Microsecond time-resolved X-ray scattering by utilizing MHz repetition rate at second-generation XFELs.

Detecting microsecond structural perturbations in biomolecules has wide relevance in biology, chemistry and medicine. Here we show how MHz repetition rates at X-ray free-electron lasers can be used to produce microsecond time-series of protein scattering with exceptionally low noise levels of 0.001%. We demonstrate the approach by examining Jɑ helix unfolding of a light-oxygen-voltage photosensory domain. This time-resolved acquisition strategy is easy to implement and widely applicable for direct observation of structural dynamics of many biochemical processes.

Tumor-targeted delivery of a STING agonist improvescancer immunotherapy.

The cGAS-STING pathway is essential for immune defense against microbial pathogens and malignant cells; as such, STING is an attractive target for cancer immunotherapy. However, systemic administration of STING agonists poses safety issues while intratumoral injection is limited by tumor accessibility. Here, we generated antibody-drug conjugates (ADCs) by conjugating a STING agonist through a cleavable linker to antibodies targeting tumor cells. Systemic administration of these ADCs was well tolerated and exhibited potent antitumor efficacy in syngeneic mouse tumor models. The STING ADC further synergized with an anti-PD-L1 antibody to achieve superior antitumor efficacy. The STING ADC promoted multiple aspects of innate and adaptive antitumor immune responses, including activation of dendritic cells, T cells, natural killer cells and natural killer T cells, as well as promotion of M2 to M1 polarization of tumor-associated macrophages. These results provided the proof of concept for clinical development of the STING ADCs.

Emerging Links between Cerebral Blood Flow Regulation and Cognitive Decline: A Role for Brain Microvascular Pericytes.

Cognitive impairment associated with vascular etiology has been of considerable interest in the development of dementia. Recent studies have started to uncover cerebral blood flow deficits in initiating cognitive deterioration. Brain microvascular pericytes, the only type of contractile cells in capillaries, are involved in the precise modulation of vascular hemodynamics due to their ability to regulate resistance in the capillaries. They exhibit potential in maintaining the capillary network geometry and basal vascular tone. In addition, pericytes can facilitate better blood flow supply in response to neurovascular coupling. Their dysfunction is thought to disturb cerebral blood flow causing metabolic imbalances or structural injuries, leading to consequent cognitive decline. In this review, we summarize the characteristics of microvascular pericytes in brain blood flow regulation and outline the framework of a two-hit hypothesis in cognitive decline, where we emphasize how pericytes serve as targets of cerebral blood flow dysregulation that occurs with neurological challenges, ranging from genetic factors, aging, and pathological proteins to ischemic stress.

Clinical application of multidisciplinary team- and evidence-based practice project in gynecological patients with perioperative hypothermia.

BACKGROUND: Perioperative hypothermia (PH) negatively affects the physical and mental health of patients to varying degrees. Currently, there is no effective multidisciplinary team (MDT) intervention for gynecological patients with PH. AIM: To apply the best evidence on the prevention and management of PH in gynecological patients, improve the quality of perioperative evidence-based care based on treatment by an MDT for gynecological patients and analyze the effect of MDT- and evidence-based practice (EBP) projects on the psychological status and cognitive function of gynecological patients with PH. METHODS: Under the guidance of knowledge translation and combined with the opinions of involved stakeholders and clinical experts, the best evidence for PH prevention and management in gynecological patients was selected and adjusted to suit the practice setting. Based on the evidence, the practice plan was developed, and the MDT intervention was carried out in the preoperative ward, the preoperative preparation room, the intraoperative operating room, the postanesthesia care unit, and the 24-hour postoperative gynecological ward through the EBP program. The incidence of hypothermia, the nurses' awareness, the implementation rate of examination indicators, and the thermal comfort level, psychological status and cognitive function of patients were compared before and after the implementation of the program. RESULTS: The incidence of PH in gynecological patients decreased from 43.33% to 13.33% after the implementation of the scheme. The implementation rate of examination indicators 6-10, 12, 14, 16-18, 21, and 22 reached 100%, and that of other indicators was above 90%, except for examination indicators 5 and 13, which was 66.67%; the indices were significantly improved compared with the baseline (before evidence application) (P < 0.05). The score of nurses' awareness of PH prevention and management in gynecological patients increased from 60.96 ± 9.70 to 88.08 ± 8.96, and the difference was statistically significant (P < 0.001). The total score of the perioperative thermal comfort level of patients undergoing gynecological surgery was 27.97 ± 2.04, which was significantly increased compared with the score of 21.27 ± 1.57 observed by researchers at baseline (P < 0.001). The perioperative Hamilton Depression Scale and Hamilton Anxiety Scale scores of patients undergoing gynecological surgery decreased from 15.03 ± 3.16 and 13.93 ± 2.64 to 4.30 ± 1.15 and 3.53 ± 0.78, respectively, with statistically significant differences (P < 0.001). The perioperative Montreal Cognitive Assessment Scale score of the gynecological surgery patients increased from 23.17 ± 1.68 to 26.93 ± 1.11, also with statistical significance (P < 0.001). CONCLUSION: MDT-based EBP for PH prevention and management in gynecological patients during the perioperative period can standardize nursing operations, improve nurses' awareness and behavioral compliance with gynecological hypothermia management, and reduce the occurrence of PH in gynecological patients while playing a positive role in reducing patients' negative emotions and enhancing their cognitive function.

Transferrable Electrospinning Nanofiber Meshes as Strongly Adhered Scaffolds for Slippery Liquid-Infused Porous Surfaces.

Slippery liquid-infused porous surfaces (SLIPS) are self-healing protective coatings that can be made by infiltration of a porous scaffold with a chemically resistant oil. A popular method to apply a SLIPS coating is using electrospinning to deposit a nanofiber mesh onto the intended substrate. However, electrospinning only lightly deposits the nanofibers onto the intended substrate, so the coating detaches easily even when unintended. We report a simple, yet effective, solution to the adhesion problem. Electrospun nanofiber meshes are typically well entangled and cohesive, so they can be detached from the electrospinning target and transferred onto the final target. Using a thin layer of adhesive on the intended surface, the electrospinning mesh can be securely attached and infiltrated with protective oil to yield a more stable SLIPS coating. An adhered coating can be submerged under corrosive solution and repeatedly self-heal from damage to the same spot. With the electrospun nanofiber meshes' flexibility and stretchability, the meshes can be fitted around a wide range of targets including ones that are otherwise difficult to apply a nanofiber mesh on. The use of an adhesive interlayer between the nanofiber mesh and substrate is a simple solution to improve coating stability, and the solution facilitates application of SLIPS onto a broader range of substrates.

Haematopoietic cell-derived exosomes in cancer development and therapeutics: From basic science to clinical practice.

BACKGROUND: The tumour microenvironment (TME) is a specialised niche involving intercellular communication among cancer cells and various host cells. Among the host cells, the quantity and quality of immune cells within the TME play essential roles in cancer development and management. The immunologically suppressive, so-called 'cold' TME established by a series of tumour-host interactions, including generating immunosuppressive cytokines and recruiting regulatory host immune cells, is associated with resistance to therapies and worse clinical outcomes. MAIN BODY: Various therapeutic approaches have been used to target the cold TME, including immune checkpoint blockade therapy and adoptive T-cell transfer. A promising, less explored therapeutic strategy involves targeting TME-associated exosomes. Exosomes are nanometer-sized, extracellular vesicles that transfer material from donor to recipient cells. These particles can reprogram the recipient cells and modulate the TME. In particular, exosomes from haematopoietic cells are known to promote or suppress cancer progression under specific conditions. Understanding the effects of haematopoietic cell-secreted exosomes may foster the development of therapeutic exosomes (tExos) for personalised cancer treatment. However, the development of exosome-based therapies has unique challenges, including scalable production, purification, storage and delivery of exosomes and controlling batch variations. Clinical trials are being conducted to verify the safety, feasibility, availability and efficacy of tExos. CONCLUSION: This review summarises our understanding of how haematopoietic cell-secreted exosomes regulate the TME and antitumour immunity and highlights present challenges and solutions for haematopoietic cell-derived exosome-based therapies.

Time-trend analysis of tuberculosis diagnosis in Shenzhen, China between 2011 and 2020.

Objective: To describe the trend of tuberculosis (TB) diagnosis in the migrant city Shenzhen, China, and analyze the risk factors of diagnosis delays. Methods: Demographic and clinical information of TB patients from 2011 to 2020 in Shenzhen were extracted. A bundle of measures to enhance TB diagnosis had been implemented since late 2017. We calculated the proportions of patients who underwent a patient delay (>30 days from syndrome onset to first care-seeking) or a hospital delay (>4 days from first care-seeking to TB diagnosis). Multivariable logistic regression was used to analyze the risk factors of diagnosis delays. Results: During the study period, 43,846 patients with active pulmonary TB were diagnosed and registered in Shenzhen. On average, the bacteriological positivity rate of the patients was 54.9%, and this increased from 38.6% in 2017 to 74.2% in 2020. Overall, 30.3 and 31.1% of patients had a patient delay or a hospital delay, respectively. Molecular testing significantly increased bacteriological positivity and decreased the risk of hospital delay. People >35 years old, the unemployed, and residents had a higher risk of delays in both patient care-seeking and hospital diagnosis than younger people, workers, or migrants. Compared with passive case-finding, active case-finding significantly decreased the risk of patient delay by 5.47 (4.85-6.19) times. Conclusion: The bacteriological positivity rate of TB patients in Shenzhen increased significantly but the diagnosis delays were still serious, which may need more attention when active case-finding in risk populations and optimization of molecular testing.

3D-printed sheet jet for stable megahertz liquid sample delivery at X-ray free-electron lasers.

X-ray free-electron lasers (XFELs) can probe chemical and biological reactions as they unfold with unprecedented spatial and temporal resolution. A principal challenge in this pursuit involves the delivery of samples to the X-ray interaction point in such a way that produces data of the highest possible quality and with maximal efficiency. This is hampered by intrinsic constraints posed by the light source and operation within a beamline environment. For liquid samples, the solution typically involves some form of high-speed liquid jet, capable of keeping up with the rate of X-ray pulses. However, conventional jets are not ideal because of radiation-induced explosions of the jet, as well as their cylindrical geometry combined with the X-ray pointing instability of many beamlines which causes the interaction volume to differ for every pulse. This complicates data analysis and contributes to measurement errors. An alternative geometry is a liquid sheet jet which, with its constant thickness over large areas, eliminates the problems related to X-ray pointing. Since liquid sheets can be made very thin, the radiation-induced explosion is reduced, boosting their stability. These are especially attractive for experiments which benefit from small interaction volumes such as fluctuation X-ray scattering and several types of spectroscopy. Although their use has increased for soft X-ray applications in recent years, there has not yet been wide-scale adoption at XFELs. Here, gas-accelerated liquid sheet jet sample injection is demonstrated at the European XFEL SPB/SFX nano focus beamline. Its performance relative to a conventional liquid jet is evaluated and superior performance across several key factors has been found. This includes a thickness profile ranging from hundreds of nanometres to 60 nm, a fourfold increase in background stability and favorable radiation-induced explosion dynamics at high repetition rates up to 1.13 MHz. Its minute thickness also suggests that ultrafast single-particle solution scattering is a possibility.

mTOR complex 2 targets Akt for proteasomal degradation via phosphorylation at the hydrophobic motif.

The protein kinase Akt (also known as protein kinase B) is a critical signaling hub downstream of various cellular stimuli such as growth factors that control cell survival, growth, and proliferation. The activity of Akt is tightly regulated, and the aberrant activation of Akt is associated with diverse human diseases including cancer. Although it is well documented that the mammalian target of rapamycin complex 2 (mTORC2)-dependent phosphorylation of the Akt hydrophobic motif (Ser-473 in Akt1) is essential for full Akt activation, it remains unclear whether this phosphorylation has additional roles in regulating Akt activity. In this study, we found that abolishing Akt Ser-473 phosphorylation stabilizes Akt following agonist stimulation. The Akt Ser-473 phosphorylation promotes a Lys-48-linked polyubiquitination of Akt, resulting in its rapid proteasomal degradation. Moreover, blockade of this proteasomal degradation pathway prolongs agonist-induced Akt activation. These data reveal that mTORC2 plays a central role in regulating the Akt protein life cycle by first stabilizing Akt protein folding through the turn motif phosphorylation and then by promoting Akt protein degradation through the hydrophobic motif phosphorylation. Taken together, this study reveals that the Akt Ser-473 phosphorylation-dependent ubiquitination and degradation is an important negative feedback regulation that specifically terminates Akt activation.

Dual role of 3-methyladenine in modulation of autophagy via different temporal patterns of inhibition on class I and III phosphoinositide 3-kinase.

A group of phosphoinositide 3-kinase (PI3K) inhibitors, such as 3-methyladenine (3-MA) and wortmannin, have been widely used as autophagy inhibitors based on their inhibitory effect on class III PI3K activity, which is known to be essential for induction of autophagy. In this study, we systematically examined and compared the effects of these two inhibitors on autophagy under both nutrient-rich and deprivation conditions. To our surprise, 3-MA is found to promote autophagy flux when treated under nutrient-rich conditions with a prolonged period of treatment, whereas it is still capable of suppressing starvation-induced autophagy. We first observed that there are marked increases of the autophagic markers in cells treated with 3-MA in full medium for a prolonged period of time (up to 9 h). Second, we provide convincing evidence that the increase of autophagic markers is the result of enhanced autophagic flux, not due to suppression of maturation of autophagosomes or lysosomal function. More importantly, we found that the autophagy promotion activity of 3-MA is due to its differential temporal effects on class I and class III PI3K; 3-MA blocks class I PI3K persistently, whereas its suppressive effect on class III PI3K is transient. Because 3-MA has been widely used as an autophagy inhibitor in the literature, understanding the dual role of 3-MA in autophagy thus suggests that caution should be exercised in the application of 3-MA in autophagy study.

Application of double circular suturing technique (DCST) in the repair of large abdominal wall defects after resection of abdominal wall tumor.

BACKGROUND: The aim of this study was to investigate the clinical effects of repairing large defects using the double circular suturing technique (DCST) after resection of abdominal wall tumor. METHODS: The clinical data of 62 patients (25 men, 37 women; average age 41.7±22.4 years) who underwent DCST between October 2010 and November 2018 for the repair of large abdominal wall defects with anti-adhesion underlay mesh after resection of abdominal wall tumor were retrospectively analyzed. The maximum diameter of abdominal wall defect after resection of abdominal wall tumor was 10.4±5.6 cm. The course of disease was 1-341 months, and the average was 32.4 months. Operative time, postoperative hospitalization time, perioperative complications, tumor recurrence in situ, incidence of postoperative chronic pain, and hernia were recorded. RESULTS: All 62 operations were completed successfully. The operative time was 73.2±31.4 minutes, and the mean postoperative hospitalization time was 9.6 days (range, 2-20 days). In total, 54 patients were followed up postoperatively for a median 6.7 years (range, 0.9-9.0 years). Partial splitting of incisions occurred in 2 patients, fat liquefaction of incisions occurred in 3 patients, and chronic pain occurred in 4 patients. No tumor in situ recurrence, hernia, or other complications were found in any cases in the follow-up. Tumor metastasis occurred in 9 patients with 6 of these patients dying of tumour progression. CONCLUSIONS: With simple operations, short procedure time, few complications, low tumor recurrence rate, and low incidence of postoperative chronic pain, application of DCST in the repair of large abdominal wall defects is effective after resection of abdominal wall tumor.

[Preparation and photoluminescence investigation of europium-doped zinc oxide nanocrystalline].

Europium-doped zinc oxide nanocrystalline was successfully prepared by sol-gel process. Photoluminescence spectrum (PL), Photoluminescence excitation spectrum(PLE), and X-ray diffraction pattern(XRD) of nanocrystalline ZnO : Eu3+ with excitation wavelength 395 nm were measured at room temperature. The XRD pattern indicates that nanocrystalline ZnO : Eu3+ has a hexagonal wurtzite structure and is polycrystalline. The mean grain size of nanocrystalline ZnO : Eu3+ was calculated by Debye-Scherrer formula. The luminescence process of Eu(3+) -doped zinc oxide nanocrystalline was investigate using PL and PLE. Emission of 5D0 --> 7F1 (595 nm), 5D0 --> 7F3 (653 nm), 5D0 --> 7F2 (611 nm) of Eu3+ ions, and a weak and wide visible band of ZnO were observed. Also, the photoluminescence of nanocrystalline ZnO : Eu3+ exhibits a blue-shift. An energy transfer from excited states of ZnO hosts to doped Eu3+ ions centers was disclosed by the fact that that photoluminescence intensity maximum of nanocrystalline ZnO : Eu3+ changs with the doping concentration of Eu3+.

[Effects of deltamethrin on neurobehavioral development of offspring of intoxicated rats].

OBJECTIVE: To investigate the effects of deltamethrin on the filial brain nitric oxide synthase (NOS) activity and neurobehavioral development of the exposed lactational rats. METHODS: Pregnant rats were randomizedly divided into the treated group and the control group. The treated group was administered orally with 3.35, 6.70 mg/kg deltamethrin every other day from postnatal day (PND) 1 to PND 19 while the control group was administered with the corn oil of same amount in the same period. The activity of NOS of filial brain and neurobehavioral functions of the filial rats were observed. RESULTS: The lactational survival rate (81.80%:78.60%) in both treated groups was decreased significantly (P < 0.01) compared with that in the control group. The body weight of filial rats on PND 10, 21 in 6.70 mg/kg DM treated group [(16.62 +/- 2.2 8), (31.34 +/- 6.94) g] was less than those in the control group (P < 0.05). The delayed time in the filial rats in 6.70 mg/kg group was (3.05 +/- 1.20) s and the positive rates of passive escaping response in 3.35 and 6.70 mg/kg DM treated group were 22.5% and 21.5% respectively. There was the trend of the developmental increase of the activity of filial brain NOS between PND 5 and PND 21 and the NOS activity of rat brain on PND 5 in 6.70 mg/kg group [(0.60 +/- 0.07) U.mg pro(-1).h(-1)] was lower than that in the control group (P < 0.05). CONCLUSION: Exposure to high dose of deltamethrin in lactational female rats will decrease the activity of NOS of brain and retard the neurobehavioral development of their filial rats.

Phosphorylation of innate immune adaptor proteins MAVS, STING, and TRIF induces IRF3 activation.

During virus infection, the adaptor proteins MAVS and STING transduce signals from the cytosolic nucleic acid sensors RIG-I and cGAS, respectively, to induce type I interferons (IFNs) and other antiviral molecules. Here we show that MAVS and STING harbor two conserved serine and threonine clusters that are phosphorylated by the kinases IKK and/or TBK1 in response to stimulation. Phosphorylated MAVS and STING then bind to a positively charged surface of interferon regulatory factor 3 (IRF3) and thereby recruit IRF3 for its phosphorylation and activation by TBK1. We further show that TRIF, an adaptor protein in Toll-like receptor signaling, activates IRF3 through a similar phosphorylation-dependent mechanism. These results reveal that phosphorylation of innate adaptor proteins is an essential and conserved mechanism that selectively recruits IRF3 to activate the type I IFN pathway.

Application of stochastic method to optimum design of energy-efficient induction motors with a target of LCC.

For an energy-efficient induction machine, the life-cycle cost (LCC) usually is the most important index to the consumer. With this target, the optimization design of a motor is a complex nonlinear problem with constraints. To solve the problem, the authors introduce a united random algorithm. At first, the problem is divided into two parts, the optimal rotor slots and the optimization of other dimensions. Before optimizing the rotor slots with genetic algorithm (GA), the second part is solved with TABU algorithm to simplify the problem. The numerical results showed that this method is better than the method using a traditional algorithm.

[Brain-derived neurotrophic factor mRNA expressions in rat brain induced by short-term in vivo exposure to deltamethrin].

OBJECTIVE: To elucidate the mechanism of damage on central nervous system (CNS) caused by deltamethrin (DM). METHODS: The mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) in the cerebral cortex and hippocampus of the rats exposed to DM were measured by retro-transcription-polymerase chain reaction (RT-PCR), dot blot, flow cytometry analysis and immunohistochemistry. RESULTS: After exposure to DM at high-dose (DM1, 25.0 mg x kg(-1) x d(-1), i.p.) once and low-dose (DM2, 12.5 mg x kg(-1) x d(-1), i.p.) for 5 days, the level of BDNF mRNA and protein expression in the cerebral cortex and hippocampus of the rats increased significantly. The levels of BDNF mRNA and protein expression in the cerebral cortex and hippocampus measured by of RT-PCR in the rats with DM1 and DM2 were higher than those in the controls by 48% and 56%, and 59% and 54%, respectively. And, those measured by dot blot in the rats with MD1 and MD2 were 186% and 161%, and 148% and 158% of those in the controls, respectively, basically similar to those measured by RT-PCR. Flow cytometric analysis showed that the levels of BDNF mRNA and protein expression in the cerebral cortex and hippocampus in the rats with DM1 and DM2 were higher than those in the controls by 53% and 89%, and 45% and 46%, respectively. Immunohistochemical analysis showed that protein expression in the cerebral cortex of the rats with DM1 and DM2 were 129% and 147% of those in the controls, same as the flow cytometric analysis, but those were significantly higher in the hippocampus mainly in the CA1 and DG areas of the rats with MD1 and the CA3 and DG areas of the rats with DM2. CONCLUSIONS: DM could induce BDNF mRNA and protein expression in the cerebral cortex and hippocampus of the rats, which could play an important role in repairing of nerve damage.

[Significance of plasma 8-iso-prostaglandin F2alpha level in acute myocardial ischemia and intervention effect of N-acetylcysteine: a study in rats].

OBJECTIVE: To examine the correlation between 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) levels in the plasma and myocardial tissue of rats with myocardial ischemia and observe the intervention effect of N-acetylcysteine (NAC), for the purpose of assessing the value of 8-iso-PGF2alpha in estimating the extent of free radical damage and implementing possible interventions. METHODS: Forty-five Wistar rats were divided into ischemia, ischemia+NAC and control groups, and in the former 2 groups, acute myocardial ischemia models were produced by pituitrin. Elevated ST segment in ECG served as the indicator for myocardial ischemia. Rats in ischemia+NAC group were pre-treated with NAC (0.1 g/kg x d) for three weeks before the ischemia 8-iso-PGF2alpha levels in the plasma and myocardial tissue were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: In ischemia group, the 8-iso-PGF2alpha levels in the plasma and myocardial tissue were 187.4+/-45.8 pg/ml and 259.3+/-47.5 pg/g, respectively, higher than those in the control group (60.4+/-13.7 pg/ml and 88.6+/-16.9 pg/g, respectively, P<0.01) and those in ischemia+NAC group (88.2+/-16.4 pg/ml and 109.4+/-24.7 pg/g, respectively, P<0.01). A positive correlation was noted between the 8-iso-PGF2alpha levels in the plasma and myocardial tissue (r=0.865, P<0.01). In comparison with the control group, elevation of the ST segment of ECG in rats with myocardial ischemia was obvious, and the peak elevation occurred 45 min after ischemia (0.34+/-0.05 mV, P<0.01). Pre-treatment with NAC proved to help alleviate the subsequent ischemia, with ST segment elevation of only 0.18+/-0.05 mV. CONCLUSION: In condition of acute myocardial ischemia in rats, 8-iso-PGF2alpha levels tend to increase, which can be indicative of the degree of myocardial ischemia. NAC pre-treatment can alleviate the ischemic condition by offsetting the damage caused by the free radicals.

[Effects of deltamethrin on cell survival rate and intracellular free Ca2+ concentration in primary cultured astrocytes of rat].

OBJECTIVE: To study the effects of deltamethrin (DM) on cell survival rate and intracellular Ca(2+) ([Ca(2+)]i) concentration in primary cultured astrocytes of rat. METHODS: The cell survival rate was measured by Typan Blue assay; the intracellular [Ca(2+)]i concentration was determined by the fluorescent Ca(2+) indicator Fura-2/AM. RESULTS: The survival rate of astrocytes was decreased to 91.9% after astrocytes were incubated with 1 x 10(-5) mol/L DM for 72 h (P < 0.05). The cell survival rates were 89.0%, 84.8%, 81.2% and 79.2% respectively when astrocytes were administered with 1 x 10(-4) mol/L DM for 4, 12, 24 and 72 h, which were remarkably lower than control groups (P < 0.01). Comparing with controls and before DM treatment, sharp increases in [Ca(2+)]i concentration [(451.4 +/- 42.3), (536.9 +/- 47.5) and (870.9 +/- 100.5) nmol/L respectively] were observed when astrocytes were incubated with 1 x 10(-7), 1 x 10(-6) and 1 x 10(-5) mol/L DM for 5 minutes (P < 0.01). After astrocytes were treated with 1 x 10(-8), 1 x 10(-7), 1 x 10(-6), 1 x 10(-5) mol/L DM for 15 minutes, the [Ca(2+)]i concentrations were decreased to (124.3 +/- 6.0), (131.3 +/- 19.1), (118.9 +/- 1.4), (136.6 +/- 3.8) nmol/L respectively, which were significantly different from those of controls and before treatment. And this situation was almost keeping stable to 30 min. CONCLUSION: The cell survival rate was decreased and the [Ca(2+)]i concentration was temporarily increased when astrocytes were treated with DM.

Effects of hypoxic exercise training on microRNA expression and lipid metabolism in obese rat livers.

To investigate the effects of hypoxic exercise training on microRNA (miRNA) expression and the role of miRNA expression in regulating lipid metabolism, 20 dietary-induced obese SD rats were divided into a normoxic sedentary group (N, n=10) and a hypoxic exercise training group (H, n=10). After four weeks, measurements were taken of body weight, body length, fat mass, serum lipid concentration, miRNAs differentially expressed in rat liver, and gene and protein expression levels of peroxisome proliferator activated receptor α (PPARα), fatty acid synthetase (FAS), and carnitine palmitoyl transferase 1A (CPT1A) in rat liver. Body weight, Lee's index, fat mass, fat/weight ratio, and serum levels of total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were all significantly lower in the H group than in the N group (P<0.01). Six miRNAs expressed significantly differently in the liver (P<0.05). Specifically, expression levels of miR-378b were significantly lower in the H group than in the N group (P<0.05). Compared with the normoxic sedentary group, hypoxic exercise training resulted in a lower ratio of FAS mRNA to CPT1A mRNA (P<0.05), as well as lower CPT1A protein levels (P<0.01), while a higher ratio of FAS to CPT1A protein levels (P<0.01) was observed. In conclusion, hypoxic training may elevate the resistance of high fat diet induced obesity in rats by reducing the expression of miR-378b, and decrease the fatty acid mitochondrial oxidation in obese rat livers by decreasing the protein expression of CPT1A and increasing the protein expression ratio of FAS/CPT1A.

AMPK mediates a pro-survival autophagy downstream of PARP-1 activation in response to DNA alkylating agents.

In this study we aim to elucidate the signaling pathway and biological function of autophagy induced by MNNG, a commonly used DNA alkylating agent. We first observed that MNNG is able to induce necrotic cell death and autophagy in Bax-/- Bak-/- double knockout MEFs. We analyzed the critical role of PARP-1 activation and ATP depletion in MNNG-mediated cell death and autophagy via AMPK activation and mTOR suppression. We provide evidence that suppression of AMPK blocks MNNG-induced autophagy and enhances cell death, suggesting the pro-survival function of autophagy in MNNG-treated cells. Taken together, data from this study reveal a novel mechanism in controlling MNNG-mediated autophagy via AMPK activation downstream of PARP-1 activation and ATP depletion.