Causal Association Between mTOR-Dependent Protein Levels and Alzheimer's Disease: A Mendelian Randomization Study.

BACKGROUND: Most previous studies supported that the mammalian target of rapamycin (mTOR) is over-activated in Alzheimer's disease (AD) and exacerbates the development of AD. It is unclear whether the causal associations between the mTOR signaling-related protein and the risk for AD exist. OBJECTIVE: This study aims to investigate the causal effects of the mTOR signaling targets on AD. METHODS: We explored whether the risk of AD varied with genetically predicted AKT, RP-S6K, EIF4E-BP, eIF4E, eIF4A, and eIF4G circulating levels using a two-sample Mendelian randomization analysis. The summary data for targets of the mTOR signaling were acquired from published genome-wide association studies for the INTERVAL study. Genetic associations with AD were retrieved from the International Genomics of Alzheimer's Project. We utilized the inverse variance weighted as the primary approach to calculate the effect estimates. RESULTS: The elevated levels of AKT (OR = 0.910, 95% CI=0.840-0.986, p = 0.02) and RP-S6K (OR = 0.910, 95% CI=0.840-0.986, p = 0.02) may decrease the AD risk. In contrast, the elevated eIF4E levels (OR = 1.805, 95% CI=1.002-1.174, p = 0.045) may genetically increase the AD risk. No statistical significance was identified for levels of EIF4-BP, eIF4A, and eIF4G with AD risk (p > 0.05). CONCLUSION: There was a causal relationship between the mTOR signaling and the risk for AD. Activating AKT and RP-S6K, or inhibiting eIF4E may be potentially beneficial to the prevention and treatment of AD.

Delayed CO2 postconditioning promotes neurological recovery after cryogenic traumatic brain injury by downregulating IRF7 expression.

AIMS: Few treatments are available in the subacute phase of traumatic brain injury (TBI) except rehabilitation training. We previously reported that transient CO2 inhalation applied within minutes after reperfusion has neuroprotective effects against cerebral ischemia/reperfusion injury. In this study, it was hypothesized that delayed CO2 postconditioning (DCPC) starting at the subacute phase may promote neurological recovery of TBI. METHODS: Using a cryogenic TBI (cTBI) model, mice received DCPC daily by inhaling 5%/10%/20% CO2 for various time-courses (one/two/three cycles of 10-min inhalation/10-min break) at Days 3-7, 3-14 or 7-18 after cTBI. Beam walking and gait tests were used to assess the effect of DCPC. Lesion size, expression of GAP-43 and synaptophysin, amoeboid microglia number and glia scar area were detected. Transcriptome and recombinant interferon regulatory factor 7 (Irf7) adeno-associated virus were applied to investigate the molecular mechanisms. RESULTS: DCPC significantly promoted recovery of motor function in a concentration and time-course dependent manner with a wide therapeutic time window of at least 7 days after cTBI. The beneficial effects of DCPC were blocked by intracerebroventricular injection of NaHCO3 . DCPC also increased puncta density of GAP-43 and synaptophysin, and reduced amoeboid microglia number and glial scar formation in the cortex surrounding the lesion. Transcriptome analysis showed many inflammation-related genes and pathways were altered by DCPC, and Irf7 was a hub gene, while overexpression of IRF7 blocked the motor function improvement of DCPC. CONCLUSIONS: We first showed that DCPC promoted functional recovery and brain tissue repair, which opens a new therapeutic time window of postconditioning for TBI. Inhibition of IRF7 is a key molecular mechanism for the beneficial effects of DCPC, and IRF7 may be a potential therapeutic target for rehabilitation after TBI.

A GLP-1/GIP Dual Receptor Agonist DA4-JC Effectively Attenuates Cognitive Impairment and Pathology in the APP/PS1/Tau Model of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is a degenerative disorder, accompanied by progressive cognitive decline, for which there is no cure. Recently, the close correlation between AD and type 2 diabetes mellitus (T2DM) has been noted, and a promising anti-AD strategy is the use of anti-T2DM drugs. OBJECTIVE: To investigate if the novel glucagon-like peptide-1 (GLP-1)/glucose-dependent insulinotropic polypeptide (GIP) receptor agonist DA4-JC shows protective effects in the triple APP/PS1/tau mouse model of AD. METHODS: A battery of behavioral tests were followed by in vivo recording of long-term potentiation (LTP) in the hippocampus, quantified synapses using the Golgi method, and biochemical analysis of biomarkers. RESULTS: DA4-JC improved cognitive impairment in a range of tests and relieved pathological features of APP/PS1/tau mice, enhanced LTP in the hippocampus, increased numbers of synapses and dendritic spines, upregulating levels of post-synaptic density protein 95 (PSD95) and synaptophysin (SYP), normalized volume and numbers of mitochondria and improving the phosphatase and tensin homologue induced putative kinase 1 (PINK1) - Parkin mitophagy signaling pathway, while downregulating amyloid, p-tau, and autophagy marker P62 levels. CONCLUSION: DA4-JC is a promising drug for the treatment of AD.

DAla2-GIP-GLU-PAL Protects Against Cognitive Deficits and Pathology in APP/PS1 Mice by Inhibiting Neuroinflammation and Upregulating cAMP/PKA/CREB Signaling Pathways.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive decline in cognitive function. Type 2 diabetes mellitus (T2DM) is an important risk factor for AD. Glucose-dependent insulinotropic polypeptide (GIP) has been identified to be effective in T2DM treatment and neuroprotection. OBJECTIVE: The present study investigated the neuroprotective effects and possible mechanisms of DAla2GIP-Glu-PAL, a novel long-lasting GIP analogue, in APP/PS1 AD mice. METHODS: Multiple behavioral tests were performed to examine the cognitive function of mice. In vivo hippocampus late-phase long-term potentiation (L-LTP) was recorded to reflect synaptic plasticity. Immunohistochemistry and immunofluorescence were used to examine the Aß plaques and neuroinflammation in the brain. IL-1ß, TNF-α, and cAMP/PKA/CREB signal molecules were also detected by ELISA or western blotting. RESULTS: DAla2GIP-Glu-PAL increased recognition index (RI) of APP/PS1 mice in novel object recognition test, elevated spontaneous alternation percentage of APP/PS1 mice in Y maze test, and increased target quadrant swimming time of APP/PS1 mice in Morris water maze test. DAla2GIP-Glu-PAL treatment enhanced in vivo L-LTP of APP/PS1 mice. DAla2GIP-Glu-PAL significantly reduced Aß deposition, inhibited astrocyte and microglia proliferation, and weakened IL-1ß and TNF-α secretion. DAla2GIP-Glu-PAL also upregulated cAMP/PKA/CREB signal transduction and inhibited NF-κB activation in the hippocampus of APP/PS1 mice. CONCLUSION: DAla2GIP-Glu-PAL can improve cognitive behavior, synaptic plasticity, and central pathological damage in APP/PS1 mice, which might be associated with the inhibition of neuroinflammation, as well as upregulation of cAMP-/PKA/CREB signaling pathway. This study suggests a potential benefit of DAla2GIP-Glu-PAL in the treatment of AD.

Delayed metformin treatment improves functional recovery following traumatic brain injury via central AMPK-dependent brain tissue repair.

Accumulating evidence suggests that chronic metformin posttreatment offers potent neuroreparative effects against acute brain injury. However, in previous studies, metformin was not initially administered beyond 24 h postinjury, and the effects of delayed metformin treatment in traumatic brain injury (TBI) and other types of acute brain injury and the related mechanisms are unclear. To test this, male C57BL/6 mice received once daily metformin treatment (20, 50 or 100 mg/kg/d, i.p.) at day 1-14, day 1-2, day 1-10, day 3-10, day 5-12 or day 5-28 after cryogenic TBI (cTBI). The results showed that 100 mg/kg/d metformin administered at day 1-14 postinjury significantly promoted motor functional recovery in the beam walking and gait tests and reduced the infarct volume. Metformin (100 mg/kg/d) administered at day 1-10 or day 3-10 but not day 1-2 or day 5-12 after cTBI significantly improved motor functional outcomes at day 7 and 14, and reduced the infarct volume at day 14. Interestingly, the therapeutic time window was further expanded when the duration of metformin treatment starting at day 5 postinjury was extended to 2 weeks. Furthermore, compared with cTBI, the administration of metformin at day 3-10 or day 5-28 after cTBI significantly elevated the expression of phosphorylated adenosine monophosphate-activated protein kinase (AMPK) and growth associated protein 43 (an axonal regeneration marker) and the number of vascular branch points and decreased the area of glial scar and the number of amoeboid microglia in the peri-infarct area at day 14 or 28 postinjury. The above beneficial effects of metformin were blocked by the intracerebroventricular injection of the AMPK inhibitor compound C (40 µg/mouse/d). Our data provide the first evidence that metformin has a wide therapeutic time window for at least 5 days after cTBI, during which it can improve functional recovery by promoting tissue repair and inhibiting glial scar formation and microglial activation in a central AMPK-dependent manner.

Sex Differences in Neuropathology and Cognitive Behavior in APP/PS1/tau Triple-Transgenic Mouse Model of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common form of dementia among the elderly, characterized by amyloid plaques, neurofibrillary tangles, and neuroinflammation in the brain, as well as impaired cognitive behaviors. A sex difference in the prevalence of AD has been noted, while sex differences in the cerebral pathology and relevant molecular mechanisms are not well clarified. In the present study, we systematically investigated the sex differences in pathological characteristics and cognitive behavior in 12-month-old male and female APP/PS1/tau triple-transgenic AD mice (3×Tg-AD mice) and examined the molecular mechanisms. We found that female 3×Tg-AD mice displayed more prominent amyloid plaques, neurofibrillary tangles, neuroinflammation, and spatial cognitive deficits than male 3×Tg-AD mice. Furthermore, the expression levels of hippocampal protein kinase A-cAMP response element-binding protein (PKA-CREB) and p38-mitogen-activated protein kinases (MAPK) also showed sex difference in the AD mice, with a significant increase in the levels of p-PKA/p-CREB and a decrease in the p-p38 in female, but not male, 3×Tg-AD mice. We suggest that an estrogen deficiency-induced PKA-CREB-MAPK signaling disorder in 12-month-old female 3×Tg-AD mice might be involved in the serious pathological and cognitive damage in these mice. Therefore, sex differences should be taken into account in investigating AD biomarkers and related target molecules, and estrogen supplementation or PKA-CREB-MAPK stabilization could be beneficial in relieving the pathological damage in AD and improving the cognitive behavior of reproductively-senescent females.

DA5-CH, a novel GLP-1/GIP dual agonist, effectively ameliorates the cognitive impairments and pathology in the APP/PS1 mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder for which there is no cure. The early primary symptom of AD is the decline of memory ability, which gradually develops into complete dementia. Type 2 diabetes mellitus (T2DM) is an important risk factor of AD; and mimetics of the incretin hormone GLP-1 developed to treat diabetes are being tested as a novel therapeutic strategy for AD. In the present study, we reported for the first time the neuroprotective effects of a novel GLP-1/GIP dual agonist DA5-CH that activates the incretin hormone GLP-1 and GIP receptors in the APP/PS1 transgenic AD mouse model. We found that: (1) DA5-CH administration effectively improved working-memory and long-term spatial memory of 9-month-old AD mice in Y-maze and Morris water maze tests; (2) DA5-CH also reduced hippocampal amyloid senile plaques and phosphorylated tau protein levels; (3) DA5-CH basically reversed the deficits in hippocampal late-phase long-term potentiation; (4) DA5-CH up-regulated the levels of p-PI3K and p-AKT growth factor kinases and prevented excessive activation of p-GSK3ß in the hippocampus of APP/PS1 mice. Therefore, the neuroprotection of DA5-CH in alleviating cognitive impairments and pathological damages might be associated with the improvement of hippocampal synaptic plasticity and activation of the PI3K/AKT signaling pathway. We propose that DA5-CH may be beneficial for the treatment of AD patients, especially those with T2DM or hyperglycemia.

A novel GLP-1/GIP/Gcg triagonist reduces cognitive deficits and pathology in the 3xTg mouse model of Alzheimer's disease.

Type 2 diabetes mellitus (T2DM) is an important risk factor for Alzheimer's disease (AD). Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) have been identified to be effective in T2DM treatment and neuroprotection. In this study, we further explored the effects of a novel unimolecular GLP-1/GIP/Gcg triagonist on the cognitive behavior and cerebral pathology in the 7-month-old triple transgenic mouse model of AD (3xTg-AD), and investigated its possible electrophysiological and molecular mechanisms. After chronic administration of the GLP-1/GIP/Gcg triagonist (10 nmol/kg bodyweight, once daily, i.p.) for 30 days, open field, Y maze and Morris water maze tests were performed, followed by in vivo electrophysiological recording, immunofluorescence and Western blotting experiments. We found that the chronic treatment with the triagonist could improve long-term spatial memory of 3xTg-AD mice in Morris water maze, as well as the working memory in Y maze task. The triagonist also alleviated the suppression of long-term potentiation (LTP) in the CA1 region of hippocampus. In addition, the triagonist significantly reduced hippocampal pathological damages, including amyloid-ß (Aß) and phosphorylated tau aggregates, and upregulated the expression levels of S133 p-CREB, T286 p-CAMKII and S9 p-GSK3ß in the hippocampus of the 3xTg-AD mice. These results demonstrate for the first time that the novel GLP-1/GIP/Gcg triagonist is efficacious in ameliorating cognitive deficits and pathological damages of 3xTg-AD mice, suggesting that the triagonist might be potentially beneficial in the treatment of AD.

Lixisenatide reduces amyloid plaques, neurofibrillary tangles and neuroinflammation in an APP/PS1/tau mouse model of Alzheimer's disease.

Type 2 diabetes mellitus (T2DM) has been identified as a high risk factor for Alzheimer's disease (AD). The impairment of insulin signaling has been found in AD brain. Glucagon-like peptide-1 (GLP-1) is an incretin hormone, normalises insulin signaling and acts as a neuroprotective growth factor. We have previously shown that the long-lasting GLP-1 receptor (GLP-1R) agonist lixisenatide plays an important role in memory formation, synaptic plasticity and cell proliferation of rats. In the follow-up study, we analysed the neuroprotective effect and mechanism of lixisenatide, injected for 60 days at 10 nmol/kg i.p. once daily in APP/PS1/tau female mice and C57BL/6J female mice (as control) aged 12 month. The results showed that lixisenatide could reduce amyloid plaques, neurofibrillary tangles and neuroinflammation in the hippocampi of 12-month-old APP/PS1/tau female mice; activation of PKA-CREB signaling pathway and inhibition of p38-MAPK might be the important mechanisms in the neuroprotective function of lixisenatide. The study demonstrated that GLP-1R agonists such as lixisenatide might have the potential to be developed as a novel therapy for AD.

[GLP-1/GIP/Gcg receptor Triagonist improves the cognitive behaviors in triple-transgenic mice of Alzheimer's disease].

Alzheimer's disease (AD) is a progressively neurodegenerative disorder, which seriously affects human health but is still irreversible up to now. Recent studies indicate that type 2 diabetes mellitus (T2DM) is an important risk factor for AD, and the drugs used for treatment of T2DM have shown some neuroprotective effects in the treatment of AD. Glucagon-like peptide-1 (GLP-1)/ glucose-dependent insulinotropic polypeptide (GIP)/glucagon (Gcg) receptor Triagonist is a new monomeric polypeptide equally activating the GLP-1/GIP/Gcg receptors, which is built on the basis of GLP-1/Gcg receptor coagonist core sequence, and incorporated with partial amino acids of GIP. Recently, the Triagonist has been reported to be effective in alleviating diabetic complications in rodent models of obesity. The present study observed for the first time the cognitive improvement effects of the Triagonist in the triple-transgenic AD mice (3xTg-AD) by using multiple behavioral techniques, and explored its probable molecular mechanisms using ELISA and Western blot. The results showed that the chronic treatment with the Triagonist (i.p.) significantly reversed the impairments in working memory of 3xTg-AD mice, with an obvious increase in the percentage of correct spontaneous alternation in the Y maze; the Triagonist treatment also improved long-term spatial memory and re-learning ability of 3xTg-AD mice in classical Morris water maze and reverse water maze tests, with decreased escape latency in under water platform tests and increased swimming time in probe tests. ELISA and Western blot experiments showed that the Triagonist up-regulated the levels of cAMP, PKA and p-CREB in the hippocampus of 3xTg-AD mice. These results indicate that GLP-1/GIP/Gcg receptor Triagonist can improve the cognitive behaviors in 3xTg-AD mice, and the up-regulation of hippocampal cAMP/PKA/CREB signal pathway may mediate the neuroprotection of the Triagonist, suggesting that the GLP-1/GIP/Gcg receptor Triagonist may be a novel therapeutic strategy for the treatment of AD.

Davunetide improves spatial learning and memory in Alzheimer's disease-associated rats.

Memory loss and cognition decline are the main clinical manifestations of Alzheimer's disease (AD). Amyloid ß protein (Aß) aggregated in the brain is one of the key pathological characteristics of AD and responsible for the deficits in learning and memory. It is reported that davunetide, an octapeptide derived from activity-dependent neuroprotective protein (ADNP), inhibited Aß aggregation and Aß-induced neurotoxicity. To further characterize the neuroprotective roles of davunetide and its possible mechanism, the present study investigated the effects of davunetide on Aß1-42-induced impairments in spatial memory, synaptic plasticity and hippocampal AKT level. In Morris water maze (MWM) test, bilateral intrahippocampal injection of Aß1-42 significantly increased escape latency and decreased target quadrant swimming time of rats, while three weeks of intranasal application of davunetide reversed the Aß1-42-induced learning deficits and memory loss in a dose-dependent manner. In vivo field potentiation recording showed that Aß1-42 suppressed long-term potentiation (LTP) of excitatory postsynaptic potential (fEPSP) in the hippocampal CA1 region of rats, while davunetide effectively blocked the suppression of LTP, without affecting paired-pulse facilitation (PPF). Western blotting experiments showed a significant decrease in the level of hippocampal p-AKT (Ser473), not total AKT, in Aß1-42 only group, which was mostly antagonized by davunetide treatment. These findings demonstrate that davunetide, probably by enhancing PI3K/AKT pathway, plays an important positive role in attenuating Aß1-42-induced impairments in spatial memory and synaptic plasticity, suggesting that davunetide could be an effective therapeutic candidate for the prevention and treatment of neurodegenerative disease such as AD.

Lixisenatide attenuates the detrimental effects of amyloid ß protein on spatial working memory and hippocampal neurons in rats.

Type 2 diabetes mellitus(T2DM) is a risk factor of Alzheimer's disease (AD), which is most likely linked to impairments of insulin signaling in the brain. Hence, drugs enhancing insulin signaling may have therapeutic potential for AD. Lixisenatide, a novel long-lasting glucagon-like peptide 1 (GLP-1) analogue, facilitates insulin signaling and has neuroprotective properties. We previously reported the protective effects of lixisenatide on memory formation and synaptic plasticity. Here, we describe additional key neuroprotective properties of lixisenatide and its possible molecular and cellular mechanisms against AD-related impairments in rats. The results show that lixisenatide effectively alleviated amyloid ß protein (Aß) 25-35-induced working memory impairment, reversed Aß25-35-triggered cytotoxicity on hippocampal cell cultures, and prevented against Aß25-35-induced suppression of the Akt-MEK1/2 signaling pathway. Lixisenatide also reduced the Aß25-35 acute application induced intracellular calcium overload, which was abolished by U0126, a specific MEK1/2 inhibitor. These results further confirmed the neuroprotective and cytoprotective action of lixisenatide against Aß-induced impairments, suggesting that the protective effects of lixisenatide may involve the activation of the Akt-MEK1/2 signaling pathway and the regulation of intracellular calcium homeostasis.

Colivelin ameliorates amyloid ß peptide-induced impairments in spatial memory, synaptic plasticity, and calcium homeostasis in rats.

Amyloid ß peptide (Aß) has been thought to be neurotoxic and responsible for the impairment of learning and memory in Alzheimer's disease (AD). Humanin (HN), a 24 amino acid polypeptide first identified from the unaffected occipital lobe of an AD patient, is believed to be neuroprotective against the AD-related neurotoxicity. In this study, we investigated the neuroprotective effects of Colivelin (CLN), a novel HN derivative, against Aß by using behavioral test, in vivo electrophysiological recording, and intracellular calcium imaging. Our results showed that intrahippocampal injection of CLN (0.2 nmol) effectively prevented Aß25-35 (4 nmol)-induced deficits in spatial learning and memory of rats in Morris water maze test; the suppression of in vivo hippocampal long term potentiation (LTP) by Aß25-35 was nearly completely prevented by CLN; in addition, CLN pretreatment also effectively inhibited Aß25-35-induced calcium overload in primary cultured hippocampal neurons. These results indicate that CLN has significant neuroprotective properties against Aß, and CLN may holds great promise for the treatment and prevention of AD.

Rechallenge with pemetrexed-based chemotherapy improves the survival of patients with advanced non-squamous non-small-cell lung cancer.

Rechallenge chemotherapy with pemetrexed was shown to be efficient in malignant pleural mesothelioma; however, its role in non-small-cell lung cancer (NSCLC) has not been investigated. In this study, we retrospectively enrolled 31 patients with non-squamous NSCLC who had achieved disease control with initial pemetrexed treatment, followed by rechallenge with pemetrexed-based chemotherapy (PBC) upon disease progression. After the rechallenge, 5 patients (16.1%) achieved partial remission (PR), 17 (54.8%) achieved stable disease (SD) and 9 (29.1%) experienced progressive disease. The treatment was generally well tolerated, with a low rate of toxicity. The median progression-free survival (PFS) was 3.8 months with the rechallenge. Patients with a PFS of ≥10 months with initial PBC exhibited longer PFS and overall survival (OS) with the rechallenge compared to those with a PFS of <10 months with initial PBC (PFS: 6.2±0.33 vs. 3.1±0.26 months, respectively; P=0.011; and OS, 19.8±3.2 vs. 9.2±1.1 months, respectively; P=0.005). The time from the termination of initial PBC to disease progression was also associated with survival after the rechallenge. However, the response to initial PBC (PR vs. SD) did not affect PFS after the rechallenge. No significant differences were observed in thymidylate synthase expression, echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase gene fusion, or epithelial growth factor receptor mutation status between pemetrexed-sensitive and pemetrexed-resistant patients. Our results demonstrated that rechallenge with PBC was well tolerated and survival after the rechallenge was associated with survival during initial PBC. Therefore, patients with a PFS of ≥10 months or time-to-disease progression ≥3 months may be considered as candidates for pemetrexed rechallenge.

[Prognosis related clinical and molecular factors in malignant pleural mesothelioma].

OBJECTIVE: To identify potential prognosis related clinical and molecular factors in malignant pleural mesothelioma (MPM). METHODS: Seventy-nine patients with MPM treated in Beijing Cancer Hospital from June 1996 to May 2012 were enrolled in this study. Clinical and pathological data were collected, including age, gender, smoking status, treatment, response, and molecular biomarkers such as thymidylate synthetase (TS) expression, echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) gene rearrangement. The primary endpoint was overall survival (OS). SPSS 16.0 statistical analysis software was used for univariate analysis. The expression of TS was detected by immunohistochemistry (IHC). Fluorescence in situ hybridization (FISH) was performed to detect EML4-ALK gene rearrangement. Efficacy of the chemotherapy regimen including pemetrexed was analyzed with these molecular biomarkers. RESULTS: The median survival time (MST) of all patients was 15.5 months (95% CI: 10.6 - 20.4). Univariate survival analysis revealed that treatment factors including receiving operation, systemic chemotherapy, pemetrexed-based chemotherapy and capability of receiving second (or above) line chemotherapy were significantly related with OS. The MST of patients receiving operation was 5.4 months (95% CI: 3.6 - 7.3), significantly shorter than the 17.7months (95% CI: 11.8 - 23.5) in those who didn't receive operation (P = 0.030). Patients receiving systemic chemotherapy had a longer MST of 18.0 months (95% CI: 12.3 - 23.8) as compared to the 7.9 months (95% CI: 1.1 - 14.7) in those who didn't (P = 0.001). The MST of pemetrexed-based chemotherapy was 21.9 months (95% CI: 14.1-29.7) compared with 8.8 months (95% CI: 4.2 - 13.4) of regimens without pemetrexed (P = 0.000). For patients capable of receiving second (or above) line chemotherapy the MST was longer (21.0 months, 95% CI: 12.7 - 29.3) than those who could not (12.1 month, 95% CI: 6.4 - 17.8 month), P = 0.022. For the 42 patients treated with pemetrexed-based chemotherapy, the objective response rate (ORR) was 33.3% (14/42), the disease control rate (DCR) was 78.6% (33/42), the median progression-free survival (PFS) was 4.8 months (95% CI: 3.6 - 6.0) and MST was 21.9 months (95% CI: 14.1 - 29.7). Twenty-nine patients provided adequate specimens for detection of TS expression and 6 cases (20.7%) were positive. EML4-ALK gene rearrangement was studied in 32 patients and 6 (18.8%) were positive. TS expression was found to be inversely related to PFS of pemetrexed-based chemotherapy (P = 0.041). The MST was 19.6 months (95% CI: 6.0 - 7.9) in EML4-ALK-positive patients and 9.57 months (95% CI: 2.7 - 4.3) in negative ones (P = 0.159). CONCLUSIONS: Systemic chemotherapy especially pemetrexed-based regimen was proved to be a superior option for MPM with a significantly prolonged OS. Correlation between TS expression or EML4-ALK rearrangement and outcome of pemetrexed-based chemotherapy for MPM may contribute to future individualized treatment, which needs further validation from large-scale prospective studies.

Liraglutide protects against amyloid-ß protein-induced impairment of spatial learning and memory in rats.

Type 2 diabetes mellitus is a risk factor of Alzheimer's disease (AD), most likely linked to an impairment of insulin signaling in the brain. Liraglutide, a novel long-lasting glucagon-like peptide 1 (GLP-1) analog, facilitates insulin signaling and shows neuroprotective properties. In the present study, we analyzed the effects of liraglutide on the impairment of learning and memory formation induced by amyloid-ß protein (Aß), and the probable underlying electrophysiological and molecular mechanisms. We found that (1) bilateral intrahippocampal injection of Aß(25-35) resulted in a significant decline of spatial learning and memory of rats in water maze tests, together with a serious depression of in vivo hippocampal late-phase long-term potentiation (L-LTP) in CA1 region of rats; (2) pretreatment with liraglutide effectively and dose-dependently protected against the Aß(25-35)-induced impairment of spatial memory and deficit of L-LTP; (3) liraglutide injection also activated cAMP signal pathway in the brain, with a nearly doubled increase in the cAMP contents compared with control. These results strongly suggest that upregulation of GLP-1 signaling in the brain, such as application of liraglutide, may be a novel and promising strategy to ameliorate the learning and memory impairment seen in AD.

Amyloid ß-protein suppressed nicotinic acetylcholine receptor-mediated currents in acutely isolated rat hippocampal CA1 pyramidal neurons.

Amyloid ß protein (Aß) is responsible for the deficits of learning and memory in Alzheimer's disease (AD). The high affinity between Aß and nicotinic acetylcholine receptors (nAChRs) suggests that the impairment of cognitive function in AD might be involved in the Aß-induced damage of nAChRs. This study investigated the effects of Aß fragments on nAChR-mediated membrane currents in acutely isolated rat hippocampal pyramidal neurons by using whole-cell patch clamp technique. The results showed that: (1) nonspecific nAChR agonist nicotine, selective α7 nAChR agonist choline, and α4ß2 nAChR agonist epibatidine all effectively evoked inward currents in CA1 neurons at normal resting membrane potential, with different desensitization characteristics; (2) acute application of different concentrations (pM-µM) of Aß25-35, Aß31-35, or Aß35-31 alone did not trigger any membrane current, but pretreatment with 1 µM Aß25-35 and Aß31-35 similarly and reversibly suppressed the nicotine-induced currents; (3) further, choline- and epibatidine-induced currents were also reversibly suppressed by the Aß pretreatment, but more prominent for the choline-induced response. These results demonstrate that the functional activity of both α7 and α4ß2 nAChRs in the membrane of acutely isolated hippocampal neurons was significantly downregulated by Aß treatment, suggesting that nAChRs, especially α7 nAChRs, in the brain may be the important biological targets of neurotoxic Aß in AD. In addition, the similar suppression of nAChR currents by Aß25-35 and Aß31-35 suggests that the sequence 31-35 in Aß molecule may be a shorter active center responsible for the neurotoxicity of Aß in AD.

[[Gly14]-humanin protects against Aß31₋35-induced impairment of spatial learning and memory in rats].

Amyloid ß protein (Aß) is closely involved in the pathogenesis of Alzheimer's disease (AD), and one of the main strategies for AD treatment is antagonizing the neurotoxicity of Aß or even clearing the Aß deposited in the brain. The present study was aimed to observe the effects of intrahippocampal injection of Aß31₋35 on the spatial learning and memory of rats by using Morris water maze technique, and explore the neuroprotective effects and possible mechanism of [Gly14]-humanin (HNG) against Aß-induced deficits in learning behavior. The results showed that bilateral intrahippocampal injection of 2.0 nmol Aß31₋35 significantly increased the mean traveled distance of rats in searching for the hidden underwater platform and decreased the distance percentage in the target quadrant in probe test after withdrawal of platform, whereas pretreatment with HNG (0.2 nmol and 2.0 nmol) suppressed Aß31₋35-induced increase in the traveled distance and decrease in swimming distance percentage. Application of Genistein (40 nmol), a specific tyrosine kinase inhibitor, almost completely blocked the antagonistic effects of HNG against Aß31₋35. These results indicate that HNG can dose-dependently prevent against Aß31₋35-induced impairment in spatial learning and memory of rats, and the neuroprotective effects of HNG might involve the activation of endogenous tyrosine kinase pathway, suggesting that up-regulation of the tyrosine kinase signaling by using HNG might be of great significance for the improvement of cognitive function in AD.

[Correlation between the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors and EGFR mutations in advanced squamous cell lung cancer].

OBJECTIVE: To investigate the frequency of epidermal growth factor receptor (EGFR) mutations and their correlation with the efficacy of tyrosine kinase inhibitors (EGFR-TKI) in advanced squamous cell lung cancer. METHODS: This retrospective study enrolled 79 patients with advanced squamous cell lung cancer who received EGFR-TKI at Department of Thoracic Medical Oncology in Peking University Cancer Hospital from June 2004 to June 2011. Among them, 67 patients had tissue and/or plasma EGFR exon 19 and 21 mutation detection in order to make an analysis on the relationship between EGFR mutation and the TKI's effect. RESULTS: The disease control rate (DCR) was 56% in all the patients. The median progression free survival (mPFS) and median overall survival (mOS) was 3.7 months (95%CI: 2.0 - 5.0) and 11.5 months (95%CI: 6.6 - 14.2), respectively. Of the 67 patients who received EGFR mutation detection, there were 31 patients harboring EGFR-mutation, for whom the DCR was 71% (22/31), and mPFS and mOS was 6.3 months (95%CI: 2.2 - 10.0) and 13.5 months (95%CI: 7.3 - 18.6) respectively. 36 patients' EGFR status were wild type, for whom the DCR was 44% (16/36), mPFS and mOS was 2.2 months (95%CI: 1.1 - 4.0) and 6.4 months (95%CI: 4.0 - 12.0). There were 17 patients who received erlotinib and 7 patients who received gefitinib as second or more line treatment. mPFS and mOS were 7.9 months and 15.8 months in the erlotinib group, respectively; and the mPFS and mOS were both 6.3 months in gefitinib group; the difference between the 2 groups did not reach statistical significance. Cox-regression analysis showed that EGFR mutation was significantly correlated with PFS and OS (P < 0.05, respectively). EGFR mutation was significantly correlated with DCR by Chi-square test, P < 0.05. CONCLUSIONS: EGFR mutation was a predictor for advanced squamous cell lung cancer to EGFR-TKI. However, the effect was inferior in advanced squamous cell lung cancer as compared to lung adenocarcinoma. Erlotinib tended to be superior to gefitinib.

[Effect of pemetrexed plus platinum for chemotherapy-naive advanced non-small cell lung cancer].

OBJECTIVE: To evaluate the effect of pemetrexed plus platinum for chemotherapy-naive advanced non-small cell lung cancer (NSCLC), and to explore thymidylate synthetase (TS) expression as the predictive and prognostic factor for this treatment. METHODS: This retrospective study enrolled 51 patients with chemotherapy-naive advanced NSCLC (non-squamous) treated at Department of Thoracic Medical Oncology in Beijing Cancer Hospital from Jan 2008 to Oct 2009. All patients received pemetrexed plus platinum as first-line treatment. TS expression was detected in 30 patients who had enough tissue samples by immunohistochemistry. RESULTS: The objective response rate (ORR) was 37.3%. Median progression-free survival (PFS) was 5.3 months (95%CI: 3.9 - 6.7), and median overall survival (OS) was 19.0 months (95%CI: 11.6 - 26.4). Univariate analysis showed that gender, pathology, smoking status and response were significantly correlated with OS. Cox-regression analysis showed that pathology was an independent prognostic factor. Rate of Grade 3/4 adverse events was low. In 30 patients with enough tissue samples were available, TS expression positive rate was 33.3% (10/30). Chi-square test showed that TS expression was not associated with ORR. Multivariate analysis showed that pathology, response and TS expression (P = 0.003, 0.005 and 0.001, respectively) were the prognostic factors. CONCLUSION: The therapeutic effect and tolerance of pemetrexed plus platinum regiment were definite as first-line treatment for chemotherapy-naive advanced NSCLC, and TS expression was an independent prognostic factor.