bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of nutrient‐responsive hippocampal neurons in feeding
Authors: Yang Mingxin , De Lartigue Guillaume 
Published: May 2022

Feeding behavior is controlled by hippocampal‐dependent learning and memory that influence decisions about where, when and what to eat. However, the neuronal subtypes and stimuli that recruit these neurons remain poorly understood.Here we leverage the unique strength of the recently‐developed Targeted Recombination in Activated Populations (TRAP2) mouse model, which provides cell type‐unbiased genetic access to neuronal populations based on their activation by defined and time‐constrained stimuli. Surprisingly, after comparing neuronal activity to separate post‐ingestive stimuli within the same animal, we identified distinct hippocampal subpopulations that respond to either fat or sugar. We validated a protocol for selective ablation of the sugar‐activated hippocampal neurons using viral mediated caspase in the TRAP2 mice. Using an automated feeding system, we found that these sugar‐ablated mice significantly reduced their chow and high‐fat diet intake compared to control littermates, and exhibited impaired food location memory in a sugar‐driven food cup task. No group differences were observed in the ability to learn a flavor‐nutrient conditioning paradigm.Overall, these results demonstrate that the hippocampus is attuned to specific macronutrients rather than the feeding state, allowing highly‐refined appetitive learning and memory in response to context‐specific feeding cues.
Role of cannabinoids and vitamin E analogues in macrophages foam cells formation
Authors: Zingg Jean‐Marc , Li Mengrui , Bertoncini‐Silva Caroline , Daunert Sylvia 
Published: May 2022

Recently, macrophages foam cells have gained attention in cases of electronic‐cigarette or vaping product use‐associated lung injury (EVALI). An increased number of foam cells was detected in bronchoalveolar lavages and lungs after inhaling e‐cigarette smoke from products containing cannabinoids and the vitamin E analogue, alpha‐tocopherol acetate (αTA), that was present as vape‐cartridge additive. Increased levels of intact αTA are reportedly detected in EVALI indicating that conversion of αTA to αT may less occur in lungs upon inhaling vapors from e‐cigarettes containing αTA.HypothesisWhereas the molecular mechanisms by which macrophages foam cells are formed after vaping are unclear, it appears possible that cannabinoid receptors play a role, as lung‐resident macrophages express cannabinoid receptors. Dysregulation of cannabinoid receptors by αTA and cannabinoids may induce the CD36 scavenger receptor/fatty acids transporter (CD36/FAT) and/or reduce the ATP binding cassette transporters A1 and G1 (ABCA1/G1) expression leading to lipid accumulation. Therefore, we analyzed the regulatory effects on lipid homeostasis of natural alpha‐tocopherol (RRR‐αT), natural RRR‐αTA (αTAn) and synthetic racemic all‐rac‐αTA (αTAr) with and without co‐treatment with cannabinoids (cannabinol (CBD), Δ9‐tetrahydrocannabinol (THC)) in THP‐1 monocytes and macrophages (differentiated for 48 h with 100 ng/ml phorbol‐12‐myristate‐13‐acetate (PMA)).ResultsQuantification of lipids in macrophages indicated that more lipids accumulate with αT, less with αTAn and αTAr, whereas control alpha‐tocopheryl phosphate (αTP) clearly inhibited. Co‐treatment with THC increased lipid accumulation with αT, αTAn as well as with CBD, whereas αTP again clearly inhibited. In THP‐1 monocytes, CD36 scavenger receptor was stimulated with αTAn and THC and with co‐treatment with THC and αTAn or CBD. In THP‐1 macrophages, CD36 was only up‐regulated by CBD and co‐treatment with αTAn or αTAr reduced it. In THP‐1 monocytes, cell cycle progression was only affected by CBD (increased G1, decreased S) and co‐treatment with αTAn and αTAr restored it. In macrophages, no significant toxicity was measured with lactate dehydrogenase (LDH) release assay by these treatments at 24 h, 48 h and 72 h at αTA concentrations below 50 μM.SummaryAlthough the mechanisms by which intact αTA may affect lungs in cases of EVALI are still unclear it may disrupt the pulmonary surfactant, act as linactant, and/or dysregulate lipid homeostasis and contribute to formation of macrophages foam cells and inflammation. Lipid accumulation in monocytes/macrophages and foam cells formation were modulated by cannabinoids and αTA but the involvement of lipid homeostasis genes such as CD36/FAT and ABCA1/G1 remains to be further elucidated. A detailed analysis of the molecular mechanisms by which foam cells are formed will not only be important to understand EVALI but also for atherosclerosis and non‐alcoholic steatohepatitis (NASH).
Partially Conserved Motifs Support an Alternating Access Model for the Human Mitochondrial NAD+ Transporter
Authors: Goyal Shivansh , Cambronne Xiaolu A. 
Published: May 2022

SLC25A51 resides in the inner mitochondrial membrane and it is required for cellular respiration and the mitochondrial production of ATP. As a member of the mitochondrial carrier family (MCF), it controls NAD+ concentrations in the mitochondrial matrix by directly importing the oxidized dinucleotide. Nevertheless, the mechanism by which SLC25A51 transports NAD+ across the inner mitochondrial membrane is not known, and its primary sequence lacks key residues that have been otherwise attributed to shared mechanisms of MCF transporters. To investigate this discrepancy, we used Molecular Dynamics simulations to characterize both the outward‐open conformation of SLC25A51 where NAD+ is expected to bind and the inward‐open conformation. We tested predictions from the simulations using a genetically‐encoded fluorescent biosensor that can directly monitor changes in free NAD+ concentrations in the mitochondrial matrix.We found that SLC25A51 lacks a three‐fold symmetry of its pore that is a characteristic of many MCF transporters. Instead, the core of SLC25A51 adopts an oblong and flattened shape. We predict this may be critical for the recognition and discrimination of the oxidized dinucleotide from other structurally related molecules, including its reduced form. A similar asymmetry was observed at the salt‐bridge network on the matrix side, produced by the asymmetric formation of a single salt‐bridge between E139 and K236 that linked helices 3 and 5. This ionic interaction was consistently observed throughout the simulations and mutation of either residue ablated SLC25A51 activity. We identified three cardiolipin binding sites on the membrane‐facing exterior of SLC25A51 that permitted cardiolipin to bridge interactions between the helical chains. We showed that these sites impact SLC25A51 function when mutated. Our simulations further predicted an energetically‐comparable single salt‐bridge on the cytoplasmic side of the transporter that could stabilize a complementary matrix‐open state. Mutation of the predicted cytoplasmic salt bridge between K198 and E291, as well as introduction of an ectopic salt bridge to imbalance the potential energetics of transport, diminished SLC25A51 activity. Together, the data indicate that although SLC25A51 lacks may conserved residues compared to other MCF family members, it functions through an alternating access mechanism and its activity depends on cardiolipin.
The Relation of Subjective and Objective Assessment of Sleep quality with Post Concussive Symptoms in Veterans
Authors: Pollin Kamila U. , Samuel Immanuel , Breneman Charity B. , Brewster Ryan , Reinhard Matthew , Costanzo Michelle E. 
Published: May 2022

Sleep complaints are a significant and persistent health problem reported by military Veterans. Veterans with traumatic brain injury (TBI) experience a higher incidence of sleep disturbances, with mild TBI (mTBI) resulting in chronic sleep disruption post injury. However, the relation between sleep and mTBI history is still poorly understood.PurposeThe purpose of this study is to assess sleep using subjective (Pittsburgh Quality Sleep index; PSQI) and objective (actigraphy) measurements in Veterans with a history of mTBI using remote assessments.MethodsSeven Veterans (7 Males; age: 54±7yrs, body mass index (BMI): 31±7 kg/m2 mean±SD) completed a telemedicine VA clinical evaluation and enrolled in the study. Participants completed web‐based versions of the PSQI to assess subjective sleep quality (range 0‐21) and the Neurobehavioral Symptom Inventory (NSI) to assess post concussive syndrome (PCS) symptoms (range 0‐88). Participants wore a wrist‐worn actigraph (wGT3X‐BT) over a 7‐day baseline period to measure total sleep time and sleep variability (standard deviation) from home. Data were analyzed using Pearson’s correlations.ResultsNSI scores are significantly correlated with global PSQI (R2=0.81, P=0.02) where higher NSI scores are associated with a greater PSQI total score. There is no relation between NSI score and sleep time (R2=0.22, P=0.34). There are trending relations between sleep time variability (R2=0.50, P=0.07) and sleep disturbances (R2=0.5, P=0.10; ex. Feeling too hot or too cold, having bad dreams) and NSI, such that those with higher NSI scores have greater sleep variability and sleep disturbances.ConclusionHome‐based assessments offer a promising means of monitoring sleep in Veterans. Our preliminary data suggests that subjective measurement of sleep relate to PCS symptoms, however trending results suggest that specific features of sleep quality may be affected by mTBI history. Remote evaluations are critical to understand sleep quality of Veterans to aid improvements in PCS symptoms following mTBI.
The Role of Carotid Body Chemoreceptor Afferents in Mediating Abnormal Ventilation in Acute Lung Injury
Authors: Kamra Kajal , Karpuk Nikolay , Adams Ryan , Schultz Harold , Wang Hanjun 
Published: May 2022

Background‐Acute lung injury (ALI) induces inflammation that disrupts the normal alveolar‐capillary endothelial barrier which impairs gas exchange to induce hypoxemia that reflexively increases respiration. Increased respiratory rate (RR) usually develops within a few hours to a few days after ALI. This disorder of acute respiratory failure affects approximately 200,000 new cases each year in the US alone and has high morbidity and mortality. The neural mechanisms underlying the respiratory dysfunction after ALI are not fully understood. The purpose of this study involved investigating the role of carotid body chemoreceptor afferents in mediating abnormal ventilation in ALI.Methods and Results‐ALI was induced in male SD rats (200‐250g) using a single intra‐tracheal injection of bleomycin (Bleo) (day 0) and respiratory variables‐ RR, TV (Tidal Volume), and MV (Minute Ventilation) in response to 10% hypoxia (10% O2, 0% CO2) and 5% hypercapnia (21% O2, 5% CO2) were measured weekly from W1‐W4 using whole‐ body plethysmography (WBP). MV at 21% O2 increased from baseline (W0) to W1 and W2 in bleo treated rats (p≤0.01 compared to saline treated sham rats). Changes in MV were due to a significant increase in RR while TV showed no changes. Chemoreflex was assessed by measuring the absolute difference between 21% O2 and hypoxia (10% O2, 0% CO2) & hypercapnia (21% O2, 5% CO2). Chemoreflex activation is a fundamental protective reflex that maintains oxygen homeostasis. Our data indicated a blunted chemoreflex at W1 and a sensitized chemoreflex in W3‐W4 during hypoxia and hypercapnia. We hypothesized that the blunted chemoreflex in W1 could be due to maximal pre‐activation of chemoreceptors, called the ‘ceiling effect’. To test this possibility, 90% hyperoxia (90% O2, 0% CO2) was given to bleo treated rats to inhibit the chemoreflex and our results showed no changes in RR, suggesting absence of the tonic activity at W1 post‐ALI.Conclusions‐These data suggest that chemoreflex activation in response to hypoxia and hypercapnia is blunted at acute stage of lung injury but became sensitized at the recovery stage.
Spontaneous Intrinsic Hepatic Vascular Oscillations
Authors: Stein Paul M. 
Published: May 2022

The liver is well known as a large blood reservoir that can shift both stressed and unstressed volumes passively and actively in response to changes in portal venous and hepatic arterial blood flow, inflow and outflow blood pressures, autonomic nervous stimulation, and various humoral and pathophysiological factors. Not described is the characteristic of the liver to intrinsically modulate its own vascular pressure and volume independent of extrinsic factors.METHODSMale Holtzman rats (n=5) were anesthetized (30 mg/kg sodium pentobarbital, i.p.) and heparinized (500 IU/kg, i.v.), the portal vein and inferior vena cava were isolated and cannulated, the liver was flushed with room temperature normal saline, and the liver quickly removed. Each liver was mounted on a scale in a 37°C chamber (95% O2‐5% CO2) and pump‐perfused (Masterflex) with donor rat blood at a baseline 1 ml/min/g of tissue. The hepatic venous pressure (Phv) was regulated by raising and lowering the blood reservoir. At each Time (see table), portal venous oscillations were counted over 3 to 12 min and the portal venous wavelet pulse pressures (Ppv) were measured over at least 40 wavelets.RESULTSThe portal venous pressures of 3 of the 5 livers oscillated spontaneously. One lasted only 26 min while the others went on for over 200 min. The characteristics of these oscillations varied widely from animal to animal, but there usually was an irregular cycle length and uneven wavelet magnitude that tended to degrade to a diminished size with higher frequency over time (see Figure 1).

Rat
Time (Min)
Maneuver
Mean Portal Venous Pulse Pressure (mmHg)
Frequency (Wavelets/Min)
Frequency (Hz)
Cycle Length (Sec)

1
0
Baseline
2.1 ± 0.9 (SD)
8.08
0.135
7.42

95
Baseline
1.5 ± 0.8
16.10
0.268
3.73

107
Change Phv
2.5 ± 1.3
17.00
0.283
3.53

(0 to 10 mmHg)
(P<0.001 vs. 95 Min Baseline)

180
Baseline
1.3 ± 0.5
18.67
0.311
3.21

2
0
Baseline
0.8 ± 0.4
14.42
0.240
4.16

60
Baseline
0.4 ± 0.3
20.00
0.333
3.00

130
Baseline
0.4 ± 0.2
23.78
0.396
2.52

3
0
Baseline
0.6 ± 0.3
8.67
0.144
6.92

CONCLUSIONSThis is a very limited data set, providing more questions than answers, but it opens a curiosity to much more investigation to understand the function of these intrinsic hepatic vascular oscillations under normal, reflex, and pathophysiological conditions.
Identification of the Activity‐Dependent Neuroprotective Protein (ADNP) as a Novel Effector of Gαi1
Authors: Momplaisir Nathalie L. , Chandan Naincy , Lefevre Tyler , Smrcka Alan V. 
Published: May 2022

The Gi family of G protein‐coupled receptors (GPCRs) drives various cellular processes to regulate physiological functions that encompass neuronal, immune, and endocrine health. Agonist‐bound GPCRS result in the activation of the heterotrimeric G protein, leading to the dissociation of the Gα subunit from the Gβγ dimer. While Gβγ has been considered to be a main driver of signaling downstream of Gi‐coupled receptors, the lack of tools to inhibit Gαi subunits without disrupting Gβγ signaling has limited our appreciation of potential novel pathways downstream of Gαi. To identify new Gαi interaction partners, our laboratory adopted an unbiased proximity‐based approach where we fused BioID2, a biotin ligase, within a specific site of the helical domain of the inactive Gαi1(Gαi‐BioID2) and the constitutively active Gαi1 (Gαi1‐Q204L‐BioID2). Using mass spectrometry, we specifically looked for targets enriched in Gαi1‐Q204L‐BioID2 samples. Among 104 targets, the activity‐dependent neuroprotective protein (ADNP) was found to be the most enriched target enriched in active Gαi1 in two separate screens. There is no previously identified relationship between Gαi and ADNP.ADNP is a transcription factor and cytoskeletal binding protein involved in brain formation and maturation. To investigate the interaction of ADNP with active Gαi1, HEK293 cells were transfected with ADNP alone, ADNP with Gαi1‐Q204L‐BioID2, and ADNP with Gαi1‐BioID2 and supplemented with biotin for 24 hours. Cells were lysed, and streptavidin beads were used to capture biotinylated proteins. Using immunoblotting, we confirmed the selective enrichment of ADNP biotinylation by Gαi1‐Q204L‐BioID2.To further determine whether ADNP interacts with Gαi1, we used a nanoluciferase‐based complementation assay where we co‐transfected HEK cells with ADNP with Gαi1 WT and Gαi1 QL respectively. In this assay, significantly greater interaction between ADNP and Gαi1 QL was observed when compared to Gαi1 WT and ADNP.Next, we addressed the subcellular localization of ADNP and Gαi1. Using cell fractionation, we observed that ADNP is localized to the nucleus of HEK cells while Gαi1 immunoreactivity was found in a cytosolic and membrane fraction, and in the nuclear fraction. Gαi1 expression does not alter the localization of ADNP, but ADNP can be exported and imported through the nucleus. Current work is focused on manipulation of the cellular localization of ADNP to determine where in the cell Gαi1 interacts with ADNP. Overall, we have identified ADNP as a novel interactor of active Gαi. Considering the distinct localization and expression of ADNP at different neurodevelopmental stages, further characterization of this interaction may provide new insight into Gαi‐mediated cAMP‐independent signaling pathways in neurophysiological and pathological states.
Soluble Isoform of ST2 is a Cardiac Inducer of Collagen Deposition in an Ex Vivo Model of Obesity
Authors: Corsi Romanelli Massimilano M. , Copes Chiara , Dozio Elena , Sitzia Clementina , Galliera Emanuela , Vianello Elena 
Published: May 2022

IntroductionOne of the main cardiac mechanosensor is the IL‐33/ST2L complex composed by the allarmin IL‐33 released into extracellular space by damaged cells during cardiac overload and its receptor, ST2L, which their binding promotes cell survival and anti‐fibrotic signaling. After damage, to stop IL‐33/ST2L signal, resident cardiac cells release sST2, the soluble isoform of transmembrane receptor of ST2, which sequesters IL‐33, functioning as a decoy receptor and blocking its signal. In obesity, the sST2 become over express especially by hypertrophic fat cells. The aim of our study is to evaluate in an ex vivo model of obesity the role of sST2 in the promotion of collagen production by cardiac cells.MethodsTen obese nondiabetic male Zucker rats (OB) (fa/fa‐, 10 weeks of age) and 10 lean littermates (L) (Fa/+) at the age of 25 weeks were weighted and scarified according to Italian Ministry of Health Authorization (N°325/2015PR of 2015/04/05) and their heart and visceral adipose tissue (VAT) were collected for the analysis. VAT biopsies were cut in 30mg pieces and added into a co‐culture system with H9C2 for 6‐24 and 48 hours. At each time points, cells and culture medium were collected. In all samples were evaluated ST2 by ELISA and collagen were quantified by quantitative Sircol assay for measurement of both acid‐soluble and pepsin‐soluble collagens.ResultsOB cardiac biopsies showed higher protein level of both ST2 and collagen than L rats (p<0.02 and p<0.002 respectively) and the rat weight positively correlates with ST2 cardiac protein level (p<0.05). Co‐culture data demonstrated that OB VAT promotes ST2 releases in both cardiac and fat cells, resulting an incremental increase of sST2 release in cell culture medium than L VAT in time. sST2 quantification in correspondent H9C2 co‐cultured lysate is more incremented in OB than L H9C2 after 48h.total collagen quantification in co‐culture medium resulted higher in OB than L (p<0.05).ConclusionOur results demonstrated in a co‐culture system that obesity promotes sST2 increase in the heart and this promotes collagen releases by cardiac cells, suggesting sST2 role in activation of pro‐fibrotic signaling and detrimental heart remodeling.
Gut commensal Coprococcus comes diminishes the blood pressure‐lowering effect of ester angiotensin‐converting enzyme inhibitors
Authors: Yang Tao , Mei Xue , Tackie‐Yarbo Ethel , Tambari Akere Millicent , Kyoung Jun , Mell Blair , Yeo Ji‐Youn , Cheng Xi , Zubcevic Jasenka , Richards Elaine M. , Pepine Carl J. , Raizada Mohan K. , Schiefer Isaac T. , Joe Bina 
Published: May 2022

IntroductionDrug resistant HTN (rHTN) affects around 15% to 20% of hypertensive (HTN) patients. The underlying mechanisms of resistance to treatment remain poorly understood. The majority of angiotensin‐converting enzyme inhibitors (ACEi) are esters, whereby we hypothesized that select gut microbiota hydrolyze ACEi rendering lower efficacy (Figure 1A). To test this hypothesis, we investigated if and which gut microbe modulates the effectiveness of ACEi.MethodsVancomycin, Meropenem and Omeprazole (VMO) were given to 16‐week‐old male Spontaneously Hypertensive Rats (SHR) at 50 mg/kg/day for five days. A single dose of 8mg/kg Quinapril was orally administered to both SHR and SHR+VMO, and blood pressure (BP) was recorded via radio‐telemetry. Liquid chromatography–mass spectrometry was used to measure the catabolism of quinapril. The hydrolysis of p‐nitro‐phenylbutyrate was used to measure the activity of bacterial esterase. 16S rRNA sequencing was used to study the microbial composition. At last, ester ACEi ramipril and non‐ester lisinopril were co‐administered with Coprococcus comes, respectively, to generalize the effect of C. comes on ACEi's effectiveness.ResultsCompared to the SHR, depletion of gut microbiota in the SHR+VMO group preserved the BP lowering effect of Quinapril, an ester ACEi (Figure 1B). The SHR+VMO group showed (1) reduced Coprococcus (Figure 1C); (2) lower esterase activity per gram of cecal microbiota to hydrolyze quinapril (Figure 1D); (3) a 50% lower reduction in quinapril quantity (nmol) after incubation with 1mg of cecal lysate for 3 hr (Figure 1E). C. comes,a species in Coprococcusgenus, catabolized quinapril in vitro and reduced its BP‐lowering effects in the SHR (Figure 2A‐B). Importantly, C. comes also reduced the BP‐lowering effects of ramipril (ester), but not lisinopril (non‐ester) in the SHR (Figure 2C‐D).ConclusionThese observations constitute the first report of an unrecognized role of a select gut microbe, C. comes, in reducing the effectiveness of ester ACEi. As such, this mechanistic study serves as the foundation for expanding clinical management of antihypertensive drug resistance via manipulation of gut microbiota.
Which Comes First: Angiogenesis or Myogenesis Following Punch Biopsy Injury?
Authors: Morton Aaron B. , Jacobsen Nicole L. , Cornelison D. D. W. , Segal Steven S. 
Published: May 2022

IntroductionSkeletal muscle is integral to metabolic homeostasis, movement, and breathing. The microcirculation supplies oxygen and nutrients to myofibers while removing their metabolic byproducts. Following skeletal muscle injury, damaged myofibers and capillaries regenerate to restore tissue structure and function. However, it is unknown if angiogenesis or myogenesis is preferred when blood vessels and myofibers are removed simultaneously and permitted to regenerate. Congruent with the dependence of myofiber function and survival on their microvascular supply, we hypothesized that angiogenesis precedes myogenesis during skeletal muscle regeneration following punch biopsy.MethodsThe left gluteus maximus muscle (GM) of anesthetized male and female Cdh5‐mTmG reporter mice (age, 4‐5 months) was injured by creating a hole (diameter, 2 mm) through the muscle with a biopsy punch. Mice were studied at four timepoints: uninjured control [0 days post injury (dpi)], 7 dpi, 14 dpi, 21 dpi.ResultsUsing intravital microscopy to observe the GM in anesthetized mice, regenerating microvessels grew into the biopsy zone by 7 dpi with networks traversing the residual gap by 14 dpi; nascent microvessels were perfused at 14 dpi as confirmed with fluorescent markers injected into the circulation. In contrast, myofibers were absent from the injured area at 7 dpi, began regenerating at wound edges by 14 dpi, and spanned the gap at 21 dpi. Confocal imaging and histology confirmed the presence of microvessels and absence of myofibers at 14 dpi, with both tissue components reoccupying the injured area at 21 dpi.ConclusionAngiogenesis precedes myogenesis during regeneration following punch biopsy of skeletal muscle.