bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacological reactivation of RBL2/p130 could be an effective antitumoral strategy for malignant pleural mesothelioma
Authors: Costa Aurora , Forte Iris Maria , Ventura Elisa , Pentimalli Francesca , Giordano Antonio 
Published: May 2022

Malignant mesothelioma (MM) is an aggressive tumor developing from the mesothelium covering the body cavities. The most common MM type affects the pleura surrounding the lungs. MM is mainly associated with asbestos exposure. At present, no curative modalities are effective against MM exist. The molecular mechanisms underlying MM development seem to depend mostly on the inactivation of tumor suppressors, among which also the dysfunction of the retinoblastoma (RB) protein pathway that is a hallmark of cancers. We previously demonstrated that RBL2/p130 is a direct AKT target and its reactivation following AKT inhibition mediates apoptosis in MM.So, we hypothesize that concomitant inhibition of CDK and AKT activity, both converging on the reactivation of RBL2/p130 tumor suppressor role, synergize in counteracting MM.We first assessed, through an MTS assay, the effect of three new generation CDK inhibitors (CDKi), palbociclib, ribociclib, abemaciclib, on the cell viability of MM (NCI‐H28, IST‐MES TWO, NCI‐H2452, MMB, MSTO‐211H, NCI‐H2052) and immortalized human normal mesothelial (MET‐5A) cells at 72h. Then, to verify whether CDKi exerted long‐term cell growth inhibition, we performed clonogenic assays upon treatment of all the MM All the MM and mesothelial cell lines. Finally, we also examined, by MTS, the possible synergistic effects of abemaciclib in combination with an AKT inhibitor (AKT1/2 VIII).Our preliminary data show that ribociclib and palbociclib only moderately reduce viability of the MPM cells, whereas abemaciclib shows cytotoxic effects at very low doses in all MM cell lines. Abemaciclib treatment induces a dose‐dependent cytotoxic effect in all the MM cell lines without meaningfully affecting the normal mesothelial cells. Interestingly, abemaciclib also induced a cytotoxic effect in the most aggressive histotype, the sarcomatoid NCI‐H2052 cells. To verify whether abemaciclib exerted long‐term cell growth inhibition, we performed clonogenic assays upon treatment with IC50 of abemaciclib and found that the CDKi dramatically reduced colony formation in all the MM cell lines. We also examined, by MTS, the possible synergistic effects of abemaciclib in combination with a kinase AKT inhibitor (iAKT1/2 VIII), so we treated the MM cell lines for 72 h with the two agents, both alone and in combination, at five different concentrations, in a constant ratio. The cell viability data were evaluated through the Chou–Talalay method and showed a strong synergism revealing a combination index (CI) values < 1 for all cell.Although reactivating oncosoppressor genes is difficult to achieve because they are hardly ‘druggable’, our preliminary findings will provide the rationale for pharmacological strategies able to unleash RBL2/p130 tumor suppressor potential. The pharmacological reactivation of RBL2/p130 could be an effective strategy against MM, which can be rapidly implemented in the clinical practice.
The Influence of Ovariectomy on Performance and Thermoregulation During Exertional Heat Stroke in Mice
Authors: Garcia Christian K. , Renteria Liliana I. , Leite‐Santos Gabriel , Valera Isela , Pindado Jose , Hickman Corrinne , Carta Jillian , Ward Jermaine R. , Ward Shauna M. , Leon Lisa R. , Laitano Orlando 
Published: May 2022

BackgroundExertional heat stroke (EHS) is a condition characterized by central nervous system dysfunction and multi‐organ injury in hyperthermic victims. Most studies addressing EHS pathophysiology are performed in males. This is a concern since there is an increasing participation of females in sports, active military service, and sex‐dependent susceptibilities to EHS. Preclinical data suggest that female mice outperform male mice regarding distance ran, speed, and time to collapse in a model of EHS. Importantly, differences in body mass between males and females do not explain these contrasting heat tolerances. Whether the female sex hormones could account for the superior performance in the heat remains unknown. Our goal was to determine the influence of female sex hormones on performance and thermoregulatory parameters in a preclinical model of EHS.MethodsWe performed ovariectomy (OVX, n=8) or sham (n=8) surgeries in young adult (18 weeks old) female C57/BL6 mice. Ovariectomy was performed by the bilateral removal of the ovaries. To allow for real time monitoring of core temperature during the entire experiment, all mice were implanted with telemetry emitters at the time of ovariectomy/sham surgeries. Upon recovery from surgeries and training (~6 weeks), all mice underwent the EHS protocol in an environmental chamber set at 37.5℃ and 40% relative humidity. Mice exercised on a running wheel until experiencing loss of consciousness.ResultsOvariectomy increased body mass by 10% at the time of EHS (Sham = 25 ± 1 vs OVX = 28 ± 2 g, P<0.05), resulted in 35% shorter distance (Sham = 753 ± 189 vs. 490 ± 87 m, P<0.05), 25% shorter time to collapse (Sham = 126 ± 21 vs. OVX = 95 ± 12 min, P<0.05), and 15% lower final speed (Sham = 9 ± 1 vs. OVX = 7.5 ± 1 m/min, P < 0.05).ConclusionOvariectomy negatively impacts tolerance to EHS. Ovariectomized mice not only displayed a marked decrease in performance during the EHS trial but also gained more mass than their controls. This suggests that female sex hormones are required for a greater tolerance against EHS.
Assessment of Ferrous Sulfate Contribution to Oxidative Stress in Post‐bariatric Surgery Patients with Iron Deficiency
Authors: Babayev Maksat , Silveyra Patricia , Klaunig James E. , Gletsu Miller Nana A. 
Published: May 2022

Obesity is a global public health problem with numbers of affected people increasing despite the policy efforts1‐3 Bariatric surgery is the common treatment for patients with severe obesity, with increasing number of patients undergoing the surgery (252,000 in 2018 to 256,000 in 2019).4 Unfortunately, 10‐60% of patients develop iron deficiency after the bariatric surgery.5, 6 High‐dose oral iron (i.e., 150‐200 mg of non‐heme iron supplement such as FeSO47) is a recommended treatment for patients with iron deficiency anemia (IDA) in post‐bariatric surgery patients.7 Studies show that oxidative stress (OxS) is an adverse effect of high dose oral iron therapy8, therefore we hypothesized that patients undergoing supplementation with high dose FeSO4 would exhibit increases in systemic oxidative stress. We tested our hypothesis with a secondary analysis using archived plasma specimens from a randomized, single‐blind study that included an arm that underwent treatment with high dose oral FeSO4and a comparison group that underwent a novel heme iron supplement (heme‐iron‐polypeptide, HIP). Participants were women who had developed IDA after bariatric surgery and findings of the study demonstrated superiority of high dose FeSO4 for 8 weeks for improving iron status.9 At baseline, the mean ± standard deviation for age, BMI, and years since surgery of the sample was 39.2 ± 8.7 years, 31.4 ± 7.2 kg/m2, and 6.9 ± 3.1 years, respectively. We used plasma from participants without obesity or bariatric surgery as a control group. We measured malondialdehyde (MDA), an established biomarker of oxidative stress (Abcam, UK). The two‐way ANOVA (IBM SPSS 27) showed no significant difference in mean MDA levels. Mean MDA values for FeSO4, HIP, and control group were 65.4 ± 38.3, 98.70 ± 63.4, and 84.9 ± 60.7 pmol/mL, respectively (all p>0.05).ConclusionsOur findings of no difference in change in oxidative stress between groups does not support our hypothesis that high dose oral iron increases OxS. Limitations of our study are the small sample size and future clinical studies need to determine the potential of oxidative following high dose oral iron therapy in bariatric surgery patients with IDA.
The effects of dietary nitrate supplementation in post‐menopausal women: Does timing matter?
Authors: Delgado Jocelyn M. , Gosalia Jigar , Studinski Matthew , Somani Yasina , Proctor David 
Published: May 2022

There is a need for low risk, non‐estrogen therapies for cardiovascular disease prevention in post‐menopausal women, a population expected to reach 1.2 billion worldwide by 2030. Consumption of beetroot juice and other nitrate‐rich products (green leafy vegetables, supplements) is a promising non‐pharmaceutical strategy for increasing circulating nitric oxide levels and improving vascular function in post‐menopausal women. Whether time since menopause (reproductive age) influences the vasoprotective effects (arterial stiffness and endothelial function) of dietary nitrate supplementation has not been established.PURPOSETo determine the vascular protective mechanisms and efficacy of a nitric oxide boosting supplement (beetroot juice) in women at two post‐ menopausal stages (early‐ vs late‐post menopause).METHODSEarly‐ (1‐6 years following their final menstrual cycle, n=5) and late‐ (n=10) postmenopausal women consumed nitrate‐rich (300 mg/70 mL) and nitrate‐depleted beet root juice acutely and for 7 days. Percent brachial artery flow‐mediated dilation (FMD) was measured at baseline, acutely (90 minutes post‐BRJ consumption), and 15‐minutes and 30‐minutes after 20‐minute upper arm ischemia‐reperfusion (IR) injury for each drink. Brachial‐ankle pulse wave velocity (baPWV) was measured pre‐ and post‐ 7‐day supplementation.RESULTSDue to the nature of this double‐blind trial, data presented are from the baseline (pre‐juice consumption) visit only. Significant (p<0.05) group differences were observed for baseline PWV (early = 1158+115 cm/s; late = 1469+296 cm/s) and FMD at the 30‐minute post‐IR injury timepoint (early = 8.4+4.6%; late = 5.8+2.7%). No group differences were observed in FMD responses at rest (p=0.2) or 15 minutes post‐IR injury (p=0.4).CONCLUSIONThese preliminary results suggest that time since menopause negatively influences arterial stiffness and may prolong recovery from endothelial IR injury in women.
Search and investigation of potential peptide agents of interaction between human organism and its microbiome
Authors: Arapidi Georgij P. , Urban Anatoly , Shender Victoria , Kuznetsov Alexandr , Ivanova Olga , Lopuhov Leonid , Laikov Alexander , Sharova Nina , Nikonova Margarita , Mitin Alexandr , Martinov Alexandr , Grigorieva Tatiana , Ilina Elena , Ivanov Vadim T. , Govorun Vadim M. 
Published: May 2022

Symbiotic interaction between the human body and its microbiota is an important issue of modern biomedicine and personalized medicine. However, little is known on molecular mechanisms of that relationship. Bearing in mind the ubiquitous participation of peptides in biomolecular interactions and regulatory processes we attempted direct search of blood peptides originated from microbial proteins. LC‐MS/MS analysis was carried out of blood serum and plasma samples taken from 20 healthy donors on Q Exactive HF‐X Hybrid Quadrupole‐Orbitrap mass‐spectrometer. Sample preparation was carried out based on our previously developed method of peptide desorption from the surface of major blood plasma proteins followed by standard chromatographic steps. Human microbiota protein sequences were taken from NIH Human Microbiome Project.As a result, out of 13,625 identified peptides 912 were unique fragments of microbial precursors, which is about 6.69% of the total amount of detected bloodstream peptides. In 30 cases peptide identification was confirmed by mass‐spectral study of individual synthetic samples. Absolute quantification by the mass‐spectrometric method of multiple reaction monitoring (MRM) confirmed the presence of bacterial peptides in plasma and serum in the range of approximately 0.1 nM to 1 uM, which is comparable to physiologically significant hormone concentrations in human blood in normal conditions. The abundance of microbiota peptides reaches its maximum 5h after a meal. Most of the peptides correlate with the bacterial composition of the small intestine and are likely obtained by hydrolysis of membrane proteins with trypsin, chymotrypsin and pepsin — the main proteases of the gastrointestinal tract.The isolated fraction of peripheral blood mononuclear cells showed increase secretion of proinflammatory cytokines, colony stimulating factors and chemoattractants as the response to the addition of some of the identified microbiotic peptides. Such peptides — identified both in the plasma and in the serum — have properties of resistance to fibrinolysis, since the pool of peptides is preserved after passing through the digestive tract. The physicochemical properties of the identified bacterial peptides are consistent with those required for the selective permeability of mucosal barriers. Our approach to the identification of microbiota peptides in the blood serum and plasma may be useful for determining the microbiota composition of hard‐to‐reach intestinal areas, such as the small intestine, and for monitoring the permeability of the intestinal mucosal barrier.
Exploring the Neuroprotective Role of Myo/Nog Cells in a Glaucomatous Mouse
Authors: Cuff Evan 
Published: May 2022

IntroductionMyo/Nog cells express MyoD, Noggin and brain‐specific angiogenesis inhibitor 1 (BAI1). They are critical for eye development and respond to injury and stress in the neonatal and adult retina. Their depletion in the embryo results in eye and retinal malformations. Myo/Nog cells increase in number and migrate to areas of injury in response to stress. Cell death in the retina increases with Myo/Nog cell depletion and decreases with their addition to the vitreous. Here we examine the effects and locations of endogenous and exogenous Myo/Nog cells in mice eyes following the induction of glaucoma.MethodsThe anterior chamber of the right eye of C57BL/6J mice was injected with magnetic microbeads and guided to the iridocorneal angle using a handheld magnet, preventing the outflow of aqueous. Intraocular pressure was measured in both eyes following microbead injection on Days 0, 4, 7, 14, D21, and 28. On D7, three of the four groups were given bilateral injections into the anterior chamber of either PBS, unsorted brain cells, or Myo/Nog cells isolated from the brain. The fourth group did not receive any follow‐up injections. Eyes were collected on D32 and labeled with an antibody to BAI1 to locate Myo/Nog cells. H&E staining was used to count living cells in the retinal ganglion layer (RGC) and measure the thickness of the nerve fiber layer and inner nuclear layer (NFL:INL).ResultsEndogenous and exogenous Myo/Nog cells increased in glaucomatous eyes around areas of stress, including the cornea, trabecular meshwork, ciliary body and retina. The highest concentration of Myo/Nog cells was present around the RGC layer and cornea. Some Myo/Nog cells had phagocytized microbeads. Glaucomatous eyes treated with Myo/Nog cells displayed a lower concentration of endogenous Myo/Nog cells when compared to PBS and mixed population treatment groups. Addition of Myo/Nog cells also decreased loss of RGC cells and increased NFL:INL thickness in glaucomatous eyes compared to the control groups.ConclusionConsistent with other types of ocular injury, Myo/Nog cells accumulate in areas of stress following damage from increased intraocular pressure. Addition of Myo/Nog cells was neuroprotective in the glaucomatous retina.
Sex Differences in the Severe‐ and Extreme‐Intensity Power‐Duration Relationships
Authors: Hurla Logan M. , Alexander Andrew M. , Didier Kaylin D. , Hammer Shane M. , Barstow Thomas J. 
Published: May 2022

We have previously shown that, similar to the severe‐intensity power duration relationship (i.e., W’sev), there exists a separate, smaller power‐duration relationship for the extreme‐intensity domain (W’­ext) in men. We have also shown that there may be differences in contributions of central and peripheral fatigue between men and women during and immediately following extreme‐intensity exercise. The current study tested the hypotheses that 1) the W’extwould be significantly less than W’sev in both sexes, but not different between men and women, 2) absolute Maximum Voluntary Contractions (MVC) would be reduced to greater extent at end‐exercise following severe‐ and extreme‐intensity exercise in men compared to women but not when scaled relative to baseline, and 3) peripheral fatigue would be greater at task failure (Tlim) in men compared to women following severe‐intensity exercise, with no sex difference following extreme‐intensity exercise. Following familiarization, 7 men and 7 women completed three severe‐ (Tlim: 2‐4 min, S3; 5‐7 min, S2; 8‐12 min, S1) and three extreme‐intensity (70, 80, 90% MVC) isometric knee‐extension bouts to task failure. MVC and potentiated twitch force (Qpot) were measured and compared at baseline, task failure, and 150 s of recovery. W’ext was significantly smaller compared to W’sev in men (2.4 ± 1.2 kJ vs 3.9 ± 1.3 kJ; p = 0.03) and in women (1.6 ± 0.8 kJ vs 2.9 ± 1.7 kJ; p = 0.05), however there were no sex differences in either W’extor W’­sev. There were no sex differences in MVC at task failure following severe‐intensity exercise. However, MVC was lower in women following extreme‐intensity exercise compared to men, although there were no sex differences in MVC relative to baseline. Further, there were no differences in MVC by the end of recovery compared to baseline in men or women following extreme‐intensity exercise.Qpot was not different at task failure following severe‐ and extreme‐intensity exercise between men and women. However, men showed lower Qpot relative to baseline, suggesting greater peripheral fatigue development, with the exception of exercise at 90% MVC. These data provide evidence that important sex differences exist in the contributions of peripheral fatigue to task failure and in recovery from exercise which depend on exercise intensity. Therefore, practitioners need to consider exercise intensity and the time course of recovery when prescribing exercise to men and women.
Structures, Mechanism, and Functional Relevance of Filament Formation by SgrAI
Authors: Ghadirian Niloofar , Shan Zelin , Lyumkis Dmitry , Horton Nancy 
Published: May 2022

SgrAI is a type II Restriction endonuclease (REases) enzyme from the bacterium Streptomyces griseus. It has been proposed that SgrAI protects the host DNA from off‐target cleavage activity, through a new regulation mechanism via filamentation. Binding of SgrAI to invading phage DNA activates the enzyme leading to DNA sequence specificity expansion from 3 recognition sites to 17 and increased DNA cleavage rate. Like other types of II REases, SgrAI cleaves DNA in a Mg2+ dependent manner. But unlike other REases that form homodimers and cleave near their 4‐6bp recognition sequence, SgrAI forms a filament when in its active form, and a dimer when found in its inactive form. In its active form, SgrAI exhibits an increased rate of DNA cleavage 200 to 1000‐fold faster. The mechanistic underlying these events remain unclear.We have been investigating the details of SgrAI’s structure and cleavage activity on its secondary site DNA sequences to complete our understanding of SgrAI’s kinetic pathway and filament formation. In our recent discoveries, we described two new structures of the SgrAI enzyme, one is the Cryo‐EM structure of the filamentous form of SgrAI bound to intact primary site DNA, and the other one is a high‐resolution x‐ray crystal structure of apo SgrAI. These structures help us to understand important conformational changes that could be contributed to the catalytic mechanism of this enzyme.
Highly conserved binding region of ACE2 as a receptor for SARS‐CoV‐2 between humans and Hippopotamus
Authors: Hayashi Takuma 
Published: May 2022

BackgroundSeveral cases of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection transmitted from human owners to their dogs have recently been reported. The first ever case of SARS‐CoV‐2 transmission from a human owner to a domestic cat was confirmed on March 27, 2020. Mother and daughter of Hippopotamus amphibius (Hippo) at the Antwerp Zoo in Belgium have been reported infected with SARS‐CoV‐2. SARS‐CoV‐2 is believed to have been infected by the hippo caretaker.ObjectiveThese reports have influenced us to perform a comparative analysis among angiotensin‐converting enzyme 2 (ACE2) homologous proteins for verifying the conservation of specific protein regions. One of the most conserved peptides is represented by the peptide “353‐KGDFR‐357 (H.sapiens ACE2 residue numbering), which is located on the surface of the ACE2 molecule and participates in the binding of SARS‐CoV‐2 spike receptor binding domain (RBD).Methods/ResultsACE2 works as a receptor for the SARS‐CoV‐2 spike glycoprotein between humans, dogs, cats, tigers, Hippo, and other animals, except for snakes. The three‐dimensional structure of the KGDFR hosting protein region involved in direct interactions with SARS‐CoV‐2 spike RBD of the Hippo ACE2 appears to form a loop structurally related to the human ACE2 corresponding protein loop, despite of the reduced available protein length (805 residues of the Hippo ACE2 available sequence vs 805 residues of the human ACE2) (Figure). The multiple sequence alignments of the ACE2 proteins shows high homology and complete conservation of the five amino acid residues: 353‐KGDFR‐357 with humans, dogs, cats, tigers, Hippo, and other animals, except for snakes.ConclusionWhere the information revealed from our examinations can support precision vaccine design and the discovery of antiviral therapeutics, which will accelerate the development of medical countermeasures, the World Health Organization recently reported on the possible risks of reciprocal infections regarding SARS‐CoV‐2 transmission from animals to humans.
Initial Characterization of the Extra Cytoplasmic Function Sigma Factor (FpvI) and Sigma Regulator (FpvR) Anti Sigma Domain Interaction in Pseudomonas aeruginosa
Authors: Zak Peyton , Sultana Tajnin , Colbert Christopher 
Published: May 2022

ObjectiveThe objective of this study is to structurally characterize the interaction between the Pseudomonas aeruginosa PA01extra‐cytoplasmic‐function (ECF) sigma factor, FpvI, and the sigma regulator, FpvR.HypothesisThe extra‐cytoplasmic‐function (ECF) sigma factor, FpvI, interacts with high affinity with the N‐terminal anti‐sigma domain of FpvR. It can be purified to homogeneity and used for structural studies by X‐ray crystallography.SummaryTranscription of the pyoverdine transport system of Pseudomonas aeruginosa PA01 is mediated by Cell Surface Signaling (CSS). This process involves binding of the siderophore ferric‐pyoverdine to the outer membrane transporter FpvA. This event triggers the regulated intramembrane proteolysis of the sigma regulator, FpvR. Release of the FpvR anti‐sigma domain (ASD) in complex with the extra‐cytoplasmic‐function (ECF) sigma factor FpvI, directs RNA polymerase to the promoter of FpvA to initiate the transcription. The molecular details of the interaction between FpvR ASD and FpvI are not known. We are using a dual expression plasmid to produce the FpvR ASD and a his‐tagged construct of FpvI. Immobilized metal affinity chromatography (IMAC) followed by size exclusion chromatography is used to purify the complex. We have characterized the complex by Circular dichroism (CD) to show it is well folded. This protein is being further characterized by sparse matrix crystal screening and Small‐angle X‐ray scattering (SAXS).