bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the synaptic regulation of kisspeptin/neurokinin B/dynorphin (KNDy) neurons in a mouse model of polycystic ovarian syndrome
Authors: Moore Aleisha M. , Coolen Lique M. , Lehman Michael N. 
Published: June 2021

Polycystic ovarian syndrome (PCOS) is the most common cause of infertility in women of reproductive age worldwide. Women with PCOS exhibit the neuroendocrine phenotype of increased luteinizing hormone (LH) pulse frequency, which drives the downstream symptoms of anovulation, cyst formation and hyperandrogenism at the ovary. LH hypersecretion is indicative of impaired central steroid hormone feedback to gonadotropin‐releasing hormone (GnRH) neurons, the final output cell in a large network controlling fertility. Steroid hormone feedback control of GnRH neuron activity and GnRH/LH pulsatile release are hypothesized to be regulated by a population of neurons in the arcuate nucleus (ARC) that co‐express the peptides Kisspeptin, Neurokinin B and Dynorphin, commonly known as KNDy neurons. Therefore, we hypothesized that changes in the regulation of KNDy neuron activity could lead to elevated GnRH neuron activity and GnRH/LH hypersecretion in PCOS. To investigate this hypothesis, we used a prenatal androgen‐induced mouse model of PCOS to determine whether synaptic input to KNDy neurons from the major neurotransmitters GABA and glutamate is altered. Pregnant proDynorphin‐Cre/yellow fluorescent protein (pDyn‐Cre/YFP) transgenic mice were injected subcutaneously with dihydrotestosterone or an oil vehicle on days 16, 17 and 18 of pregnancy. Female PNA (n=4) and prenatal vehicle‐treated (PNV, n=4) pDyn‐Cre/YFP offspring were studied at 60–80 days of age during adult life. Triple‐label immunofluorescence was performed in coronal brain sections for YFP, the vesicular glutamate transporter 2 (vGluT2) and the vesicular GABA transporter (vGaT) to enhance YFP in KNDy neurons and visualize glutamatergic and GABAergic terminals, respectively. The soma of twenty KNDy neurons were analyzed per animal using confocal microscopy. PNA treatment had no effect on the number and density of vGluT2 appositions to KNDy neurons, indicating glutamatergic input is not altered in PNA mice. However, the number (p<0.01) and density (p<0.01) of vGaT appositions to KNDy neurons was significantly reduced in PNA mice when compared to controls. These results indicate that PNA treatment reduces GABAergic input to KNDy neurons. As GABA is classically an inhibitory neurotransmitter, this may lead to increased KNDy neuron firing in PNA mice that drives higher GnRH neuron activity and GnRH/LH pulsatile release, replicating the PCOS neuroendocrine phenotype. The location and phenotype of GABAergic neurons with reduced input to KNDy neurons in PNA mice is so far unknown and deserves further study.Support or Funding InformationAleisha M Moore is an American Association of Anatomists Scholar and this research was in part funded by the American Association of AnatomistsThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Proteomic Determination of the Rat Native Inner Medullary Collecting Duct Lysine Acetylome and Phosphoproteome
Authors: Hyndman Kelly Anne , Yang Chin‐Rang , Jung Hyun Jun , Umejiego Ezigbobiara N. , Chou Chung‐Ling , Knepper Mark A. 
Published: June 2021

Phosphorylation and lysine (K)‐acetylation are dynamic post‐translational modifications of proteins. K‐acetylation of histone proteins is classically regarded as a critical regulatory pathway for “opening” chromatin structure and promoting transcription. Previous proteomic studies have identified over 170,000 phosphorylation sites, and greater than 15,000 K‐acetylation sites of mammalian proteins. We recently reported that the inner medullary collecting duct (IMCD), which functions in the regulation of vasopressin‐dependent water‐reabsorption, expresses many of the enzymes (acetyltransferases and deacetylases) that can modulate K‐acetylation. The purpose of this study was to determine the K‐acetylated or phosphorylated proteins expressed in IMCD cells. Second, we asked whether vasopressin V2 receptor activation significantly affects the IMCD acetylome or phosphoproteome? K‐acetylated or serine‐, threonine‐, or tyrosine‐phosphorylated peptides were identified from native rat IMCDs using proteomic analysis with four different enzymes (trypsin, chymotrypsin, ASP‐N, or Glu‐C) to generate a high‐resolution proteome. We identified 709 K‐acetylated sites that mapped to 431 unique proteins. Of these K‐acetylated sites 583 (64%) were novel. The K‐acetylated proteins were expressed in all compartments of the cell, and were enriched in pathways including glycolysis (12 proteins), the TCA cycle (8 proteins), and vasopressin‐regulated water reabsorption (8 proteins). In these same IMCD cells, we detected 312 phosphorylated sites that mapped to 215 proteins, including AQP2 peptides that were phosphorylated at 4 serines: 256, 261, 264, and 269. Moreover, we identified 155 novel phosphorylation sites. Acute dDAVP did not significantly affect the IMCD acetylome; however it did significantly affect previously known vasopressin‐regulated phosphorylation sites. In conclusion, presence of K‐acetylated proteins involved in metabolism, ion and water transport in the IMCD points to multiple roles of K‐acetylation beyond its canonical role in transcriptional regulation.Support or Funding InformationK01‐DK‐105038 to K. A. H., projects ZIA‐HL‐001285 and ZIA‐HL‐006129, M. A. K.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Female Spontaneous Hypertensive Rats (SHR) Have Better Recovery In Response To Renal Ischemia Reperfusion Injury Than Males
Authors: Mohamed Riyaz , Crislip Ryan G. , Ray Sarah , Wei Qingqing , Sullivan Jennifer C. 
Published: June 2021

Hypertension is a known risk factor for acute kidney injury (AKI) but there is little research on the link between the two. Normotensive males are considered to be more susceptible to AKI compared with females. However, how hypersensitive males and females respond to AKI is not well understood. The purpose of the present study is to test the hypothesis that male SHR have worse outcomes than females following renal ischemia reperfusion (IR). 13 week old male and female SHR were subjected to sham‐operated or 25‐minute warm bilateral ischemia followed by 7 days of reperfusion (n=5–6). Renal injury and function were assessed by the following methods: 1) plasma creatinine quantified by Quantichrome creatinine kit, 2) peritubular capillary congestion by Masson's trichrome staining, and 3) tubular damage by hematoxylin and eosin staining of kidney sections and Western blot analysis of kidney injury molecule‐1 (KIM‐1). 24 hours following IR, both male and female SHR showed a significant increase in plasma creatinine compared to respective sham‐operated controls, although the increase in creatinine was greater in males (males: 0.55±0.22 vs. 0.25 ±0.06 mg/dl; females: 0.45±0.06 vs. 0.26±0.06 mg/dl; PIR=0.02; Psex=0.3; Psex*IR=0.03). After 7 days of reperfusion, plasma creatinine remained elevated in male SHR compared to baseline (0.46±0.21 mg/dl vs 0.26±0.065), whereas plasma creatinine in female SHR returned to baseline levels (0.27±0.06 vs 0.26±0.06 mg/dl; PIR=0.03; Psex=0.05; Psex*IR=0.04). Further, histological examination of kidneys following 7 days of reperfusion showed a significant increase in the percentage of peritubular capillary congestion (male: 20±6% increase; female: 0% increase: PIR=0.642; Psex=0.018; Psex*IR=0.002) and damaged tubules (male: 42±13% increase; female: 6±3% increase; PIR=0.0001; Psex=0.0019; Psex*IR=0.0019) compared to sham controls only in males. KIM‐1 protein expression also remained significantly elevated in the outer medulla of both male and female SHR following 7 days of reperfusion, although levels were higher in males compared to female SHR (male: 0.779±0.012 vs 0.073±0.006; female: 0.240±0.147 vs 0.0374±0.038; PIR=0.0002; Psex=0.0092; Psex*IR=0.019). In conclusion, our data support the hypothesis that there is a sex difference in recovery from IR where female SHR recovered faster than male SHR. Further studies are ongoing in SHR to dissect the molecular mechanism(s) driving sex differences in IR outcomes.Support or Funding InformationThis work was supported by National Institute of Health (1P01HL134604‐01 to J.C. Sullivan)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Beneficial effects of Tetrahydrobiopterin on intracellular PO2 and skeletal muscle metabolic demand in patients with COPD
Authors: Layec Gwenael , Decker Stephen , Kwon Oh‐Sung , Thurston Taylor , Le Fur Yann , Trinity Joel , Jeong Eun‐Kee 
Published: June 2021

Poor exercise tolerance and peripheral muscle dysfunction are frequent complications associated with chronic obstructive pulmonary disease (COPD). A key peripheral abnormality in these patients is the greater metabolic demand from the skeletal muscle, which occurs in the face of a compromised O2 transport to the limb and therefore exacerbates the development of muscle fatigue. While the etiology of limb muscle dysfunction is still unclear, increasing evidence suggest that chronic oxidative stress and diminished nitric oxide (NO) bioavailablity might play a central role. Therefore, using an integrative approach, the goal of the present study was to determine the effects of acute tetrahydrobiopterin (BH4) supplementation on O2 availability and muscle metabolic demand during exercise in patients with COPD. Five patients with COPD performed dynamic plantar flexion exercise at 40% of maximal work rate with proton/phosphorus magnetic resonance spectroscopy (1H/31P‐MRS), near‐infrared spectroscopy (NIRS), and vascular Doppler ultrasound assessments following oral supplementation of BH4 (10 mg.kg−1) or placebo (PL). BH4 supplementation attenuated the exercise‐induced changes in phosphocreatine (PL: Δ10 ± 4 mM; BH4: Δ 8 ± 4 mM, P<0.05) and pH (PL: 6.89 ± 0.11; BH4: 6.96 ± 0.06, P=0.06). In addition, the ATP synthesis rate was reduced by ~30% (PL: 32 ± 13 mM.min−1; BH4: 22 ± 18 mM.min−1, P=0.11). In contrast, end‐exercise limb blood flow was not significantly different between conditions (PL: 758 ± 255 ml.min−1; BH4: 796 ± 227 ml.min−1, P=0.77), which resulted in a non‐significant, but substantial increase in the intracellular partial O2 pressure (iPO2) measured by 1H‐MRS of myoglobin (PL: 9 ± 4 mmHg; BH4: 14 ± 12 ml.min−1, P=0.3). Together, these preliminary results suggest that NO synthase uncoupling, induced by a deficit in BH4 bioavailability, plays a central role in the development of peripheral dysfunction in O2 transport and muscle metabolism in patients with COPD. From a clinical standpoint, oral BH4 supplementation appears to be a promising therapy to improve the exquisite matching between O2 supply and metabolic demand in the skeletal muscle of patients with COPD, with the prospective that BH4 supplementation may be able to restore functional capacity and improve the quality of life of these patients.Support or Funding InformationThis study was funded, in part by NIH Heart, Lung, and Blood Institute (K99HL125756), the Flight Attendant Medical Research Institute (FAMRI), the Veterans Affairs Rehabilitation Research and Development Service (Merit Awards: E6910‐R, E1697‐R), SPiRe Awards (E1433‐P), Career Development award (IK2RX001215), the American Heart Association (1850039),This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Electrical Stimulation Frequency and Pattern on Muscle Fatigue in Spinal Cord Injured Individuals
Authors: Draghici Adina E. , Qiu Shuang , Picard Glen , Taylor J. Andrew 
Published: June 2021

Spinal cord injury (SCI) leads to an extensive skeletal muscle atrophy in the regions below the level of injury. Moreover, the paralyzed skeletal muscles shift towards predominantly Type II (fast‐twitch and highly fatigable) fibers. Functional electrical stimulation (FES) has been used to produce purposeful and controlled muscle contractions to restore functional movements, but rapid muscle fatigue remains a problem. Both pattern and frequency of stimulation can influence muscle fatigue rate, but optimization of stimulation parameters has rarely been investigated for those with SCI. FES has traditionally used constant‐frequency trains (CFT; brief stimulation pulses separated by regular interpulse intervals). However, it has been suggested that doublet‐frequency trains (DFT; close‐spaced pulse trains separated by longer intervals) can result in lesser fatigue. Also, stimulation frequency may determine muscle fatigue, with high‐frequency trains resulting in lesser fatigue compared to low‐frequency trains. However, most studies comparing muscle fatigue across stimulation parameters have been only examined in able‐bodied individuals and it is unknown whether paralyzed muscles respond similarly. There are a few studies suggesting that low‐frequency trains produce less fatigue than high‐frequency trains in those with SCI, in direct contrast to the able‐bodied. Therefore, we examined differences in muscle fatigue across and within able‐bodied individuals (N=8) and those with SCI (N=6) during CFT and DFT stimulation patterns at high‐ (40 Hz) and low‐ (20 Hz) frequencies. Fatigue was defined as a sustained reduction in force of >20% at a constant stimulation intensity. Differences were considered significant at p<0.05 and values are mean ± SEM. For both groups, low‐frequency trains delayed fatigue onset compared to high‐frequency trains, on average by 30 ± 3 %. In the able‐bodied, CFT resulted in slower fatigue onset (#contractions to fatigue CFT vs DFT: 20 Hz 39 ± 4 vs. 34 ± 4, 40 Hz 26 ± 4 vs. 23 ± 3). In those with SCI, DFT resulted in slower fatigue onset (#contractions to fatigue CFT vs DFT: 20 Hz 26 ± 2 vs. 35 ± 4, 40 Hz 20 ± 2 vs. 25 ± 2). In fact, DFT resulted in similar #contractions to fatigue in both populations, whereas CFT induced muscle fatigue significantly faster in those with SCI. These results may indicate that DFT preferentially recruit fast‐twitch fibers, leading to similar fatigue in both able‐bodied and those with SCI. DFT has been previously shown to limit fatigue potentially by increasing calcium release from the sarcoplasmic reticulum and/or by increasing muscle stiffness. These data indicate that DFT trains appear to be preferable for fatigue reduction in the SCI population.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Do sprinters and distance runners have the same autonomic nervous system activity and hemodynamic responses?
Authors: SUN XINRU , Saito Sayaka , Yang Hongxia , Hoshi Junko , Tanno Hiromasa , Kanno Emi , Maruyama Ryoko 
Published: June 2021

The autonomic nervous system (ANS) has an important role in physical performance. However, the cardiac ANS activity between sprinters (SPR) and distance runners (DR) has been poorly explored. Not much research has been conducted to determine the differences between sprinters (SPR) and distance runners (DR). We aimed to investigate the influences of ANS activity and circulatory dynamics on different types of exercise training. For this study, five male SPR and seven male DR, aged 18–24 years old (21.2±2.0 years), were recruited from Tohoku University sports club. They had trained using the same exercise type for more than 3 years. We measured weight, height, body mass index, muscle mass, bone mass, visceral fat rating, basal metabolic rate, and part fat percentage and part muscle mass. We also measured blood pressure (BP) and heart rate variability (HRV) at rest and during the postural change from the supine position to the sitting position. Spectral analysis of HRV was performed to evaluate low‐frequency power (LF), high‐frequency power (HF), and the LF/HF ratio to observe the changes in cardiac sympathetic and parasympathetic nerve activity. Data regarding type, duration, and content of the training were obtained using questionnaires after the measurements. Significant differences were observed between both groups with regards to bone mass and left‐hand muscle mass. SPR had significantly higher HRV in supine position compared with DR. The HF of SPR was significant higher than DR in all positions. During postural change from the supine to the sitting position, LF/HF was significantly higher in DR compared with the SPR. Systolic BP in SPR was observed to significantly increase during postural change from the supine position to sitting position, while the systolic BP during postural change was reduced in the DR group. We thus observed different responses in both groups suggesting significant differences in ANS activity and circulatory dynamics between SPR and DR.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
High‐intensity Interval Training Enhanced Platelet Mitochondrial Bioenergetics in Patients with Heart Failure
Authors: Wang Jong‐Shyan 
Published: June 2021

Mitochondrial functionalities in platelets involve the cellular bioenergetics and thrombogenesis. This study elucidates how high‐intensity interval training (HIIT) affects systemic aerobic capacity and platelet mitochondrial bioenergetics in the patients with heart failure (HF). Thirty‐four HF patients with were randomized to engage HIIT (3‐minute intervals at 40% and 80% VO2peak, n=17) for 30 minutes/day, 3 days/week for 12 weeks, or to a general health care group (GHC, n=17) that did not received exercise intervention. Systemic aerobic capacity (i.e., peak O2 consumption, VO2peak) and platelet mitochondrial O2 consumption rate (OCR) in the HF patients were measured using automatic gas analysis and high‐resolution respirometry, respectively. The experimental results demonstrated that the HIIT group exhibited higher VO2peak and O2 uptake efficiency slope, as well as, lower VE‐VCO2 slope following the 12‐week intervention, compared to those of the GHC group. Moreover, the HIIT, but not the GHC, regimen (i) increased the capacities for the maximal and reserve of OCR, (ii) enhanced the Complex I‐ and II‐mediated OCRs, and (iii) elevated the bioenergetics health index in platelets. Additionally, the VO2max levels were positively correlated with the maximal and reserve capacities of OCR and Complex I‐ and II‐mediated OCRs in platelets. Hence, the HIIT regimen improves aerobic fitness and ventilatory efficiency, which is accompanied by enhanced capacity for platelet mitochondrial bioenergetics in patients with HF.Support or Funding InformationNational Science Council of Taiwan (grant number NSC 106‐2314‐B‐182 ‐048 ‐MY3).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Overexpression of SOD2 in the diaphragm provides partial protection against ventilator‐induced diaphragm atrophy and contractile dysfunction.
Authors: Morton Aaron B. , Smuder Ashley J. , Hyatt Hayden W. , Hinkley J Matthew , Ichinoseki‐Sekine Noriko , Mor Andres , Powers Scott K. 
Published: June 2021

Mechanical ventilation (MV) is used clinically to maintain adequate pulmonary ventilation in patients that are unable to on their own. Unfortunately, an undesired side‐effect of prolonged MV is the rapid development of diaphragmatic atrophy and contractile dysfunction, termed collectively as ventilator‐induced diaphragm dysfunction (VIDD). The development of VIDD is clinically important because diaphragmatic weakness is a primary risk factor for difficult weaning from the ventilator. While the mechanism(s) leading to VIDD are not fully understood, increased mitochondrial production of reactive oxygen species (ROS) is a requirement for the development of VIDD. In this regard, superoxide dismutase 2 (SOD2) resides in the mitochondrial matrix and operates as the first line of defense to eliminate superoxide radicals. Therefore, we tested the hypothesis that overexpression of SOD2 in diaphragm fibers will protect against VIDD. Compared to control, viral transfection (rAAV9) of the SOD2 transgene in the diaphragm resulted in a ~70% increase in SOD2 protein abundance in diaphragm fibers. This overexpression of SOD2 in the diaphragm resulted in partial protection against VIDD by diminishing MV‐induced diaphragmatic contractile dysfunction. Nonetheless, overexpression of SOD2 did not protect against MV‐induced diaphragmatic atrophy. These findings demonstrate that increased expression of SOD2 alone in the diaphragm is not sufficient to prevent MV‐induced diaphragm atrophy but does provide partial protection against MV‐induced diaphragmatic contractile dysfunction.Support or Funding InformationSupported by NIH R01 AR064189 awarded to SKPThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Identification and Characterization of Protein Phosphatase Methylesterase 1 (Ppme1) in Skeletal Muscle
Authors: Labuzan Sydney , Waddell David 
Published: June 2021

Skeletal muscle atrophy results from a variety of physiological conditions, including immobilization, denervation, glucocorticoid treatment, cancer, and aging. In order to elucidate a better understanding of the molecular and genetic mechanisms of skeletal muscle atrophy, a microarray study was performed using muscle tissue isolated from mice undergoing neurogenic atrophy in response to denervation. The data generated from this microarray identified a suite of several hundred predicted genes that displayed differential expression under conditions of muscle wasting, including protein phosphatase methylesterase 1 (Ppme1). The Ppme1 gene was observed to be transcriptionally upregulated in response to neurogenic skeletal muscle atrophy (i.e. denervation). To confirm that Ppme1 is expressed in muscle, we successfully cloned the predicted Ppme1 cDNA from mouse muscle cells. Additionally, Ppme1 mRNA expression levels were analyzed by quantitative polymerase chain reaction (qPCR) and found to be highly expressed in both proliferating and differentiated muscle cells. Furthermore, Ppme1 protein levels were analyzed by Western blot using protein homogenates isolated from muscle cells and Ppme1 was found to be ubiquitously and uniformly expressed at all time points throughout muscle cell proliferation and differentiation. In order to assess the transcriptional activity of the Ppme1 gene, a fragment of the promoter was cloned, fused to a reporter gene, transfected into C2C12 cells, and found to be transcriptionally active. Additionally, the Ppme1 reporter gene was transfected in combination with MyoD1 and myogenin expression plasmids and differential effects on the Ppme1 reporter gene activity were observed in response to myogenic regulatory factor ectopic expression. The results presented here help contribute new insight into the molecular and genetic mechanisms of muscle atrophy and help provide a better understanding of the genome‐wide transcriptional changes that occur during neurogenic atrophy‐induced muscle wasting.Support or Funding InformationThe work was support by University of North Florida Transformational Learning Opportunity grants to D.W.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.