Deferoxamine Counteracts Cisplatin Resistance in A549 Lung Adenocarcinoma Cells by Increasing Vulnerability to Glutamine Deprivation-Induced Cell Death.

Glutamine, like glucose, is a major nutrient consumed by cancer cells, yet these cells undergo glutamine starvation in the cores of tumors, forcing them to evolve adaptive metabolic responses. Pharmacologically targeting glutamine metabolism or withdrawal has been exploited for therapeutic purposes, but does not always induce cancer cell death. The mechanism by which cancer cells adapt to resist glutamine starvation in cisplatin-resistant non-small-cell lung cancer (NSCLC) also remains uncertain. Here, we report the potential metabolic vulnerabilities of A549/DDP (drug-resistant human lung adenocarcinoma cell lines) cells, which were more easily killed by the iron chelator deferoxamine (DFO) during glutamine deprivation than their parental cisplatin-sensitive A549 cells. We demonstrate that phenotype resistance to cisplatin is accompanied by adaptive responses during glutamine deprivation partly via higher levels of autophagic activity and apoptosis resistance characteristics. Moreover, this adaptation could be explained by sustained glucose instead of glutamine-dominant complex II-dependent oxidative phosphorylation (OXPHOS). Further investigation revealed that cisplatin-resistant cells sustain OXPHOS partly via iron metabolism reprogramming during glutamine deprivation. This reprogramming might be responsible for mitochondrial iron-sulfur [Fe-S] cluster biogenesis, which has become an "Achilles' heel," rendering cancer cells vulnerable to DFO-induced autophagic cell death and apoptosis through c-Jun N-terminal kinase (JNK) signaling. Finally, in vivo studies using xenograft mouse models also confirmed the growth-slowing effect of DFO. In summary, we have elucidated the adaptive responses of cisplatin-resistant NSCLC cells, which balanced stability and plasticity to overcome metabolic reprogramming and permitted them to survive under stress induced by chemotherapy or glutamine starvation. In addition, for the first time, we show that suppressing the growth of cisplatin-resistant NSCLC cells via iron chelator-induced autophagic cell death and apoptosis was possible with DFO treatment. These findings provide a solid basis for targeting mitochondria iron metabolism in cisplatin-resistant NSCLC for therapeutic purposes, and it is plausible to consider that DFO facilitates in the improvement of treatment responses in cisplatin-resistant NSCLC patients.

[Electroacupuncture of "Zusanli" (ST 36) Raises Muscular Force by Adjusting AMPK/PGC-1 α Signaling in Rats with Chronic Fatigue Syndrome].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Zusanli" (ST 36) on mitochondrial oxidative stress of skeletal muscle in rats with chronic fatigue syndrome (CFS) based on adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/ peroxlsome proliferator-activated receptor-γ coactivator-1 α (PGC-1 α) signaling, in order to reveal its mechanism underlying improvement of CFS. METHODS: Forty SD rats were randomly divided into normal control, CFS model, EA-Zusanli (ST 36) and EA-non-acupoint groups (n=10 rats in each group). The CFS model was established by forced exhausted load-bearing swimming (twice daily), chronic constraint (1 h) and sleep deprivation (20 h/day) for 14 days. Following modeling, EA (2 Hz/100 Hz, 2 V) was applied to bilateral Zusanli (ST 36) or non-acupoint (about 10-15 mm superior to the bilateral Iliac creast and about 20 mm lateral to the posterior median line) for 20 min, once a day for 10 days. The expression levels of ATP synthase, AMPK, phosphorylated (p)-AMPK, silent mating type information regulation 2 homolog-1 (SIRT 1) and PGC-1 α proteins, and ATP synthase, SIRT 1 and PGC-1 α mRNAs of the quadriceps femoris muscle were detected by Western blot and fluorescence quantitative PCR, respectively. The rats' grabbing force was detected by using a grabbing-force detector. RESULTS: Compared with the normal group, the grabbing force, and the expression levels of ATP synthase and PGC-1 α proteins and mRNAs were significantly decreased (P<0.05, P<0.01), while the expression of SIRT 1 protein was significantly up-regulated (P<0.05) in the CFS model group. Following EA intervention, the grabbing force and the expression levels of ATP synthase mRNA, SIRT 1 and PGC-1 α proteins and mRNAs, and p-AMPK/AMPK were significantly up-regulated in the EA-Zusanli (ST 36) group (P<0.05, P<0.01). CONCLUSION: EA of ST 36 can raise the grabbing force of CFS rats, which may be related to its effects in up-regulating the expression of ATP synthase mRNA, SIRT 1 and PGC-1 α proteins and mRNAs, and p-AMPK/AMPK to reduce mitochondrial oxidative stress reaction and in increasing ATP synthesis.

Astragaloside IV, a Natural PPARγ Agonist, Reduces Aß Production in Alzheimer's Disease Through Inhibition of BACE1.

A number of epidemiological studies have established a link between Alzheimer's disease (AD) and diabetes mellitus (DM). So, nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) plays an important role in the treatment of AD. However, current PPARγ-targeting drugs such as thiazolidinediones (TZDs) are associated with undesirable side effects. We identified herbal extract with a small molecular, astragaloside IV (AS-IV), as a selective PPARγ natural agonist in nervous cells by developing a PPAR-PPRE pathway regulatory system. Cultured SH-SY5Y cells transfected with pEGFP-N1-BACE1 were treated with AS-IV for 24 h or AS-IV plus the PPAR-γ antagonist GW9662 in vitro. APP/PS1 mice were intragastrically treated with AS-IV or AS-IV plus the GW9662 every 48 h for 3 months. Immunofluorescence, western blotting, and real-time PCR were used to examine the expression of PPARγ and BACE1. Immunohistochemical staining was performed to analyze the distribution of Aß plaques in the APP/PS1 mouse brain. The levels of Aß were determined using ELISA kits. AS-IV was shown to be a PPARγ agonist by establishing a high-throughput screening model for PPARγ agonists. The results showed that AS-IV treatment increased activity of PPARγ and inhibited BACE1 in vitro. As a result, Aß levels decreased significantly. GW9662, which is a PPARγ antagonist, significantly blocked the beneficial role of AS-IV. In vivo, AS-IV treatment increased PPARγ and BACE1 expression and reduced neuritic plaque formation and Aß levels in the brains of APP/PS1 mice. These effects of AS-IV could be effectively inhibited by GW9662. These results indicate that AS-IV may be a natural PPARγ agonist that suppressed activity of BACE1 and ultimately attenuates generation of Aß. Therefore, AS-IV may be a promising agent for modulating Aß-related pathology in AD.

[Effect of astragaloside on mRNA expression of PI3K/Akt/mTOR signal transduction in anemia model mice induced by chemotherapy].

To study the influence of astragaloside on mRNA expression of PI3K/Akt/mTOR signal transduction in anemia model mice induced by chemotherapy, 48 male BALB/c mice which were 6-7 week old were picked as the research objects and randomly divided into four groups, blank group, model group, astragaloside group and astragaloside IV group. Each group was 12 mice. Chemotherapy anemia model was established by cyclophosphamide. The mice were drawn blood from eyeball after 14 days treatment. The QPCR was used to test the mRNA concentrations of Akt, PI3K, BCL-xl, bad, FoxO, mTOR, PTEN in mouse spleen. In comparison of blank group, astragaloside group and astragaloside IV group,the erythrocyte counting and values of Hb in model group were significantly lower (P<0.05). The volumes mRNA of Akt,PI3K,BCL-xl,bad,mTOR were lower in blank group, compared with other groups (P<0.05 or P<0.01). The similar trend in astragaloside IV group except PI3K, comparing with blank group (P<0.05 or P<0.01). The contents of these five genes were no significant differentiations between astragaloside group and blank group. The statistics were obvious between astragaloside group and astragaloside IV group (P<0.05 or P<0.01). The concentrations of FoxO, PTEN were higher in model group,compared with blank group and astragaloside group (P<0.05 or P<0.01), but no difference with astragaloside IV group. Comparing with blank group, the volumes of these two genes were increased in astragaloside IV group (P<0.05), FoxO was higher in astragaloside group (P<0.05), but PTEN was not significant. There was no the same as astragaloside group and Astragaloside IV group. Therefore, astragaloside could increase the contents of Akt, PI3K, BCL-xl, bad, mTOR (P<0.01), decrease the concentrations of FoxO, PTEN (P<0.05). The changes in cyclophosphamide-induced anemia were highly significant by astragaloside. It could be related to the mRNA expression of PI3K/Akt/mTOR Signal Transduction.

[Effect of Electroacupuncture at "Zusanli"(ST 36) on the Expression of Ghrelin/cAMP/PKA in the Jejunum in Rats with Spleen Qi Deficiency Syndrome].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Zusanli"(ST 36) on Ghrelin/cAMP/PKA expression in the jejunum in rats with spleen qi deficiency syndrome, so as to reveal its underlying mechanism in improving energy metabolism. METHODS: Forty male SD rats were randomly divided into 4 groups:normal group, spleen qi deficiency syndrome (model) group, EA group and non-acupoint group (n=10 in each group).The model of spleen qi deficiency syndrome was established by improper diet and overstrain. EA (2 Hz/15 Hz, 0.5 mA) was applied to bilateral "Zusanli" (ST 36) in the EA group and non-acupoint in non-acupoint group for 20 min, once a day for 6 days. The pathologic changes of the jejunum tissue were detected by H&E staining. Ghrelin, ATP and cAMP levels in jejunum tissue were determined by ELISA. The expression levels of PKA protein in jejunum tissue were determined by Western blot. RESULTS: H&E staining showed that the intestinal villi of the model group were swelling, shortening and thickening, with a damaged or broken top-part in the model group, and basically restored to normal after EA treatment. ELISA results showed that the contents of Ghrelin, ATP and cAMP in the jejunum tissue were significantly lower in the model group than in the normal group (P<0.05), while significantly higher in the EA group than in the model group (P<0.05). Western blot results showed that the expression of PKA protein in the jejunum tissue was significantly lower in the model group than in the normal group (P<0.05), and significantly higher in the EA group than in the model group and non-acupoint group (P<0.05). CONCLUSIONS: EA at ST 36 can improve the morphological changes in the jejunum of spleen qi deficiency rats, which may be associated with its effects in increasing Ghrelin, ATP and cAMP contents, and up-regulating PKA expression, leading to an increase of energy metabolism and spleen qi at last.

Advanced glycation end products induce oxidative stress and mitochondrial dysfunction in SH-SY5Y cells.

This study aimed to investigate the direct effects of advanced glycation end products (AGEs) on the mitochondrial structure and function of SH-SY5Y cells and the possible molecular mechanism(s) underlying mitochondria dysfunction by AGEs. SH-SY5Y cells were cultured in 400 µg/ml of AGE-bovine serum albumin (BSA) for 24 h, and changes in the mitochondrial function of SH-SY5Y cells were analysed as follows. Reactive oxygen species (ROS) were detected using 2',7'-dichlorodihydrofluorescein diacetate molecular probes. Mitochondrial membrane potential (ΔΨm) was determined by flow cytometry using fluorescent probes. The expression of cytochrome c (Cyt c) protein level was assessed by Western blotting. Mitochondrial structures were observed by transmission electron microscopy. Our results showed that AGE-BSA induced an increase in ROS levels, a decrease in mitochondrial ΔΨm, and the release of Cyt c from mitochondria in SH-SY5Y cells. The mitochondria of SH-SY5Y cells showed remarkable swelling and vacuolisation, but these changes were recovered after pretreatment with neutralising anti-receptor for advanced glycation end products (RAGE) antibody. Our results suggested that AGE-BSA induced mitochondrial dysfunction in SH-SY5Y cells through RAGE pathways. Thus, AGEs are potential mechanistic links between diabetes mellitus and Alzheimer's disease.

Fano resonance in anodic aluminum oxide based photonic crystals.

Anodic aluminum oxide based photonic crystals with periodic porous structure have been prepared using voltage compensation method. The as-prepared sample showed an ultra-narrow photonic bandgap. Asymmetric line-shape profiles of the photonic bandgaps have been observed, which is attributed to Fano resonance between the photonic bandgap state of photonic crystal and continuum scattering state of porous structure. And the exhibited Fano resonance shows more clearly when the sample is saturated ethanol gas than air-filled. Further theoretical analysis by transfer matrix method verified these results. These findings provide a better understanding on the nature of photonic bandgaps of photonic crystals made up of porous materials, in which the porous structures not only exist as layers of effective-refractive-index material providing Bragg scattering, but also provide a continuum light scattering state to interact with Bragg scattering state to show an asymmetric line-shape profile.