bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Cannabidiol (CBD) in a Cisplatin‐Induced Model of Chronic Neuropathic Pain
Authors: Henderson‐Redmond Angela N. , Lulek Courtney F. , Morgan Daniel J.
Published: May 2022

Cannabinoid‐based therapies offer a safer, non‐opioid alternative for the management of chronic pain. While most studies focus on the analgesic potential of the main psychoactive component of marijuana, Δ9‐tetrahydrocannabinol, fewer studies have investigated the role of the non‐psychoactive component, cannabidiol (CBD). CBD has been purported to have analgesic, anti‐inflammatory, anticonvulsant, and anxiolytic effects. In addition to having actions at both cannabinoid receptors (CB1 and CB2), CBD has been shown to interact with both the transient receptor potential vanilloid‐1 (TRPV1) and serotonergic (5‐HT) receptors. Clinically, CBD’s lack of psychoactivity and decreased abuse liability make it an appealing pharmacotherapeutic for the management of chronic pain. Therefore, the purpose of the current study was to determine whether CBD sex‐ or dose‐dependently reverses antinociception in an acute model of thermal pain and/or mechanical allodynia in a model of cisplatin‐induced chronic neuropathic pain. Furthermore, we observed the degree to which CB1, CB2, 5‐HT, and TRPV1 receptors may be mediating these anti‐allodynic responses. Male and female wild‐type mice were assessed for either the anti‐allodynic effects of 0, 1, 3, 10, and 30 mg/kg CBD in a cisplatin‐induced model of neuropathic pain or the antinociceptive effects of 0, 1, 3, 10, 30, and 100 mg/kg CBD in a model of acute thermal (tail‐flick) pain 60 minutes following CBD administration. To determine the relative contributions of each receptor subtype in mediating the anti‐allodynic effects of CBD, male and female mice were pretreated with either: vehicle, the CB1 inverse agonist SR141716A (10 mg/kg), the CB2 antagonist SR144528 (10 mg/kg), the TRPV1 antagonist capsazepine (10 mg/kg), or the 5‐HT2 antagonist methysergide (4 mg/kg) 30 minutes prior to treatment with CBD. Mice were assessed for the effects of the pretreatment alone and in combination with CBD. CBD at a dose of 3 mg/kg was able to partially reverse cisplatin‐induced allodynia in male and female mice, while doses of 10 and 30 mg/kg resulted in nearly complete reversal. Our preliminary findings showed that the anti‐allodynic effects of 30 mg/kg CBD were completely blocked following pretreatment with SR141716A and SR144528, and partially blocked by capsazepine in both male and female mice. Interestingly, pretreatment with methysergide partially attenuated the anti‐allodynic effects of CBD in females alone. In contrast, CBD (0‐100 mg/kg) failed to induce antinociception on the tail‐flick assay. CBD did induce mild hypothermia with males showing a greater degree of CBD‐mediated hypothermia than female mice. Taken together, these findings suggest that CBD may be a more effective treatment option for the management of chronic pain. This study highlights the therapeutic potential of CBD in a model of neuropathic pain and suggests that these effects may have clinical implications for the use of cannabinoids in chronic pain management.
Differences in Immune Cell Mitochondrial Function in Black and White Patients with Heart Failure with Preserved Ejection Fraction
Authors: Bohmke Natalie J. , Chavez Domenico A. , Billingsley Hayley E. , Damonte Juan I. , Del Buono Marco G. , Robinson Austin T. , Markley Roshanak , Carbone Salvatore , Abbate Antonio , Kirkman Danielle L.
Published: May 2022

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) affects patients of all races and ethnicities. However, Black/African American patients are historically underrepresented in clinical research of HFpEF and have been reported to have unfavorable outcomes, yet the underlying mechanisms are not entirely understood. Excess proinflammatory cytokine and reactive oxygen species production from immune cells contributes to increased cardiovascular risk and may be a cause or consequence of alterations in immune cell metabolism. The aim of this study was to describe the immune cell bioenergetic profile in Black and White patients with HFpEF.

METHODS

We studied 20 patients with HFpEF. 13 patients self‐reported as Black or African‐American (11 female; Median [IQR]: Age: 55 [50, 66] yrs; BMI 39 [36, 43] kg/m2; hsCRP 5.3 [3.5, 9.3] mg/dL; BNP 50 [50, 200] pg/mL) and 7 self‐reported as White (7 female; Age: 68 [43, 72] yrs; BMI 34 [33, 40] kg/m2; hsCRP 3 [1, 4.9] mg/dL; BNP 109 [50, 168] pg/mL). The mitochondrial bioenergetic profile was assessed in isolated peripheral blood mononuclear cells by a Seahorse XFp Analyzer. Respirometry coupled with modulators of cellular respiration were used to obtain basal respiration, ATP‐linked respiration, maximal respiration, proton linked respiration, spare respiratory capacity, and non‐mitochondrial respiration. The Mann Whitney U test was used to compare variables between groups.

RESULTS

Proton leak respiration (Median [IQR]: 29 [4, 66] vs. 2.5 [1, 3] pmol/min, p=0.013), basal respiration 93 [60, 138] vs. 57 [53, 69] pmol/min, p = 0.008), maximal respiration (323 [191, 432] vs. 185 [162, 238] pmol/min, p = 0.0370) were higher in Black versus White patients. Raw spare respiratory capacity (232 [128, 293] vs. 125 [105, 145] pmol/min, p = 0.037) was also higher in Black versus White patients, whereas relative spare respiratory capacity (293% [276, 378] vs. 307% [259, 357] pmol/min, p=0.87) was not different between groups. There was a trend for lower coupling efficiency (94% [55, 95] vs. 97% [94, 99] pmol/min, p = 0.08) in Black vs White patients.

CONCLUSION

In an unselected cohort of patients with HFpEF, immune cell mitochondria basal respiration and respiratory reserve, as indicated by maximal respiration and spare respiratory capacity, are higher in Black versus White patients. Future studies are warranted to better understand the potential pathophysiological consequences of the observed differences.
Developmental Morphospace of Embryonic Brain and Face Growth in the Chicken (Gallus gallus)
Authors: Vavrušová Zuzana , Hu Diane , Liu Wei , Marcucio Ralph S. , Hallgrímsson Benedikt , Young Nathan M.
Published: May 2022

Normal facial morphogenesis involves the precise spatiotemporal choreography of independent facial prominences that must grow, contact each other, and fuse to form a functional upper jaw. We previously identified in reptiles, birds, and mammals (amniotes) a significant shift in the trajectory of facial growth at the time of primary palatal prominence fusion that is associated with reduced variance in shape across species. We speculated that this period is associated with developmental constraints derived from a shared embryonic bauplan, while reduced variance represents selection to minimize the likelihood of palatal clefts. We further hypothesized that these constraints operate within species and so should observe a similar pattern not only across but within species. In addition, because facial growth occurs in the context of underlying brain growth, we hypothesized that it is a significant co‐factor in establishing this pattern. To begin to test these ideas we collected a sample of iodine‐contrast chicken (Gallus gallus) embryos (N=200) spanning the period of facial prominence formation, fusion, and outgrowth (HH16‐30), imaged them using micro‐computed tomography, and used three‐dimensional geometric morphometrics and principal components analysis (PCA) constructed a “developmental morphospace”. Our results confirm that chickens undergo a U‐shaped shift in developmental trajectory and reduced shape variance at the time of primary palatal fusion, that this occurs in both the face and brain, and it is highly coordinated (partial least squares (PLS) analysis: RV=0.995, P<0.0001). Specifically, after contact and fusion the relative the frontonasal and maxillary growth rates (i.e., allometry) switch, as does the relative growth of the forebrain and eyes. Future analyses will focus on identifying key regulators of this switch in growth profile and whether a similar pattern occur in other species (mouse, human). Ultimately, this developmental morphospace approach may provide a generalized model for predicting how perturbations to facial prominence shape variability, growth trajectory, and brain size can combine to impact a range of contact and fusion events, both normal and abnormal.
MicroRNA Drivers for Regenerative Capacity in Liver Transplantation
Authors: Srivastava Ankita , Barnhart Benjamin K. , Hoek Jan B. , Vadigepalli Rajanikanth
Published: May 2022

Liver diseases, including alcoholic liver disease, nonalcoholic fatty liver disease, hepatitis, hepatocellular carcinoma, and other end‐stage chronic liver disease complications, often require liver transplantation. There is an unmet demand for liver transplantation due to a limited availability of deceased‐donor livers with adequate regenerative capacity. Current efforts to address this need involve treatments to improve transplant outcomes and utilize livers with diminished regenerative potential. Hence it is imperative to characterize the regenerative potential of donor livers for maximizing the utilization of available organs. We aim to identify microRNAs that can serve as potential markers of regeneration potential of the donor livers. For this study, flash‐frozen wedge‐biopsy samples were received from the Thomas Jefferson surgical team collected under the approved consent to research authorization obtained by the Gift of Life Donor Program. We compared samples of donor livers selected for transplant to those deemed non‐transplantable by the surgical staff. We profiled 798 microRNAs using the NanoString miRNA nCounter assay. The data normalization was performed using tools in the R platform. ANOVA test revealed a cohort of 15 microRNAs upregulated in the rejected livers compared to the livers accepted for transplantation. Further evaluation of microRNA targets will provide insights into mechanisms driving regenerative capacity of donor livers, which can aid the development of therapeutic interventions using microRNAs in liver transplantation.
Understanding Molecular Heterogeneity in Hepatocellular Carcinoma
Authors: Delgado Evan R. , Tao Junyan , Bell Aaron W. , Hu Shikai , Poddar Minakshi , Singh Sucha , Monga Satdarshan P.
Published: May 2022

Hepatocellular carcinoma (HCC) is the 5th most common cause of cancer‐related death in the United States with an estimated 32,000 annual deaths. Roughly 30% of HCC cases demonstrate mutations in the CTNNB1 oncogene that encodes a form of the ꞵ‐catenin protein that cannot be degraded. Recently, we developed a mouse model of HCC that genetically represents ~9‐12% of all human HCCs. Here, we combine hydrodynamic tail vein injections with the Sleeping Beauty Transposase – a non‐viral method of expressing genes of interest. Our model uses a clinically observed mutant of ꞵ‐catenin‐(T41A) that is co‐expressed with a mutant form of the nuclear factor erythroid 2–related factor 2 (Nrf2‐G31A) in the livers of wild‐type mice (B+N). This system results in microscopic HCC within 3 weeks and evident macroscopic disease by 7 weeks after induction.

ꞵ‐catenin activation can be identified by the expression of its downstream target gene Glutamine Synthetase (GS) in the liver. Patient HCCs with ꞵ‐catenin mutations strongly correlate with GS expression. The evolution and function of GS in b‐catenin‐mutated HCC, remains unclear. Also, there is a gap in the knowledge whether elevated GS expression correlates with HCC biology, which were all subjects of the current study. B+N mouse model of HCC was examined temporally for development of HCC along with GS expression. B+N mice develop HCCs with heterogeneous GS expression in the form of GS‐high and GS‐low to GS‐negative foci. We next asked whether GS expression is associated with cell proliferation or death in the B+N model. We stained tissues for TUNEL and PCNA to mark cell apoptosis and proliferation, respectively in 7‐ and 9.5 weeks post‐injection livers, which were then correlated to GS staining of HCC nodules. While we found no correlation between apoptosis and GS, we found nodules with lower GS expression to have higher proliferation and vice versa. Finally, we asked if eliminating GS expression from B+N HCCs will impact tumor burden. Five weeks after B+N tumor induction in GS‐floxed mice, these animals were injected with AAV8‐TBG‐Cre virus to delete Glul,and mice were harvested after 2‐ or 4.5‐weeks. We found B+N mice with Glul deletion show increased liver weight to body weight ratio, a measurement of HCC burden, compared to controls. The livers of these mice were enriched for GS‐negative tumors. Together, our data suggests that HCC nodules with lower GS expression may outperform GS‐positive foci, and thus are more aggressive compared to the nodules with higher GS expression, which may be more differentiated. The mechanisms of GS heterogeneity and elucidation of its functional significance may help select the most effective targeted therapies for HCC patients with ꞵ‐catenin mutations.
The Effects of Elevated Sodium on Mitochondrial Function in Peripheral Blood Mononuclear Cells
Authors: Mehrer Justin , Patik Jordan C. , Shenouda Ninette , Edwards David G.
Published: May 2022

INTRODUCTION

Diets high in sodium are associated with impaired vascular function independent of blood pressure. Recent data suggests that sodium accumulation from high salt diets reduces mitochondrial respiration in monocytes and macrophages, resembling what occurs during an inflammatory response. A similar response in circulating peripheral blood mononuclear cells (PBMCs) could implicate systemic inflammation as a mechanism contributing to high salt‐induced vascular dysfunction. Therefore, we aimed to test the hypothesis that exposure to a high sodium environment reduces PBMC mitochondrial respiration.

METHODS

PBMCs were separated from whole blood of ten healthy subjects (7 men/3 women, 18‐30 years, blood pressure ≤ 130/80mmHg; BMI < 30 kg/m2). PBMCs were then seeded at 2x105 cells/well in Poly‐D‐lysine treated cell culture plates. Plated cells were incubated for 24 hours in RPMI 1640 medium with 10% FBS at 137.7 mM sodium (normal sodium, NS) and 180 mM sodium (high sodium, HS). Basal, maximal, and ATP‐linked oxygen consumption rates were assessed post‐incubation by respirometry assay via Seahorse XFp analyzer (Agilent). Spare respiratory capacity was calculated as the difference between maximal and basal oxygen consumption rate.

RESULTS

Basal oxygen consumption rate was significantly reduced in HS compared to NS (65.0 ± 12.7 vs. 39.6 ± 6.5 pmol/min, p = 0.03), as was maximal oxygen consumption rate (198.3 ± 32.6 vs. 148.4 ± 27.2 pmol/min, p = 0.008). Basal ATP‐linked oxygen consumption rate was also significantly reduced in HS compared to NS (57.3 ± 9.8 vs. 34.4 ± 5.4 pmol/min, p = 0.01). Spare respiratory capacity in HS was significantly reduced compared to NS (133.2 ± 23.4 vs. 108.8 ± 21.2 pmol/min, p = 0.03).

CONCLUSION

Reduced basal and maximal oxygen consumption rates and spare respiratory capacity provide evidence that elevated sodium exposure reduces PBMC mitochondrial respiration. Additionally, high sodium exposure reduced ATP‐linked respiration potentially indicating alterations in PBMC energetics, resembling what occurs during inflammation. Collectively, our preliminary findings warrant further investigation into the role of sodium induced mitochondrial dysfunction in PBMCs as a potential mechanism contributing to high salt‐induced vascular dysfunction.
The potential role of microRNA as bio markers in canine congestive heart failure
Authors: Mitchell Carol L.
Published: May 2022

Objective

In our focus regarding microRNA, single‐stranded, small non‐coding RNAs, we aim to understand miRNA's roll and functional importance concerning congestive heart failure (CHF) and myxomatous mitral valve degeneration (MMVD). Characterizing expression profiles of circulating microRNAs via genome‐wide sequencing for dogs with CHF secondary to MMVD.

Animals

8 healthy client‐owned dogs and 8 middle age‐matched client‐owned dogs with CHF secondary to MMVD.

Procedures

Blood samples were collected before administering cardiac medications for the management of CHF. Quantitative reverse transcription PCR (qRT‐PCR) assays were used to validate expression profiles of differentially expressed circulating microRNAs identified from NGS analysis of dogs with CHF.

Conclusion and Clinical Relevance

Awaiting data indicating the patterns of microRNA expression are distinctive and denote molecular biomarkers with CHF in dogs with MMV.
Kynurenine Infusion Disrupts Normal Blood Pressure Circadian Rhythms
Authors: Irsik Debra L. , Bollag Wendy B. , Isales Carlos M.
Published: May 2022

Kynurenine is the first stable product of tryptophan metabolism, and its level increases with age. Elevated kynurenine/tryptophan ratios have been implicated in many aging‐related diseases including chronic kidney disease (CKD). We hypothesized that chronic infusion of kynurenine would induce alterations in renal‐related parameters, such as blood pressure, sodium excretion and glomerular filtration rate (GFR), that could contribute to development of age‐related CKD. In an IACUC‐approved study, three‐month‐old male Sprague Dawley rats were instrumented with aortic and venous catheters, as well as telemeters for blood pressure monitoring, and then housed in metabolic cages for urine collection. Following a five‐day control period, rats received continuous kynurenine infusion (5 mg/kg, 10 mg/kg, 50 mg/kg) or vehicle for 4 weeks. We found that GFR decreased after 2 weeks of KYN treatment [1.29 (n=5) vs. 1.51 (control, n=16) or 1.50 (vehicle, n=3) mL/min p=0.04]. The normal circadian rhythm for blood pressure was disrupted by all doses of kynurenine while heart rate maintained its normal diurnal pattern. Mean arterial pressure in kynurenine‐treated rats tended to increase over time compared to vehicle‐treated. Kynurenine infusion also induced increased water consumption. These data suggest that kynurenine treatment impacts renal function and may contribute to the development of CKD. Non‐dipping blood pressure is a significant risk factor for cardiovascular disease, even in the context of normotension. Further studies will be needed to determine the mechanism of this effect.
Extracellular vesicles from ALI models induce endothelial dysfunction
Authors: Guarino Brianna , Braza Julie , Chichger Havovi , Harrington Elizabeth O.
Published: May 2022

One distinguishing characteristic of acute respiratory distress syndrome (ARDS) or its lesser form, acute lung injury (ALI), is dysfunction of the lung endothelium. This dysfunction leads to increased permeability and eventual pulmonary edema. Despite the globally climbing rates of ARDS, the mechanisms of endothelial dysfunction are poorly understood. Recently, extracellular vesicles (EVs) have been shown to induce various microvascular disease states, as they contain various endothelial‐targeting cargo in the form of mRNA, proteins, lipids, and miRNAs. Therefore, we hypothesized that EVs play a role in the endothelial dysfunction observed in ARDS/ALI. EVs were isolated from the plasma of male Sprague Dawley rats which were given saline or P. aeruginosa (PA103) via intratracheal (IT) injection for 48h. ALI was confirmed by determining the wet to dry weights of the rodent lungs. We then tested the effect of the EVs isolated from saline‐ and ALI treated animals (sEVs and ALI‐EVs, respectively) on endothelial barrier function and modifications in gene expression. We found that treatment with ALI‐EVs, but not sEVs, increased rat lung microvascular endothelial cell (RLMVEC) permeability in the presence of lipopolysaccharide (LPS). Interestingly, ALI‐EVs did not induce endothelial dysfunction on their own, rather exacerbated the damage induced by LPS. We further noted ALI‐EVs, but not sEVs, increased gene expression of toll‐like receptor 4 (TLR4), which is the main pattern recognition receptor (PRR) for LPS and its downstream signaling molecule, MyD88 in the presence of LPS in RLMVEC. Further, we found that ALI‐EVs, together with LPS, increased gene expression of intracellular adhesion molecule 1 (ICAM‐1), vascular adhesion molecule 1 (VCAM‐1), and interleukin 6 (IL‐6), which are all involved in inflammatory signaling. Thus, it is likely that through the modulation of inflammatory signaling mediators, ALI‐EVs contain select cargo that worsen the endothelial barrier in settings where LPS is present, such as bacterial‐ARDS.
Possible Short‐Term Memory Loss of Adult Drosophila With Applied Ultrasonic Waves
Authors: Martinez Matthew N. , Moreno Carol , Roman Jade , Iniguez Jorge
Published: May 2022

People exposed to ultrasonic frequencies have symptoms that include fatigue, headache, insomnia, irritability, lack of concentration, and other symptoms (Hocking, 2001; Johnson Liakouris, 1998). Drosophila have been model organisms in experiments for decades, leading to advancements in science. The ability to reproduce quickly, short‐generation time, and well‐defined fully sequenced genome make drosophila the ideal candidate for studies related to behavioral genetics and neurophysiology. Third instar larvae (Child et al., 1981) and Drosophila Pupa (Fritz‐Niggli and Boni, 1950) have been shown to be sensitive to pulses of ultrasound. Here we investigate how repeated ultrasonic frequency exposure impact learning and memory in adult Drosophila.
Heat Stress Increases Mitochondrial Complex I Capacity in Female Pigs but Favors Reliance on Complex II in Males
Authors: Wesolowski Lauren T. , Semanchik Pier L. , Simons Jessica L. , Rudolph Tori E. , Roths Melissa , Freestone Alyssa D. , Rhoads Robert P. , Baumgard Lance H. , Selsby Joshua T. , White‐Springer Sarah H.
Published: May 2022

Heat stress (HS) negatively impacts animal health and impairs growth, but little is known about sex‐specific responses of skeletal muscle mitochondria to HS. To test the hypothesis that HS would have more adverse effects on mitochondria in females than males, samples were collected from the oxidative portion of the semitendinosus muscle of 3‐month‐old female and castrated male pigs under thermoneutral (TN) conditions or after 1 or 7 d of HS at 39.4°C (n=8/sex/group). Mitochondrial volume density and function were determined via citrate synthase (CS) and cytochrome c oxidase activities. Mitochondrial oxidative phosphorylation (P) and electron transfer (E) capacities were evaluated by high resolution respirometry. Data were analyzed using mixed linear models in SAS v9.4 with treatment, sex, and treatment × sex as fixed effects. Overall, integrative (relative to tissue weight) maximal P with complex I and II (PCI+II) and E (ECI+II) were greater after 1 and 7 d of HS compared to TN conditions (P≤0.05). The contribution of PCI+II to maximal E (flux control ratio; FCRPCI+II) was greater in TN pigs compared to either HS group (P≤0.03), suggesting decreased efficiency of mitochondrial energy production following HS. However, there appeared to be some adaptation to heat over time as FCRPCI+IIwas greater in pigs that were heat stressed for 7 d compared to 1 d (P=0.05). As hypothesized, some measures differed by sex. Specifically, in females, intrinsic (relative to CS activity) complex I‐supported P (PCI) tended to be greater following 7 d of HS compared to TN (P=0.07); PCI was unaffected by heat in males, resulting in females having greater intrinsic PCI than males following 7 d of HS (P=0.05). The contribution of PCI to total E (FCRPCI) was lesser with 7 d HS than 1 d or TN conditions in male pigs (P≤0.01) but unchanged in females, resulting in females also having greater FCRPCIthan males following 7 d of HS (P=0.008). Conversely, the contribution of electron transfer supported by complex II to total E (FCRECII) was greater in TN compared to 1 d of HS in males (P=0.004) but then increased at 7 d of HS (P=0.02) so that TN and 7 d HS were similar. In females, FCRECII tended to be lesser following 7 d of HS compared to TN, resulting in a trend for males to have greater FCRECII than females after 7 d of HS (P=0.08). Finally, males tended to have greater FCRPCI+IIthan females (P≤0.08). These results suggest HS increased mitochondrial utilization of complex I in females but reliance on complex II in males, resulting in more efficient mitochondria following HS in males than in females. Therefore, skeletal muscle in females may be more susceptible to negative cellular impacts of HS.
Arhgap29 is Required for Proper Palatogenesis and its Loss in Ectodermal‐Derived Cells Results in a Kinked Tail Phenotype
Authors: Adelizzi Emily C. , Doolittle Bethany , Dunnwald Martine
Published: May 2022

Craniofacial deformities, specifically non‐syndromic cleft lip with or without palate (NSCL/P), are among the most common class of birth defects. Complex interactions between genetic and environmental factors contribute to the development of NSCL/P. Many genes have been associated with this disease, including ARHGAP29. ARHGAP29, Rho GTPase Activating Protein (GAP) 29, functions in the cyclical regulation of the small GTPase RhoA. Previous studies have identified genetic variants of ARHGAP29 in NSCL/P and have found that ARHGAP29 levels were reduced in mice deficient for Irf6. Data from these studies suggest a role for ARHGAP29 in craniofacial morphogenesis but it remains unknown if ARHGAP29 is required for, or regulates craniofacial development. ARHGAP29 is detected in many tissues, including the oral epithelium. Using the Keratin14‐driven Cre‐recombinase allele, Krt14Cre;Arhgap29fl/fl mice displayed a delay in palatal shelf elevation and did not exhibit a cleft palate. We hypothesized that the absence of a cleft palate was due to the late activation of the Krt14‐Cre driver. EctCre drives Cre recombinase specifically in the ectoderm a couple of days before the Krt14‐Cre. Our results show that EctCre;Arhgap29fl/fl mice survive to birth and display a non‐mendelian pattern of inheritance. Interestingly, EctCre;Arhgap29fl/fl mice display a fully penetrant kinked tail phenotype, which has been described in other murine models of NSCL/P, and has been attributed to neural tube and skeletal defects. Additionally, at embryonic (E) day 14.5, while all the wild‐type embryos showed adherent palatal shelves, 75% of EctCre;Arhgap29fl/fl mice displayed palatal shelves not elevated or adherent. Our preliminary data also identified one EctCre;Arhgap29fl/fl embryo out of 3 total analyzed with a cleft palate at E18.5. These data show that ARHGAP29 is required for on‐time palatal shelves movement, supporting a role for ARHGAP29 in craniofacial development.
Myostatin Deletion Protects Against Renal Dysfunction During a High Salt Diet
Authors: Wright Carson L. , Nunan Emily L. , Butcher Joshua T.
Published: May 2022

Chronic Kidney Disease (CKD) afflicts ~15% of U.S. adults and occurs when the kidneys are ineffective in filtering the blood of waste products. CKD is irreversible and current interventions are focused on protecting and preserving renal function. Risk factors for CKD are multifactorial but growing evidence suggest that a key risk factor is dietary salt intake. A diet high in sodium will increase fluid retention, blood pressure, proteinuria, and ultimately drive the progression of kidney damage. Currently, it is estimated that 90% of the U.S. population consumes excess dietary sodium. As such, it is a medical necessity that interventions focus on ways to optimize renal sodium excretion and protect kidney function over time.

Exercise is a key therapy to improve kidney function but a large amount of people are unable to exercise due to disability, lack of time or money, or a pandemic. Our lab has previously discovered that when myostatin, a negative regulator of skeletal muscle mass, is deleted from lean mice it also improves kidney function in diabetes. However, it is unknown whether myostatin deletion will also improve renal sodium handling. Thus, the hypothesis is that myostatin deletion improves sodium handling and protects against renal damage during a high salt diet.

The experiment used adult lean mice with and without myostatin constitutively deleted. Both groups of mice were placed on a high salt (HS) diet (4% NaCl) for 14 days. Food consumption, water intake, and urine production was assessed at baseline, acutely (first 3 days on HS diet) and at the end of the experiment using metabolic cages. Blood pressure studies (in vivo) are ongoing and markers of renal (dys)function are currently being assessed, along plasma hormones that regulate fluid balance. Significance was determined at P<0.05.

The results showed that myostatin deletion protects against kidney dysfunction during a high salt diet, as the myostatin KO mice consumed significantly more food, but maintained fluid balance (drank and urinated similar amounts to the lean control). Blood pressure remained lower in the myostatin KO compared to control. Importantly, myostatin deletion significantly blunted renal hypertrophy (68% less mass) compared to the control. Taken together, myostatin deletion improves the efficiency of the kidney in handling sodium and maintains fluid balance during a high salt diet. Thus, pharmaceutical inhibition of myostatin may prove an effective target for long‐term protection against high salt diets and preserving kidney function during CKD.
Anatomical Variations of the Lumbrical Muscles of the Hand, Regarding Origin, Insertion, Innervation and its Clinical Significance: A Cadaveric Study
Authors: Veras Wilson R. , Hernandez Fernando , Ostolaza Kyara , Vega Carlos , Zanko Nikita
Published: May 2022

The Lumbrical muscles originate in the hand from the tendons of the flexor digitorum profundus muscle and extend to the radial side of the metacarpophalangeal joints. Usually, the median nerve innervates the lumbrical muscles I and II, and the ulnar nerve the lumbrical muscles III and IV. Each lumbrical muscle flexes the metacarpophalangeal joint and extends the interphalangeal joints. Also, it assists in the fine motor movements of the hand.

Numerous lumbrical muscle variants have been described, absence, accessory slips, variations in origin, insertion, innervation, between others. The objective of this study is to record the anatomical variations related to the origin, insertion, and innervation of this group of intrinsic muscles of the hand and discuss the clinical significance of these variations.

For this study, we used ten hands of formalin embalmed cadavers from the anatomy laboratory of San Juan Bautista School of Medicine in Caguas, Puerto Rico. The hands were identified by number, right or left, and male or female. Recollection of Data of anatomical variations of the lumbrical muscles was done through delicate dissection techniques.

Results

From the 76 lumbrical muscles in regards to origin, insertion, and innervation. 64% of the lumbrical muscles were normal in origin, innervation, and insertion. Variations were found in various specimens. 13% of the lumbrical muscles showed a proximal origin inside the carpal tunnel. 11% showed Variations in the insertion site. 8% showed variation in the innervation regarded the third and fourth lumbricals. Also, in 4% of specimens, variations regarding the morphology of the lumbrical muscles were found.

Anatomical variations of the lumbrical muscles could be associated with the development of pathologies that affect the mechanical functions of the hand. Carpal tunnel syndrome is the most common hand neuropathy in the United States, accounting for 90% of all neuropathies. One of the contributing pathogenetic factors is median nerve compression due to lumbrical muscles variations inside the carpal tunnel. Also, variant innervation of the lumbrical muscles can lead to a misdiagnosis in the event of nerve injuries at the level of the forearm or the hand.
Lysine deacetylases (KDACs) regulate PKCõ phosphorylation in response to muscle atrophy
Authors: Habibian Justine , Ferguson Bradley
Published: May 2022

Post‐translational modifications (PTMs) such as acetylation and phosphorylation have been implicated in contractile dysfunction and muscle wasting. Indeed, lysine deacetylase (KDAC) inhibitors attenuate muscle atrophy and delay muscle damage in response to nutrient deprivation, in models of metabolic dysfunction and genetic models of muscle disease (e.g. muscle dystrophy). Historically, lysine acetylation was studied in the regulation of gene transcription, where for instance HDACs remove acetyl groups on lysine residues of histone proteins to suppress gene expression. However, recent evidence demonstrates that non‐histone proteins are acetylated; functioning in protein stability, intracellular signaling, mitochondrial function and muscle contraction. Using C2C12 myotubes stimulated with dexamethasone (Dex) as a model of muscle atrophy, we report that KDAC inhibition using Trichostatin A (TSA) restored myotube size and attenuated Dex‐induced atrophy genes, Murf1 and Atrogin‐1. Despite our current understanding for lysine acetylation in muscle physiology; a role for KDACs in the regulation of muscle signal transduction remains a ‘black box.’ We report that protein kinase C delta (PKCδ) phosphorylation decreased at threonine 505 (T505) and serine 643 (S643), residues important for PKCδ activity, in myotubes in response to muscle atrophy. Interestingly, PKCδ phosphorylation was restored in myotubes treated with a pan‐HDAC inhibitor (TSA) or a class I selective HDAC inhibitor (Apicidin) targeting HDAC1, ‐2, and ‐3 in response to Dex. Moreover, we observed that Dex induced skeletal muscle atrophy rapidly in mice, with weight loss noted by day 3 post Dex and muscle weight loss noted by day 7. Similar to our findings in C2C12 myotubes, Dex attenuated phosphorylation of PKCδ at S643, while KDAC inhibition restored or increased PKCδ phosphorylation at both T505 and S643 in the tibialis anterior. These findings suggest that KDACs act as endogenous regulators of skeletal muscle atrophy through the regulation of PKCδ phosphorylation. Consistent with this hypothesis, we report that KDAC inhibition could not restore myotube size in response to Dex in the presence of a PKCδ inhibitor or when overexpressing a dominant negative PKCδ. Combined, these suggest a non‐canonical role for KDACs in the regulation of muscle physiology outside of its role in chromatin condensation and gene regulation.
Characterization of a splice variant of perilipin 5
Authors: Vanhorenbeck Kaylee , Tansey John T.
Published: May 2022

Lipid storage provides energy stores for the body in times of increased oxidative requirements, such as fasting or exercise, but when the balance of lipid storage and mobilization is disrupted human health suffers. Implications for increased lipid storage include risk factors for developing type II diabetes mellitus and non‐alcoholic fatty liver disease. The perilipin family of proteins associate with the surface of lipid droplets and are essential to regulation of stored triacylglycerols. Perilipin 5 functions to maintain a balance between the storage of triacylglycerols in lipid droplets or their mobilization when energetically required. Several members of the perilipin gene family exhibit differential splicing, most notably perilipin 1 but reports exist of alternative messages for shortened forms of perilipins 2 and 3. We have identified a shortened form of perilipin 5 we have termed perilipin 5b. Western blots indicate that the protein, of approximately 35 kDa, is present in C2C12 cultured myoblasts and in heart and liver tissue from fed and fasted mice. Analysis of murine genomic DNA sequences reveals stop codons found in the introns between exons 6 and 7 and 7 and 8, either of which could give rise to a protein of approximately 35 kDa, indicating the likelihood of the observed protein being a splice variant, rather than a post‐translationally modified protein. Using RT‐PCR we have identified multiple amplicons suggesting that perilipin‐5b contains a read through of intron 6 of the murine perilipin 5 gene. Mining transcriptome databases reveals several transcripts with retained introns. Analysis of the amino acid sequence of perilipin 5b indicates that this truncation would lack the reported C‐terminal domain essential for interactions with ATGL and CGI‐58 but would retain the PKA site found at Ser155. The function of perilipin 5b is yet unknown, but the fact that it is found primarily in heart tissue seems to suggest that it plays a role in the oxidation of the lipid droplet. These data are consistent with what is currently known about Perilipin‐5 and the other PAT family proteins. Determination of perilipin 5b function will give a more accurate picture of the overall mechanism of lipid storage and metabolism.
Dopamine May Exacerbate Neuroinflammation in the Context of HIV by Driving Inflammatory Phenotypes in Macrophages
Authors: Channer Breana , Nolan Rachel , Matt Stephanie , Nickoloff‐Bybel Emily , Canagarajah Joanna , Gaskill Peter J.
Published: May 2022

Globally, there are around 38 million people living with HIV (PLWH). Treatment with anti‐retroviral therapy (ART) can suppress HIV replication and improve the length and quality of life, but chronic infection and ART treatment has resulted in the development of a variety of new co‐morbidities. Among these are the constellation of neuropathological, behavioral, cognitive and motor symptoms collectively known as neuroHIV. These symptoms are found in approximately 50% of the infected population, and multiple lines of evidence indicate that neuroHIV is primarily mediated by chronic CNS infection and inflammatory response in CNS myeloid populations such as macrophages and microglia. In many PLWH, these inflammatory conditions can be exacerbated by substance use disorders, which are highly comorbid with HIV infection and disproportionately common in HIV‐infected populations. Substance use disorders of all types are a major risk factor for the development of neuroHIV, suggesting a common mechanism by which substances of abuse interact with HIV to promote inflammation. All addictive substances increase extracellular dopamine in the CNS and our previous data show that dopamine promotes an inflammatory phenotype in human macrophages. Thus, we hypothesize that exposure to dopamine concentrations (10‐6M) induced by stimulant use will more robustly increase inflammation in HIV‐infected human monocyte‐derived macrophages (MDM) than in uninfected MDM. To test this, uninfected and HIV‐infected human MDM were treated with dopamine and changes in inflammatory profiles were assessed by measuring NF‐κB nuclear translocation using high content imaging and quantifying cytokine production by AlphaLISA analysis. Dopamine significantly increased the production of the inflammatory cytokines IL‐6 and IL‐1β, and these were specifically mediated via dopamine receptors and the activation of NF‐κB. These findings correlate with expression of dopaminergic receptors and nod‐like receptor (NLR) inflammasome transcripts and were altered in the presence of HIV infection. We also found that baseline macrophage activation could be attributed to culture medium type. Overall, these studies provide a broader understanding of the immunological role of dopamine, particularly in the development of neuroHIV and may suggest a potential mechanism for further pharmacological investigation to target HIV infection.
Microvascular Function in Skeletal Muscle of Adiponectin Knockout Mice
Authors: Medarev Steven L. , Machin Daniel , Da Costa Antonio , Hernandez Juan , Auger Lauryn , Qasim Muhammad , Trupiano Samuel , Clark Robert , Hendrickson Dylan , Schaeffer Mackenzie , Schaeffer Hannah , Muller‐Delp Judy
Published: May 2022

Adiponectin is known to be an important regulator of both metabolic and vascular function in skeletal muscle; however, a direct role for adiponectin in exercise training‐induced microvascular adaptation of skeletal muscle has not been documented. We assessed oxidative metabolism, capillarity, and endothelium‐dependent vasodilation in soleus and gastrocnemius muscles of sedentary and exercise trained, wild type (WT) and adiponectin knockout (AdipoKO) mice. WT and AdipoKO mice were obtained at 10‐12 wks of age and underwent treadmill exercise training (1 hr/day, 5 days/wk for 8 wks) or remained sedentary in cages. In sedentary mice, citrate synthase activity and capillarity were increased in soleus muscle of AdiopKO mice as compared to WT mice. In soleus muscle feed arteries from sedentary mice, endothelium‐dependent vasodilation to acetylcholine was reduced in AdipoKO mice as compared to WT mice. Exercise training increased capillarity and citrate synthase activity in soleus muscle of WT mice, but not AdipoKO mice. Exercise training did not alter endothelium‐dependent dilation in soleus feed arteries from either AdipoKO or WT mice. In 1A arterioles from the gastrocnemius muscle of sedentary mice, endothelium‐dependent vasodilation to acetylcholine was not altered in AdipoKO compared to WT mice; however, exercise training increased endothelium‐dependent vasodilation to acetylcholine in WT, but not AdipoKO mice. These data suggest that deletion of adiponectin and a reduction of endothelial vasodilatory function stimulates a compensatory increase in oxidative capacity and capillarity in soleus muscle; however, no further increase in these parameters occurs in soleus muscle of AdipoKO mice in response to exercise training. In contrast, in gastrocnemius muscle, endothelial vasodilatory function was not affected by deletion of adiponectin in sedentary mice, but endothelium‐dependent vasodilation of 1A arterioles increased in response to exercise training in WT, but not in AdipoKO mice. Taken together, these data suggest that the role of adiponectin in adaptation of metabolic and microvascular function in response to exercise training is muscle‐specific.
Investigating Atypical Inflammatory Signaling in Vascular Pericytes as Potential Target for Controlling Blood‐Retinal‐Barrier (BRB) Inflammation in Diabetic Retinopathy
Authors: Ghosh Sneha , Campagna Courtney , Roos Morgan , Lane Payton , Yoder Megan , Marklein Ross , Grimsey Neil
Published: May 2022

Pericytes are master regulators of vascular homeostasis and play key roles in the progression of many vasculopathies, including neurovascular inflammation and diabetic retinopathy. During inflammation, pericytes can be activated by many signals, leading to pericyte induced proinflammatory signaling and pericyte migration away from the vasculature leaving endothelial tubules exposed and fragile. Despite a clear role for G protein‐coupled receptors (GPCR) in the regulation of vascular endothelial inflammation, GPCR control of pericytes has been understudied. Furthermore, pericytes represent a promising candidate for blocking inflammatory responses that could mitigate the onset and progression of neurovascular disease. Our prior studies revealed an atypical inflammatory pathway in endothelial cells, regulated by GPCR induced autoactivation of the mitogen‐activated protein kinase (MAPK) p38 pathway. This Atypical inflammatory pathway has not been studied in pericytes and is a promising therapeutic target. Our central hypothesis is that neurovascular inflammation in the brain and eye is controlled by atypical p38 signaling in vascular pericytes. To investigate this we are initially using primary human brain pericytes. We show that that thrombin, histamine and prostaglandin E2 (PGE2) can activate p38 via the atypical p38 signaling pathway in primary human pericytes and that a peptide inhibitor of atypical p38 signaling, blocks PGE2 dependent p38 activation, suppressing proinflammatory cytokine expression. Furthermore we are currently using single cell morphometric analysis to characterize heterogeneous pericyte responses to proinflammatory stimuli. This will enable the correlation of morphological variations to proinflammatory roles in T‐cell modulation, cytokine regulation, and migration. These studies are revealing novel insights into GPCR dependent control of pericytes and will be extrapolated into studies investigating pericyte‐endothelial cell interactions and the dysregulation of the blood‐retinal‐barrier during diabetic retinopathy. Our current studies focus on defining this role and in understanding how the neurovascular unit in the eye is regulated through atypical signaling, and whether inhibition of atypical signaling can protect the retina from damage. Thus, these studies represent a novel approach to regulate vascular p38 activity and pro‐inflammatory signaling in retinal disease.
Glucocorticoid Receptor Beta as a Contributor to Prostate Cancer Growth and Migration
Authors: Xu Mei , Martinez Genesee , Kipp Zachary , Hinds Terry D.
Published: May 2022

Adenocarcinoma of the prostate is commonly diagnosed in the United States. Prostate cancer (PC) is second only to lung cancer as a leading cause of male cancer deaths (CDC & NCI). African‐Americans (AA) are nearly 1.6 times more likely to be diagnosed with PC than Caucasian‐American (CA) men and 2.4 times more likely to die from the disease. There are known growth‐inhibitory roles of glucocorticoid (GC) hormones in PC. However, eventually, the PC growth and the disease “escapes” become refractory to hormone therapy. Glucocorticoid receptor (GR) consists of two isoforms, GRα, which has been the most studied, and another isoform, GRβ, is less understood. The role of GRβ or GRα in the spectrum of the disease of prostate adenocarcinoma is unknown. Previously, our lab discovered the GRβ gene in mice and found that GRβ has a role in enhancing the growth of cancer cells via the PTEN/Akt1 pathway. In our studies, we found high levels of GRβ in adenocarcinomas from prostate cancer specimens and no change in the GRα level. Analysis of E006AA prostate cancer cells from African Americans showed significantly higher GRβ levels (p<0.01) compared to cells from Caucasian Americans. We, therefore, used lentivirus to overexpress GRβ in LNCaP cells that are derived from Caucasian men. We found that GRβ induces growth pathways and sensitizes to androgen‐induced growth. Migration studies in the E006AA prostate cancer cells from African Americans showed that antagonizing GRβ by lentiviral shRNA or by the Sweet‐P inhibitor significantly (p<0.05) decreased migration rates of the prostate cancer cells. Our findings here indicate that GRβ inhibits GRα to cause GC resistance, which may cultivate hormone‐refractory PC for growth and migration. The research findings may impact PC treatment by allowing for the development of strategies for rational drug design that may lead to novel treatments targeting GRβ and provide the basis for studies in the management of prostate cancer.