bluuebunny/crossref_metadata_2025 huggingface dataset:
Identifying Substrates of KDAC6
Authors: Bornes Kiara E. , Nichols Kyara A. , Toro Tasha B. , Skripnikova Elena V. , Watt Terry J.
Published: May 2022

Lysine acetylation is a post‐translational modification that occurs on human proteins. The presence of acetylation on these proteins is important for the development of diseases; therefore, deacetylation is also important. KDAC6 is part of a metal‐dependent enzyme family that is responsible for reversing lysine acetylation. To gain insight into how KDAC6 selects substrates to deacetylate, we hypothesized that KDAC6 activity with peptides derived from putative substrate proteins would predict activity with the corresponding full‐length protein. Using an in vitro fluorescence‐based assay, we determined that several such peptides are substrates of KDAC6. However, the peptides derived from the putative substrates were not always predictive of activity of the full‐length protein with KDAC6. To determine whether KDAC6 is responsible for deacetylation of the corresponding full‐length protein in their biological context, we utilized cell‐based studies that detect changes in acetylation status of target proteins dependent on cellular KDAC6 activity. Target proteins were isolated by immunoprecipitation and the acetylation status determined using an acetyl‐specific antibody of the protein. Isolated target proteins were then reacted with a recombinant KDAC in vitro to determine whether the enzyme is capable of deacetylating the full‐length protein. Overall, we observed that only some putative substrates previously attributed to KDAC6 show evidence of a direct deacetylation by KDAC6. Altogether, our data provide robust evidence for biologically‐relevant KDAC6 substrates. Identifying direct targets of KDAC6, as well as other KDACs, is important for understanding the specificity of KDAC6 in a biological context, and will ultimately contribute to our understanding of the role of KDAC6 in disease.
Extent of Internal Hydration influence the Activation of GPCR Rhodopsin
Authors: Weerasinghe Nipuna , Fried Steven D. E. , Struts Andrey V. , Perera Suchithranga M. D. C. , Brown Michael F.
Published: May 2022

Rhodopsin is an archetypical GPCR responsible for dim‐light vision, which adopts a dynamic equilibrium between two metastable intermediates, metarhodopsin‐I (MI) and metarhodopsin‐II (MII), upon absorption of light. MI is an inactive conformational state of this GPCR, while MII is a fully active conformational state. We hypothesized that the MI to MII transition following isomerization of the retinal ligand involves a flood of bulk water into the protein core. To observe this change in the hydration level of the receptor during activation that is typically invisible to structural techniques such as X‐ray crystallography or cryo‐EM, we carried out a set of experiments using an osmotic stress approach. In this approach, the hydration level of rhodopsin was changed by placing the protein in native disk membranes in solutions with varying levels of osmotic pressure. Inert hydrophilic polyethylene glycol (PEG) solutes with different molecular weights and concentrations were used as the osmolytes. The effect of osmotic pressure on conformational dynamics was then quantified by measuring the reversible shifting of the metarhodopsin equilibrium using UV‐Visible spectroscopy. Results from these experiments show an influx of 80–100 water molecules into the rhodopsin interior, forming a partially disordered, solvent‐swollen active MII conformational state during photoactivation, a result supported by atomistic molecular dynamics simulations work [1, 2]. Additionally, we observed that the size of the polymer osmolyte played an important role in the modulation of rhodopsin’s activation: large osmolytes (PEG > 600) back shift the equilibrium to inactive MI state, while small osmolytes (PEG < 600) forward‐shift the equilibrium to MII state. We attribute this size dependence to the degree of osmolyte penetration into the rhodopsin core. Large polymers behave similarly to ideal osmolytes and dehydrate rhodopsin, while smaller polymers wriggle into the rhodopsin interior and stabilize the open MII conformation. These results necessitate a new understanding of GPCR activation in which the hydration level of protein is paramount in governing conformational energy landscapes. [1] U. Chawla et al. (2021) Angew. Chem. Int. Ed. 60, 2288–2295. [2] N. Leioatts et al. (2014) Biochemistry 53, 376−385.
Anatomical variations of the splenic artery and its relationship with vascular or abdominal pathologies: Systematic review
Authors: Valenzuela Juan Jose J. , Orquera Paulo , Perez Daniela , Santana Andres , Vargas Pamela , Orellana Mathias I.
Published: May 2022

Introduction

The spleen is an abdominal organ whose weight represents 0.2% of total body weight. It contains 3% of cardiac output, constituting one of the most vascularized abdominal organs. This corresponds to the thickness of your blood vessels and their main function, which is to destroy old erythrocytes and the production of blood cells for the maintenance of a blood reserve.

Methods

A systematized search was carried out in electronic databases, in order to compile the available literature on the subject to be treated. The search process was carried out in the following databases; MEDLINE, SCIELO, WOS, CINHAL, SCOPUS and GOOGLE SCHOLAR, using as search terms; “Splenic artery”, “Vacularization splenic,” Anatomical variations “,” Splenic organ “and” Clinical anatomy “.

Results

Of a total of 16 studies included in this review, 8 studies reported in their results clinical correlations of anatomical variations in the splenic artery with surgical procedures in the abdominal region, mostly associated with surgery of the pancreas, liver, stomach and bile ducts. While 8 studies reported clinical correlations of the anatomical variations in the splenic artery in their results with the diagnostic and therapeutic study through images of the abdominal region, the included studies were analyzed with the respective risk of bias for anatomical studies.

Conclusion

Knowing the normal anatomy and the anatomical variants of the splenic artery are crucial for knowledge both for professionals in the morphological area and for clinical professionals who address the abdominal region and its vascular components, in this review we have been able to know that the variation of the splenic artery can be in different regions of its trajectory, which gives us to understand that in any abdominal intervention of the region of the trajectory of this artery there could be some complication if the possible variations of the splenic artery are not known, for which It is suggested to carry out new clinical anatomical studies that consider this variation in both the diagnostic and surgical processes.
Setting up the CURE: approaches to introducing scientific literature into course‐based research projects studying Malate Dehydrogenase function in Trypanosoma brucei
Authors: Springer Amy L.
Published: May 2022

We are using course‐based research experiences (CUREs) to provide opportunities for upper‐level Biochemistry and Molecular Biology majors to gain exposure to laboratory research and learn hypothesis‐development in biochemistry. One challenge to this research is the constraint of the academic calendar, limiting the amount of time students have to learn background information, develop a good hypothesis and perform proposed experiments within an academic term. The research projects in this CURE involve metabolic regulation in Trypanosoma brucei, the protozoan parasite that causes African sleeping sickness, pathogenesis by this unicellular eukaryote is dependent on a metabolic transition from oxidative phosphorylation in the Tsetse fly host to glycolytic metabolism in mammalian hosts. We are interested in exploring potential substrate‐channeling functions of malate dehydrogenase (MDH) isoforms in T. brucei,by exploring protein‐protein interactions and post‐translational modifications using recombinant T. bruceiMDH. This research is performed in collaboration with the protein‐centric MDH CURE community (MCC), a consortium of faculty working on MDH research. MCC CUREs have been shown to support student learning and ownership of research, and provide a wealth of opportunities for comparative studies, access to scientific information and community to assist with course design and sharing of reagents. In one timeline of our MDH CURE, the semester begins with a four‐week “boot camp” of common laboratory techniques and, at the same time, student teams learn some background within a defined research area and choose projects. They spend the remaining eight weeks performing research then present their fundings at the end. This approach provides several weeks for research, but students have little time to learn the background about their projects before they actually begin. Recently a new timeline was tried for the CURE in which the first three weeks is spent on assignments related to reading and discussing relevant scientific literature, then two weeks of “boot camp” before student teams begin their research projects. In this approach, there was more focus on literature and previous experiments as they developed their hypotheses. Students in both semesters had the opportunity to share their ideas and projects with other members of the MCC. Comparing the outcomes from these two timelines, the longer “boot camp” model provided students one more week to perform research, while the earlier literature assignments resulted in greater use of outside sources and understanding of the context of the research in final reports. This provides a model for ways to prepare students for CURE research projects.
Fungal polysaccharides are altered by lyophilization resulting in decreased antibody binding
Authors: Wear Maggie P. , Hargett Audra A. , Kelly John E. , McConnell Scott A. , Freedberg Darón I. , Casadevall Arturo , Crawford Conor J. , Stark Ruth E.
Published: May 2022

The capsule of Cryptococcus neoformans is unique in the fungal kingdom. Its hydrophilic nature and relative neutrality have complicated characterization (1). Even the synthesis of the polysaccharide capsule, being nutrient costly yet induced by nutrient poor conditions, seems counter intuitive. While the encapsulation of cryptococcal species is unique, the secretion of its signature polysaccharide – glucuronoxylomannan (GXM) – is not. Histoplasma capsulatum (2), Paracoccidioides brasiliensis (3), and many of the Trichosporonaceae family including Trichosporon asahii, Trichosporon inkin, Apiotrichum montevideense, Trichosporon japonicum, Trichosporon faecale, Trichosporon ovoides, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis all produce GXM‐like polymers (4, 5). Even basidiomycete fungal symbionts of many lichens Tremella and Cyphobasidium are predicted to produce a GXM‐like polysaccharide (6). As we investigate the role these glycans play in other fungal species it is important that physicochemical properties be conserved. Recent work by our group has shown that the lyophilization of polysaccharide preparations alters them such that antibody binding is reducing, suggesting that these changes have a functional effect. The difference between the polysaccharides before and after lyophilization is stark. Natively isolated polysaccharide preparations have ordered polymers that form small, loosely packed aggregates and contain extracellular vesicles. However, after lyophilization polymers are disordered and form dense rosette‐like aggregates and are absent extracellular vesicles. In addition, lyophilized and re‐solubilized samples allowed to incubate for 28 days did not return to the pre‐lyophilized, native state. This suggests that the changes induced by lyophilization many not be reversible. As we explore the role of these glycans in host‐microbe interactions, we need to consider the effects of lyophilization on the biological and immunological attributes of polysaccharides.
TNFα signaling impairs endothelial calcium signaling and elevates blood pressure in obesity
Authors: Kuppusamy Maniselvan , Ottolini Matteo , Daneva Zdravka , Chen Yen‐Lin , Sonkusare Swapnil K.
Published: May 2022

Endothelial dysfunction in small arteries is a hallmark of obesity‐induced hypertension. Recent studies show that endothelial upregulation of inducible nitric oxide synthase (iNOS) and NADPH oxidase 1 (NOX1) plays a critical role in obesity‐induced endothelial dysfunction. Endothelial upregulation of iNOS and NOX1 results in excessive formation of peroxynitrite, a reactive nitrogen species, which impairs endothelium‐dependent vasodilation. It is well‐known that inflammatory mediators elevate cellular iNOS, NOX1, and peroxynitrite levels. In this regard, tumor necrosis factor alpha (TNFa) signaling has been proposed as a key contributor to endothelial dysfunction in obesity. Notably, vascular smooth muscle cells (SMCs) were shown to generate TNFa in heart failure and diabetes. Therefore, we hypothesized that vascular wall‐derived TNFa acts locally to impair endothelial function in obesity. Flow cytometry studies showed an increase in TNFa levels in freshly isolated SMCs from small mesenteric arteries (MAs) of high‐fat diet‐fed (14 weeks) obese mice compared to normal chow‐fed control mice. However, TNFa levels in endothelial cells (ECs) from obese mice were not different from those in ECs from control mice. The levels of two other cytokines, IL‐1b and IL‐6, were not different between in SMCs and ECs from normal and obese mice. Additionally, qPCR studies in endothelium‐denuded MAs provided further evidence that TNFa expression is increased in SMCs from obese mice compared to control mice. The pro‐inflammatory effects of TNFa are mediated mainly through TNFa receptor I activation. Treating the obese mice with a selective inhibitor of TNFa receptor I signaling (R7050, 10 mg/kg, i.p., once a day for 14 days) reduced the blood pressure to normal levels in obese mice, but had no effect on blood pressure in control mice. Treatment with R7050 also abolished obesity‐induced increase in iNOS and NOX1 expression in endothelial cells. Further, R7050 administration restored acetylcholine‐induced, endothelium‐dependent vasodilation of MAs in pressure myography experiments. Previous studies showed that a decrease in Ca2+ influx through endothelial transient receptor potential vanilloid 4 (TRPV4) channels contributes to blood pressure elevation in obese mice. Notably, R7050 administration restored the Ca2+ influx signals through endothelial TRPV4 channels in MAs, as studied using high‐speed confocal Ca2+ imaging. Collectively, our findings indicate that TNFa signaling contributes to the impairment of endothelial calcium signaling and blood pressure elevation in obesity, and highlight the role of SMCs as a source of TNFa in obesity.
Potent and selective inhibition of anion exchange activity of SLC26A9 by A9‐301
Authors: Park Jinhong , Jo Sungwoo , Namkung Wan
Published: May 2022

SLC26A9 (solute carrier family 26, member 9) is highly expressed epithelial cells of the respiratory tract, stomach, pancreas and kidney, and acts as a Cl‐/HCO3‐ exchanger. SLC26A9 plays a pivotal role in HCO3‐ secretion in lung, and emerging evidence suggests that SLC26A9 is a therapeutic target for cystic fibrosis (CF) and potentially other mucosal obstructive pulmonary diseases. In this study, a cell‐based high‐throughput screening (HTS) assay was established and performed to identify highly potent and selective small molecule inhibitors of SLC26A9. Screening of 30,000 synthetic small molecules identified three novel SLC26A9 inhibitors. Unlike the previous non‐selective SLC26A9 inhibitors, the novel SLC26A9 inhibitors potently and selectively inhibited anion exchange activity of SLC26A9. The most potent inhibitor, A9‐301, significantly blocked Cl‐/I‐ exchange activity of SLC26A9 (IC50 of ~100 nM) without affecting other anion exchanges and chloride channels, including SLC26A3 (DRA), SLC26A4 (pendrin), SLC26A7, CFTR and ANO1. These results suggest that the novel potent and selective inhibitors of SLC26A9 are useful tools for pharmacological dissection of SLC26A9 and may be potential therapeutic candidates for airway inflammatory diseases.
Klebsiella pneumoniae Cross‐feeds Clostridioides difficile and Enhances Colonic Pro‐inflammatory Responses
Authors: Ticer Taylor , Stine Rachel , Ellis Terri , Horvath Thomas D. , Haidacher Sigmund J. , Hoch Kathleen M. , Haag Anthony M. , Engevik Amy C. , Engevik Melinda A.
Published: May 2022

Background

Recent in‐depth analysis of the human gut microbiota demonstrates that many intestinal disorders are polymicrobial in origin and manifestation. Select microbes can interact synergistically with pathobionts to induce virulence traits, modify environmental niches, and modulate host responses. In the setting of Clostridioides difficile infection, polymicrobial interactions are incompletely understood. C. difficile is an intestinal pathogen responsible for 500,000 infections and 30,000 deaths annually in the US. Using stool‐seeded bioreactors with mucus‐coated inserts, we identified Klebsiella pneumoniae in the mucus‐associated microbiota along with C. difficile.

Hypothesis

We hypothesized that K. pneumoniaemay enhance C. difficile traits required for colonization.

Methods & Results

To test this hypothesis, we cultured 11 K. pneumoniae strains with four C. difficile strains (representing 4 different ribotypes) in a fully defined bacteria media ZMB1. We observed that cell‐free supernatant from all K. pneumoniae strains enhanced the growth of all C. difficile strains, indicating that metabolites produced by K. pneumoniae enhanced C. difficile growth. Importantly, C. difficile grew well with K. pneumoniae bacteria and both bacteria were identified in co‐cultures by gram staining. Non‐targeted metabolomics revealed that K. pneumoniae shifted the metabolism of C. difficile away from amino acid utilization. K. pneumoniae metabolites also suppressed toxin production in an in vitro model of nutrient starvation as assessed by live‐imaging of LifeAct expressing Vero cell rounding. These findings further confirm the ability of K. pneumoniae to cross‐feed C. difficile. Although K. pneumoniae is well known for robust biofilm production, K. pneumoniae did not significantly enhance C. difficile biofilm formation, indicating that biofilm synthesis is not a significant component of C. difficile‐Klebsiella interactions. RNA sequencing of mouse colonic inside‐out organoids incubated with live C. difficile and/or K. pneumoniae revealed increased pro‐inflammatory responses when the two microbes were added together compared to either microbe alone or media controls.

Conclusions

These results suggest that K. pneumoniae can cross‐feed and shift the metabolism of C. difficile, as well as enhance the pro‐inflammatory capacity of C. difficile. We speculate that interspecies interactions could be among the earliest events that occur as C. difficile colonizes the host. As a result, we believe that an improved understanding of how mucus associated microbes like K. pneumoniae interact with C. difficile will continue to clarify the mechanisms of C. difficile infection.
Shugoshin‐1 Depletion Reduces Tumor Growth in Triple‐Negative Breast Cancer
Authors: Rodríguez Rodríguez Patricia C. , Jusino Shirley , Rivera Rivera Yainyrette , Chardón Colón Camille , Román González Janeishly , Saavedra Harold
Published: May 2022

Breast cancer is the most common and deadliest cancer that affects females around the world. Triple‐negative breast cancer (TNBC) is a subtype of cancer characterized by the lack of progesterone, estrogen, and Her2 receptors expression. TNBC have the worst prognosis because of its elevated growth rate, limited options for treatment, rapid development of chemoresistance, and its high metastatic potential. Recent studies have correlated Shugoshin‐1 (SGO1) with epithelial‐to‐mesenchymal transition and tumor growth in cancer; however, none of the studies published so far were done in breast cancer. Therefore, we aimed to identify the role of SGO1 in tumor growth of TNBC. We hypothesize that tumor growth will be reduced in shSGO1, given its biological role in other cancers. To test our hypothesis, 2.5x106 MDA‐MB‐231 cell containing either shRNA Control or shRNA SGO1 were injected into female NSG mice that were 6‐8 weeks old. Tumors were allowed to growth for an 8‐weeks period. Following this timepoint, mice were sacrificed to harvest tumors (primary and secondary). Protein lysates were isolated from tumor samples and SGO1 depletion was characterized by Western blot. Tumors were measured, embedded in paraffin, sectioned, and stained with Hematoxylin and Eosin. A student t‐ test was used to evaluate statistical significance. Our results show that the average tumor size for shRNA Control group (n=10) was significantly higher than for shRNA SGO1 group (n=10) at any time point once the tumors were palpable. At the end‐point measurement the average tumor size for shRNA Control group was 848 mm3, while for shRNA SGO1 was 50 mm3. These results suggest that silencing SGO1 reduces tumor growth. Therefore, SGO1 may be a potential line of treatment for TNBC.
Mouse Strain Differences in Female Mice Fed a Short‐Term Western Diet
Authors: Knappenberger Mya A. , Sprankle Kenyon W. , Locke Erica J. , Kolwicz Stephen C.
Published: May 2022

Mouse models of diet‐induced obesity are commonly used for studies of metabolic disease. Since sex and strain differences are suggested to influence the results, studies have been generally limited to males of one mouse strain. This limited study population may impact the understanding of the effect of sex and genetic background on metabolic parameters. Therefore, the purpose of this study was to examine potential differences in short‐term feeding of a high fat diet in two popular strains of female mice. Ten‐week‐old, female FVB/N (FVB, n=20) and C57BL/6‐Ncrl (C57, n=20) mice were fed a Western Diet (WD; 40% calories from fat) or standard chow diet (13% calories from fat) for 6 weeks. Body weight was measured at weekly intervals and the Open Field Test (OFT) was administered to assess changes in activity and behavior at baseline and 6 weeks. The OFT consists of a circular arena, where mice were observed for 10 minutes using a video tracking software system to determine distance, speed, and motion. Tissues and blood were harvested after the 6‐week feeding period. Body weights and organ masses (i.e., heart, liver, adipose, and spleen) were significantly greater in FVB‐chow compared to C57‐chow mice. After 6‐weeks of feeding, body weights, adipose mass, and liver mass were significantly higher in FVB‐WD but not in C57‐WD compared to respective chow groups. FVB‐WD had reduced heart weight to tibial length ratios (FVB‐WD: 6.05±0.14 vs. FVB‐chow: 5.41±0.14, P<0.05) and higher serum ketone body levels compared to FVB‐chow (FVB‐WD: 0.42±0.03 vs. FVB‐chow: 0.76±0.15 mM, P<0.05), changes that were not observed in C57‐WD. OFT results revealed significant effects of diet and mouse strain. At baseline, FVB mice spent greater time moving (422± vs. 379±11 sec, P<0.05) and greater time in the border zone (515±9 vs. 452±11 sec, P<0.05) compared to C57 mice. After 6 weeks, time spent moving tended to decrease in C57‐WD compared to C57‐Chow (42% vs. 30%, P<0.10) while FVB‐WD and FVB‐chow had similar decreases (15% vs. 13% in FVB‐chow). Time in the border zone significantly increased by 8% in C57‐WD compared to a 20% decrease in C57‐chow. In contrast, border zone time decreased by 9% and 10% in FVB‐chow and FVB‐WD, respectively. In summary, in response to 6 weeks of WD, female FVB mice exhibit a more pronounced physical phenotype whereas female C57 mice are more prone to changes in activity and behavior. Overall, these results highlight important strain differences in response to a short‐term high fat diet in female mice
Genetic variants and prostate cancer susceptibility
Authors: Zhang Yuxiong
Published: May 2022

Prostate cancer (PCa) kills one man in forty five and represents the most frequently diagnosed cancer in American men. As is true with cancer, early detection through digital rectal exam and serum testing for prostate specific antigen have greatly reduced the number of fatalities yet these same methods sometimes lead to overdiagnosis and overtreatment. Previous studies have highlighted the association between single nucleotide polymorphisms (SNPs) and cancer. In our studies, we sought to find correlations between SNPs on chromosome 8 and PCa. Normal and PCa patient sequencing data was obtained from the Sequence Read Archive and then analysis pipelines were constructed to map the sequences against chromosome 8 followed by indexing and variant calling. Our studies were able to identify four SNPs specific to DNA sequences isolated from prostate cancer tissues but that were absent in normal tissues. We hope that our findings might help improve personalized medicine and possibly reduce the incidences of overdiagnosis and overtreatment of PCa.
Acute Impact of JUUL Electronic Cigarette use on Cerebral Vascular Vasodilator Responsiveness
Authors: Campbell Jeremiah C. , Akins John D. , Dabroy Danny M. , Yesmin Farjana , Nelson Michael D. , Ben Taleb Ziyad , Brothers R. Matthew
Published: May 2022

Background

Cardiovascular disease is a major cause of death among cigarette smokers and is responsible for ~30% of heart disease related mortality in the U.S each year. Although cigarette smoking rates have declined in recent years, the use of electronic cigarettes (e‐cigarettes) continues to gain popularity in the U.S. and have generated widespread debate within the public health community, mostly due to the lack of scientific evidence regarding their safety and impact on health and behavior. The increasing rates of e‐cigarette use in the U.S have been largely attributed to the recent emergence of the high‐nicotine‐delivery pod‐based devices such as JUUL. Unlike e‐cigarettes, the literature surrounding the health impact of combustible cigarette smoking is well developed with overwhelming evidence of an adverse impact on various cardiovascular outcomes including impaired cerebral perfusion/vascular function. However, the impact of e‐cigarettes on cerebral vascular function remains to be elucidated, representing a major knowledge gap and research priority.

Hypothesis

This study tested the hypothesis that acute e‐cigarette vaping (JUUL) will impair cerebral vascular function as indexed by the cerebral vasodilatory responsiveness to a hypercapnic stimulus.

Methods

A total of 16 adult smokers (mean age=25±5 yrs.) participated in this pilot study which occurred following an overnight fast. Cerebral vascular function was assessed as the hyperemic response to rebreathing‐induced hypercapnia before and ~45 min following a vaping session (10 puffs; 3s each, separated by 30s intervals). Heart rate (ECG), respiration (Pneumotrace), beat‐to‐beat blood pressure (Finometer), middle cerebral artery mean blood velocity (MCAv ‐ transcranial Doppler) and breath‐by‐breath end‐tidal carbon dioxide concentration (PETCO2‐ capnograph) were continuously measured. Cerebral vascular conductance index (CVCi) was calculated as MCAv / mean arterial pressure. Cerebral vasodilatory responsiveness was assessed as % increase in CVCi (%CVCi) during the highest common magnitude of hypercapnia achieved during the pre‐ and post‐vaping trials.

Results

All CVCi data are reported at the highest common magnitude of hypercapnia achieved during the pre‐ and post‐vaping sessions (ΔPETCO2Pre: 13±2 mmHg, ΔPETCO2 Post: 12±2 mmHg; P=0.11). Cerebral vascular function/vasodilatory responsiveness, as assessed by the CVCi response to the hypercapnic challenge was significantly blunted following the vaping session (Pre: +52±25%, Post: +42±14%; P=0.04).

Conclusions

Our preliminary results suggest that e‐cigarette vaping using JUUL acutely impairs cerebral vascular function as indexed by cerebral vasodilatory responsiveness to a hypercapnic challenge. These findings highlight the need for longitudinal studies to assess the long‐term impact of JUUL use on cerebral vascular function as well as other indices of cardiovascular health.
Elucidating the Bitter Taste Signaling Paradox in Airway Smooth Muscle Relaxation
Authors: Conaway Stanley , Huang Weiliang , Kane Maureen , Shapiro Paul , Deshpande Deepak A.
Published: May 2022

RATIONALE

Airway smooth muscle (ASM) hypersensitivity and hypercontractility play a pivotal role in the pathophysiology of obstructive airway diseases such as asthma. Furthermore, over half of affected individuals are unable to reliably control these disorders using the current standard of care, β‐(adrenergic) agonists. Previously, our group discovered the expression of a novel group of G protein‐coupled receptors (GPCRs), type 2 taste receptors (TAS2Rs), in the human airway which evoke ASM relaxation. Previous work in our lab suggests that TAS2R agonists evoke relaxation in a G protein beta‐gamma subunit‐, phospholipase C beta‐ and calcium‐dependent manner. We hypothesized that the downstream molecular targets of contractile‐related signaling components are differentially regulated by TAS2Rs compared to other GPCRs. The goal of this study was to establish the molecular mechanism by which TAS2Rs induce ASM relaxation.

METHODS

We employed a phosphoproteomic approach, involving dual‐mass spectrometry, to determine differences in the phosphorylation status of contractile‐related proteins in ASM following the stimulation of TAS2Rs and other GPCRs. Healthy human ASM cells were treated with the TAS2R agonist chloroquine or β‐agonist isoproterenol alone or in combination with the bronchoconstrictive agonist histamine to study the ability of each relaxant compound to attenuate the histamine‐mediated phosphorylation profile of contractile‐related proteins. These phosphoproteomic profiles were compared and a select set of targets were validated using western blot analysis.

RESULTS

Our phosphoproteomic data demonstrated that histamine stimulation results in increased phosphorylation of Ras homolog family member A (RhoA) guanine nucleotide exchange factor (ARHGEF) 12 and A kinase anchoring proteins (AKAP) 2 and 12, as well as decreased phosphorylation of RhoA GTPase‐activating protein (ARHGAP) 6. Furthermore, chloroquine treatment attenuated histamine‐induced phosphorylation of ARHGEF12 but not AKAP2 or AKAP12. Interestingly, isoproterenol attenuated histamine‐induced phosphorylation of AKAP2 and AKAP12 but not ARHGEF12. Validation studies using western blot analysis revealed chloroquine mediated inhibition of histamine‐induced RhoA activation and myosin phosphatase target subunit 1 (MYPT1) phosphorylation at the T853 residue, which was not observed with isoproterenol.

CONCLUSION

Our findings were able to show that contractile‐related proteins are phosphorylated differentially by chloroquine and isoproterenol to elicit ASM relaxation. Furthermore, our studies strongly suggest the importance of RhoA and the T853 residue on MYPT1 as points of mechanistic divergence between TAS2R and other GPCR pathways. These findings provide further insight into the mechanism by which TAS2R signaling reduces airway contractility and its potential as a novel therapy for obstructive airway disease.
Maternal adiposity inversely associates with physical activity in 2‐year‐old girls
Authors: Diaz Eva C. , Williams David K. , Howie Erin K. , Borsheim Elisabet , Andres Aline
Published: May 2022

Background

Animal studies suggest that maternal obesity and high fat diet during pregnancy program physical activity (PA) patterns in the offspring. However, such nexus has not been established in humans. The purpose of this study was to evaluate the association of maternal adiposity measured early in pregnancy with offspring PA at age 2 years while taking into consideration confounding and modifying factors.

Methods

Women (n=152) were enrolled early in pregnancy (<10 weeks). At enrollment, maternal adiposity [air displacement plethysmography, fat mass index (FMI, kg/m2] was measured, and maternal dietary quality (Healthy Eating Index), age, race, and education level were assessed. Gestational weight gain was measured at the research facility. Offspring birthweight and sex were self‐reported. At age 2 years, parental feeding practices (child feeding questionnaire) were assessed whereas anthropometrics (length and weight) and physical activity (ankle worn accelerometers) were objectively measured. Offspring body mass index z‐scores were calculated. Generalized linear regression analysis with a natural log link was done to model the association of maternal FMI and offspring PA. The interaction between maternal FMI and covariates (i.e., all variables listed above) was assessed. Our final model was created using principles of purposeful selection. The best subset of these terms was identified by observation of minimum model AIC statistic.

Results

There was interaction between maternal FMI and offspring sex in association with offspring total PA [average activity counts (AC)/day] at 2 years of age. Specifically, PA decreased with increasing maternal FMI but only in girls (β=‐0.02, p=0.0470). In addition, total PA was higher in children born to women with college education compared to children born to women without college education (β=0.09, p=0.0369). Minutes spent in sedentary time increased (β= 0.01, p=0.0422) while minutes spent in light PA tended to decrease (β=‐0.01, p=0.0536) with increasing maternal FMI in girls compared to boys.

Conclusions

There is sexual dimorphism in the association of maternal adiposity measured early in pregnancy with offspring PA at age 2 years. PA levels in 2‐year‐old girls was negatively associated with increasing maternal adiposity.
A Consideration for Intersectional Framing Within Physiological Training
Authors: Cisneros Marissa , McNeely Andrew , Quick Christopher M. , Gatson Sarah
Published: May 2022

Objectives

Previous scholars have identified the need to increase diversity in medical education in terms of diversifying the student base, cultural competency curricula, and increasing health equity (Awosogba et al 2015; Sharma 2019; Hordjik 2019; Muntinga et al 2016). Establishing an intersectional theoretical framework, and other feminist theoretical frameworks, within medical education has been put forth, however literature indicates there are many obstacles in optimizing this implementation (Sharma 2019). In line with Bentabos et al (2014), we argue that much can be gained from addressing health equity at the biomedical undergraduate level, as healthcare is an institution of workers beyond the medical field (e.g. clinical research). Further, we posit that, given AAMC data points (AAMC Diversity in Medicine: Facts and Figures 2019), addressing diversity at the medical education level addresses the problem too late. Finally, the traditional medical education environment likely does not provide space to adequately develop a critical framing of cultural competency (Moore 2007; Muntinga et al 2016). As such, the purpose is to demonstrate how intersectional framing embedded within the Health Disparities track of a Biomedical Research Certificate provides a multidimensional analytical tool able to equip health & care workers, including future medical students to: (1) Increase a diversity minded environment in medical education. (2) Apply reflective and reflexive tools to professional and graduate biomedical aimed curricula thus impacting the organizational discourse overall.

Methods

Thematic analysis applied to Intersectional Methodology to identify the interaction of curricula content and scaffolded collaborative learning through the Research‐Intensive Community (RIC) Model (Desai et al 2008). The major themes we seek to identify and reflect upon are the Guideposts of Intersectionality laid out by Collins and Bilge (2016). The research question we seek to answer is: how does intersectional curricula within the RIC model interact to create a reflexive lens that can identify and act on inequity at the micro, macro and meso level. Practical Implications:The framework provided here can supply a starting point of implementation that goes beyond an additive framework or simple gesture to intercategorization.
Elucidation of Bacterial Peptidoglycan Signaling and Recognition in the Human Commensal Candida. albicans through the LRR domain of the peripheral Membrane Protein Cyr1p
Authors: Crump Geneva , Grimes Catherine , Williams Caroline
Published: May 2022

The human commensal Candida. albicans (C. albicans) is the most common fungal resident of the human microbiome. In healthy individuals this fungus occupies a budding morphology, but during immune incompetence morphologically transitions to a pathogenic hyphal form. The long filamentous form of hyphae readily invades human epithelial cells and if not successfully treated, cause lethal systemic infections. One of the key molecular integrators in this morphological transition is the binding of bacterial peptidoglycan (PG) fragments to the Leucine Rich Repeat (LRR) domain of the adenyl cyclase Cyr1p. PG is a highly complex polymer consisting of repeating units of the disaccharide N‐acetyl glucosamine‐N acetyl muramic acid, which are crosslinked by pentapeptide side chains. Considerable diversity exists in this polymer within and among Gram (‐) and Gram (+) species of bacteria, rendering a plethora of potential ligands for Cyr1p. Identification of specific PG fragments that are able to induce hyphal formation in C. albicans, and stabilize Cyr1p through the LRR domain can elude to small molecule inhibitors to combat these lethal fungal infections that are continuously becoming resistant to current antifungal therapies. To approach a congruency of PG fragments from both Gram (‐) and Gram (+) bacterium that can serve as ligands for the LRR domain, we began by characterizing recombinant LRR and in doing so have determined this protein is a peripheral membrane protein that adopts an alpha helical conformation. Furthermore, to assess Cyr1p's ability to interact with a repertoire of PG fragments, we conducted Cellular Thermal Shift Assays (CETSA) with various PG fragments and have observed a temperature induced stabilization in comparison to apo‐protein, suggesting that there is a positive interaction with the LRR domain and the fragments. We further investigated the ability of these PG fragments to induce hyphal formation in WT C. albicans cells via microscopy assays and evaluated upregulation of hyphae specific genes at various timepoints via RT‐PCR. We observed differential hyphal gene regulation at various timepoints, suggesting that some fragments although able to initiate hyphal growth, failed to maintain growth and subsequent elongation. In addition, we observed that despite a positive association of the LRR with some fragments through CETSA assays, these fragments failed to illicit hyphal formation in WT cells. We infer that stabilization of the LRR is not linearly attributed to hyphal elongation, although hyphal initiation may be present. Collectively, these data help to identify new mechanisms to treat pathogenic fungal infections through the elucidation of promiscuity of the Cyr1p LRR domain, and steers us towards the identification of PG decoys and/or small molecule inhibitors for the treatment of these infections.
Pathology Encountered During Cadaver Dissection Provides an Opportunity for Case‐based Learning
Authors: Bachand Amanda , Nikolaidis Daniel , Blake Jonathan , Lee Nikita , Sundquist Skylar , Barremkala Malli
Published: May 2022

Dissection based anatomy education engages medical students in building several skills, including professionalism, problem solving, and critical thinking. During the first semester of medical school at Oakland University William Beaumont (OUWB) School of Medicine, students spend a significant amount of time dissecting and learning anatomy regionally. In addition to viewing typical structures throughout the body, cadaveric dissection also allows for the opportunity to discover and learn from pathology that may be encountered. In this case, students observed a malignant tumor (adenocarcinoma) in the right lung, accompanied by severe fibrosis of the right diaphragmatic parietal pleura. The superior, middle, and inferior lobes of the right lung were significantly reduced in size within the thoracic cavity compared with the left lung. Additionally, several gross malformations in the pulmonary tissue and cavity were observed, likely due to the malignancy. As part of this analysis, histopathology and radiology for the malignant lung tumor will be compared and reviewed against normal lung tissue and mechanisms for adenocarcinoma will be discussed. These will be used to develop a case study to facilitate peer teaching. This case provides a valuable opportunity for medical students at OUWB to connect basic anatomy to clinical presentation and develop a deeper understanding of pathophysiology of disease prior to clinical rotations.
Effect of a single individualized precise constant power exercise on pulse wave in patients with new‐onset chronic disease
Authors: Tai Wenqi , Sun Xingguo
Published: May 2022

Objective

To observe the changes of pulse wave after exercise and to explore the effect of a single individualized precise constant power exercise on pulse wave in patients with new‐onset chronic disease.

Methods

13 patients with new‐onset chronic disease, 16 normal persons and 16 patients with long‐term chronic disease were selected, all subjects were tested for symptom‐limited maximal cardiopulmonary exercise test (CPET), and individualized exercise prescriptions were formulated based on Δ50% power. First, the 50s pulse wave data in the resting state was measured and recorded. The subjects exercised for 30 minutes according to the established exercise intensity, and then measured and recorded the pulse wave data at 10, 20, and 30 minutes after the exercise, next analyzed and compared the pulse wave changes between patients and normal people.

Results

10min after exercise in newly‐onset chronic patients, YPL (the amplitude of the trough of a pulse wave notch), ΔPL (the amplitude difference between the trough of a pulse wave notch and the starting point of a pulse wave), TPL (the time of trough of a pulse wave notch), TE (time at the end of the pulse wave), and TE‐TPL (the duration of a pulse wave notch) were all reduced, while ΔTP2′(TP2‐TPL, the duration of trough to peak of a pulse wave notch) and notched pulse wave ratio increased. In other words, the pulse wave notch was more obvious, and the duration of a single pulse wave was shortened. This trend was maintained at 20min and 30min after exercise, but the duration of a single pulse wave increased with time. After exercise, the occurrence rate and apparent degree of the pulse wave notch in new‐onset chronic disease patients are not as good as those of normal people, but they are better than those of long‐term chronic disease patients.

Conclusion

A single individualized precise constant power exercise makes the pulse wave of patients with new‐onset chronic disease tend to be normal, but it is still worse than that of normal people, which prompts us to further explore the impact of long‐term exercise strengthening control on the pulse wave of patients with new‐onset chronic disease.
Watching or Waiting?: Effects of In‐Person Active Learning Sessions on Student Engagement with Lecture Recordings and Course Resources
Authors: Bauer Frederick W. , Dunham Stacey M. , Husmann Polly R.
Published: May 2022

It is no surprise that the Covid‐19 pandemic severely affected higher education during the 2020‐2021 academic year. However, these effects continue to be felt throughout many classrooms as students and instructors struggle to return to any semblance of normalcy. Our research sought to investigate the following question: How do students’ interactions with lecture recordings and perceptions of their study strategies differ between the Fall 2020 and Fall 2021 semesters? We examined this question in a large undergraduate anatomy class in the Midwest. During the Fall of 2020, all of our lectures were pre‐recorded and posted online. During the Fall of 2021, these same recordings were used again, but in‐person active learning sessions were also provided to enhance student engagement with the material. We hypothesized that students having in‐person active learning sessions would help students to stay caught up with the lecture recordings compared to when there were no in‐person sessions. We also hypothesized that student study strategies would change with the presence of in‐person active learning. The present study utilized learning analytics from the course management system to assess student engagement with the video recordings and student survey responses to examine student perceptions and study strategies for each semester. These data were then compared with both lab and lecture exam grades and course outcomes to determine how effectively students are interacting with these materials within the context of each semester. The results found that students continue to struggle with staying caught up on lecture recordings and are even less likely to engage with the lecture recordings when in‐person active learning sessions are offered as well. However, this lack of engagement with these resources also corresponded with a significant drop in the average exam grades for the course despite the availability of additional resources. These results have significant implications for course management and student expectations as we (hopefully) move forward from the Covid‐19 pandemic.
Abnormal hypoxic and hypercapnic ventilatory responses in 5XFAD Alzheimer’s disease mice
Authors: Sprenger Ryan J. , Ewald Andrea , Ulland Tyler , Baker Tracy , Watters Jyoti
Published: May 2022

Alzheimer’s disease (AD) is a neurodegenerative disease commonly associated with aging. Along with regression in cognition and memory, AD patients often have respiratory disturbances such as sleep apnea, insufficient ventilation during sleep, and shortness of breath. Further, at least one chemosensitive region located in the pons, the locus coeruleus, undergoes dramatic degeneration during AD progression. These observations suggest chemoreception may be altered during the progression of AD. To begin testing this hypothesis, we examined the hypoxic (HVR) and hypercapnic (HCVR) ventilatory responses on 5XFAD mice (>6months) using whole body plethysmography. Preliminary data showed a reduced capacity to lower metabolic rate and body temperature during hypoxia (5.5% inspired O2) in 5XFAD mice, such that average oxygen consumption was reduced by 34.8 ± 2.8% (S.E.M) and body temperature fell to 33.5 ± 0.4°C. In wild type (WT) mice oxygen consumption was reduced by 53% and body temperature fell to 32.8°C. Further, 5XFAD mice sustained a slight ventilatory increase (1.3 ± 3.6% increase from baseline) during hypoxia while WT mice reduced ventilation by 5%. 5XFAD mice also displayed a reduced hypercapnic ventilatory response, showing little increase in tidal volume in response to hypercapnia; but they appeared to augment this with a greater increase in breathing frequency compared to WT mice. The net result, however, was an increase in ventilation by 122 ± 22% from baseline in response to 5% CO2 while WT mice had a 181 ± 26% increase from baseline to the same challenge. Our data suggest that ventilatory chemoresponses are altered by disease progression in the 5XFAD mouse model. These alterations may contribute to the respiratory disturbances observed in AD patients.