bluuebunny/crossref_metadata_2025_split huggingface dataset:
LPS transport during fat absorption is inhibited in caveolin‐1 knockout murine jejunum
Authors: Nishii Shin , Akiba Yasutada , Mizoguchi Akinori , Kaunitz Jonathan D. 
Published: May 2022

Lipopolysaccharides (LPS) entry from the intestinal lumen to the circulation is associated with systemic inflammation. We have found that LPS is transcellularly transported to portal vein during long‐chain fatty acid (LCFA) exposure via CD36‐ and lipid raft‐mediated pathways in rats, suggesting the involvement of caveolae‐mediated endocytosis. We thus examined LPS transport in caveolin‐1 (Cav1) knockout (KO) murine jejunum.FITC‐LPS was applied to the mucosal bath of Ussing chambered muscle‐stripped jejunal mucosa‐submucosa preparations of Cav1 KO and wild type (WT) mice. Serosal appearance of FITC‐LPS was measured with or without luminal application of oleic acid (OA, 30 mM) with taurocholic acid (TCA, 0.1 mM), or medium‐chain fatty acid sodium caprate (C10, 10 mM).Luminal application of OA/TCA increased FITC‐LPS m‐to‐s transport in WT jejunum, inhibited by the CD36 inhibitor sulfosuccinimidyl oleate (SSO, 0.1 mM) or the lipid raft inhibitor methyl‐β‐cyclodextrin (MβCD, 0.1 mM), not by the clathrin inhibitor chlorpromazine (0.1 mM) or Pitstop2 (30 µM), suggesting that LCFA‐induced LPS transport is mediated by caveolae‐mediated endocytosis, not by clathrin‐mediated endocytosis. In contrast, OA/TCA‐induced FITC‐LPS transport was abolished in Cav1 KO jejunum. Nevertheless, luminal application of C10 increased FITC‐LPS transport both in WT and Cav1 KO jejuna without transepithelial electrical resistance changes, suggesting that C10 enhances transcellular LPS transport via caveolin‐independent endocytosis in the jejunum.These results suggest that LPS transport during LCFA exposure is mediated by Cav1‐mediated endocytosis, whereas MCFA‐induced LPS transport is likely via clathrin‐mediated endocytosis. Modulation of epithelial endocytosis may be a new therapeutic target for LPS‐associated diseases mediated by dietary fatty acids, including metabolic syndrome.
Depletion of gut microbiota suppresses spontaneous ileitis in mice driven by mitochondrial dysfunction induced by Phb1 deficiency
Authors: Alula Kibrom , Theiss Arianne 
Published: May 2022

IntroductionDysbiosis in gut microbiota is associated with inflammatory bowel diseases (IBD), such as Crohn’s disease. Prohibitin 1 (PHB1) is a mitochondrial protein important in optimal mitochondrial respiration and is decreased in biopsies from IBD patients. Intestinal epithelial mitochondrial dysfunction is emerging as an underlying contributor to inflammation in IBD. Previous studies from our laboratory have demonstrated that mice with Phb1‐deficiency in the intestinal epithelium (Phb1iΔIEC) manifest mitochondrial dysfunction, Paneth cell defects, and spontaneous inflammation in the ileum with a penetrance of 87% at 12 weeks after inducing Phb1 deletion. This inflammation is associated with a reduction in the abundance of short chain acid (SCFA)‐producing bacteria, such as Blautia, Roseburia, Ruminococcus, and Coprococccus. However, little is known whether gut dysbiosis is a driver or consequence of ileitis during intestinal epithelial mitochondrial dysfunction. In the present study, we hypothesized that the gut microbiota is necessary to induce intestinal inflammation during epithelial cell mitochondrial dysfunction.MethodsPhb1iΔIEC mice and control Phb1fl/fllittermates were co‐housed and treated with broad spectrum antibiotics (ABX) (1 g/L ampicillin sodium salt, 1 g/L neomycin sulfate, 1 g/L metronidazole, and 500 mg/L vancomycin) in autoclaved drinking water for 4 weeks beginning 8 weeks after the induction of Phb1 deletion. Ileal stools were collected for 16S rRNA sequencing and quantification of SCFAs by liquid chromatography‐mass spectrometry. Ileum was collected for histological (inflammation) scoring after H&E staining and for immunofluorescent staining of lysozyme and Muc2 to quantitate Paneth cell defects (lysozyme allocation patterns, increase of lysozyme+/Muc2+ staining, and crypts devoid of lysozyme+ cells). Spleen weight was also measured at the time of sacrifice.ResultsIleal stool from Phb1iΔIEC mice exhibited a significant reduction in the SCFA butyrate compared to Phb1fl/fl littermates. 16S rRNA sequencing showed that ABX treatment abolished the ileal bacterial population in both Phb1fl/fland Phb1iΔIEC mice. ABX treatment ameliorated enlarged spleen weights, histological inflammation, and Paneth cell defects characteristic of Phb1iΔIEC mice to measurements noted in Phb1fl/fl mice.ConclusionsThese results suggest that mitochondrial dysfunction in IECs on its own is not sufficient to cause inflammation, but triggers disease when coupled with gut microbiota interaction. This is especially relevant to IBD given the prevalence of epithelial mitochondrial dysfunction in these patients.
PGE receptor EP4 signaling increased hyaluronan‐vesican complex in abdominal aortic aneurysm
Authors: Hiromi Taro , Iida Saki , Nakamura Takashi , Yokoyama Utako 
Published: May 2022

Chronic inflammation and dysregulation of extracellular matrices are hallmarks of abdominal aortic aneurysm (AAA) pathophysiology. We have demonstrated that PGE receptor EP4 signaling in vascular smooth muscle cells (VSMCs) has a pivotal role in AAA formation via immune infiltrates and impairment of elastic fiber repair. However, EP4 signaling‐mediated changes in extracellular matrices have not been fully understood, and expressions of the chondroitin sulfate proteoglycan versican are controversial. Versican has multiple binding partners (e.g., hyaluronan and fibrillin‐1) and modulates VSMC phenotypes. We, therefore, aimed to clarify an expression change in versican in AAA.We administrated angiotensin‐II (AngII) to VSMC‐specific EP4 overexpression mice (EP4‐Tg) to induce AAA. The expression level of versican V0/V1 was gradually increased in the tunica media of EP4‐Tg mice 4 days after AngII administration, but not in Non‐Tg mice. This increase in versican V0/V1 became prominent 14 days after AngII administration in EP4‐Tg mice. Protein expression of versican V0/V1 was increased in the tunica media of human AAA tissues. EP4 stimulation in VSMCs derived from EP4‐Tg mice increased levels of versican mRNAs (20.0±1.4‐fold, n=5, p<0.01) and versican V0/V1 proteins (4.1±0.7‐fold, n=5, p<0.01), while administration of EP1/3 or EP2 agonist did not. The EP4‐mediated increase in versican mRNAs was completely suppressed by Actinomycin D. Versican V0/V1 are cleaved by a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS‐1) and ADAMTS‐5. The expression levels of ADAMTS‐1, ADAMTS‐5, and cleaved versican protein expressions were not changed in EP4‐Tg VSMCs. The expression level of Hyaluronan synthase1 (Has1) mRNA was also increased in EP4‐Tg VSMCs (66.9±10.1‐fold, n=5, p<0.01). Western blotting revealed that versican V0/V1 proteins of approximately 200‐400 kDa in size in the supernatants of EP4‐Tg VSMCs stimulated with an EP4 agonist were increased by hyaluronan digestion with hyaluronidase (6.3±1.5‐fold, n=6, p<0.01). Transmission electron microscopic analysis demonstrated that elastin contractile units between elastic laminae and VSMCs were disrupted in EP4‐Tg mice administrated with 10 days of AngII, but not in Non‐Tg mice.These data suggested that EP4 signaling in VSMCs increased hyaluronan‐versican V0/V1 complex. Versican V0/V1 proteins were increased in the early stage of a mouse AAA model. It has been suggested that versican has inhibitory roles in elastic fiber formation. EP4‐mediated hyaluronan‐versican V0/V1 complex may exacerbate AAA via disruption of elastin contractile units.
Microbial multidimensional signature assessment reveals microbial SNVs as the superior non‐invasive biomarkers for early detection of colorectal cancer
Authors: Gao Wenxing , Sun Ruicong , Zhu Lixin , Gao Sheng , Feng Zhongsheng , Wu Dingfeng , Gao Xiang , Zhao Rui , Yao Ye , Liu Zhanjiu , Zhu Ruixin , Jiao Na 
Published: May 2022

BackgroundThe early detection of colorectal cancer (CRC), especially at precancerous adenoma stage, significantly reduces its incidence. Gut microbiome has become a promising non‐invasive tool for CRC screening, whereas the potential of microbial multidimensional signatures remains poorly understood. Here we performed a cross‐cohort analysis to evaluate the capability of microbial multidimensional biomarkers for adenoma detection.DesignWhole metagenome sequencing data of four public datasets including 183 adenoma patients and 439 healthy controls were reprocessed consistently to obtain taxonomic‐, functional‐ and single‐nucleotide variants (SNVs)‐profiling. With MMUPHin, differential multidimensional signatures were identified after adjusting confounders, based on which random forest (RF) models were constructed and then optimized by recursive feature elimination. Finally, internal validation and external validation with in‐house dataset (10 controls and 6 adenomas) and five resampled datasets were conducted to further assess the robustness of the best biomarker panel.ResultsThe integrated analysis identified 103 multi‐kingdom differential species between adenoma and control group, of which 15 optimal species were selected to construct a RF model achieving an AUC of 0.75. Meanwhile, the model constructed with 31 optimal biomarkers out of 386 differential KO genes reached an AUC of 0.74. Notably, the diagnostic model with 75 SNVs from 10 species showed superior accuracy (AUC = 0.85) with high specificity to adenoma. Co‐abundance analysis revealed intensive bacterial‐fungal associations in line with functional abnormalities related to microbial quorum sensing, purine and butanoate metabolism.ConclusionMicrobial SNV biomarkers outperform other biomarkers and display high specificity to adenoma, which may serve as a novel non‐invasive tool for early detection of CRC. Furthermore, multidimensional signatures provide potential therapeutic targets for adenoma.
Oxidative Crosstalk with Venular Capillary Mitochondria Mediates Barrier Failure in Acute Lung Injury
Authors: Hough Rebecca F. , Emin Memet T. , Jin Guangchun , Bhattacharya Jahar 
Published: May 2022

OBJECTIVE. To elucidate mechanisms underlying alveolar‐capillary crosstalk in the context of lipopolysaccharide (LPS)‐induced Acute Lung Injury (ALI), which causes The Acute Respiratory Distress Syndrome (ARDS).HYPOTHESISOxidative crosstalk between alveolar epithelium and adjacent endothelium causes mitochondrial injury and barrier failure in Acute Lung InjuryMETHODS. We instilled LPS (5mg/kg) by the intranasal (i.n.) route in anesthetized mice. We evaluated microvascular endothelia of isolated blood‐perfused mouse lungs by confocal microscopy, and ALI by bronchoalveolar lavage (BAL) 48h later. For microscopy, we gave the potentiometric mitochondrial dye MTDR, and the reactive oxygen species (ROS) indicator DCF by intravascular infusion. We determined the role of endothelial uncoupling protein 2 (UCP2) by (1) UCP2 knockdown in endothelia by vascular siRNA injection, and (2) endothelial‐specific knockout of UCP2. We transfected alveolar epithelium by i.n. instillation of catalase‐expressing plasmid, or depleted neutrophils by intraperitoneal injection of anti‐Gr1 antibody, 24 hours before i.n. LPS. We quantified barrier permeability through BAL protein content.RESULTS. Confocal imaging indicated that baseline fluorescence intensity of both endothelial MTDR and DCF was steady, indicating that endothelial mitochondrial potential and endothelial ROS were stable. However, 48 hours after LPS instillation, MTDR fluorescence decreased in venular capillaries more than in alveolar capillaries (n=4, p<0.05), indicating endothelial mitochondrial depolarization. Simultaneously, DCF fluorescence increased in venular capillaries more than in alveolar capillaries (n=4, p<0.05), indicating an increase in endothelial ROS. LPS instillation increased BAL protein (n=4, p<0.05). Knockdown of endothelial UCP2 expression, or expression of transfected catalase in the alveolar epithelium blocked LPS‐induced endothelial mitochondrial depolarization and BAL protein increase (p<0.05). Endothelial‐specific knockout of UCP2, but not neutrophil depletion, blocked LPS‐induced BAL protein increase (p<0.05).CONCLUSIONS. We show here for the first time that the hyper‐permeable responses of LPS‐induced ALI result from mitochondrial depolarization in venular capillaries. Transfer of H2O2 from alveoli, not neutrophils activated UCP2, causing proton influx into the mitochondrial matrix. Our findings reveal a novel mechanism of LPS‐induced ALI, implicating mitochondria‐oxidant coupling in barrier failure. Thus, UCP2 presents a potential therapeutic target for ARDS.
Optimal tip position of peripherally inserted central catheter (PICC) using electrocardiogram–a retrospective analysis
Authors: Lee Kichang , Kelly Linda , Sabouri A. S. , Jung Ki T. 
Published: May 2022

BackgroundCorrect tip location of a peripherally inserted central catheter (PICC) is crucial to ensure optimal drug delivery and avoid creating potential complications. P‐wave amplitude changes in the intravascular electrogram (ivECG) can guide the PICC tip to the optimal location during the catheter placement procedure, but its accuracy is limited. Therefore, the main objective of this study was to evaluate the ratios of different waves in ivECG and body external ECG (exECG) when the correct tip location was confirmed by chest X‐ray (CXR).MethodsIn this retrospective study, we analyzed the ivECG, exECG, and CXR of 146 patients who underwent a PICC placement procedure. The optimal location of the PICC tip was defined in the lower 1/3 of the superior vena cava (SVC) to the junction of the SVC and right atrium, known as the cavo‐atrial junction (CAJ). The catheter tip to carina distance (TCD) was also measured using vertebral body units (VBU). The PICC tip location was categorized as follows: Zone 1, malposition with TCD < 1.2 VBU; Zone 2, suboptimal with 1.2 VBU ≤ TCD < 1.8 VBU; Zone 3, optimal with 1.8 VBU ≤ TCD < 2.8 VBU; Zone 4 deep with TCD > 2.8 VBU. The amplitude ratios between/within the ivECG and the exECG of the corresponding waves were calculated and compared.ResultsThe external/internal ratio of the amplitude of uprising P‐wave (Psp) and declining P‐wave (Ppe) in Zone 3 was significantly higher than in Zone 1 (p < 0.001) and Zone 2 (p = 0.004). The amplitude ratio in the ivECG of uprising P and QR (Pspiv/QRiv), uprising P and RS (Pspiv/RSiv), declining P and QR (Ppeiv/QRiv), and declining P and RS (Ppeiv/RSiv) were significantly lower in Zone 3 compared to Zone 1 (p < 0.001, respectively). There was a moderate correlation between TCD using VBU and ECG height ratios such as Pspiv, Ppeiv, Pspiv/QRiv, and Pspiv/RSiv (p < 0.001, respectively).ConclusionsThe height ratios of ECG waves such as Pspiv, Ppeiv, Pspiv/QRiv, and Pspiv/RSiv can help determine the catheter tip location during the catheter insertion procedure; however, caution is required for accurate positioning of the PICC tip.
Angiotensin‐(1‐7) Restores Gut Barrier Integrity and Ameliorates Systemic Inflammation in Aging
Authors: Chittimalli Kishore , Jahan Jesmin , Sakamuri Anil , Jarajapu Yagna P. 
Published: May 2022

BackgroundAdvancing of age decreases the barrier properties of intestinal epithelium which leads to sterile systemic inflammation. Chronic low‐grade chronic inflammation is an underlying cause for the age‐related comorbidities such as cardiovascular disorders. Renin Angiotensin System (RAS) plays an important role in the homeostasis of cardiovascular functions however, the role of RAS in the aging gut is poorly studied. The protective axis of RAS, which constitutes Angiotensin converting enzyme‐2 (ACE2)/ Angiotensin‐(1‐7) (Ang‐(1‐7))/Mas receptor (MasR) is known to be counter‐regulatory to the classical axis, ACE/Ang II/AT1 receptor (AT1R). This study tested the hypothesis that leaky gut with aging is associated with ACE2/ACE imbalance and that activation of MasR with Ang‐(1‐7) would restore gut barrier integrity and ameliorates systemic inflammation.MethodsStudy was carried out in Young (3‐4 months) and Old (20‐24 months) male mice. ACE and ACE2 enzyme activities were evaluated in the colon. Gene and protein expressions of RAS components were determined by western blotting. Ang‐(1‐7) was administered by subcutaneous osmotic pump (1 µg/Kg/min) for four weeks and the gut permeability was evaluated by using FITC‐dextran. Colon wall integrity was evaluated by immunohistochemistry of claudin 1 and occludin. Zonulin‐1, IL‐6, and TNFα were analyzed in the plasma. A779, MasR antagonist, was administered by an osmotic pump in selected experiments (1 µg/Kg/min, subcutaneous).ResultsACE2 protein and activity were decreased in Old group while that of ACE were increased (n=6) (n=8) in the colon of the Old mice compared to the Young. Protein expression of both AT1R and MasR was higher while that of AT2R was lower in the Old (P<0.05, n=8). Protein expression of ACE2, ACE AT1R and MasR in the Old colons were restored to Young levels by treatment with Ang‐(1‐7). Gut permeability was higher in Old mice (P<0.01 vs Young, n=6) that was reversed by Ang‐(1‐7). The beneficial effect of Ang‐(1‐7) was abolished by concurrent administration of A779. Hematoxylin & Eosin staining revealed that aging was associated with atrophied villi in the gut wall that was normalized by Ang‐(1‐7). Gene expression of claudin 1 and occludin were lower in the Old colon wall that were restored by Ang‐(1‐7) and similar observations were made by immunohistochemistry. Importantly, plasma levels of Zonulin‐1, (P<0.01) IL‐6 and TNFα (P<0.05) (n=8) were higher in the Old group compared to the Young, which were lowered by Ang‐(1‐7) (n=5).ConclusionThese results suggest that activation of MasR ameliorates aging‐associated systemic inflammation by restoring gut barrier integrity, which at least in part contributes to the cardiovascular‐protective functions.
Inhibition of CHRM1 reverts docetaxel resistance in castration‐resistant prostate cancer
Authors: Wang Jing , Bland Tyler , Wei Jing , Pu Tianjie , Lin Tzu‐Ping , Wu Boyang 
Published: May 2022

BackgroundChemotherapy remains the major treatment option for castration‐resistant prostate cancer (CRPC). Docetaxel (DTX)‐based chemotherapy provides significant survival benefit in patients with CRPC. However, the clinical utility of DTX is compromised when resistance is encountered. Therefore, a more thorough understanding of mechanisms underlying DTX resistance may potentially improve survival in patients with CRPC. The objective of this study is to investigate the role and mechanism of cholinergic receptor muscarinic 1 (CHRM1) activation upon chemotherapy resistance in PC and the efficacy of the CHRM1 antagonist dicyclomine (Dic) in treating DTX‐resistant PC. The hypothesis is that CHRM1 is essential for developing chemotherapy resistance in PC cells and driving survival and growth of DTX‐resistant PC cells.MethodsThe CHRM1 expression levels and their association with DTX resistance were determined in PC clinical specimens and cultured cells. Human PC cells subjected to stable knockdown or overexpression of CHRM1 were evaluated for their response to DTX by cell proliferation, colony and tumorsphere formation, and TUNEL assays. Synergistic growth inhibition by combination treatment with DTX and Dic was assessed by cell viability and tumorgenicity assays.ResultsCHRM1 expression was elevated under DTX treatment in CRPC 22Rv1 and DU145 cells, which was paralleled by higher CHRM1 expression in these cells after acquiring resistance to DTX (22Rv1DTXR and DU145DTXR). Immunohistochemical analyses revealed higher CHRM1 protein levels in longitudinally collected tumor tissues post‐ versus pre‐chemotherapy from a PC patient cohort. Enforced expression of CHRM1 increased DTX IC50 by up to 5‐fold, along with reduced cell apoptosis marker c‐PARP1 expression, in 22Rv1 and DU145 cells. Conversely, silencing of CHRM1 in 22Rv1DTXR cells decreased cell proliferation, invasion, and colony and tumorsphere formation. CHRM1 inactivation with Dic in combination with DTX resulted in more cell death of both DTX‐sensitive (22Rv1 and DU145) and ‐resistant (22Rv1DTXR, DU145DTXR and PC‐3DTXR) cells compared to either treatment alone. Further, Dic restored DTX sensitivity to suppress the growth of DTX‐resistant cells and xenograft tumors (22Rv1DTXR and PC‐3DTXR). Mechanistically, CHRM1 activation upregulated phosphoprotein levels of ERK, JNK and p38, which all are key players in the MAPK pathway and potential mediators driving chemoresistance in cancer cells, while Dic treatment reduced their phosphorylation levels in 22Rv1DTXR and DU145DTXR cells.ConclusionOur results suggest that CHRM1 contributes to the development of DTX resistance in CRPC, which can be reversed by genetic or pharmacologic inactivation of CHRM1, providing new insights into developing a CHRM1‐targeted therapeutic strategy for overcoming DTX‐based chemotherapy resistance in CRPC.
Molecular Signalling Cascade Time in Sympathetic Stimulation of Angiotensin Renin Axis and Its Correlation With Ultra Low Frequency (ULF) of Heart Rate Variability (HRV)
Authors: Acero Mondragon Edward J. , Cortes Cabrera Jorge Armando , Gallego Correa John Jairo , Urdaneta Paredes Danial Antonio , Chaustre Nieto Luis Carlos , Serrano Contreras Samuel Ernesto , Vasquez Bazurto Maria Paula , Zabala Rodíguez Laura Daniela 
Published: May 2022

INTRODUCTIONIn Heart Rate Variability (HRV), Ultra Low Frequency Band (ULF) ranges between 0.003 to 0.03 Hz. It is believed that metabolism, body temperature as well as the renin‐angiotensin axis is related to ULF. Within juxtaglomerular cells, all the different biochemical events times may be quantified. Such chain of events start from B1 receptor activation, including renin secretion all the way through angiotensinogen conversion to angiotensin II. The present study’s objective is to correlate sympathetic stimulation of juxtaglomerular cells to ULF bands found on heart rate variability.MATERIAL AND METHODSGoogle Scholar and National Library of Medicine databases were used to search articles published between 1990 and 2021. The time involved in juxtaglomerular cell intracellular signalling after sympathetic stimulation was searched, with the combination of the following terms: 1) ((“Titer (TI) = (FRET), TI = (BRET), TI = (EDANS) and ‘Adrenergic B1 activation time’ ‘Gs protein activation’ ‘Adenylate Cyclase activation time’ ‘cAMP Activation time’ ‘Activation time Protein Kinase A “Renin Secretion Time” Angiotensinogen Conversion Time “Angiotensin I Conversion Time” Angiotensin II Conversion Time “In Vitro Cell Model ‘Y)].” Inclusion criteria for each study consisted in Ligand‐Receptor and renin related secretion cellular cascade timelines. Studies that satisfied the previously mentioned conditions were included. Times for events that ranged from B1 adrenergic receptor activation, renin secretion all the way to angiotensinogen conversion to angiotensin II were estimated. Such times were added together and later converted in Hertz using time and frequency inverse relationship.RESULTSJuxtaglomerular cell signalling cascade involving B1 adrenergic receptor activation and its related renin secretion summed around 300 seconds. On the other hand, renin activation time to angiotensin 2 was 89 seconds. Once these values were added, total time was 389 seconds that once converted to frequency yielded a value of 0,00257 Hz. Such value is close to the lower limit of ULF bands that range between 0,003 and 0,03 Hz in HRV domain frequency.CONCLUSIONSThe biochemical sequence of events that start from renin secretion and ends in angiotensin II production takes approximately 389 seconds. Such time once converted, through the inverse relationship of time and frequency, is 0,00257 Hertz. Such value suggests that ULF band with HRV domain may correspond to renin angiotensin axis activity.