Long-term running exercise alleviates cognitive dysfunction in APP/PSEN1 transgenic mice via enhancing brain lysosomal function.

Amyloid-ß peptide (Aß) aggregation is the hallmark of Alzheimer's disease (AD). The imbalance between the production and clearance of Aß results in the accumulation and aggregation of Aß in the brain. Thus far, few drugs are available for AD treatment, but exercise has been recognized for its cognition-enhancing properties in AD patients. The underlying mechanisms remain unclear. Our recent study showed that long-term running exercise could activate the lysosomal function in the brains of mice. In this study, we investigated whether exercise could reduce Aß accumulation by activating lysosomal function in APP/PSEN1 transgenic mice. Started at the age of 5 months, the mice were trained with a running wheel at the speed of 18 r/min, 40 min/d, 6 d/week for 5 months, and were killed at the end of the 10th month, then brain tissue was collected for biochemical analyses. The cognitive ability was assessed in the 9th month. We showed that long-term exercise significantly mitigated cognitive dysfunction in AD mice, accompanied by the enhanced lysosomal function and the clearance of Aß in the brain. Exercise significantly promoted the nuclear translocation of transcription factor EB (TFEB), and increased the interaction between nuclear TFEB with AMPK-mediated acetyl-CoA synthetase 2, thus enhancing transcription of the genes associated with the biogenesis of lysosomes. Exercise also raised the levels of mature cathepsin D and cathepsin L, suggesting that more Aß peptides could be degraded in the activated lysosomes. This study demonstrates that exercise may improve the cognitive dysfunction of AD by enhancing lysosomal function.

NADPH is superior to NADH or edaravone in ameliorating metabolic disturbance and brain injury in ischemic stroke.

Our previous studies confirm that exogenous reduced nicotinamide adenine dinucleotide phosphate (NADPH) exerts a neuroprotective effect in animal models of ischemic stroke, and its primary mechanism is related to anti-oxidative stress and improved energy metabolism. However, it is unknown whether nicotinamide adenine dinucleotide (NADH) also plays a neuroprotective role and whether NADPH is superior to NADH against ischemic stroke? In this study we compared the efficacy of NADH, NADPH, and edaravone in ameliorating brain injury and metabolic stress in ischemic stroke. Transient middle cerebral artery occlusion/reperfusion (t-MCAO/R) mouse model and in vitro oxygen glucose deprivation/reoxygenation (OGD/R) model were established. The mice were intravenously administered the optimal dose of NADPH (7.5 mg/kg), NADH (22.5 mg/kg), or edaravone (3 mg/kg) immediately after reperfusion. We showed that the overall efficacy of NADPH in ameliorating ischemic injury was superior to NADH and edaravone. NADPH had a longer therapeutic time window (within 5 h) after reperfusion than NADH and edaravone (within 2 h) for ischemic stroke. In addition, NADPH and edaravone were better in alleviating the brain atrophy, while NADH and NADPH were better in increasing the long-term survival rate. NADPH showed stronger antioxidant effects than NADH and edaravone; but NADH was the best in terms of maintaining energy metabolism. Taken together, this study demonstrates that NADPH exerts better neuroprotective effects against ischemic stroke than NADH and edaravone.

[Establishment of a prostate cancer prognostic risk model based on the TCGA database and inflammation-related genes].

OBJECTIVE: To investigate the effect of inflammation-related genes on the prognosis of prostate cancer (PCa). METHODS: We downloaded PCa-related clinical data and mRNA sequencing data from the database Cancer Genome Atlas (TCGA) and inflammation-related pathway gene sets from MsigDB. Using univariate regression and LASSO regression analyses, we screened inflammation-related genes for the construction of a prognostic risk model and evaluated the performance of the model in predicting the prognosis of PCa by Kaplan-Meier and ROC analyses. Based on the nomogram, we calculated the risk scores of the patients, divided them into a high-risk and a low-risk group based on the median values of their risk scores, identified differentially expressed genes for enrichment analysis and verified the expression level of SPHK1 in the PCa tissue microarrays by immunohistochemical staining. RESULTS: Totally 19 inflammation-related genes were identified from 172 candidate genes for the construction of the prognostic risk model, including the risk genes CD14, PIK3R5, GABBR1, RELA, IRF7, SCARF1, MSR1, SPHK1, OSM and STAB1, and the protective genes AQP9, LPAR1, ATP2C1, NDP, CXCL6, P2RY2, DCBLD2, PCDH7, and IFNAR1. Kaplan-Meier analysis showed that the patients with high risk scores had a significantly lower recurrence-free survival and a worse prognosis than those with low risk scores. Differentially expressed genes were involved mainly in the activation of inflammatory response pathways. Immunohistochemical results indicated that the expression of SPHK1 was significantly higher in the tumorous than in the normal tissue and increased with the Gleason score. There was a correlation between the SPHK1 expression and envelope invasion. CONCLUSION: The prognostic risk model of inflammation-related genes constructed based on the TCGA database can effectively predict the prognosis of PCa.

Neuroprotective effects of olanzapine against rotenone-induced toxicity in PC12 cells.

Olanzapine is an antipsychotic drug used to treat patients with schizophrenia due to its lower incidence of extrapyramidal symptoms. Previous studies have shown that olanzapine activates AMP-activated protein kinase (AMPK), and induce autophagy in SH-SY5Y cell line. In this study, we investigated whether olanzapine protected against rotenone-induced neurotoxicity in PC12 cells. We showed that treatment with olanzapine increased the phosphorylation of AMPK in both dose- and time-dependent manners in PC12 cells. In addition, olanzapine activated autophagy and increased autophagic vacuoles. Furthermore, olanzapine pretreatment could protect PC12 cells from rotenone-induced apoptosis. Besides, olanzapine pretreatment could suppress the rotenone-induced depolarization of mitochondrial potential and thus protect the cells. Moreover, pretreatment with specific AMPK inhibitor compound C or with autophagy inhibitor 3-methyladenine impaired the protective effect of olanzapine on rotenone-treated PC12 cells. In summary, our results show for the first time that olanzapine ameliorates rotenone-induced injury by activating autophagy through AMPK pathway.

NADPH ameliorates MPTP-induced dopaminergic neurodegeneration through inhibiting p38MAPK activation.

Parkinson's disease (PD) is the second most common neurodegenerative disorder characterized by the selective loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). Although the pathogenic mechanism underlying PD remains largely unknown, decreased nigral glutathione (GSH) in postmortem brains of PD patients supports the presence of oxidative stress in PD. We found that Nicotinamide adenine dinucleotide phosphate (NADPH), which is important for maintaining the level of GSH, protected dopaminergic (DA) neurons from neurotoxicity of MPTP/MPP+. In the present study, NADPH prevented DA neurons from MPTP toxicity with increased GSH and decreased reactive oxygen species (ROS) levels in the ventral midbrain of mice, and improved motor activity. Our present results demonstrated that NADPH inhibited the phosphorylation of p38MAPK, decreased the level of TP53 protein, and inhibited TP53 nuclear translocation in DA neurons of SNpc and in MES23.5 cells. Furthermore, NADPH decreased the protein level of TP53 target gene, Bax, cleavage of PARP, and nuclei condensation. Taken together, NADPH abrogated MPTP-induced p38MAPK phosphorylation, TP53 nuclear translocation, and Bax induction, and finally, MPTP/MPP+-induced apoptosis of DA neurons. This study suggests that NADPH may be a novel therapeutic candidate for PD.

[Diagnosis and Minimally Invasive Endoscopic Treatment of Early Esophageal Cancer and Precancerous Lesions].

Esophageal cancer is a common malignancy of digestive tract, and its prognosis is closely related to early diagnosis and treatment. In recent years, with the development of endoscopic diagnosis and treatment technology, especially the breakthrough progress of new endoscopic equipments, the detection rate of early esophageal cancer and precancerous lesions is significantly improved, and more and more patients with early esophageal cancer can be treated with minimally invasive endoscopic treatment. At present, endoscopic dissection has become the preferred treatment for early esophageal cancer and precancerous lesions. The advantages is not only less traumatic than traditional surgery, but also retain the physiological structure of esophagus, achieve accurate postoperative pathology and better postoperative quality of life of patients. However, endoscopic minimally invasive treatment in progress also face new problems to be solved, such as how to deal with multifocal esophageal lesions, how to estimate esophageal lesions infiltration depth and lymph node metastasis risk accurately, how to understand the discrepancy between biopsy and postoperative pathology, how to deal with the positive resection margins as well as intraoperative and postoperative complications, how to manage endoscopic treatment of the special subpopulation of the patients, whether and when additional radical surgery should be provided to the patients with non-curative endoscopic treatment, and so on. Aiming to the above problems and the purpose to improve the prognosis and the quality of life of esophageal cancer patients, this topic includes a series studies to explore standardized treatment scheme and management strategy for postoperative complications in the endoscopic treatment of early esophageal cancer and precancerious lesions.

[Accuracy of EUS and ME-NBI for Evaluating the Invasion Depth of Early Esophageal Cancer].

OBJECTIVE: To assess the accuracy of endoscopic ultrasound (EUS) and magnifying endoscopy with narrow-band imaging (ME-NBI) in evaluating the invasion depth of early esophageal carcinoma. METHODS: Patients who underwent endoscopic resection for early esophageal cancer from March 2013 to October 2017 were enrolled. The EUS and ME-NBI results were compared with the pathology results. RESULTS: A total of 392 lesions from 333 patients were assessed, including 83 mild and moderate dysplasia, 72 severe dysplasia, 235 squamous cell carcinoma, and 2 adenosquamous carcinoma. About 308 lesions were given EUS only, 7 had ME-NBI only, 77 underwent both EUS and ME-NBI. EUS resulted in a 43.9% accuracy for the 385 lesions, with poor consistency (Kappa=0.1) with the pathology results. But higher accuracy (68.2%) was found for lesions infiltrating into the submucosa of the lesions, compared with 40.5% for lesions contained within the mucosa (P=0.001). ME-NBI resulted in a 72.6% accuracy for the 84 lesions, with a medium consistency (Kappa=0.4). The accuracy for lesions contained within the mucosa was 91.0%, compared with 16.7% for lesions infilrtrating into the submucosa (P=0.001). EUS and ME-NBI for the 77 lesions demonstrated an accuracy of 42.9% for the EUS and 84.3% for the ME-NBI (P=0.001). CONCLUSIONS: ME-NBI has higher accuracy than EUS in evaluating the invasion depth of early esophageal carcinoma.

[Efficacy of Oral Corticosteroids in Preventing Esophageal Stenosis after Large Area Endoscopic Submucosal Tunnel Dissection].

OBJECTIVE: To evaluate the efficacy of oral corticosteroids in preventing esophageal stenosis after large area esophageal endoscopic submucosal tunnel dissection (ESTD). METHODS: The patients undertook esophageal ESTD were included from January 2014 to January 2018. The inclusion criteria was single lesion of esophageal early esophagus cancer with the extent more than 3/4 of circumferential degree. According to the inclusion time, the patients were divided into the trial group (ESTD + oral corticosteroids) and the control group (simple ESTD). The incidence of the total esophageal stenosis, intractable esophageal stenosis, the remission rate of dysphagia and the period from the dysphagia present were observed and compared in the two groups. RESULTS: A total of 101 cases of esophageal ESTD patients were included. There were 48 cases in the trial group, 28 cases of male and 20 cases of female, with an average age of (62.98±7.52) years; 53 cases in the control group, 28 cases of male and 25 cases of female, with an average age of (62.67±8.04) years. The rate of intractable esophageal stenosis in the trial group was lower than that in the control group (6.25% vs. 20.75%, P<0.05). The average endoscopic treatment times in the non-refractory stenosis patients in the trial group were significantly less than those in the control group 〔(1.85±0.27) times vs. (3.24±0.49) times, P<0.05〕, and the occurrence time of esophageal stenosis in the trial group was 51.06 d after ESTD, significantly later than that in the control group (29.12 d, P<0.05). CONCLUSIONS: Oral corticosteroids can effectively reduce the degree of esophageal stenosis after large area ESTD, as well as the incidence of intractable esophageal stenosis and the number of endoscopic treatment in non-refractory esophageal stenosis patients.

[Endoscopic Characteristics and Pathological Analysis of Esophageal Low-grade Intraepithelial Neoplasm].

OBJECTIVE: To explore endoscopic characteristics and pathological changes of esophageal low-grade intraepithelial neoplasm (LGIN) as well as its risk factors. METHODS: A total of 201 LGIN lesions from 169 cases were included from January 2009 to August 2017. The endoscopic characteristics and pathological changes were analysis. Logistic regression analysis was used to analyze the risk factors of LGIN. The endoscopic morphologic findings of esophageal mucosa lesions and the pathological findings of simple inflammatory lesions were enrolled as controls. RESULTS: LGIN occurred more common in elderly patients, the ratio of male to female was 2.5∶1. The maximum transverse and the maximum longitudinal diameter (MLD) were (0.9±0.8) cm,(1.4±1.3) cm, respectively. The most common location of lesion was in the middle segment of esophagus (52.2%). The morphological types of lesions were dominantly 0-Ⅱb (45.8%) and 0-Ⅱa (31.8%). There were 42 LGIN lesions with reflux esophagitis. Multiple dysplastic lesions accounted for 57.4%. After (10.3±12.1) months follow-up, 58.2% lesions were pathological reversal with 24.9% (50/201) of the lesion completely disappeared, and 28.9% lesions had no pathological changes, but 12.9% (26/201) lesions progressed to high-grade intraepithelial neoplasia and invasive cancer. Multivariate analysis indicated that age (compared to <45 years old) and longitudinal diameter of the lesion (compared to ≤0.5 cm) were independent risk factors for LGIN. The risk of esophageal LGIN in lesions with MLD > 0.5-1 cm was 1.96 times higher than that in lesions with MLD ≤ 0.5 cm. CONCLUSIONS: The MLD of esophageal mucosal lesions >0.5 cm and age >45 years old may increase the possibility of esophageal LGIN. Close follow-up is required for LGIN lesions with MLD>1 cm.

Endoscopic Submucosal Tunnel Dissection: A Feasible Solution for Large Superficial Rectal Neoplastic Lesions.

BACKGROUND: Although endoscopic submucosal tunnel dissection has been used for the resection of esophageal and stomach neoplastic lesions, there are still no reports about large superficial rectal neoplastic lesions. Compared with esophageal and stomach endoscopic submucosal dissection, the dissection of large superficial rectal neoplastic lesions is more difficult because of the flimsy bowel wall with abundant vasculature in the submucosal region, which results in poor endoscopic maneuverability and serious complications, such as bleeding and perforation. OBJECTIVE: The study aimed to assess the efficacy and safety of endoscopic submucosal tunnel dissection for large superficial rectal neoplastic lesions over 5 to 24 months in selected patients. DESIGN: This was a prospective, single-center evaluation. SETTINGS: The study was conducted at a digestive endoscopic center. PATIENTS: Patients with large superficial rectal neoplastic lesions were included. INTERVENTIONS: Endoscopic submucosal tunnel dissection was performed in all of the patients with large, superficial rectal neoplastic lesions. The submucosal tunnel was created via a submucosal incision from the anal incision to the oral incision. Next, tunnel wall resection was performed to completely remove the lesion. MAIN OUTCOME MEASURES: Dissection speed, complications, and recurrence rate were measured. RESULTS: A total of 19 patients, including 13 men and 6 women, with an average age of 60.1 ± 12.2 years (range, 34.0-75.0 y) underwent endoscopic submucosal tunnel dissection. The average size of lesions was 17.54 ± 13.47 cm. The mean operative time was 84.84 ± 53.49 minutes, and the operating speed was 21.01 ± 9.00 mm/min. En bloc resections with negative basal margins were achieved in all cases without serious intraoperative complications. No recurrence was observed in any patient within 5 to 24 months after the operations. LIMITATIONS: This was a single-center study. CONCLUSIONS: Endoscopic submucosal tunnel dissection is feasible, safe, and effective for the treatment of large, superficial rectal neoplastic lesions in selected patients. See Video Abstract at http://links.lww.com/DCR/A321.

Reduced Nicotinamide Adenine Dinucleotide Phosphate, a Pentose Phosphate Pathway Product, Might Be a Novel Drug Candidate for Ischemic Stroke.

BACKGROUND AND PURPOSE: Our previous study has defined a role of TP53-induced glycolysis and apoptosis regulator in neuroprotection against ischemic injury through increasing the flow of pentose phosphate pathway. We hypothesized that the pentose phosphate pathway product nicotinamide adenine dinucleotide phosphate (NADPH) could be a novel drug for treatment of ischemic stroke. METHODS: The NADPH was given before, at the onset, or after stroke onset with single or repeated intravenous (mice and rats) or intraperitoneal injections (monkey). The short- and long-term therapeutic effects of NADPH were evaluated in male adult ICR mice (total=614) with transient middle cerebral artery occlusion, in male adult Sprague-Dawley rats (total=114) with permanent middle cerebral artery occlusion, and in male adult rhesus monkey (total=12) with thrombotic middle cerebral artery occlusion. RESULTS: Administration of NADPH led to a dramatic increase in the levels of ATP and reduced form of glutathione, whereas it decreased the levels of reactive oxygen species. NADPH significantly reduced infarct volume, improved poststroke survival, and recovery of neurological functions in mouse and rat models of stroke. Robust neuroprotection of a single dose of NADPH was seen when it was administered within 5 hours after reperfusion; however, repeat administration of NADPH twice a day for 7 days starting 24 hours after the onset of stroke also offered therapeutic effects. Pretreatment with NADPH also significantly improved the outcome of stroke insult. CONCLUSIONS: Administration of exogenous NADPH significantly protected neurons against ischemia/reperfusion-induced injury in 2 rodent stroke models. Thus, NADPH might be a promising drug candidate for treatment of ischemic stroke.

Endoscopic submucosal multi-tunnel dissection for circumferential superficial esophageal neoplastic lesions (with videos).

BACKGROUND AND AIMS: Endoscopic submucosal tunnel dissection (ESTD) has been used for dissection of large esophageal neoplastic lesions, but there are still some technical problems in treating circumferential superficial esophageal neoplastic lesions. This study aimed to assess the efficacy and safety of endoscopic submucosal multi-tunnel dissection (ESMTD) for circumferential superficial esophageal neoplastic lesions in selected patients followed up for 1 to 12 months. METHODS: From July 2014 to February 2015, the first series of 7 consecutive patients with circumferential superficial esophageal neoplastic lesions underwent ESMTD at our endoscopic center. The macroscopic types were classified according to the Paris endoscopic classification of superficial neoplastic lesions. RESULTS: The average length of lesions was 6.1 cm in 7 selected patients. The operative time ranged from 69 to 169 minutes (mean 121 minutes). En bloc dissection with negative basal margins was achieved in all lesions without serious intraoperative adverse events. Esophageal stricture was observed in all patients 1 to 3 months after the operation and was relieved after a retrievable metal stent was placed or esophageal water balloon dilatation was performed; however, one patient died of cerebral infarction 2 months after ESMTD. CONCLUSIONS: ESMTD is feasible, safe, and effective for the treatment of circumferential superficial esophageal neoplastic lesions in select patients.

[Early Diagnosis And Endoscopic Minimally Invasive Treatment of Gastrointestinal Tumor].

Gastrointestinal tumor could be aggressive and life threaten if it was not be diagnosed and treated at early stage. Digestive endoscopy plays a very important role in the early diagnosis and treatment of gastrointestinal tumor, and shows rapid evolution with novel technologies in the past years, such as endoscopic ultrasonography, magnifying endoscopy, electronic staining endoscopy, endoscopic confocal laser microscopy. Nowaday it becomes feasible to learn more about the endoscopic manifestation in early stage GI tumor. Besides, several new endoscopic surgical techniques, such as endoscopic submucosal dissection (ESD), endoscopicsubmucosal tunnel dissection (ESTD), submucosal tunneling endoscopic resection (STER), has been applied in clinical treatment of early stage GI tumor with curative effect. However, there are some new problems emerged, such as how to determine the depth of the lesion, how to avoid or reduce the incidence of postoperative complications, and how to standardize the pathological classification and the treatment of positive margin, which need multidisciplinary solution with the efforts from endoscopist, clinician and pathologist. With the deep insight on, molecular pathogenesis of GI tumor, new technologies combinding endoscopy, imaging and pathological measures, will promote more GI tumor early diagnosed and effectively treated, thus improve the survival and prognosis of GI tumor patients.

[The Efficiency and Complications of ESD and ESTD in the Treatment of Large Esophageal Mucosal Lesions].

OBJECTIVE: To study the efficiency and complications of endoscopic submucosal dissection (ESD) and endoscopic submucosal tunnel dissection (ESTD) in the treatment of large esophageal mucosal lesions. METHODS: The clinical data were collected from the patients who received ESD or ESTD for the treatment of early esophageal lesions in our hospital during January 1, 2014 to July 15, 2015, including the en bloc resection rate, curative resection rate, postoperative complication rate, the risk factors of complications were explored by univariate and multivariate analysis. RESULTS: A total of 50 patients were involved in the study, ESD or ESTD were performed successfully in 53 times, including 6 cases of ESD,47 cases of ESTD, The average age was (61.9 +/- 6.8) yr., the average operating time was (83.57 +/- 32.33) min, the average dissected lesion was (14.82 +/- 3.18) cm2, En bloc resection rate was 94.34%, the curative rate was 84.90%. There were 1 case of bleeding, 1 case of perforation, 45 (84.90%) cases of fever, 13 cases (24.53%) of esophageal stricture. The severity of stricture was associated with the operation time Codds ratio (OR) = 1.040, 95% confidence interal (CI): 1.007-1.075) and esophageal circumference (OR=9.972, 95% CI: 1.221-81.416). The residual resection margin appeared in 8 patients, and the lesion area (OR=1.145, 95% CI: 1.013-1.294) was the only risk factor. CONCLUSION: ESD and ESTD are safe and effective in the treatment of early esophageal lesions, but seems have relatively high incidence of esopgageal stricture and residual resection margin in the treatment of large esophageal lesions.

[Factors Associated with Successful Submucosal Tunneling Endoscopic Resection Treatment for Upper Gastrointestinal Submucosal Tumors].

OBJECTIVE: To determine the influence of location, depth and size of upper gastrointestinal (GI) submucosal tumors (SMTs) on the success of submucosal tunneling endoscopic resection (STER). METHODS: Patient records of 31 cases with upper GI SMTs who had STER between Jan. 1, 2014 and June 30, 2015 in West China Hospital of Sichuan University were retrieved. The success of STER was determined by its efficiency, complete resection rate, and incidence of complications. RESULTS: Of the 31 cases, 29 were treated successfully, with an average of (13.76 +/- 9.70) min and (32.00 +/- 27.35) min for tunnel formation of esophageal and stomach mucosal tumors respectively (P = 0.045). The 2 unsuccessful cases were gastric tumors. SMTs resection for mucous layer and muscularis propria took (17.50 +/- 9.06) min and (36.24 +/- 15.68) min, respectively (P=0.004). SMTs resection for tumors diameter < 2.0 cm and > or = 2.0 cm took (25.78 +/- 12.13) min and (39.73 +/- 19.23) min, respectively (P=0.023). Six cases of gastric tumors from muscularis propria had complications (19.4%) during or after surgery. CONCLUSION: Location, depth and size of upper GI SMTs has implications on duration of different STER stages, which may determine complete resection rate and incidence of complications.

[Risk Factors of Lymph Node Metastasis in Superficial Esophageal Squamous Cell Carcinoma].

OBJECTIVE: To analysis the risk factors of lymph node metastasis (LNM) in superficial esophageal squamous cell carcinoma (SESCC). METHODS: The clinical data and pathological results of 344 SESCC patients, who underwent surgical treatments between January 2009 and December 2013 in West China Hospital, Sichuan University, were analyzed retrospectively. Clinicopathologic characteristics were compared between different histological types, and their possible relationships with LNM were explored by univariate and multivariate analysis. RESULTS: There were no LNM found in the patients with tumor limited to the mucous, tumor diameter <3 cm, highly and moderate differentiated SESCC. Univariate analysis showed that tumor diameter (P=0.004), depth of tumor invasion (P=0.009), histological type (P=0.030) and lymphatic involvement (P=0.002) were correlated with LNM. Multivariate analysis revealed that tumor diameter (P=0.007), depth of tumor invasion (P=0.003), histological type (P=0.010) and lymphatic involvement (P<0.001) were independent risk factors of LNM. CONCLUSION: To the patients with low risk of LNM, such as tumor limited to the mucous, tumor diameter <3 cm, and highly and moderate differentiation, endoscopic excision may be considered as an absolute indications.

Regulation of FSP1 myristoylation by NADPH: A novel mechanism for ferroptosis inhibition.

Excitotoxicity is a prevalent pathological event in neurodegenerative diseases. The involvement of ferroptosis in the pathogenesis of excitotoxicity remains elusive. Transcriptome analysis has revealed that cytoplasmic reduced nicotinamide adenine dinucleotide phosphate (NADPH) levels are associated with susceptibility to ferroptosis-inducing compounds. Here we show that exogenous NADPH, besides being reductant, interacts with N-myristoyltransferase 2 (NMT2) and upregulates the N-myristoylated ferroptosis suppressor protein 1 (FSP1). NADPH increases membrane-localized FSP1 and strengthens resistance to ferroptosis. Arg-291 of NMT2 is critical for the NADPH-NMT2-FSP1 axis-mediated suppression of ferroptosis. This study suggests that NMT2 plays a pivotal role by bridging NADPH levels and neuronal susceptibility to ferroptosis. We propose a mechanism by which the NADPH regulates N-myristoylation, which has important implications for ferroptosis and disease treatment.

PIK3CA hypomethylation plays a key role in activation of the PI3K/AKT pathway in esophageal cancer in Chinese patients.

AIM: To investigate the role of PIK3CA oncogene in tumorigenesis and development of esophageal cancer in Chinese patients at the levels of genetic mutation and epigenetics. METHODS: Seventy six esophageal tumor samples and corresponding adjacent normal tissues were collected, and the genomic DNA was extracted. Mutations in the 9th and 20th exons of PIK3CA gene were detected using conventional sequencing. PIK3CA methylation rates in two selected CpG islands (CpG island 1 and 2) were detected using sub-bisulfate modified sequencing. P110α and pAKT expression levels were detected with Western blotting. RESULTS: In PIK3CA gene of the tumor tissues, G1633C (E545Q) mutation was detected in the 9th exon with a rate of 3.95% (3/76), whereas mutation was not found in the 20th exon. Nor mutation did occur in PIK3CA gene of the adjacent normal tissues. The methylation rate of the CpG island 1 had no significant difference between the tumor and adjacent tissues (0.77%±0.009% vs 0.89%±0.008%), but the methylation rate of the CpG island 2 in the esophageal tumors was significantly lower than that in the adjacent tissues (6.00%±2.80% vs 10.45%±5.51%). Furthermore, the rate of methylation of the CpG island 2 in TNM stage III and IV esophageal cancer (3.84%±2.08%) was significantly lower than in stage I (8.52%±2.55%) and stage II (6.42%±2.36%). PIK3CA gene hypomethylation in esophageal cancer was significantly correlated with high expression of p110α. CONCLUSION: PIK3CA gene hypomethylation plays a key role in the tumorigenesis and development of esophageal cancer in Chinese patients, while the mutations of PIK3CA gene have little effect on the development of esophageal cancer.

Rapamycin prevents the mutant huntingtin-suppressed GLT-1 expression in cultured astrocytes.

AIM: To investigate the effects of rapamycin on glutamate uptake in cultured rat astrocytes expressing N-terminal 552 residues of mutant huntingtin (Htt-552). METHODS: Primary astrocyte cultures were prepared from the cortex of postnatal rat pups. An astrocytes model of Huntington's disease was established using the astrocytes infected with adenovirus carrying coden gene of N-terminal 552 residues of Huntingtin. The protein levels of glutamate transporters GLT-1 and GLAST, the autophagic marker microtubule-associated protein 1A/1B-light chain 3 (LC3) and the autophagy substrate p62 in the astrocytes were examined using Western blotting. The mRNA expression levels of GLT-1 and GLAST in the astrocytes were determined using Real-time PCR. [(3)H]glutamate uptake by the astrocytes was measured with liquid scintillation counting. RESULTS: The expression of mutant Htt-552 in the astrocytes significantly decreased both the mRNA and protein levels of GLT-1 but not those of GLAST. Furthermore, Htt-552 significantly reduced [(3)H]glutamate uptake by the astrocytes. Treatment with the autophagy inhibitor 3-MA (10 mmol/L) significantly increased the accumulation of mutant Htt-552, and reduced the expression of GLT-1 and [(3)H]glutamate uptake in the astrocytes. Treatment with the autophagy stimulator rapamycin (0.2 mg/mL) significantly reduced the accumulation of mutant Htt-552, and reversed the changes in GLT-1 expression and [(3)H]glutamate uptake in the astrocytes. CONCLUSION: Rapamcin, an autophagy stimulator, can prevent the suppression of GLT-1 expression and glutamate uptake by mutant Htt-552 in cultured astrocytes.

The regulation of N-terminal Huntingtin (Htt552) accumulation by Beclin1.

AIM: Huntingtin protein (Htt) was a neuropathological hallmark in human Huntington's Disease. The study aimed to investigate whether the macroautophagy regulator, Beclin1, was involved in the degradation of Htt. METHODS: PC12 cells and primary cultured brain neurons of rats were examined. pDC316 adenovirus shuttle plasmid was used to mediate the expression of wild-type Htt-18Q-552 or mutant Htt-100Q-552 in PC12 cells. The expression of the autophagy-related proteins LC3 II and Beclin1, as well as the lysosome-associated enzymes Cathepsin B and L was evaluated using Western blotting. The locations of Beclin1 and Htt were observed with immunofluorescence and confocal microscope. RESULTS: Htt552 expression increased the expression of LC3 II, Beclin1, cathepsin B and L in autophagy/lysosomal degradation pathway. Treatment with the autophagy inhibitor 3-MA or the proteasome inhibitors lactacystin and MG-132 increased Htt552 levels in PC12 cells infected with Ad-Htt-18Q-552 or Ad-Htt-100Q-552. The proteasome inhibitor caused a higher accumulation of Htt552-18Q than Htt552-100Q, and the autophagy inhibitor resulted in a higher accumulation of Htt552-100Q than Htt552-18Q. Similar results were observed in primary cultured neurons infected with adenovirus. In Htt552-expressing cells, Beclin1 was redistributed from the nucleus to the cytoplasm. Htt siRNA prevented Beclin1 redistribution in starvation conditions. Blockade of Beclin1 nuclear export by leptomycin B or Beclin1 deficiency caused by RNA interference induced the formation of mHtt552 aggregates. CONCLUSION: Beclin1 regulates the accumulation of Htt via macroautophagy.