The incorporation of strontium and barium into the otoliths of the flounder Paralichthys olivaceus at early life stages demonstrates resilience to ocean acidification.

Ocean acidification could modify the bioavailability and chemical properties of trace elements in seawater, which could affect their incorporation into the calcareous structures of marine organisms. Fish otoliths, biomineralized ear stones made by aragonite, are suspended within the endolymph fluid of teleosts, indicating that the elemental incorporation of otoliths might also be susceptible to ocean acidification. In this study, we evaluated the combined effects of CO2-induced ocean acidification (pH 8.10, 7.70, and 7.30, corresponding to ocean acidification scenarios under the representative concentration pathway 8.5 model as projected by the Intergovernmental Panel on Climate Change) and water elemental concentrations of strontium (Sr) and barium (Ba; low, medium, and high) on elemental incorporation into otoliths of the flounder Paralichthys olivaceus at early life stages. Our results revealed that the elemental incorporation of Sr and Ba into otoliths was principally dependent on the corresponding water elemental concentrations rather than on ocean acidification. Moreover, the partition coefficients (DMe) of Sr and Ba may stabilize after dynamic equilibrium is reached as the water elemental concentration increases, but are not affected by ocean acidification. Therefore, the incorporation of Sr and Ba into otoliths of the flounder at early life stages may not serve as an effective indicator of ocean acidification. In other words, the findings suggest that ocean acidification does not impact the incorporation of Sr and Ba incorporation into otoliths when tracing the temperature or salinity experiences of the flounder. Our findings will provide new knowledge for understanding the potential ecological effects of ocean acidification on the recruitment dynamics of fish species.

Random flap survival with hyperbaric oxygen: daily versus twice-daily treatments.

PURPOSE: Hyperbaric oxygen (HBO2) therapy is used to improve the survival of compromised flaps. Compromised flaps are complications encountered postsurgically, or in traumatic degloving or avulsion injuries. Failed flaps lead to persistence of the defect, requirement of another donor site, and psychosocial sequelae. Although evidence of the benefit of HBO2 therapy is significant, there is no consensus on the optimal treatment regimen. The purpose of this study is to examine whether twice-daily treatments (BID HBO2) provide additional benefit compared to daily treatments (QD HBO2) in a rat compromised random flap model. METHODS: A rat random flap model was used with subjects divided into three groups: 1) control group; 2) QD HBO2; and 3) BID HBO2, where HBO2 was performed with 100% oxygen at 2.5 atmospheres absolute/ATA (253 kPa) for 90 minutes. After 10 days, areas of flap necrosis were measured and biopsies were taken for histologic analysis. Statistical analysis was performed using ANOVA and paired t-tests. A P-value ⟨0.05 was considered significant. RESULT: Both treatment groups had significantly increased mean flap survival compared to controls (P⟨0.05). There was no significant difference in flap survival between the QD and BID groups. Capillary proliferation in the QD group was increased compared with controls. CONCLUSION: Both QD and BID HBO2 protocols can significantly decrease random flap necrosis. However, the results of this study suggest there is no additional benefit gained with BID treatments. Clinical studies are warranted to confirm these findings and assist in formalization of protocols for the use of HBO2in treating compromised random flaps.

Regulation of nuclear TDP-43 by NR2A-containing NMDA receptors and PTEN.

The dysfunction of TAR DNA-binding protein-43 (TDP-43) is implicated in neurodegenerative diseases. However, the function of TDP-43 is not fully elucidated. Here we show that the protein level of endogenous TDP-43 in the nucleus is increased in mouse cortical neurons in the early stages, but return to basal level in the later stages after glutamate accumulation-induced injury. The elevation of TDP-43 results from a downregulation of phosphatase and tensin homolog (PTEN). We further demonstrate that activation of NR2A-containing NMDA receptors (NR2ARs) leads to PTEN downregulation and subsequent reduction of PTEN import from the cytoplasm to the nucleus after glutamate accumulation. The decrease of PTEN in the nucleus contributes to its reduced association with TDP-43, and thereby mediates the elevation of nuclear TDP-43. We provide evidence that the elevation of nuclear TDP-43, mediated by NR2AR activation and PTEN downregulation, confers protection against cortical neuronal death in the late stages after glutamate accumulation. Thus, this study reveals a NR2AR-PTEN-TDP-43 signaling pathway by which nuclear TDP-43 promotes neuronal survival. These results suggest that upregulation of nuclear TDP-43 represents a self-protection mechanism to delay neurodegeneration in the early stages after glutamate accumulation and that prolonging the upregulation process of nuclear TDP-43 might have therapeutic significance.

MicroRNA PC-5p-3991_515 mediates triflumezopyrim susceptibility in the small brown planthopper through regulating the post-transcriptional expression of P450 CYP417A2.

BACKGROUND: Cytochrome P450 monooxygenases (P450s) are recognized as a major contributor to metabolic resistance in insects to most insecticides, through gene overexpressions and protein mutations. MicroRNA (miRNA), an important post-transcriptional regulator, has been reported to promote insecticide resistance by mediating the expression of detoxification enzyme genes. RESULTS: In the present study, we reported that a novel microRNA PC-5p-3991_515 was involved in the post-transcriptional regulation of CYP417A2 and mediated the triflumezopyrim susceptibility in the small brown planthopper (SBPH), Laodelphax striatellus (Fallén). The tissue expression profiles showed that CYP417A2 was highly expressed in fat body. CYP417A2 was significantly up-regulated at 12, 36, 60, 84 and 108 h after the triflumezopyrim treatment. RNA interference (RNAi) against CYP417A2 significantly increased triflumezopyrim susceptibility in SBPH. According to the prediction by miRanda and TargetScan software, three miRNAs were indicated to bind to CYP417A2. However, when oversupply of agomir, only two miRNAs, PC-3p-625_4405 and PC-5p-3991_515, significantly increased the susceptibility to triflumezopyrim and decreased CYP417A2 levels. Furthermore, PC-5p-3991_515 was confirmed to be involved in the post-transcriptional regulation of CYP417A2 by dual luciferase reporter assay. Meanwhile, PC-5p-3991_515 was co-localized with CYP417A2 in the midgut in situ hybridization. CONCLUSION: Our findings revealed that the novel microRNA, PC-5p-3991_515, post-transcriptionally regulated CYP417A2 expression, which then mediated the triflumezopyrim susceptibility in SBPH. © 2023 Society of Chemical Industry.

TRPC1 and Orai1 interact with STIM1 and mediate capacitative Ca(2+) entry caused by acute hypoxia in mouse pulmonary arterial smooth muscle cells.

Previous studies in pulmonary artery smooth muscle cells (PASMCs) showed that acute hypoxia activates capacitative Ca(2+) entry (CCE) but the molecular candidate(s) mediating CCE caused by acute hypoxia remain unclear. The present study aimed to determine if transient receptor potential canonical 1 (TRPC1) and Orai1 interact with stromal interacting molecule 1 (STIM1) and mediate CCE caused by acute hypoxia in mouse PASMCs. In primary cultured PASMCs loaded with fura-2, acute hypoxia caused a transient followed by a sustained rise in intracellular Ca(2+) concentration ([Ca(2+)](i)). The transient but not sustained rise in [Ca(2+)](i) was partially inhibited by nifedipine. Acute hypoxia also increased the rate of Mn(2+) quench of fura-2 fluorescence that was inhibited by SKF 96365, Ni(2+), La(3+), and Gd(3+), exhibiting pharmacological properties characteristic of CCE. The nifedipine-insensitive rise in [Ca(2+)](i) and the increase in Mn(2+) quench rate were both inhibited in cells treated with TRPC1 antibody or TRPC1 small interfering (si)RNA, in STIM1 siRNA-transfected cells and in Orai1 siRNA-transfected cells. Moreover, overexpression of STIM1 resulted in a marked increase in [Ca(2+)](i) and Mn(2+) quench rate caused by acute hypoxia, and they were reduced in cells treated with TRPC1 antibody and in cells transfected with Orai1 siRNA. Furthermore, TRPC1 and Orai1 coimmunoprecipitated with STIM1 and the precipitation levels of TRPC1 and Orai1 were increased in cells exposed to acute hypoxia. Immunostaining showed colocalizations of TRPC1-STIM1 and Orai1-STIM1, and the colocalizations of these proteins were more apparent in acute hypoxia. These data provide direct evidence that TRPC1 and Orai1 channels mediate CCE through activation of STIM1 in acute hypoxic mouse PASMCs.

Cardiac-specific, inducible ClC-3 gene deletion eliminates native volume-sensitive chloride channels and produces myocardial hypertrophy in adult mice.

Native volume-sensitive outwardly rectifying anion channels (VSOACs) play a significant role in cell volume homeostasis in mammalian cells. However, the molecular correlate of VSOACs has been elusive to identify. The short isoform of ClC-3 (sClC-3) is a member of the mammalian ClC gene family and has been proposed to be a molecular candidate for VSOACs in cardiac myocytes and vascular smooth muscle cells. To directly test this hypothesis, and assess the physiological role of ClC-3 in cardiac function, we generated a novel line of cardiac-specific inducible ClC-3 knock-out mice. These transgenic mice were maintained on a doxycycline diet to preserve ClC-3 expression; removal of doxycycline activates Cre recombinase to inactivate the Clcn3 gene. Echocardiography revealed dramatically reduced ejection fraction and fractional shortening, and severe signs of myocardial hypertrophy and heart failure in the knock-out mice at both 1.5 and 3 weeks off doxycycline. In mice off doxycycline, time-dependent inactivation of ClC-3 gene expression was confirmed in atrial and ventricular cells by qRT-PCR and Western blot analysis. Electrophysiological examination of native VSOACs in isolated atrial and ventricular myocytes 3 weeks off doxycycline revealed a complete elimination of the currents, whereas at 1.5 weeks, VSOAC current densities were significantly reduced, compared to age-matched control mice maintained on doxycycline. These results indicate that ClC-3 is a key component of native VSOACs in mammalian heart and plays a significant cardioprotective role against cardiac hypertrophy and failure.

Orai1 interacts with STIM1 and mediates capacitative Ca2+ entry in mouse pulmonary arterial smooth muscle cells.

Previous studies in mouse pulmonary arterial smooth muscle cells (PASMCs) showed that cannonical transient receptor potential channel TRPC1 and stromal interaction molecule 1 (STIM1) mediate the sustained component of capacitative Ca(2+) entry (CCE), but the molecular candidate(s) that mediate the transient component of CCE remain unknown. The aim of the present study was to examine whether Orai1 mediates the transient component of CCE through activation of STIM1 in mouse PASMCs. In primary cultured mouse PASMCs loaded with fura-2, cyclopiazonic acid (CPA) caused a transient followed by a sustained rise in intracellular Ca(2+) concentration ([Ca(2+)](i)). The transient but not the sustained rise in [Ca(2+)](i) was partially inhibited by nifedipine. The nifedipine-insensitive transient rise in [Ca(2+)](i) and the increase in Mn(2+) quench of fura-2 fluorescence caused by CPA were both reduced in cells treated with Orai1 siRNA. These responses to CPA were further reduced in cells treated with Orai1 and STIM1 small interfering (si)RNA. Moreover, overexpression of STIM1 enhanced the rise in [Ca(2+)](i) and the increase in Mn(2+) quench of fura-2 fluorescence caused by CPA, and these responses were reduced in cells treated with Orai1 siRNA. RT-PCR revealed Orai1 and STIM1 mRNAs, and Western blot analysis identified Orai1 and STIM1 proteins in mouse PASMCs. Furthermore, Orai1 was found to coimmunoprecipitate with STIM1, and the precipitation level of Orai1 was increased in cells subjected to store-depletion. Immunostaining revealed colocalization of Orai1 and STIM1 proteins, and the colocalization of these proteins was more apparent after store-depletion. These data provide direct evidence that the transient component of CCE is mediated by Orai1 channel as a result of STIM1 activation in mouse PASMCs.

High-Throughput Transcription-mediated amplification on the Hologic Panther is a highly sensitive method of detection for SARS-CoV-2.

BACKGROUND: As the demand for laboratory testing for SARS-CoV-2 increases, additional varieties of testing methodologies are being considered. While real time polymerase chain reaction (RT-PCR) has performed as the main method for virus detection, other methods are becoming available, including transcription mediated amplification (TMA). The Hologic Aptima SARS-CoV-2 Assay utilizes TMA as a target amplification mechanism, and it has only recently received Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA). OBJECTIVES: We sought to compare the sensitivity and specificity of the Aptima SARS-CoV-2 Assay to RTPCR as a means of SARS-CoV-2 detection in a diagnostic setting. STUDY DESIGN: We performed a limit-of-detection study (LoD) to assess the analytical sensitivity of TMA and RT-PCR. This preceded a comparison of the methods using previously evaluated clinical specimens (nasopharyngeal swabs) using 116 human specimens tested by both methodologies. Specimens included sixty-one (61) specimens found reactive by real-time PCR, fifty-one (51) found non-reactive, and four (4) deemed inconclusive. RESULTS: The Aptima SARS-CoV-2 Assay showed a markedly higher analytical sensitivity than RT-PCR by LoD study. Evaluation of clinical specimens resulted in fewer inconclusive results by the SARS-CoV-2 assay, leading to potentially higher clinical sensitivity. CONCLUSIONS: Higher analytical sensitivity may explain TMA's ability to ascertain for the presence of SARS-CoV-2 genome in human specimens deemed inconclusive by real-time PCR. TMA provides an effective, highly sensitive means of detection of SARS-CoV-2 in nasopharyngeal specimens.

Sensitive and Specific Detection of SARS-CoV-2 Antibodies Using a High-Throughput, Fully Automated Liquid-Handling Robotic System.

As of July 22, 2020, more than 14.7 million infections of SARS-CoV-2, the virus responsible for Coronavirus Disease 2019 (COVID-19), have been confirmed globally. Serological assays are essential for community screening, assessing infection prevalence, aiding identification of infected patients, and enacting appropriate treatment and quarantine protocols in the battle against this rapidly expanding pandemic. Antibody detection by agglutination-PCR (ADAP) is a pure solution phase immunoassay that generates a PCR amplifiable signal when patient antibodies agglutinate DNA-barcoded antigen probes into a dense immune complex. Here, we present an ultrasensitive and high-throughput automated liquid biopsy assay based on the Hamilton Microlab ADAP STAR automated liquid-handling platform, which was developed and validated for the qualitative detection of total antibodies against spike protein 1 (S1) of SARS-CoV-2 that uses as little as 4 µL of serum. To assess the clinical performance of the ADAP assay, 57 PCR-confirmed COVID-19 patients and 223 control patients were tested. The assay showed a sensitivity of 98% (56/57) and a specificity of 99.55% (222/223). Notably, the SARS-CoV-2-negative control patients included individuals with other common coronaviral infections, such as CoV-NL63 and CoV-HKU, which did not cross-react. In addition to high performance, the hands-free automated workstation enabled high-throughput sample processing to reduce screening workload while helping to minimize analyst contact with biohazardous samples. Therefore, the ADAP STAR liquid-handling workstation can be used as a valuable tool to address the COVID-19 global pandemic.

Cardiac-specific overexpression of the human short CLC-3 chloride channel isoform in mice.

1. ClC-3 has been proposed as a molecular candidate responsible for volume-sensitive outwardly rectifying anion channels (VSOAC) in cardiac and smooth muscle cells. To further test this hypothesis, we produced a novel line of transgenic mice with cardiac-specific overexpression of the human short ClC-3 isoform (hsClC-3). 2. Northern and western blot analyses demonstrated that mRNA and protein levels of the short isoform (sClC-3) in the heart were significantly increased in hsClC-3-overexpressing (OE) mice compared with wild-type (WT) mice. Heart weight : bodyweight ratios for OE mice were significantly smaller compared with age-matched WT mice. 3. Electrocardiogram recordings indicated no difference at rest, whereas echocardiographic recordings revealed consistent reductions in left ventricular diastolic diameter, left ventricular posterior wall thickness at end of diastole and interventricular septum thickness in diastole in OE mice. 4. The VSOAC current densities in atrial cardiomyocytes were significantly increased by ClC-3 overexpression compared with WT cells. No differences in VSOAC current properties in OE and WT atrial myocytes were observed in terms of outward rectification, anion permeability (I(-) > Cl(-) > Asp(-)) and inhibition by 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid and glibenclamide. The VSOAC in atrial myocytes from both groups were totally abolished by phorbol-12,13-dibutyrate (a protein kinase C activator) and by intracellular dialysis of an N-terminal anti-ClC-3 antibody. 5. Cardiac cell volume measurements revealed a significant acceleration of the rate of regulatory volume decrease (RVD) in OE myocytes compared with WT. 6. In conclusion, enhanced VSOAC currents and acceleration of the time-course of RVD in atrial myocytes of OE mice is strong evidence supporting an essential role of sClC-3 in native VSOAC function in mouse atrial myocytes.

Interactive effects of strontium and barium water concentration on otolith incorporation in juvenile flounder Paralichthys olivaceus.

Although the relationship between the incorporation of an element into otoliths and the concentration of the element in water has been extensively investigated in many fish species, the interactive effects of multiple elements in water on the otolith incorporation of an element are not adequately explored or well understood. In this study, 16 treatments in triplicate using strontium (Sr; 1, 2, 3 and 4 times the ambient baseline, 6.5 mg l-1) and barium (Ba; 1, 2, 4 and 6 times the ambient baseline, 40 µg l-1) as categorical variables in an orthogonal design were established to evaluate the relative or interactive effects of water elements on otolith elemental incorporation in juvenile flounder Paralichthys olivaceus (from 15 to 116 days post hatching). The results revealed that otolith incorporation (Me:CaOtolith) of Sr and Ba were positively dependent on the concentrations of the elements in water (Me:CaWater). Overall, Sr was incorporated into otoliths more efficiently than was Ba, and the partition efficiency (DMe) of both elements decreased with increasing water elemental concentrations. Increasing Sr concentrations in water appeared to negatively affect the uptake of Ba into otoliths rather than facilitate it, as previously reported in fish reared in freshwater and brackish water, or showed no effect on fish in seawater. Conversely, the Ba concentration in water did not influence the otolith uptake of Sr, which agrees with the findings for other fish species. When applying otolith microchemistry to fish ecology studies, it is essential to cautiously address the interactive effects of multiple elements in the environment on otolith elemental incorporation.

Upregulation of profilin, cofilin-2 and LIMK2 in cultured pulmonary artery smooth muscle cells and in pulmonary arteries of monocrotaline-treated rats.

Pulmonary hypertension is associated with remodeling of the smooth muscle layer of pulmonary arteries, manifested by reduced smooth muscle cell (SMC) contractility and enhanced motility and growth. These responses are underlied by increased dynamics of the peripheral actin network. Thus, we hypothesized that pulmonary hypertension is associated with upregulation of two proteins that regulate the dynamics of peripheral actin filaments, i.e., profilin and cofilin. We also analyzed the expression of LIMK2, which regulates the actin remodeling capacity of cofilin by phosphorylation. Experimental inflammation was induced by incubation of cultured pulmonary artery SMCs (PASMCs) with inflammatory mediators in vitro, and by subcutaneous administration of monocrotaline to Sprague-Dawley rats in vivo. Expression of messenger RNA (mRNA) was assessed by quantitative RT-PCR, protein levels and phosphorylation were analyzed by immunoblotting. Immune and Masson trichrome stained lung cryosections were analyzed by microscopy. PDGF, IL-1beta, ET-1 and TNFalpha upregulated the profilin, cofilin-2 and LIMK2 mRNA in cultured pulmonary artery SMCs (PASMCs). Along with the development of rat pulmonary artery and right ventricular hypertrophy, monocrotaline treatment also induced the mRNA and protein contents of profilin, cofilin-2 and LIMK2 in PASMCs. The cofilin upregulation was paralleled by a relative decrease of the phospho-cofilin content. The upregulation of profilin, cofilin and LIMK2 in experimental inflammation suggests that by intensifying the remodeling of subcortical actin filaments these proteins may contribute to the enhanced invasiveness and growth of SMCs, and to the development of increased vascular resistance and pulmonary hypertension.

Targeted inactivation of cystic fibrosis transmembrane conductance regulator chloride channel gene prevents ischemic preconditioning in isolated mouse heart.

BACKGROUND: Recent evidence suggests that chloride channels may be involved in ischemic preconditioning (IPC). In this study, we tested whether the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels, which are expressed in the heart and activated by protein kinase A and protein kinase C, are important for IPC in isolated heart preparations from wild-type (WT) and CFTR knockout (CFTR-/-) mice. METHODS AND RESULTS: Hearts were isolated from age-matched WT or CFTR-/- (B6.129P2-Cftr(tm1Unc) and STOCKCftr(tm1Unc)-TgN 1Jaw) mice and perfused in the Langendorff or working-heart mode. All hearts were allowed to stabilize for 10 minutes before they were subjected to 30 or 45 minutes of global ischemia followed by 40 minutes of reperfusion (control group) or 3 cycles of 5 minutes of ischemia and reperfusion (IPC group) before 30 or 45 minutes of global ischemia and 40 minutes of reperfusion. Hemodynamic indices were recorded to evaluate cardiac functions. Release of creatine phosphate kinase (CPK) in the samples of coronary effluent and infarct size of the ventricles were used to estimate myocardial tissue injury. In WT adult hearts, IPC protected cardiac function during reperfusion and significantly decreased ischemia-induced CPK release and infarct size. A selective CFTR channel blocker, gemfibrozil, abrogated the protective effect of IPC. Furthermore, targeted inactivation of the CFTR gene in 2 different strains of CFTR-/- mice also prevented IPC's protection of cardiac function and myocardial injury against sustained ischemia. CONCLUSIONS: CFTR Cl- channels may serve as novel and crucial mediators in mouse heart IPC.

Early to intermediate steps of tumor embolic formation involve specific proteolytic processing of E-cadherin regulated by Rab7.

The lymphovascular embolus is an enigmatic entity adept at metastatic dissemination and chemotherapy resistance. Using MARY-X, a human breast cancer xenograft that exhibits florid lymphovascular emboli in mice and spheroids in vitro, we established a model where the in vitro transition stages from minced tumoral aggregates to well-formed spheroids served as a surrogate for in vivo emboli formation. MARY-X well-formed spheroids and emboli exhibited strong similarity of expression. The aggregate-to-spheroid transition stages were characterized by increased ExoC5, decreased Hgs and Rab7, increased calpains, increased full-length E-cadherin (E-cad/FL), and the transient appearance of E-cad/NTF2, a 95 kDa E-cadherin fragment and increased Notch3icd (N3icd), the latter two fragments produced by increased γ-secretase. Both transient and permanent knockdowns of Rab7 in MCF-7 cells increased protein but not transcription of E-cad/FL and resulted in the de novo appearance of E-cad/NTF2, the presence of nuclear E-cad/CTF2, and increased Notch1icd (N1icd). Overexpression of Rab7 conversely decreased E-cad/FL, γ-secretase (PS1/NTF), and E-cad/NTF2. Overexpression of calpains did not alter PS1/NTF but decreased E-cad/FL and E-cad/NTF2 and increased N1icd. Well-formed spheroids showed increased Rab7, absent E-cad/NTF2, decreased PS1/NTF, increased E-cad/NTF1, and increased N3icd, the latter two fragments being the direct and indirect consequences, respectively, of increased calpains (calpain 1 and calpain 2). Inhibition of calpains decreased E-cad/NTF1 but increased E-cad/NTF2 showing that calpains compete with γ-secretase (PS1) for closely located cleavage/binding sites on E-cadherin and that increased calpains can shuttle even decreased levels of γ-secretase to Notch 3, resulting in increased Notch 3 signaling in the well-formed spheroids.