Expression Of Stress-related Proteins Research Articles

Dapagliflozin protects Doxorubicin induced cardiotoxicity in patients with diabetes via suppressing ER stress

Abstract Objectives Cancer patients with diabetes have an increasing risk of Doxorubicin (Dox)-induced cardiotoxicity. Despite previous studies reporting benefits of dapagliflozin on the cardiovascular system, it remains unknown whether dapagliflozin has a cardioprotective effect in cancer patients with diabetes receiving Dox therapy. The purpose of this study is to investigate the potentials of dapagliflozin in preventing Dox induced cardiotoxicity. Methods Using National Health Insurance Database, the incidence of heart failure of breast cancer patients with or without diabetes was investigated. Also, streptozotocin (STZ) induced diabetic rats were pretreated with oral dapagliflozin (10 mg/kg/day) for 6 weeks and received Dox (5 mg/kg/week) for 4 weeks via intraperitoneally injection. Sequential echocardiography was applied to assess the cardiac function. For in vitro analysis, H9C2 cardiomyocytes, cultured in high glucose (30 mM), were treated with dapagliflozin at 10 mM and subsequently exposed to Dox at 1 mM. The apoptosis and endoplasmic reticulum (ER) stress related protein expression were measured by immunohistochemistry and western blotting. Results Among the studied patients, those with diabetes have a higher risk of heart failure while patients prescribed with dapagliflozin lowered the risks. Correspondingly, dapagliflozin treatment effectively inhibited Dox-induced apoptosis and reactive oxygen species accumulation in cardiomyocytes. Also, the reduction of cardiac fibrosis as well as apoptosis in rats treated with dapagliflozin resulted in significantly improved cardiac function. Dapagliflozin also decreased the cardiac expression of Bax, cleaved caspase 3 and increased Bcl-2. Mechanistically, we showed that dapagliflozin significantly reduced ER stress-associated proteins including GRP78, PERK, eIF 2a, ATF-4, and CHOP. Conclusions Our study revealed for the first time that dapagliflozin mitigated Dox-induced cardiomyocyte apoptosis in diabetes via inhibiting ER stress. These results indicate that dapagliflozin could be useful in preventing cardiotoxicity in diabetic cancer patients receiving Dox treatment. Funding Acknowledgement Type of funding source: Private hospital(s). Main funding source(s): Chi-Mei Medical Center, Tainan, Taiwan

Hydrogen Sulfide Attenuated Angiotensin II-Induced Sympathetic Excitation in Offspring of Renovascular Hypertensive Rats.

ObjectiveNumerous findings have demonstrated a strong association between parental health during pregnancy and cardiovascular disease in adult offspring. This study investigated whether sensitivity to angiotensin II (Ang II) is enhanced in offspring of renovascular hypertensive animals and whether hydrogen sulfide (H2S) can attenuate the increased response to Ang II in offspring.MethodThe systolic blood pressure (SBP) was measured by non-invasive tail-cuff plethysmograpy every two weeks in all offspring from 8 to 16 weeks. After intracerebroventricular microinjection of Ang II in the offspring, blood pressure, heart rate (HR), and renal sympathetic nerve activity (RSNA) were recorded to test the response to Ang II in the offspring. Western blot analysis was used to examine the protein expression of AT1R, AT1R-associated protein (ATRAP), Nox2, p67phox, and nitrotyrosine in the nucleus tractus solitarii (NTS).ResultsThe SBP in the offspring of hypertensive rats were significantly higher than that in control group, and the above effects were significantly improved by prenatal or postnatal administration of H2S. Intralateroventricular microinjection of Ang II induced greater sympathetic responses in offspring of hypertensive rats than control group. The expression of AT1R and oxidative stress-related protein was increased, whereas that of ATRAP was decreased in the NTS in offspring of hypertensive rats. Exogenous administration of H2S prenatally or postnatally improved the above effects.ConclusionPrenatal or postnatal administration of H2S attenuated AngII-induced sympathetic excitation in offspring of hypertensive rats, which may occur by modulating the balance between AT1R and ATRAP and downregulating oxidative stress-related protein expression in the NTS.

Dl-3-n-butylphthalide attenuates hypoxic-ischemic brain injury through inhibiting endoplasmic reticulum stress-induced cell apoptosis and alleviating blood-brain barrier disruption in newborn rats

Dl-3-n-butylphthalide (NBP) has been demonstrated to exert neuroprotective effects in experimental models and human patients. This study was performed to assess the therapeutic effects and the underlying molecular mechanisms of NBP in a neonatal hypoxic-ischemic rat model. The results showed that NBP treatment significantly reduced the infarct volume, improved histological recovery, decreased neuronal cell loss, enhanced neuronal cell rehabilitation, promoted neurite growth and decreased white matter injury. In addition, NBP treatment effectively improved long-term neurobehavioral development and prognosis after HI injury. We further demonstrated an inhibitory effect of NBP on endoplasmic reticulum (ER) stress-induced apoptosis, evidenced by reduction in ER stress-related protein expressions (GRP78, XBP-1, PDI and CHOP), decrease in TUNEL-positive cells, down-regulation in pro-apoptosis protein (Bax and cleaved caspase-3), up-regulation in anti-apoptosis protein (Bcl-2). Moreover, NBP exerted a protective effect in blood-brain barrier disruption, which ameliorated brain edema and reduced the degeneration of the tight junction proteins (Occludin and Claudin-5) and adherens junction proteins (P120-Catenin, VE-Cadherin and β-Catenin). Overall, our findings demonstrated that NBP treatment attenuated HI brain injury through inhibiting ER stress-induced apoptosis and alleviating blood-brain barrier disruption in newborn rats. This work provides an effective therapeutic strategy to reduce brain damage and enhance recovery after neonatal HI brain injury.

UV-B Priming of Oryza sativa Seeds Augments the Innate Tolerance Potential in a Tolerant Variety more Effectively Toward NaCl and PEG Stressors

NaCl and polyethylene glycol-6000 (PEG) stressors are the major limitation factors for successful seedling establishment in rice. The present study was carried out to investigate the role of UV-B priming on the augmentation of stress tolerance in tolerant and sensitive rice seedlings exposed to NaCl and PEG stresses. The result shows that the severity of drought than salinity stress was experienced by emerging rice seedlings as evidenced from increased content of H2O2, O2− and MDA. However, the seed priming with UV-B results in the enhanced production of defense agents, there by activating innate tolerance potential of the seedlings. UV-B priming reduces excess ROS accumulation during NaCl and PEG stresses and thus eliminates the chance of oxidative stress in the rice seedlings. This was possible by enhancing the crucial role of innate immune system, which imparts tolerance toward NaCl and PEG stresses. UV-B seed priming maintained maximal photochemical efficiency of PSI and PSII as well as mitochondrial activity of tolerant and sensitive varieties under NaCl and PEG stresses due to the increased activity of osmolytes and non-enzymatic antioxidants as well as induced expression of enzymatic antioxidants (Cu/Zn SOD, CatA and APx1) and stress-related proteins (Hsp90 and Group3 LEA) in tolerant variety at large, followed by sensitive variety.

Molecular Insights Into Di(2-Picolyl) Amine-Induced Cytotoxicity and Apoptosis in Human Kidney (HEK293) Cells.

Di(2-picolyl) amine (DPA) is a pyridine derivative known to chelate metal ions and thus has potential anticancer properties; however, its effect on normal cells remains unchartered necessitating further research. This study, therefore, investigated the mechanistic effects of DPA-induced cytotoxicity and apoptosis in the HEK293 cell line. Methods required that an half the maximum inhibition concentration (IC50) was derived using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Analyses aimed to assess oxidative stress, membrane damage, and DNA fragmentation by means of biochemical assays were performed. Luminometry analysis was carried out to understand the mechanism of apoptosis induction by determining the levels of adenosine triphosphate (ATP) and the activities of caspase-8, -9, and -3/7. Western blotting was used to ascertain the expression of apoptotic and stress-related proteins. An IC50 of 1,079 µM DPA was obtained. Antioxidant effect correlated with a minimum increase in reactive oxygen species induced lipid peroxidation. The increase in initiator caspase-8 and -9 and executioner caspase-3/7 activities by DPA-induced apoptosis albeit prompting a decline in the levels of ATP. Furthermore, DPA brought about the following consequences on HEK293 cells: markedly elevated tail lengths of the comets, poly (ADP-ribose) polymerase 1 cleavage, and apoptotic body formation observed in the late stages. The cytotoxic effects of DPA in HEK293 cells may be mediated by induction of apoptosis via the caspase-dependent mechanism.

High-fat diet induces dry eye-like ocular surface damages in murine

PurposeA high-fat diet leads to dysfunction in multiple systems of the body. Herein we investigate the effects of a high-fat diet on the ocular surface using a murine model. MethodsFour-week-old male C57BL/6 mice were fed with a standard-fat diet (10 kcal% fat, SFD) or a high-fat diet (60 kcal% fat, HFD) for 1 or 3 months. Phenol red thread test was used to detect tear production, oregon green dextran (OGD) staining was performed to assess corneal epithelial permeability, and PAS staining was conducted to ascertain the presence of conjunctival goblet cells. Squamous metaplasia in the ocular surface and corneal epithelial barrier function were detected by immunofluorescent staining, zymography and Western blot analysis. Oxidative stress related protein expression was evaluated by immunostaining and Western blot analysis. Corneal and conjunctival cell apoptosis was determined by TUNEL assay and caspase-3 expression. ResultsA HFD induced obvious ocular surface damages, including decreased tear production, notable OGD staining and distinct goblet cell loss. It also resulted in corneal epithelial barrier dysfunction and significant squamous metaplasia of the corneal and conjunctival epithelia. The HFD also upregulated key factors that regulate oxidative stress in the ocular surface, and upregulated cell apoptosis in ocular surface epithelial cells. ConclusionsA HFD induces dry eye-like ocular surface damages in mice via the activation of oxidative stress and an induction of apoptosis in the cells of the ocular surface.

Butyrate alleviates oxidative stress by regulating NRF2 nuclear accumulation and H3K9/14 acetylation via GPR109A in bovine mammary epithelial cells and mammary glands

Oxidative stress consistently affects lactation length and quality in dairy cows. Oxidative stress in the mammary gland of high-yielding dairy cows is a serious problem. Therefore, we studied the role of butyrate in dairy cow oxidative stress and further elucidated the mechanism of the antioxidative action of mammary epithelial cells in dairy cows. Oxidative stress and activated GPR109A were present in high-yielding dairy cows. Then, bovine mammary epithelial cells (BMECs) were isolated, and oxidative stress-related protein expression was measured, confirming that sodium butyrate (NaB) exerted antioxidant effects through GPR109A, NRF2 and H3K9/14 acetylation. To further study the antioxidative mechanism of butyrate in dairy cows, we also confirmed that butyrate promoted NRF2 nuclear accumulation and H3K9/14 acetylation through the AMPK signaling pathway by western blotting. Additionally, we preliminarily clarified the interaction between NRF2 and H3K9/14 acetylation by Co-IP and ChIP. Butyrate activated the AMPK signaling pathway through GPR109A to promote NRF2 nuclear accumulation and H3K9/14 acetylation, subsequently exerting antioxidant effects through the synergistic functions of these two processes. Then, we studied the effect of butyrate on oxidative stress in dairy cows in vivo, and the results were consistent with those in vitro. Therefore, butyrate played an antioxidant and antiapoptotic role through the GPR109A/AMPK/NRF2 signaling pathway, while H3K9/14 acetylation could promote NRF2 transcription and enhance the antioxidant capacity of BMECs.

Manganese activates autophagy to alleviate endoplasmic reticulum stress–induced apoptosis via PERK pathway

Overexposure to manganese (Mn) is neurotoxic. Our previous research has demonstrated that the interaction of endoplasmic reticulum (ER) stress and autophagy participates in the early stage of Mn‐mediated neurotoxicity in mouse. However, the mechanisms of ER stress signalling pathways in the initiation of autophagy remain confused. In the current study, we first validated that ER stress–mediated cell apoptosis is accompanied by autophagy in SH‐SY5Y cells. Then, we found that inhibiting ER stress with 4‐phenylbutyrate (4‐PBA) decreased ER stress–related protein expression and reduced cell apoptosis, whereas blocking autophagy with 3‐methyladenine (3‐MA) increased cell apoptosis. These data indicate that protective autophagy was activated to alleviate ER stress–mediated apoptosis. Knockdown of the protein kinase RNA‐like ER kinase (PERK) gene inhibited Mn‐induced autophagy and weakened the interaction between ATF4 and the LC3 promoter. Our results reveal a novel molecular mechanism in which ER stress may regulate autophagy via the PERK/eIF2α/ATF4 signalling pathway. Additionally, Mn may activate protective autophagy to alleviate ER stress–mediated apoptosis via the PERK/eIF2α/ATF4 signalling pathway in SH‐SY5Y cells.

A mechanical acupuncture instrument mitigates the endoplasmic reticulum stress and oxidative stress of ovariectomized rats

BackgroundAcupuncture has become a common complementary and alternative treatment approach for anxiety and depression. However, there is little research on the detailed mechanism of acupuncture therapy relieving depression. Previously, 17β-estradiol (E2) was shown to prevent oxidative stress and endoplasmic reticulum (ER) stress in ovariectomized (OVX) rats. This study investigated whether stimulation of Sanyinjiao (SP6) using a mechanical acupuncture instrument can alleviate depression-like behavior caused by estrogen deficiency in OVX rats. Furthermore, we found that acupuncture reduced ER stress and oxidative stress-related proteins expression. MethodsThe OVX operation was performed on female SD rats that were separated into four groups: The E2 (2.5μg/kg, i.p.) injection group (OVX+E2), the OVX group (OVX), and the OVX with acupuncture stimulation group (OVX+SP6). Non-acupoint stimulation group (OVX+NonAcu). The acupuncture point stimulation began three weeks after surgery. The depressive behavior was analyzed by the forced swim test and open field test. The 8-OHDG, BiP, Sigma receptor 1, pJNK, PDI, Ero1-Iα and Calnexin protein levels were evaluated by immunoreactivity in the amygdala. ResultsAcupuncture stimulation reduced depressive behavior and altered depression-related proteins. Stimulation of SP6 decreased the immobility time of the FST and altered the ER stress and oxidative stress marker proteins, such as 8-OHDG, BiP, pJNK, PDI, Ero1-Ia and Calnexin. ConclusionOur results indicated that acupuncture at SP6 showed a significant antidepressant-like effect on an OVX-induced depression rat model by mitigation of ER stress and oxidative stress in amygdala.

Phytohormones enabled endophytic Penicillium funiculosum LHL06 protects Glycine max L. from synergistic toxicity of heavy metals by hormonal and stress-responsive proteins modulation.

This study investigates the stress-mitigating effects of endophytic Penicillium funiculosum LHL06 on soybean roots via modulation of physio-biochemical, molecular, and proteomic responses to combined heavy metal (Ni, Cu, Pb, Cr, and Al) toxicity. Preliminary screening revealed that LHL06 can tolerate and remediate combined heavy metal contamination in its media and upregulate gibberellins (GA1, GA3, GA4, GA7 and GA9) and indole-3-acetic acid (IAA) production. Inoculation of LHL06 resulted in marked reduction of metals uptake in roots and shoots by downregulating heavy metal ATPase genes (GmHMA13, GmHMA14, GmHMA19) and GmMATE1 compared to non-inoculated plants; in turn, this decreased abscisic acid and jasmonic acid levels. Moreover, triggering of free amino acid metabolism in LHL06-inoculated roots significantly upregulated expression of stress-related proteins (glutathione S-transferase L3, isoflavone reductase-like, chalcone isomerase A, NAD(P)H dehydrogenase (quinone), FQR1-like 1 isoform X2, and Peroxidase 3) to combat metals toxicity. Compared to non-inoculated-plants, LHL06-inoculated-plants exhibited higher antioxidant activity and transcript accumulation of glutathione S-transferase (GmGST8 and GmGST3), G6PDH, and GmSOD1[Cu-Zn], which decreased metal-induced reactive oxygen species. Therefore, LHL06-inoculation remediate combined metal contamination in soil, activate signaling network of stress-responsive hormones and antioxidant systems for promoting growth and tolerance, and reduce metal-accumulation, thereby making plants safer for consumption.

Pyridoxine Preferentially Induces Auditory Neuropathy Through Mitochondrial Dysfunction and Endoplasmic Reticulum Stress-Mediated Apoptosis.

Auditory neuropathy due to toxicity mechanism of pyridoxine has not yet been fully documented. Therefore, the present study explored a direct mechanism underlying the effects of pyridoxine on auditory neuropathy in organ of Corti (OC) explants ex vivo and cochlear neuroblast cell line, VOT-33 in vitro. Primary OC explants containing spiral ganglion neurons and cultured VOT-33 cells were treated with pyridoxine. In nerve fiber of primary OC explants, pyridoxine decreased staining for NF200, a neuro-cytoskeletal protein. We also found that pyridoxine-induced VOT-33 apoptosis, as indicated by accumulation of the sub-G0/G1 fraction, caspase-3 activation, and PARP cleavage. In addition, pyridoxine induced reactive oxygen species (ROS) generation and alteration of mitochondrial membrane potential transition (MPT), including Bcl-2 family protein expression and consequently Ca2+ accumulation and changes of endoplasmic reticulum (ER) stress-related protein expression such as phospho-PERK, caspase-12, Grp78, and CHOP. Pyridoxine preferentially induced severe cell death on nerve fiber in primary OC explants and markedly increased apoptotic cell death via mitochondria-mediated ER stress in VOT-33 cells.

Defining lower limits of biodegradation: atrazine degradation regulated by mass transfer and maintenance demand in Arthrobacter aurescens TC1

Exploring adaptive strategies by which microorganisms function and survive in low-energy natural environments remains a grand goal of microbiology, and may help address a prime challenge of the 21st century: degradation of man-made chemicals at low concentrations (“micropollutants”). Here we explore physiological adaptation and maintenance energy requirements of a herbicide (atrazine)-degrading microorganism (Arthrobacter aurescens TC1) while concomitantly observing mass transfer limitations directly by compound-specific isotope fractionation analysis. Chemostat-based growth triggered the onset of mass transfer limitation at residual concentrations of 30 μg L−1 of atrazine with a bacterial population doubling time (td) of 14 days, whereas exacerbated energy limitation was induced by retentostat-based near-zero growth (td = 265 days) at 12 ± 3 μg L−1 residual concentration. Retentostat cultivation resulted in (i) complete mass transfer limitation evidenced by the disappearance of isotope fractionation (ε13C = −0.45‰ ± 0.36‰) and (ii) a twofold decrease in maintenance energy requirement compared with chemostat cultivation. Proteomics revealed that retentostat and chemostat cultivation under mass transfer limitation share low protein turnover and expression of stress-related proteins. Mass transfer limitation effectuated slow-down of metabolism in retentostats and a transition from growth phase to maintenance phase indicating a limit of ≈10 μg L−1 for long-term atrazine degradation. Further studies on other ecosystem-relevant microorganisms will substantiate the general applicability of our finding that mass transfer limitation serves as a trigger for physiological adaptation, which subsequently defines a lower limit of biodegradation.

The Cardiotoxicity Induced by Arsenic Trioxide is Alleviated by Salvianolic Acid A via Maintaining Calcium Homeostasis and Inhibiting Endoplasmic Reticulum Stress.

Arsenic trioxide (ATO) has been verified as a breakthrough with respect to the management of acute promyelocytic leukemia (APL) in recent decades but associated with some serious adverse phenomena, particularly cardiac functional abnormalities. Salvianolic acid A (Sal A) is a major effective component in treating ATO-induced cardiotoxicity. Therefore, the objective of our study was to assess whether Sal A had protective effects by the regulation of calcium homeostasis and endoplasmic reticulum (ER) stress. For the in vivo study, BALB/c mice were treated with ATO and/or Sal A via daily tail vein injections for two weeks. For the in vitro study, we detected the effects of ATO and/or Sal A in real time using adult rat ventricular myocytes (ARVMs) and an IonOptix MyoCam system. Our results showed that Sal A pretreatment alleviated cardiac dysfunction and Ca2+ overload induced by ATO in vivo and vitro. Moreover, Sal A increased sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) activity and expression, alleviated [Ca2+]ER depletion, and decreased ER stress-related protein expression. Sal A protects the heart from ATO-induced injury and its administration correlates with the modulation of SERCA, the recovery of Ca2+ homeostasis, and the down-regulation of ER stress-mediated apoptosis.

GPER agonist G1 suppresses neuronal apoptosis mediated by endoplasmic reticulum stress after cerebral ischemia/reperfusion injury.

Studies have confirmed a strong association between activation of the endoplasmic reticulum stress pathway and cerebral ischemia/reperfusion (I/R) injury. In this study, three key proteins in the endoplasmic reticulum stress pathway (glucose-regulated protein 78, caspase-12, and C/EBP homologous protein) were selected to examine the potential mechanism of endoplasmic reticulum stress in the neuroprotective effect of G protein-coupled estrogen receptor. Female Sprague-Dawley rats received ovariectomy (OVX), and then cerebral I/R rat models (OVX + I/R) were established by middle cerebral artery occlusion. Immediately after I/R, rat models were injected with 100 μg/kg E2 (OVX + I/R + E2), or 100 μg/kg G protein-coupled estrogen receptor agonist G1 (OVX + I/R + G1) in the lateral ventricle. Longa scoring was used to detect neurobehavioral changes in each group. Infarct volumes were measured by 2,3,5-triphenyltetrazolium chloride staining. Morphological changes in neurons were observed by Nissl staining. Terminal dexynucleotidyl transferase-mediated nick end-labeling staining revealed that compared with the OVX + I/R group, neurological function was remarkably improved, infarct volume was reduced, number of normal Nissl bodies was dramatically increased, and number of apoptotic neurons in the hippocampus was decreased after E2 and G1 intervention. To detect the expression and distribution of endoplasmic reticulum stress-related proteins in the endoplasmic reticulum, caspase-12 distribution and expression were detected by immunofluorescence, and mRNA and protein levels of glucose-regulated protein 78, caspase-12, and C/EBP homologous protein were determined by polymerase chain reaction and western blot assay. The results showed that compared with the OVX + I/R group, E2 and G1 treatment obviously decreased mRNA and protein expression levels of glucose-regulated protein 78, C/EBP homologous protein, and caspase-12. However, the G protein-coupled estrogen receptor antagonist G15 (OVX + I/R + E2 + G15) could eliminate the effect of E2 on cerebral I/R injury. These results confirm that E2 and G protein-coupled estrogen receptor can inhibit the expression of endoplasmic reticulum stress-related proteins and neuronal apoptosis in the hippocampus, thereby improving dysfunction caused by cerebral I/R injury. Every experimental protocol was approved by the Institutional Ethics Review Board at the First Affiliated Hospital of Shihezi University School of Medicine, China (approval No. SHZ A2017-171) on February 27, 2017.

Use of magnoflorine-phospholipid complex to permeate blood-brain barrier and treat depression in the CUMS animal model

To improve the liposolubility and blood-brain barrier permeability of magnoflorine, a new formulation of magnoflorine-phospholipid complex was prepared, characterized, and pharmacologically evaluated in the chronic unpredictable mild stress animal model. In this paper, the magnoflorine-phospholipid complex was synthesized and its characterization was determined. The antidepressant-like and antioxidant activity of magnoflorine-phospholipid complex was investigated by behavioral tests and western blotting analysis. As a result, the magnoflorine-phospholipid complex displayed high encapsulation efficiency and significantly improved the oil-water participate coefficient. In vivo blood-brain distribution study, the magnoflorine-phospholipid complex extended the duration of magnoflorine in blood and help magnoflorine to permeate the blood-brain barrier into brain. In behavioral tests, the magnoflorine-phospholipid complex significantly decreased immobility time compared to model control group in both FST and TST. Furthermore, the magnoflorine-phospholipid complex increased the expression of antioxidative stress-related proteins by the western blotting analysis. These findings strongly suggest that the phospholipid complex could significantly improve liposolubility, drug properties of magnoflorine and help magnoflorine permeate blood-brain barrier and exert the antidepressant effect.

Proteogenomic Analysis of Epibacterium Mobile BBCC367, a Relevant Marine Bacterium Isolated From the South Pacific Ocean.

Epibacterium mobile BBCC367 is a marine bacterium that is common in coastal areas. It belongs to the Roseobacter clade, a widespread group in pelagic marine ecosystems. Species of the Roseobacter clade are regularly used as models to understand the evolution and physiological adaptability of generalist bacteria. E. mobile BBCC367 comprises two chromosomes and two plasmids. We used gel-free shotgun proteomics to assess its protein expression under 16 different conditions, including stress factors such as elevated temperature, nutrient limitation, high metal concentration, and UVB exposure. Comparison of the different conditions allowed us not only to retrieve almost 70% of the predicted proteins, but also to define three main protein assemblages: 584 essential core proteins, 2,144 facultative accessory proteins and 355 specific unique proteins. While the core proteome mainly exhibited proteins involved in essential functions to sustain life such as DNA, amino acids, carbohydrates, cofactors, vitamins and lipids metabolisms, the accessory and unique proteomes revealed a more specific adaptation with the expression of stress-related proteins, such as DNA repair proteins (accessory proteome), transcription regulators and a significant predominance of transporters (unique proteome). Our study provides insights into how E. mobile BBCC367 adapts to environmental changes and copes with diverse stresses.

Ethanolic extract of Cordyceps cicadae exerts antitumor effect on human gastric cancer SGC-7901 cells by inducing apoptosis, cell cycle arrest and endoplasmic reticulum stress

Ethnopharmacological relevanceCordyceps cicadae (Miq.) Massee is a traditional Chinese medicine that has been used for approximately 1600 years in China. C. cicadae, a member of the Cordyceps genus, exerts a therapeutic effect on many diseases, such as cancer. ObjectiveThis study aimed to evaluate the antineoplasmic activity of C. cicadae and to identify its molecular mechanism of cell death. Materials and methodsThe toxicity of the ethanolic extract of C. cicadae (EEC) against different cancer cell lines was determined through MTT assay. Human gastric cancer SGC-7901 cells were treated with EEC for 48 h. Cell morphology was examined by using an Olympus phase-contrast microscope. The cell apoptosis was quantified through Annexin V-FITC/PI staining. Cells were stained with PI and then subjected to flow cytometry for the investigation of cell cycle status. Cells were subjected to mitochondrial membrane potential (MMP) assay after incubation with JC-1 probes and to intracellular Ca2+ measurement through flow cytometry after incubation with Fluo-3 AM fluorescent probes. Western blot analysis was conducted to quantify the expression of proteins related to apoptosis, cell cycle and endoplasmic reticulum stress. High-performance liquid chromatography (HPLC) analysis was performed to analyse the biological activity components of EEC. ResultsEEC suppressed the proliferation of SGC-7901 cells and induced the development of abnormal morphological features in a dose-dependent manner. Flow cytometry results indicated that EEC treatment caused cell apoptosis and arrested the cell cycle in the S phase. In addition, EEC treatment triggered MMP depolarization and Ca2+ overloading in the cytosol of SGC-7901 cells. Western blot analysis demonstrated that EEC increased Bax, AIF, caspase-8, caspase-6 and caspase-3 activities and decreased Bcl-2 activity. The release of cytochrome c from mitochondria was associated with mitochondrial dysfunction, which was caused by the activation of the cell surface receptor Fas and the cleavage of PARP. EEC-induced S phase arrest was associated with the up-regulation of E2F1, cyclin A2, cyclin E and p53 expression levels and the down-regulation of CDK2 expression. In addition, EEC increased the expression of endoplasmic reticulum stress-related proteins, such as calpain-1, caspase-12 and caspase-9. HPLC assay results suggested that EEC contained adenine, uridine, adenosine and N6-(2-Hydroxyethyl)-adenosine. ConclusionEEC inhibited the proliferation of SGC-7901 cells by inducing caspase-dependent apoptosis, arresting the cell cycle in the S phase and increasing endoplasmic reticulum stress. This study revealed that C. cicadae is a potential natural source of anticancer drugs.

Protective effects of selenium against zearalenone-induced apoptosis in chicken spleen lymphocyte via an endoplasmic reticulum stress signaling pathway.

Selenium (Se), an antioxidant agent, provides significant protection from reactive oxygen species (ROS)-induced cell damage in vivo and in vitro. However, it is unclear whether Se can protect against zearalenone (ZEN)-induced apoptosis in chicken spleen lymphocyte. In this study, we investigated the underlying mechanism of the apoptosis induced by ZEN in chicken spleen lymphocyte and further evaluated the protective mechanism of Se on ZEN-induced apoptosis. The results show that ZEN induced an increase in ROS generation and lipid peroxidation, and a decrease in levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione (GSH). The results of apoptosis morphologically from acridine orange/ethidium bromide (AO/EB) fluorescent staining and flow cytometry analysis show apparent apoptosis in the ZEN-treated group, and was confirmed by the upregulation of caspase-3, -12 and downregulation of Bcl-2. Meanwhile, ZEN activated the endoplasmic reticulum (ER) stress by upregulating ER stress-related molecular sensors (GRP78, ATF6, ATF4, IRE). However, co-treatment with Se effectively blocked ROS generation, improved antioxdative capacity, and reversed apoptosis and ER stress-related genes and protein expression. Taken together, these data suggest that oxidative stress and ER stress play a vital role in ZEN-induced apoptosis, and Se had a significant preventive effect on ZEN-induced apoptosis in chicken spleen lymphocyte via ameliorating the ER stress signaling pathway.

Desiccation tolerance in Acinetobacter baumannii is mediated by the two-component response regulator BfmR.

For the opportunistic pathogen Acinetobacter baumannii, desiccation tolerance is thought to contribute significantly to the persistence of these bacteria in the healthcare environment. We investigated the ability of A. baumannii to survive rapid drying, and found that some strains exhibited a profoundly desiccation-resistant phenotype, characterized by the ability of a large proportion of cells to survive on a dry surface for an extended period of time. However, this phenotype was only displayed during the stationary phase of growth. Most interestingly, we found that drying resistance could be lost after extended cultivation in liquid medium. Genome sequencing of isolates that became drying-sensitive identified mutations in bfmR, which encodes a two-component response regulator that is important for A. baumannii virulence. Additionally, BfmR was necessary for the expression of stress-related proteins during stationary phase, and one of these, KatE, was important for long-term drying survival. These results suggested that BfmR may control stress responses, and we demonstrated that the ΔbfmR mutant was more sensitive to hydrogen peroxide, nutrient starvation, and increased osmolarity. We also found that cross-protection against drying could be stimulated by either starvation, which required BfmR, or increased osmolarity. These results imply that BfmR plays a role in controlling stress responses in A. baumannii which help protect cells during desiccation, and they provide a regulatory link between this organism’s ability to persist in the environment and pathogenicity.

UBIAD1 protects against oxygen-glucose deprivation/reperfusion-induced multiple subcellular organelles injury through PI3K/AKT pathway in N2A cells.

Cerebral ischemia/reperfusion-induced injury plays a significant role in the development of multi-subcellular organelles injury after ischemic stroke. UBIAD1 was discovered originally as a potential tumor suppressor protein. Recently, analysis of UBIAD1 has indicated it is a prenyltransferase enzyme for both non-mitochondrial CoQ10 and vitamin K2 production. Further, UBIAD1 has been localized to multiple subcellular organelles. Particularly, UBIAD1 plays an important role in the regulation of oxidative stress, apoptosis and cell proliferation, cholesterol and lipid metabolism, which was closely associated with the cerebral ischemic/reperfusion mechanism. However, the mechanism underlying effects of UBIAD1 on cerebral ischemia/reperfusion-induced injury remains largely unknown. We aimed to investigate the effects of UBIAD1 on ischemia/reperfusion-induced multiple subcellular organelles injury in vitro, mouse N2A cells were subjected to a classical oxygen-glucose deprivation and reperfusion (OGD/R) insult. The expression of UBIAD1 was reduced in mouse N2A cells after OGD/R. UBIAD1 exhibits multi-subcellular organelles co-localization in N2a cells, including in the mitochondria, endoplasmic reticulum, and Golgi apparatus. The over-expression of UBIAD1 significantly protects against OGD/R-induced cell death. UBIAD1 over-expression also attenuated OGD/R-induced mitochondrial fragmentation and dysfunction and mediated the level of apoptosis-associated protein. Moreover, we observed that the over-expression of UBIAD1 ameliorated OGD/R-induced fragmentation and reduced the level of oxidative stress-related protein expression in both the endoplasmic reticulum and Golgi apparatus. Besides, the neuroprotective effect of UBIAD1 was correlated with the PI3K/AKT pathway, which was demonstrated using the PI3K inhibitor LY294002 and perifosion. Collectively, these findings identified that UBIAD1 protects against OGD/R-induced multiple subcellular organelles injury through PI3K/AKT Pathway.