do not contribute to the livers of WT mice. Furthermore, the reduction in AST and ALT seen in PHx/Tx mice at D30 suggests that these transplanted hepatocytes may help to ameliorate damage and improve function. Currently ongoing cell transplantation experiments in which hepatocytes overexpressing TG mutated β‐catenin are transplanted into KO animals will elucidate the role of β‐catenin in repopulation of damaged livers.
CXC Chemokines are Not Direct Mitogens for Hepatocytes
Authors: Clarke Callisia N , Sakai Nozomu , Tevar Amit D , Edwards Michael J , Lentsch Alex B
Published: June 2021

PURPOSE

CXC chemokines have been implicated as important mediators of liver growth and regeneration after partial hepatectomy by promoting hepatocyte proliferation. Little is known about the way these chemokines mediate hepatocyte proliferation. Here we investigate whether CXC chemokines are direct mitogens for primary hepatocytes in culture.

METHODS

Hepatocytes were isolated from male Balb/c mice and initially plated in Williams media fortified with fetal bovine serum(FBS), distributed onto 96‐well plates and incubated overnight to allow cell adherence. Media was removed and hepatocytes were incubated for 24 hrs in Williams media or HepatoZYME, (a complete media), with or without FBS in the presence of murine CXC chemokine, macrophage inflammatory protein‐2 at 0, 10 or 10,000 ng/ml. Cytotoxicity was determined by LDH release assay and proliferation by DNA incorporation of BrdU.

RESULTS

Williams media without FBS resulted in nearly 100% cell death therefore, subsequent experiments were conducted with HepatoZYME (HZ) media. There was no difference in MIP‐2‐induced hepatocyte cytotoxicity between HZ media containing or lacking FBS. However, hepatocyte proliferation induced by MIP‐2 was present only in HZ media containing FBS.

CONCLUSION

CXC chemokines are not direct mitogens for hepatocytes, but stimulate hepatocyte proliferation in the presence of serum factors.
Post‐Session Administration of Selective Dopamine D3 Receptor Antagonists Disrupts Water‐Reinforced Operant Responding: Involvement of Cholinergic Receptors
Authors: Bertz Jeremiah William , Woods James Henry
Published: June 2021

Previous research has shown that post‐session administration of dopamine receptor agonists disrupts fluid‐reinforced operant responding. The present study examined the ability of post‐session administration of dopamine receptor antagonists to disrupt water‐reinforced responding. Post‐session administration of the selective D3 receptor (D3R) antagonists, PG01037 and SB‐277011A, caused progressive, monotonic declines in responding across sessions. These inter‐session declines were paralleled by progressive intra‐session response decrements. These effects were not observed when PG01037 was given on a quasi‐random schedule designed to minimize the contingencies between the session and drug administration. Responding was not disrupted by post‐session administration of the non‐selective D2‐like receptor antagonist, haloperidol; the selective D2 receptor antagonist, L‐741,626; or the D1‐like receptor antagonist, SCH23390. Thus, these effects are specific to D3R‐selective antagonists. This ability of D3R antagonists to disrupt responding may be related to their effects on cholinergic transmission: the disruptions caused by post‐session PG01037, but not those caused by post‐session administration of the D3R preferring agonist, pramipexole, are significantly attenuated by pretreatment with scopolamine. Support: USPHS/NIDA grant R01 DA020669 and an NSF Graduate Research Fellowship.
Tumor necrosis factor α is involved in the myogenic response of resistance arteries
Authors: Kroetsch Jeffrey Thomas , Lidington Darcy , Bolz Steffen‐Sebastian
Published: June 2021

The increase in vascular resistance observed in heart failure primarily results from an enhanced myogenic response (MR), the intrinsic property of resistance arteries (RA) to adapt their diameter and hence, resistance, to changes in pressure. We have recently shown that the cytokine tumor necrosis factor α (TNFα) augments the MR by activating sphingosine kinase‐1 (Sk1). We hypothesized that the TNFα‐Sk1 axis also operates under physiological conditions and that TNFα is an integral signaling element underlying the MR. Isolated hamster RA (n=6) were cultured in a pressure myograph for 20hrs prior to functional tests. Elevation of transmural pressure induced a robust MR (80±23% reversal of pressure‐induced distension). The soluble TNFα receptor etanercept (ETAN; 10μg/mL), which sequesters TNFα, abrogated the MR. This result was confirmed in mouse cremaster RA (n=5). Constriction to norepinephrine (NE) and dilation to acetylcholine (ACh) remained unaffected by ETAN. Heat‐inactivated ETAN (n=6) did not affect the MR or NE‐/ACh‐stimulated responses. TNFα increased Erk1/2 phosphorylation, which is tightly linked to Sk1 activation in resistance arteries.

Our data suggest that: (i) TNFα is readily available in the artery wall, (ii) its activation is sensitive to changes in transmural pressure and (iii) TNFα is a key element of the signaling pathway that regulates the MR.

Funding: NSERC/Heart and Stoke Foundation
Lessons learned from yeast about human leukemia
Authors: Shilatifard Ali
Published: June 2021

MLL translocations result in the pathogenesis of hematological malignancies. To learn more about MLL's function and its role in leukemia, we have taken advantage of genetics and biochemical tools in S. cerevisiae to identify the molecular properties of the yeast MLL homologue, the Set1 protein. We have isolated Set1 in a macromolecular complex, which we call COMPASS (COMplex Proteins ASsociated with Set1). We identified COMPASS as the first histone H3 lysine (H3K4) methylase and showed that it associates with transcribing RNA polymerase II. Our biochemical and genetic studies in yeast have identified the molecular pathway required for COMPASS's function. Based on these yeast studies, we now know that the human MLL complex is also found in a COMPASS‐like complex capable of methylating H3K4. Our yeast studies have allowed us to learn more about MLL's function and to determine how its translocations may result in the pathogenesis of leukemia. We will discuss our recent findings in this regard.
CARDIAC NORADRENALINE SPILLOVER IS NOT CORRELATED WITH HRV AND QT VARIABILITY IN PATIENTS WITH DEPRESSION AND PANIC DISORDER
Authors: Nalivaiko Eugene , Baumert Mathias , Lambert Gavin , Dawood Tye , Lambert Elisabeth , Esler Murray , McGrane Mariee , Barton David
Published: June 2021

Relationship between heart rate variability (HRV) or QT variability and autonomic effects on the ventricular myocardium are unknown. To address these issues in the most direct way, we computed HRV and QT variability indices and correlated them with the amount of noradrenaline (NA) spillover from the heart. The study was performed in 17 subjects (12 with major depression disorder and 5 with panic disorder). Cardiac NA spillover was assessed using catheter technique coupled with isotope dilution. We compured standard HRV measures in the time and frequency domain (meanNN, SDNN, RMSSD, VLF, LF, HF, LF/HF ratio), and short‐term heart rate complexity was quantified using detrended fluctuation analysis, symbolic dynamics and sample entropy. QT variability was quantified using QT variability index, QT variance, rate‐corrected QT, QT/RR ratio, hysteresis of QT rate adaptation, global regression residual of the [QTi, RRi] fit, and QT/RR coherence. Overall, none of HRV indices, short‐term heart rate complexity indices, or QT interval variability indices correlated with cardiac NA spillover. We conclude that most currently available ECG‐derived indices do not reflect sympathetic influences in the myocardium.
Variability in spinal and supraspinal respiratory motor output in a mouse model of Pompe Disease
Authors: Fuller David D , Qiu Kai , Lee Kun‐Ze , Reier Paul J , Byrne Barry J
Published: June 2021

Pompe disease is a lysosomal storage disorder reflecting systemic acid α‐glucosidase (Gaa) deficiency. We recently reported that a murine Pompe model (the Gaa−/− mouse) shows glycogen accumulation in phrenic motoneurons, reduced breathing frequency and an apparent reduction in phrenic burst amplitude (DeRuisseau et al. PNAS, 2009). We hypothesized that alterations in the neural control of breathing in Gaa−/− mice would result in increased breath‐to‐breath variability in the timing and amplitude of efferent spinal (phrenic) and brainstem (hypoglossal, XII) signals. Neurograms recorded in anesthetized, vagotomized, and ventilated mice showed that the coefficient of variation (CV) of inspiratory duration was larger in Gaa−/− vs. B6/129 control mice (P<0.05). The burst amplitude CV for Gaa−/− mice tended to be greater for phrenic (P=0.07) and was greater for XII output (P<0.05). Additional experiments are testing the hypothesis that intraspinal delivery of the Gaa gene via adeno‐associated virus (AAV5‐GAA) mitigates glycogen accumulation and respiratory control deficits in Gaa−/− mice. Immunhistological data obtained 4–8 wks post AAV5‐GAA injection (4–6 0.5 μL injections, 4.5×1013 vg/ml) indicate Gaa expression in cervical spinal motoneurons and interneurons. We are presently evaluating the impact of the spinal injection on glycogen accumulation and ventilation.
Evidence of a circadian rhythm for muscle sympathetic nerve activity in humans
Authors: Cook Jonathan S , Chin‐Sang Stephanie A , Sauder Charity L , Ray Chester A
Published: June 2021

We previously observed that exogenous melatonin (3 mg) increases muscle sympathetic nerve activity (MSNA) at rest in humans (Cook and Ray, Clin Auton Res 19:303, 2009). Because melatonin exhibits a circadian rhythm in humans by increasing at night, it was hypothesized that MSNA at rest would be greater at night compared to day. Melatonin typically increases 8–10 times over daytime concentrations during the late evening hours. To test this hypothesis, arterial blood pressure, heart rate, calf blood flow and MSNA was measured in 9 healthy subjects (28 ± 1 yr; 5 male, 4 female) while in the prone position. Each subject was tested around noon and 10–12 hr later that evening (day: 11:34 ± 13 min, night: 22:10 ± 5 min). Subjects were instructed not to sleep between the two testing sessions. Contrary to our hypothesis, MSNA at rest was significantly decreased at night compared to day (8 ± 1 vs. 11 ± 2 bursts/min, respectively) (P < 0.05). Calf blood flow, heart rate, and arterial blood pressure were not significantly different at night compared to day (calf blood flow: 3.2 ± 0.3 vs. 2.8 ± 0.5 ml*100 ml−1*min−1, heart rate: 70 ± 4 vs. 66 ± 4 beats/min, arterial blood pressure: 91 ± 2 vs. 87 ± 1 mmHg, respectively). The data indicate that MSNA at rest decreases during the late evening hours suggesting there is diurnal variation in muscle sympathetic nerve activity in humans.

Supported by: NIH HL077670 and a NASA Space Grant Fellowship
Western diet increases wheel running in mice selectively bred for high voluntary wheel running
Authors: Garland Theodore , Meek Thomas H , Eisenmann Joey C
Published: June 2021

Mice from a long‐term breeding selective experiment for high wheel running offer a unique model to examine contributions of genetic and environmental factors in determining aspects of behavior and metabolism relevant to body‐weight regulation and obesity. Since generation 16 and continuing through 52, mice from the 4 replicate high runner (HR) lines have run 2.5–3‐fold more revs/day as compared with 4 non‐selected control (C) lines, but the nature of this selection limit is not understood. Wheel running, food consumption (Teklad Rodent Diet (W) 8604, 14% kJ from fat, or Harlan Teklad TD.88137 Western Diet, 42% kJ from fat, plus added sucrose), and body mass were measured every 1–2 weeks in 100 males for 2 months starting 3 days after weaning. Western diet (WD) was obesogenic for both HR and C, increasing body and retroperitoneal fat pad mass, the latter even controlling statistically for running distance and caloric intake. HR mice had less fat than C, explainable statistically by their greater running. Adjusting for body mass, HR had higher caloric intake than C, also explainable by their higher running. WD had little effect on running in C, but increased revs/day by up to 75% in HR. The remarkable stimulation of voluntary running by Western diet in HR mice may involve fuel usage during prolonged endurance exercise and/or direct behavioral effects on motivation. Supported by MSU Seed Grant to JCE and NSF IOB‐0543429 to TG.
Changes in cardiovascular response to Six‐minute walk test in some chronic heart failure patients
Authors: Anigbogu Chikodi Nnanyelu , Ajiboye Olufunke
Published: June 2021

Objective estimates of cardiovascular performance and fitness can be obtained through standardized exercise tests. This study was to evaluate the cardiovascular responses of Nigerian population of adult patients with chronic heart failure (CHF) to the 6‐minute walk test (6MWT).

Participants were 15 adult patients with CHF and 30 age‐matched, apparently healthy individuals with no history of cardiovascular disorders. Ethical clearance was secured from the institutional committee and informed consent obtained from the subjects. On the day of exercise, pre‐test cardiovascular parameters – heart rate (HR), respiratory rate and blood pressure (systolic ‐SBP and diastolic ‐DBP) – were taken; after which the subjects went through the standardized procedures of 6MWT. Differences between the pre‐test and post‐test values and percentage differences were computed. For male and female study and control subjects, paired t‐tests were used to evaluate the significance differences between the pre‐test and post‐test mean values of HR, SBP and DBP. After the 6MWT in male patients, there was 9% increase in HR while female patients had an 8.5% increase (P>0.05). The male control subjects had a 13.4% increase while female control subjects had 9% increase (P>0.05). Significant increases were obtained in DBP for male patients, male control subjects and female control subjects. The 6MWT is a safe and simple instrument for demonstrating cardiovascular responses to sub‐maximal exercise in patients with heart disease and will be useful in compromised communities with limited resources.
Brain chemokine stromal cell‐derived factor‐1/CXCL12 modulates cardiovascular function and sympathetic drive in sham‐operated and heart failure rats
Authors: Wei Shunguang , Zhang Zhihua , Yu Yang , Weiss Robert , Felder Robert B.
Published: June 2021

Chemokines play a critical role in coordinating inflammatory and immune responses. In the brain, chemokines and their receptors are predominantly expressed in the cardiovascular and autonomic regions, including the paraventricular nucleus (PVN) of hypothalamus, the subfornical organ (SFO) and the supraoptic nucleus (SON). Chemokine stromal cell‐derived factor‐1 (SDF‐1)/CXCL12 has been reported to modulate arginine vasopressin release via its CXCR4 receptor in PVN and SON. This study investigated a potential role for brain chemokine SDF‐1 and CXCR4 in regulating blood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA) in sham‐operated (SHAM) and heart failure (HF) rats. Adult male Sprague Dawley rats were studied 4–5 weeks after coronary artery ligation to induce HF, or sham ligation. Confocal images revealed more intense SDF‐1 expression in PVN and SFO of HF than SHAM rats. Intracerebroventricular injection of recombinant SDF‐1 significantly (p<0.05) decreased BP, HR and RSNA in both SHAM and HF rats. Blockade of CXCR4 with a blocking peptide or a selective antagonist AMD3100 markedly (p<0.01) increased BP, HR and RSNA in SHAM and HF rats. These data suggest that brain chemokine SDF‐1 and its receptor play an important role in regulating cardiovascular function and sympathetic drive in normal and pathophysiological conditions. Supported by a VA Merit Review Award and NIH RO1 HL073986.
Understanding zebrafish habituation responses to novelty
Authors: Bartels Brett , Tien David , Wong Keith , Tan Julia , Cachat Jonathan , Suciu Chris , Goodspeed Jason , Roy Sudipta , Elegante Marco , Elkhayat Salem , Grimes Chelsea , Rosenberg Michael , Jackson Andrew , Chung Amanda , Gaikwad Siddharth , Duncan Ashley , Kadri Ferdous , Stewart Adam , Chung Kyung Min , Strong Michael , Gilder Thomas , Zapolsky Ivan , Kalueff Allan V
Published: June 2021

Though widely used to characterize animal cognitive phenotypes and their modulation, habituation phenotypes have not been extensively investigated in zebrafish (Danio rerio). Utilizing the novel tank test, we examined intra‐ and intersession habituation and demonstrated robust habituation responses in zebrafish. Intrasession habituation analysis determined that selected anxiogenic drugs (caffeine, pentylenetetrazol), as well as stress‐inducing alarm pheromone, attenuated habituation, while the acute anxiolytic agents, morphine and ethanol, had no effect on it. Chronic ethanol and chronic fluoxetine treatment attenuated intrasession habituation in zebrafish. Our study parallels rodent literature on habituation responses to novelty and reconfirms zebrafish as a promising model for cognitive neurobehavioral research. The study was supported by NARSAD, TUNF, TSEF, and TUIRF.
Angiotensin II Stimulates Thick Ascending Limb Superoxide Production via activation of AT1 Receptors and PKCα‐stimulated NADPH oxidase
Authors: Herrera Marcela , Silva Guillermo B , Garvin Jeffrey L
Published: June 2021

Angiotensin II (Ang II) stimulates thick ascending limb (TAL) O2− production but the receptor involved and signaling cascade is unknown. In other cells, activation of AT1 receptors (AT1R) results in PKC‐stimulated NADPH oxidase. We hypothesized that Ang II stimulates TAL O2− production via AT1R and PKC‐stimulated NADPH oxidase. In TAL suspensions, 1nM Ang II stimulated O2− production from 0.8 ± 0.2 to 2.0 ± 0.2 nmoles/min/mg (p<0.003). Losartan, an AT1 antagonist (1μM), blocked the effect of Ang II on O2− (0.9 ± 0.3 nmoles/min/mg; p < 0.02 vs. Ang II alone). PD123319, an AT2 antagonist (1μM), had no effect. Apocynin, a NADPH oxidase inhibitor (10μM), blocked the Ang II‐stimulated O2− by 90% (p<0.01). In isolated TALs, Ang II increased PKC activity, as measured by FRET, from 0.2 ± 0.3 to 1.3 ± 0.2 arbitrary units (p<0.02). A PKC inhibitor, Gö6976 (100nM), blocked the Ang II‐stimulated O2− (0.6 ± 0.2 vs. 2.1 ± 0.3 nmoles/min/mg; p<0.008). To investigate which PKC isoform was involved, we measured O2− in tubules expressing dominant‐negative (dn) PKCα or β1. In control TALs, Ang II stimulated O2− from 1.4 ± 0.1 to 3.6 ± 0.5 nmoles/min/mg (p<0.003). In TALs expressing the dn‐PKCα, Ang II failed to stimulate O2−. In tubules expressing the dn‐PKCβ1, Ang II stimulated O2− from 1.8 ± 0.4 to 3.9 ± 0.4 nmoles/min/mg (p<0.002). We conclude that Ang II stimulates TAL O2− production via activation of AT1R and in PKCα‐stimulation of NADPH oxidase.

Support: PO1 HL028982
Phospholipase C is required for histone acetylation in Saccharomyces cerevisiae
Authors: Galdieri Luciano , Vancura Ales
Published: June 2021

Phospholipase C (Plc1p) is required for the initial step of inositol polyphosphates (InsPs) synthesis and yeast cells with deletion of PLC1 gene are completely devoid of any InsPs and display aberrations in transcriptional regulation. To address the mechanism how InsPs affect transcriptional regulation, we have utilized inducible FLR1 promoter, which depends on Plc1p for activation. We show that Plc1p is required for normal level of histone H3 acetylation, recruitment of Swi/Snf and SAGA complexes, and nucleosome eviction in the FLR1 promoter. In addition, plc1Δ cells display decreased cellular levels of acetylated histones H3, H4, and histone H2A variant Htz1p. In accordance with the role of Plc1p in supporting histone acetylation, plc1Δ mutation is synthetically lethal with mutations in several subunits of SAGA and NuA4 histone acetyltransferase complexes. Moreover, the growth rate, sensitivity to multiple stresses, and the transcriptional defects of plc1Δ cells are partially suppressed by deletion of histone deacetylase HDA1. The results thus provide evidence that Plc1p and InsPs are important for normal level of histone acetylation and that InsPs deprivation results in histone hypoacetylation that negatively affects number of physiological processes in plc1Δ cells.
Binding of nBmp2 to PLSCR1 suggests a possible mechanism for nBmp2 regulation of Ca2+‐modulating proteins
Authors: McCune Broc T , Fox Christopher L , Schmidt Alina D , Mayo Jaime L , Finley Maegan J , Bridgewater Laura
Published: June 2021

Bone morphogenetic protein 2 (Bmp2) is a secreted growth factor that affects many aspects of development and differentiation. We have recently discovered a novel nuclear variant of Bmp2, called nBmp2. Mice lacking nBmp2 in the nucleus exhibit impaired intracellular handling of Ca2+ in skeletal muscle. To delineate the molecular connection between nBmp2 and Ca2+ management, a yeast two‐hybrid screen was performed which resulted in the identification of phospholipid scramblase 1 (Plscr1) as a protein that interacts with nBmp2. Plscr1 is known to bind a 15‐bp sequence in the promoter of the inositol triphosphate receptor 1 (ITPR1) gene, which codes for a Ca2+ channel, to activate its transcription. These results suggest that nBmp2 may affect Ca2+ transport in skeletal muscle by modulating the transcription of ITPR1 and possibly other genes that code for Ca2+ transport proteins. Research supportedby NIH/NIAMS grant #AR48839.
Overexpression of Act1 drives beta‐defensin expression
Authors: Velichko Sharlene , Anderson Johnathon David , Li Olivia , Huang Fei , Wu Reen
Published: June 2021

Overexpression of Act1 (CIKS) drives the expression of the human beta defensin gene, DEFB4, in a human bronchial epithelial cell line (HBE1). Act1 is an adaptor protein that is known to interact with I‐kappa‐kinases, as well as the interleukin‐17 receptor chain IL17RA, and is a potent activator of NFκB. We have previously shown that induction of DEFB4 by interleukin‐17 is largely NFκB dependent. Using DEFB4 promoter‐reporter constructs, we surprisingly show that induction of DEFB4 by Act1 overexpression is NFκB independent. Furthermore, we show that induction depends primarily on a region of the DEFB4 promoter that is located between −2.2 kb and −1 kb upstream of the transcriptional start site.

This research was supported in part by grants from the NIH (HL077902, HL077315, ES00628)
KLF 4 is involved in ATRA‐induced mitofusin 2 expression in vascular smooth muscle cells
Authors: Zhang Rui , Han Mei , Zheng Bin , Li Ying‐jie , Shu Ya‐nan , Wen Jin‐kun
Published: June 2021

The expression of mitofusin 2 (mfn‐2) and Krüppel‐like factor 4 (KLF4) was increased by all‐trans retinoic acid (ATRA) in vascular smooth muscle cell (VSMC) differentiation. However, the role of KLF4 and mechanism of KLF4 actions in regulating mfn‐2 expression remain unknown. In this report, Western blotting and RT‐PCR showed that overexpression of KLF4 in VSMCs increases mfn‐2 expression at both the protein and mRNA levels. Silencing of KLF4 expression by KLF4‐specific small interfering RNA (siRNA) abrogated the inducing effects of ATRA on mfn‐2 expression, indicating that KLF4 mediates ATRA‐induced mfn‐2 expression. Chromatin immunoprecipitation (ChIP) and reporter gene assays revealed that KLF4 binds directly to the mfn‐2 promoter and activates its transcription. Promoter deletion from 5' region and point mutation analysis indicated that the KLF4‐binding site 3 of mfn‐2 promoter is required for the induction of the mfn‐2 promoter activity by KLF4. Furthermore, co‐immunoprecipitation assays showed that ATRA increases the interaction of KLF4 with p300 through inducing KLF4 phosphorylation mediated by the JNK and p38 MAPK signaling, subsequently leading to the increase in KLF4 acetylation and KLF4‐mediated transcriptional activation of the mfn‐2 promoter. Our results provide a novel mechanism by which KLF4 activates mfn‐2 expression and further expand the net work of KLF4 actions in VSMCs.