bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cigarette smoke and Pseudomonas aeruginosa synergistically cause ARDS via impairment of mitophagic flux and NLRP3 inflammasome activation
Authors: Lu Qing , White Alexis , Wang Zhengke , Chambers Eboni , Ayala Alfred , Rounds Sharon , Wang Xing 
Published: June 2021

Itis increasingly recognized that cigarette smoke (CS) increases the incidenceand mortality associated with acute respiratory distress syndrome (ARDS), however, the underlying mechanism(s) for this is unknown. Pseudomonas aeruginosa is a frequent pathogen causing pneumonia, which is the most prevalent cause of ARDS. Whether CS increases prevalence of ARDS in individuals with P. aeruginosa infection is unknown. We have previously shown that CS increases severity of acute lung injury in mice challenged by lipopolysaccharide. In this study, we demonstrated that exposure of mice to CS either briefly (6h) or sub‐acutely (2weeks) suppressed lung bacterial clearance and exacerbated P. aeruginosa (PA103)‐induced lung edema, inflammation and mortality. CS and PA103 also synergistically increased lung microvascular endothelial cell permeability in vitro. To investigate the mechanisms of CS priming for lung injury, we used the clinically relevant double‐hit mouse model of ARDS induced by CS priming, followed by PA103 infection. We found that CS increased mitochondrial fission and mitochondrial oxidativestress and inhibition of mitochondrial fission and oxidative stress prevented CS‐induced increase in endothelial permeability. CS pre‐exposure did not affect PA103‐induced increase in steady‐state mitophagy, but impaired mitophagic fluxin alveolar macrophages and lung endothelial cells; an effect associated with accumulation of fragmented/swollen mitochondria and double‐membraned mitophagosomes in the lungs and NLRP3 inflammasome activation in alveolar macrophages. We further found that inhibition of NLRP3 inflammasome signaling attenuated CS/PA103 double‐hit‐induced lung inflammation and lung edema and improved bacterial clearance, as well as overall animal survival. Our results suggest that CS/PA103 double‐hit injury causes ARDS via enhancement of mitochondrial fission and impairment of mitophagic flux and resultant NLRP3 inflammasome activation. Suppression of mitochondrial fission, improvement of mitophagic flux and inhibition of the inflammasome may be novel targeted therapeutic strategies for smokers with ARDS.Support or Funding InformationCOBREP20GM103652 (Rounds, Lu), R01 HL130230 (Lu), VA Merit Review (Rounds)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Influenza virus NS1 protein upregulates epithelial sodium channel expression and function by inhibiting ubiquitin ligase Nedd4‐2
Authors: Lazrak Ahmed , Lazrak Samuel , Liu Evan , Yu Zhihong , Matalon Sadis 
Published: June 2021

Influenza is a contagious respiratory virus that infects epithelial cells throughout the respiratory tract. The viral infection is facilitated by the attachment of the viral hemagglutinin to the sialic acid residues on the host cell membrane. Once the virus is inside the host cell, the acidic endosomal environment facilitates the release of the viral ribonucleoproteins, which are, subsequently, transported to the host cell nucleus for replication. The mechanism by which replicating influenza viruses affect the function of ion channels in the lung epithelia is not well understood. We have studied the effects of the matrix protein 2 (M2) on the Epithelial Sodium Channel (ENaC) and the Cystic Fibrosis Transmembrane Conductance regulator1,2. However, the effects of other viral proteins is still unknown. In this study we explored the mechanisms by which the Non‐Structural protein 1 (NS1) regulates the expression and the function of ENaC heterologously expressed in Xenopus Laevis oocytes. in‐vivo, NS1 acts by, mainly, inhibiting the host immune response. Herein, we found NS1 to act by a dual mechanism when heterologously expressed with ENaC in Xenopus Laevis oocytes. 1) We observe an inhibition of ENaC expression and function (−5.64±2.7 μA to −1.14±0.71 μA; p<0.001) when both cRNAs, ENaC's and NS1's, were consecutively injected the same day, NS1 acted by inhibiting the replication and proteins synthesis, a known effect of NS1 on host proteins and RNAs. 2) NS1 acted by enhancing ENaC expression and function when its cRNA was injected 24 hours after ENaC cRNA was injected, a situation simulating the infection of an epithelail cell by a flu virus. NS1 increased the expression of ENaC proteins at the surface of the oocytes, at least, three times the control values, measured by western blot. The increased ENaC proteins at the membrane of the oocyte resulted in a 3 fold increase of recorded amiloride sensitive sodium currents (from −6.62±0.67 μA to −17.15±0.62 μA; p<0.001) measured by the double voltage clamp technique. In conclusion, NS1 acted by increasing the number of active ENaC at the surface of oocytes. NS1 may have acted by inhibiting Nedd4‐2, the ubiquitin ligase, responsible th regulation of ENaC expression at the cell surface. Nedd4‐2 acts by ubiquitinilating and marking ENaC proteins for removal by endocytosis, internalization, and degradation in the proteasome or lysosome.Support or Funding Information5U01ES026458 and 1U01ES02769701This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Lung Hydrogel Implantation System to Study the Pathogenesis of Pulmonary Hypertension
Authors: Mammoto Akiko , Mammoto Tadanori 
Published: June 2021

Remodeling of distal pulmonary arterioles (PAs) associated with marked accumulation of pulmonary artery smooth muscle cells (PASMCs) represents one of the major pathologic features of pulmonary hypertension (PH). The levels of a transcription factor, Twist1 are upregulated in the lungs of patients with pulmonary arterial hypertension (PAH). However, the mechanism by which endothelial Twist1 stimulates SMC accumulation to distal PAs in PH remains unclear. Here we have found that Twist1 overexpression increases the expression of platelet‐derived growth factor (PDGFB) in cultured human pulmonary arterial endothelial cells (HPAECs). Conditioned media collected from Twist1 overexpressing HPAECs induce SMC migration and growth. Knockdown of Twist1 in ECs attenuates hypoxia‐induced accumulation of alpha‐smooth muscle actin (SMA)‐positive cells to the PAs in mice. To further study the mechanism by which endothelial Twist1 controls vascular remodeling and SMC accumulation in the lung, we implant fibrin gel supplemented with fluorescently labeled HPAECs on the mouse lung. Supplemented HPAECs form vascular structures and hypoxia treatment stimulates accumulation of alpha‐SMA–positive cells to blood vessels and upregulates expression of PDGFB in the gel. Twist1 overexpression in supplemented HPAECs or hypoxia treatment also induces endothelial‐to‐mesenchymal transition (EndMT) in the implanted gel, which also partly contributes to the pathogenesis of PH. Endothelial Twist1 plays a key role in SMC accumulation to PAs through PDGFB signaling and the mouse lung gel implantation system would be a good model system to study the pathogenesis of PH and other lung diseases.Support or Funding InformationAHA18TPA34170129, MCW Research Affair Committee New Investigator AwardThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Responses of Caudal NTS Neurons to Acute Tissue Hypoxia
Authors: Paundralingga Obed , Wang Lei , Mifflin Steve Wayne 
Published: June 2021

The neurons of caudal nucleus tractus solitarii (nTS) initiate an integrated response to hypoxia by virtue of its afferent inputs and efferent projections. Furthermore, these neurons are also subjected to tissue hypoxia. In this study we investigated the effects of acute tissue hypoxia on intracellular Ca2+ ([Ca2+]i) levels in neurons from rat caudal nTS. Adult male Sprague‐Dawley rats were anesthetized with isoflurane and the hindbrain removed and cut into 250 μm thick sections. The NTS slices were then incubated for 45 min with 10 μM Fura‐2AM and 30 μL of F127 at room temperature and then washed for 20 min in artificial cerebrospinal fluid (aCSF) bubbled with 95% O2/5%CO2. A single slice was transferred to the recording chamber on an upright epifluorescent microscope and superfused with normal aCSF at a rate of 2.5 ml/min. Acute hypoxia was established by exposing hindbrain slices containing nTS to aCSF bubbled with 95% N2/5% CO2. The slice was superfused with either 20 μM nifedipine, 10 μM ruthenium red, or 10 μM ryanodine dissolved in aCSF. Cell viability was confirmed by 63 mM KCl. Fluorescence of Fura‐2AM was excited by epi‐illumination with light provided by a 75 W Xenon lamp band‐pass filtered alternatively at 340 or 380 nm. Emission light pass through a barrier filter (510 nm). Pairs of 340 and 380 nm images were acquired at intervals of 5 s and analyzed off‐line with NIS‐Elements AR 3.2 software. All images were captured with a charge‐coupled device (CCD) camera. A total of 20 sections were examined from 9 rats and an average of 4 cells/slice were analyzed in each section. Five minutes of hypoxic aCSF triggered a 41.37±20.95 % reversible increase in 340/380 ratio normalized to KCl relative to baseline with a latency of 56.9 s ± 25.1 s. This increase was due to calcium influx from extracellular compartment as removing calcium from extracellular bathing solution abolished the response. Nifedipine reduced the increase in [Ca2+]i during hypoxia by 14.62±11.88% (n=25 cells, p<0.05). Neither ryanodine nor ruthenium red altered the [Ca2+]i response to hypoxia. These findings suggest that the elevated [Ca2+]i as a response to acute tissue hypoxia in caudal NTS is dependent, at least in part, upon influx through L‐type voltage gated calcium channel. Other types of Ca channels, ROS generation, and mitochondrial release could also contribute to the response and are being investigated. Hypoxia‐induced elevations in intracellular Ca are likely to alter caudal NTS neuronal function under hypoxic conditions.Support or Funding InformationSupported by HL088052This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
H2S synthesis inhibitor prevents hypoxia‐evoked periodic breathing in spontaneous hypertensive rats
Authors: Zhang Xiuli , Peng Ying‐Jie , Nanduri Jayasri , Muzzio Miguel , McCormick David L , Prabhakar Nanduri R 
Published: June 2021

An augmented carotid body (CB) response to hypoxia has been implicated as one of the mechanism for evoking periodic breathing (PB). Spontaneous hypertensive (SH) rats exhibit CB hypersensitivity to hypoxia; this hypersensitivity is mediated by H2S produced by cystathionine‐g‐lyase (CSE; Peng et al. PNAS, 2017). Using whole‐body plethysmography, we demonstrate that acute hypoxia evokes PB in unsedated 2–4 month old SH rats; PB was characterized by episodes of hyperventilation and hypoventilation (decreased tidal volume and respiratory rate). The magnitude of PB in SH rats was linked to the severity of hypoxia: exposure to 12% O2 elicited 40 ± 3 episodes/hr of PB, while more severe hypoxia (8–10% O2) elicited 114 ± 4 episodes/hr of PB. Oral administration of the CSE inhibitor, L‐propargylglycine (L‐PAG) prevented CB hypersensitivity to hypoxia and stabilized breathing in dose‐related fashion. L‐PAG is rapidly absorbed after oral dosing (Tmax = 0.25 to 0.5 hr) and oral bioavailability is 100%. These data demonstrate that CSE inhibition provides a viable mechanism for prevention of breathing instability arising from CB hypersensitivity to hypoxiaSupport or Funding Information(Supported by NHLBI grant UH3HL‐123610).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Enhanced Carotid Body Chemosensory Discharge is Essential for the Hypertension Induced by Chronic Intermittent Hypoxia
Authors: Dias Ana Carolina , Arias Paulina , Andrade David , Del Rio Rodrigo , Iturriaga Rodrigo 
Published: June 2021

Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea, enhances carotid body (CB) discharges, leading to sympathetic overflow and hypertension. CIH produces oxidative stress (ROS) in the CB, which contributes to enhance the CB drive to the brainstem and hypothalamic nuclei related to the cardiorespiratory control, such as the nucleus of the tractus solitary (NTS), the rostral ventrolateral medulla (RVLM) and the paraventricular nucleus (PVN). We hypothesized whether the enhanced CB chemosensory drive may increase ROS levels in central cardiovascular nuclei during CIH‐induced hypertension. Accordingly, we studied the effects of CB ablation on ROS formation in the NTS, PVN and RVLM of hypertensive CIH‐rats. Male Sprague‐Dawley rats (200 g) were exposed to CIH (5–6% inspired O2 for 20s, followed by room air for 280s, 12 times/h, 8 h/day), for 28 days. Arterial blood pressure (BP) was measured by radio‐telemetry (DSI, USA). Following 21 days of CIH exposure, rats were anesthetized with isofluorane in 2% O2, and the CBs were cryogenically destroyed bilaterally using a fine‐tipped forcep cooled in liquid N2. Then, rats were maintained in CIH conditions for one more week. Another group of rats were maintained in CIH or Sham conditions for 28 days. At the end of the experiments, all animals were euthanized (pentobarbital 120mg/kg i.p.) and brains were removed and frozen at −20°C. Coronal sections of the NTS, RVLM and PVN were cut and incubated for 30 min in the dark with the ROS sensitive fluorescent probe dihydroethidium (DHE 10μM, Invitrogen USA). DHE fluorescence was measured using epifluorescence microscopy (Olympus Optical, Japan) at an excitation wavelength of 543 nm. Data were analyzed by one‐way ANOVA followed by Bonferroni's test. Compared to Sham rats, CIH‐rats showed a significant increase in mean BP (□ 10 mmHg, p<0.05). The CIH‐induced hypertension was abolished by the ablation of the CBs (CBA). ROS formation was markedly reduced by CBA in the NTS, RVLM and PVN of CIH‐exposed rats (CIH vs. CIH‐CBA: NTS: 6.2±1.5 vs. 1.5±02 au, RVLM: 4.9± 1.5 vs. 2.1±1.6 au, PVN: 5.4±1.8 vs. 1.6±05 au, p <0.05, n= 5–6 rats). Results support the evidence for an essential role of the CBs in the development and maintenance of the CIH‐induced hypertension and oxidative stress present in the NTS, RVLM and PVNSupport or Funding InformationFONDECYT 1150040This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The role of NLRP3 inflammasome in regulating the progression of prostate cancer
Authors: Wu Hsin‐En , Lai Yi‐Xin , Li Chia‐Yang 
Published: June 2021

Chronic inflammation is a hallmark of cancers and plays a critical role in modulating tumor progression and metastasis. Inflammasomes are a group of cytosolic protein complexes, composed of an NOD‐like protein (NLR), the adaptor apoptosis‐associated speck‐like protein containing a caspase recruitment domain (ASC), and caspase‐1, which are responsible for the cleavage of pro‐IL‐1β and pro‐IL‐18 proteins into mature and biologically active IL‐1β and IL‐18, respectively. IL‐1β levels in tumor tissues were previously connected to poor prognosis for cancer patients. However, it remains unclear the function of inflammasomes in tumor growth and metastasis. The aim of this study is to examine whether the activation of NLRP3 inflammasome regulates the progression of prostate cancer. First, we screened the ability of NLRP3 inflammasome activation in prostate cells due to cancer heterogeneity. Prostate cell lines were primed with LPS, followed by treated with ATP or nigericin to induce NLRP3 inflammasome activation. Our results showed that the secretion of IL‐1β was significantly increased in PC3 (human prostate cancer cell line), BPH‐1 (human benign prostate hyperplasia epithelial cell line) and RWPE‐1 (human prostate epithelial cell line) cells. Second, we tested the effect of hypoxic condition in regulating the activation of NLRP3 inflammasome. Our results showed that hypoxia also induced the secretion of IL‐1β in PC3, BPH‐1 and RWPE‐1 cells. Third, we found that NLRP3 inflammasome activation involved in regulating tumor growth and metastasis. Our results indicated that the activation of NLRP3 inflammation plays an important role in modulating the progression of prostate cancer. Therefore, targeting NLRP3 inflammasome could be a strategy for prostate cancer therapy.Support or Funding InformationThis study was supported by the Ministry of Science and Technology, Taiwan, R.O.C. (Grant No. MOST 107‐2320‐B‐037‐019).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The effect of gonadotropin releasing hormone (GnRH) antagonism on feeding behavior in female rats
Authors: Izumi Ayana , Hirano Ayaka , Iida Kurumi , Nouchi Mizuki , Fujimaki Saori , Morimoto Keiko , Takamata Akira 
Published: June 2021

Estrogen replacement in ovariectomized rats reduces food intake specifically during the light phase, suggesting that estrogen exerts an anorectic action by modifying circadian feeding rhythm. Ovariectomy is known to elevate levels of gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) via the negative feedback system of the hypothalamic‐pituitary‐gonadal (HPG) axis. However, the contribution of GnRH and/or LH to the hypophagia induced by ovariectomy remains unknown. To elucidate the role of GnRH and/or LH in the feeding regulation, we examined the effect of GnRH antagonism on feeding behavior in female rats. Female Wistar rats were injected subcutaneously with either 1mg/kg degarelix, a GnRH antagonist, (De group) or 5% mannitol (Veh group), and were provided free access to water and a standard rodent chow. We found that daily food intake and body weight gain were significantly greater in the De group than the Veh group. Food intake during the light phase was not different between the groups, while food intake during the dark phase was greater in the De group than the Veh group. These results suggest that estrogen regulates daily energy intake, and GnRH and/or LH possibly modulate diurnal pattern of feeding behavior.Support or Funding InformationJPSP KAKENHI #15K12355 and 24500975 to Akira TakamataThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Gene expression profile and cytokine analysis in experimental autoimmune encephalomyelitis (EAE) in AVP deficient rats
Authors: Quintanar‐Stephano Andres , Viñuela‐Berni Verónica , Macías‐Segura Noe , Valdez‐Urias Fernando , Kovacs Kalman 
Published: June 2021

IntroductionHuman Multiple Sclerosis (MS) is a medically important disease. MS and its experimental autoimmune encephalomyelitis (EAE) paradigm are central nervous system demyelinizing diseases in which the immune system is directly involved. The pursuit for new treatments for MS still as an important goal for research. The use of the EAE animals to study the immune mechanisms that mediate the disease still being the best strategy to deep into the immune‐neuroendocrine interactions during the pathogenesis. Previously we have demonstrated that neurointermediate pituitary lobectomy (NIL) decreases humoral and cell‐mediated immune responses and that AVP is directly involved. Nevertheless, the role of AVP has not been entirely clarified.ObjectiveTo investigate the mechanism by which AVP deficiency (by NIL) and desmopressin (DP, a synthetic analog of AVP) affects the development of the clinical signs, the immune response and gene expression profile in the EAE.MethodsFemale Lewis rats were divided into intact control (IC), EAE immunized, NIL and NIL treated with desmopressin (NIL+DP). Except the IC, the remaining groups were immunized for EAE. The EAE was induced by encephalitogen subcutaneous injection. Animals were sacrificed at the peak of the disease (15 days after immunization). EAE clinical signs, cytokine serum profiles (IL‐17A, IL‐4, IL‐2, IL‐10, IL‐6, TNF‐α and INF‐γ) (flow cytometry) and spleen gene expression profile (microarray) were evaluated. DP treatment started 3 days before immunization.ResultsAs compared with the EAE group, NIL animals developed just a mild clinical signs of EAE and significant decreased IFN‐γ and IL‐17 levels. NIL+DP treated animals restored its susceptibility to EAE clinical signs, whereas no‐significant differences on cytokine levels occurred. Significant differences in gene expression profile among groups were evident; in the NIL group the expression pattern of the TGF‐β pathway was down‐regulated as compared with the EAE group, whereas in the NIL+DP group the same genes were up‐regulated.ConclusionsFindings add novel data indicating that directly AVP plays a crucial role in regulating the immune responses and suggests that AVP receptor blockers may be used for the MS treatment and possibly autoimmune diseases and other inflammatory processes.Support or Funding InformationSupported by UAA‐PIFF14‐1 and CONACYT‐221262 (AQS). México. VVB: CONACT Doctoral scholarship. NMS: CONACYT post doctoral Fellow. México.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.