Genetically predicted alterations in thyroid function are associated with the risk of benign prostatic disease.

Background: Benign prostatic diseases (BPDs), such as benign prostate hyperplasia (BPH) and prostatitis, harm the quality of life of affected patients. However, observational studies exploring the association between thyroid function and BPDs have hitherto yielded inconsistent results. In this study, we explored whether there is a causal genetic association between them using Mendelian randomization (MR) analysis. Methods: We used publicly available summary statistics from the Thyroidomics Consortium and 23andMe on thyrotropin (TSH; 54,288 participants), thyroxine [free tetraiodothyronine (FT4); 49,269 participants], subclinical hypothyroidism (3,440 cases and 49,983 controls), overt hypothyroidism (8,000 cases and 117,000 controls), and subclinical hyperthyroidism (1,840 cases and 49,983 controls) to screen for instrumental variables of thyroid function. Results for BPD such as prostatic hyperplasia (13,118 cases and 72,799 controls) and prostatitis (1,859 cases and 72,799 controls) were obtained from the FinnGen study. The causal relationship between thyroid function and BPD was primarily assessed using MR with an inverse variance weighted approach. In addition, sensitivity analyses were performed to test the robustness of the results. Results: We found that TSH [OR (95% CI) = 0.912(0.845-0.984), p =1.8 x 10-2], subclinical hypothyroidism [OR (95% CI) = 0.864(0.810-0.922), p =1.04 x 10-5], and overt hypothyroidism [OR (95% CI) = 0.885 (0.831-0. 944), p =2 x 10-4] had a significant effect on genetic susceptibility to BPH, unlike hyperthyroidism [OR (95% CI) = 1.049(0.990-1.111), p =1.05 x 10-1] and FT4 [OR (95% CI) = 0.979(0.857-1.119), p = 7.59 x 10-1] had no effect. We also found that TSH [OR (95% CI) =0.823(0.700-0.967), p = 1.8 x 10-2] and overt hypothyroidism [OR (95% CI) = 0.853(0.730-0.997), p = 4.6 x 10-2] significantly influenced the prostatitis, whereas FT4 levels [OR (95% CI) = 1.141(0.901-1.444), p = 2.75 x 10-1], subclinical hypothyroidism [OR (95% CI) =0. 897(0.784- 1.026), p = 1.12 x 10-1], and hyperthyroidism [OR (95% CI) = 1.069(0.947-1.206), p = 2.79 x 10-1] did not have a significant effect. Conclusion: Overall, our study results suggest that hypothyroidism and TSH levels influence the risk of genetically predicted BPH and prostatitis, providing new insights into the causal relationship between thyroid function and BPD.

Chrysophanol postconditioning attenuated cerebral ischemia-reperfusion injury induced NLRP3-related pyroptosis in a TRAF6-dependent manner.

Individuals who suffer from post-CA (cardiac arrest) brain injury experience higher mortality and more severe functional disability. Neuroinflammation has been identified as a vital factor in cerebral ischemia-reperfusion injury (CIRI) following CA. Pyroptosis induces neuronal death by triggering an excessive inflammatory injury. Chrysophanol possesses robust anti-inflammatory features, and it is protective against CIRI. The purpose of this research was to assess the effect of Chrysophanol postconditioning on CIRI-induced pyroptotic cell death, and to explore its underlying mechanisms. CIRI was induced in rats by CA and subsequent cardiopulmonary resuscitation, and PC12 cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to imitate CIRI in vitro. It was found that post-CA brain injury led to a notable cerebral damage revealed by histopathological changes and neurological outcomes. The existence of pyroptosis was also confirmed in in vivo and in vitro CIRI models. Moreover, we further confirmed that Chrysophanol, the main bioactive ingredient of Rhubarb, significantly suppressed expressions of pyroptosis-associated proteins, e.g., NLRP3, ASC, cleaved-caspase-1 and N-terminal GSDMD, and inhibited the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6). Furthermore, NLRP3 overexpression neutralized the neuroprotection of Chrysophanol postconditioning, suggesting that pyroptosis was the major neuronal death pathway modulated by Chrysophanol postconditioning in OGD/R. Additionally, the neuroprotection of Chrysophanol postconditioning was also abolished by gain-of-function analyses of TRAF6. Finally, the results demonstrated that Chrysophanol postconditioning suppressed the interaction between TRAF6 and NLRP3. Taken together, our findings revealed that Chrysophanol postconditioning was protective against CIRI by inhibiting NLRP3-related pyroptosis in a TRAF6-dependent manner.

Long noncoding RNA Meg3 mediates ferroptosis induced by oxygen and glucose deprivation combined with hyperglycemia in rat brain microvascular endothelial cells, through modulating the p53/GPX4 axis.

Individuals with diabetes are exposed to a higher risk of perioperative stroke than non-diabetics mainly due to persistent hyperglycemia. LncRNA Meg3 has been considered as an important mediator in regulating ischemic stroke. However, the functional and regulatory roles of Meg3 in diabetic brain ischemic injury remain unclear. In this study, rat brain microvascular endothelial cells (RBMVECs) were exposed to 6 h of oxygen and glucose deprivation (OGD), and subsequent reperfusion via incubating cells with glucose of various high concentrations for 24 h to imitate in vitro diabetic brain ischemic injury. It was shown that the marker events of ferroptosis and increased Meg3 expression occurred after the injury induced by OGD combined with hyperglycemia. However, all ferroptotic events were reversed with the treatment of Meg3-siRNA. Moreover, in this in vitro model, p53 was also characterized as a downstream target of Meg3. Furthermore, p53 knockdown protected RBMVECs against OGD + hyperglycemic reperfusion-induced ferroptosis, while the overexpression of p53 exerted opposite effects, implying that p53 served as a positive regulator of ferroptosis. Additionally, the overexpression or knockdown of p53 significantly modulated GPX4 expression in RBMVECs exposed to the injury induced by OGD combined with hyperglycemic treatment. Furthermore, GPX4 expression was suppressed again after the reintroduction of p53 into cells silenced by Meg3. Finally, chromatin immunoprecipitation assay uncovered that p53 was bound to GPX4 promoter. Altogether, these data revealed that, by modulating GPX4 transcription and expression, the Meg3-p53 signaling pathway mediated the ferroptosis of RBMVECs upon injury induced by OGD combined with hyperglycemic reperfusion.

Radiogenomic signatures reveal multiscale intratumour heterogeneity associated with biological functions and survival in breast cancer.

Advanced tumours are often heterogeneous, consisting of subclones with various genetic alterations and functional roles. The precise molecular features that characterize the contributions of multiscale intratumour heterogeneity to malignant progression, metastasis, and poor survival are largely unknown. Here, we address these challenges in breast cancer by defining the landscape of heterogeneous tumour subclones and their biological functions using radiogenomic signatures. Molecular heterogeneity is identified by a fully unsupervised deconvolution of gene expression data. Relative prevalence of two subclones associated with cell cycle and primary immunodeficiency pathways identifies patients with significantly different survival outcomes. Radiogenomic signatures of imaging scale heterogeneity are extracted and used to classify patients into groups with distinct subclone compositions. Prognostic value is confirmed by survival analysis accounting for clinical variables. These findings provide insight into how a radiogenomic analysis can identify the biological activities of specific subclones that predict prognosis in a noninvasive and clinically relevant manner.

Rac1 relieves neuronal injury induced by oxygenglucose deprivation and re-oxygenation via regulation of mitochondrial biogenesis and function.

Certain microRNAs (miRNAs) can function as neuroprotective factors after reperfusion/ischemia brain injury. miRNA-142-3p can participate in the occurrence and development of tumors and myocardial ischemic injury by negatively regulating the activity of Rac1, but it remains unclear whether miRNA-142-3p also participates in cerebral ischemia/reperfusion injury. In this study, a model of oxygen-glucose deprivation/re-oxygenation in primary cortical neurons was established and the neurons were transfected with miR-142-3p agomirs or miR-142-3p antagomirs. miR-142-3p expression was down-regulated in neurons when exposed to oxygen-glucose deprivation/re-oxygenation. Over-expression of miR-142-3p using its agomir remarkably promoted cell death and apoptosis induced by oxygen-glucose deprivation/re-oxygenation and improved mitochondrial biogenesis and function, including the expression of peroxisome proliferator-activated receptor-γ coactivator-1α, mitochondrial transcription factor A, and nuclear respiratory factor 1. However, the opposite effects were produced if miR-142-3p was inhibited. Luciferase reporter assays verified that Rac Family Small GTPase 1 (Rac1) was a target gene of miR-142-3p. Over-expressed miR-142-3p inhibited NOX2 activity and expression of Rac1 and Rac1-GTPase (its activated form). miR-142-3p antagomirs had opposite effects after oxygen-glucose deprivation/re-oxygenation. Our results indicate that miR-142-3p down-regulates the expression and activation of Rac1, regulates mitochondrial biogenesis and function, and inhibits oxygen-glucose deprivation damage, thus exerting a neuroprotective effect. The experiments were approved by the Committee of Experimental Animal Use and Care of Central South University, China (approval No. 201703346) on March 7, 2017.

Tumour heterogeneity revealed by unsupervised decomposition of dynamic contrast-enhanced magnetic resonance imaging is associated with underlying gene expression patterns and poor survival in breast cancer patients.

BACKGROUND: Heterogeneity is a common finding within tumours. We evaluated the imaging features of tumours based on the decomposition of tumoural dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data to identify their prognostic value for breast cancer survival and to explore their biological importance. METHODS: Imaging features (n = 14), such as texture, histogram distribution and morphological features, were extracted to determine their associations with recurrence-free survival (RFS) in patients in the training cohort (n = 61) from The Cancer Imaging Archive (TCIA). The prognostic value of the features was evaluated in an independent dataset of 173 patients (i.e. the reproducibility cohort) from the TCIA I-SPY 1 TRIAL dataset. Radiogenomic analysis was performed in an additional cohort, the radiogenomic cohort (n = 87), using DCE-MRI from TCGA-BRCA and corresponding gene expression data from The Cancer Genome Atlas (TCGA). The MRI tumour area was decomposed by convex analysis of mixtures (CAM), resulting in 3 components that represent plasma input, fast-flow kinetics and slow-flow kinetics. The prognostic MRI features were associated with the gene expression module in which the pathway was analysed. Furthermore, a multigene signature for each prognostic imaging feature was built, and the prognostic value for RFS and overall survival (OS) was confirmed in an additional cohort from TCGA. RESULTS: Three image features (i.e. the maximum probability from the precontrast MR series, the median value from the second postcontrast series and the overall tumour volume) were independently correlated with RFS (p values of 0.0018, 0.0036 and 0.0032, respectively). The maximum probability feature from the fast-flow kinetics subregion was also significantly associated with RFS and OS in the reproducibility cohort. Additionally, this feature had a high correlation with the gene expression module (r = 0.59), and the pathway analysis showed that Ras signalling, a breast cancer-related pathway, was significantly enriched (corrected p value = 0.0044). Gene signatures (n = 43) associated with the maximum probability feature were assessed for associations with RFS (p = 0.035) and OS (p = 0.027) in an independent dataset containing 1010 gene expression samples. Among the 43 gene signatures, Ras signalling was also significantly enriched. CONCLUSIONS: Dynamic pattern deconvolution revealed that tumour heterogeneity was associated with poor survival and cancer-related pathways in breast cancer.

Inhibition of Rac1 ameliorates neuronal oxidative stress damage via reducing Bcl-2/Rac1 complex formation in mitochondria through PI3K/Akt/mTOR pathway.

Although the neuroprotective effects of Rac1 inhibition have been reported in various cerebral ischemic models, the molecular mechanisms of action have not yet been fully elucidated. In this study, we investigated whether the inhibition of Rac1 provided neuroprotection in a diabetic rat model of focal cerebral ischemia and hyperglycemia-exposed PC-12 cells. Intracerebroventricular administration of lentivirus expressing the Rac1 small hairpin RNA (shRNA) and specific Rac1 inhibitor NSC23766 not only decreased the infarct volumes and improved neurologic deficits with a correlated significant activation of mitochondrial DNA specific proteins, such as OGG1 and POLG, but also elevated Bcl-2 S70 phosphorylation in mitochondria. Furthermore, the levels of p-PI3K, p-Akt and p-mTOR increased, while 8-OHdG, ROS production and Bcl-2/Rac1 complex formation in mitochondria reduced in both Rac1-shRNA- and NSC23766-treated rats. Moreover, to confirm our in vivo observations, inhibition of Rac1 activity by NSC23766 suppressed the interactions between Bcl-2 and Rac1 in the mitochondria of PC-12 cells cultured in high glucose conditions and protected PC-12 cells from high glucose-induced neurotoxicity. More importantly, these beneficial effects of Rac1 inhibition were abolished by PI3K inhibitor LY294002. In contrast to NSC23766 treatment, LY294002 had little effect on the decrement of p-PTEN level. Taken together, these findings revealed novel neuroprotective roles of Rac1 inhibition against cerebral ischemic reperfusion injury in vivo and high glucose-induced neurotoxicity in PC-12 cells in vitro, by reducing Bcl-2/Rac1 complex formation in mitochondria through the activation of PI3K/Akt/mTOR survival pathway.

Neuroprotection induced by sevoflurane-delayed post-conditioning is attributable to increased phosphorylation of mitochondrial GSK-3ß through the PI3K/Akt survival pathway.

BACKGROUND AND PURPOSE: Post-conditioning with volatile anesthetics can create ischemic tolerance against cerebral ischemia-reperfusion injury. The present study was designed to determine whether delayed exposure to sevoflurane could induce ischemic tolerance and if this effect was dependent on increasing phosphorylated Akt-Ser473 and GSK-3ß-Ser9 expression in the mitochondria, via a mechanism involving the PI3K/Akt pathway. METHODS: Adult male Sprague-Dawley rats were subjected to focal cerebral ischemia. Sevoflurane post-conditioning was achieved by administration of 2.5% sevoflurane for 60 min, 15 min after reperfusion. Phosphorylated Akt-Ser473 and GSK-3ß-Ser9 in the cytosol and mitochondria of the ischemic penumbra were evaluated 4, 12, 24, and 72 h after reperfusion. Neurological deficit score and activity of caspase-3 and -9 were evaluated 24 and 72 h after reperfusion. Apoptosis, as measured by TUNEL staining and cerebral infarct size,was determined 24h after reperfusion. RESULTS: Sevoflurane-delayed post-conditioning significantly increased levels of phosphorylated Akt-Ser473 and GSK-3ß-Ser9 in the mitochondria and inhibited the activities of caspase-3 and -9, showing an improved neurological deficit score and a decreased infarct size. However, LY294002, a selective PI3K inhibitor, not only eliminated the neuroprotection of sevoflurane, as indicated by an increased infarct size and a larger number of TUNEL-positive cells, but also reversed the elevation of p-Akt and p-GSK-3ß expression in the mitochondria induced by sevoflurane post-conditioning. CONCLUSIONS: Our data suggested that delayed application of sevoflurane after reperfusion provides neuroprotection by activating phosphorylated Akt-Ser473 and GSK-3ß-Ser9 in the mitochondria via the PI3K/Akt pathway.

Sevoflurane postconditioning involves an up-regulation of HIF-1α and HO-1 expression via PI3K/Akt pathway in a rat model of focal cerebral ischemia.

Administration of sevoflurane at the onset of reperfusion has been confirmed to provide a cerebral protection. However, little is known about the mechanism. In this study, we tested the hypothesis that sevoflurane postconditioning induces neuroprotection through the up-regulation hypoxia inducible factor-1α (HIF-1α) and heme oxygenase-1 (HO-1) involving phosphatidylinositol-3-kinase (PI3K)/Akt pathway. In the first experiment, male Sprague-Dawley rats were subjected to focal cerebral ischemia. Postconditioning was performed by exposure to 2.5% sevoflurane immediately at the onset of reperfusion. The mRNA and protein expression of HIF-1α and its target gene, HO-1, intact neurons and the activity of caspase-3 was evaluated at 6, 24 and 72h after reperfusion. In the second experiment, we investigated the relationship between PI3K/Akt pathway and the expression of HIF-1α and HO-1 in the neuroprotection induced by sevoflurane. Cerebral infarct volume, apoptotic neuron and the expression of HIF-1α, HO-1 and p-Akt were evaluated at 24h after reperfusion. Compared with the control group, sevoflurane postconditiong significantly ameliorated neuronal injury, up-regulated mRNA and protein levels of HIF-1α and HO-1, inhibited the activity of caspase-3, and decreased the number of TUNEL-positive cells and infarct sizes. However, the selective PI3K inhibitor, wortmannin not only partly eliminated the neuroprotection of sevoflurane as shown by reducing infarct size and apoptotic neuronal cells, but also reversed the elevation of HIF-1α, HO-1 and p-Akt expression in the ischemic penumbra induced by sevoflurane. Therefore, our data demonstrate that the cerebral protection from sevoflurane postconditioning is partly mediated by PI3K/Akt pathway via the up-regulation of HIF-1α and HO-1.

Delayed administration of parecoxib, a specific COX-2 inhibitor, attenuated postischemic neuronal apoptosis by phosphorylation Akt and GSK-3ß.

Parecoxib is a recently described novel COX-2 inhibitor whose functional significance and neuroprotective mechanisms remain elusive. Therefore, in this study, we aimed to investigate whether delayed administration of parecoxib inhibited mitochondria-mediated neuronal apoptosis induced by ischemic reperfusion injury via phosphorylating Akt and its downstream target protein, glycogen synthase kinase 3ß (GSK-3ß). Adult male Sprague-Dawley rats were administered parecoxib (10 or 30 mg kg(-1), IP) or isotonic saline twice a day starting 24 h after middle cerebral artery occlusion (MCAO) for three consecutive days. Cerebral infarct volume, apoptotic neuron, caspase-3 immunoreactivity and the protein expression of p-Akt, p-GSK-3ß and Cytochrome C in cerebral ischemic cortex were evaluated at 96 h after reperfusion. Parecoxib significantly diminished infarct volume and attenuated neuron apoptosis in a dose-independent manner, compared with MCAO group alone. Increased p-Akt and p-GSK-3ß was observed in the ischemic penumbra of parecoxib group after stroke. Moreover, parecoxib also reduced the release of Cytochrome C from mitochondrial into cytosol and attenuated the caspase-3 immunoreactivity in the penumbra. Taken together, these results suggested that parecoxib ameliorated postischemic mitochondria-mediated neuronal apoptosis induced by focal cerebral ischemia in rats and this neuroprotective potential is involved in phosphorylation of Akt and GSK-3ß.

Preconditioning of intravenous parecoxib attenuates focal cerebral ischemia/reperfusion injury in rats.

BACKGROUND: Several studies suggest that cyclooxygenase-2 (COX-2) contributes to the delayed progression of ischemic brain damage. This study was designed to investigate whether COX-2 inhibition with parecoxib reduces focal cerebral ischemia/reperfusion injury in rats. METHODS: Ninety male Sprague-Dawley rats were randomly assigned to three groups: the sham group, ischemia/reperfusion (I/R) group and parecoxib group. The parecoxib group received 4 mg/kg of parecoxib intravenously via the vena dorsalis penis 15 minutes before ischemia and again at 12 hours after ischemia. The neurological deficit scores (NDSs) were evaluated at 24 and 72 hours after reperfusion. The rats then were euthanized. Brains were removed and processed for hematoxylin and eosin staining, Nissl staining, and measurements of high mobility group Box 1 protein (HMGB1) and tumor necrosis factor-α (TNF-α) levels. Infarct volume was assessed with 2,3,5-triphenyltetrazolium chloride (TTC) staining. RESULTS: The rats in the I/R group had lower NDSs (P < 0.05), larger infarct volume (P < 0.05), lower HMGB1 levels (P < 0.05), and higher TNF-α levels (P < 0.05) compared with those in the sham group. Parecoxib administration significantly improved NDSs, reduced infarct volume, and decreased HMGB1 and TNF-α levels (P < 0.05). CONCLUSIONS: Pretreatment with intravenous parecoxib was neuroprotective. Its effects may be associated with the attenuation of inflammatory reaction and the inhibition of inflammatory mediators.

[Damage on lung and systemic inflammation induced by nickel sulfate intratracheal instillation in rats].

OBJECTIVE: To investigate the acute toxic effects induced by nickel sulfate (NiSO4) in order to clarify the possible role of nickel in PM2.5. METHODS: Twenty-eight male Wistar rats were divided into four groups, NiSO4 was administered by intratracheal instillation at the doses of Ni 0, 7.5, 75 and 750 microg/kg for 24h respectively. The rats were sacrificed and bronchoalveolar lavage fluid (BALF) were collected and analyzed to estimate the injury (total protein (TP) and lactate dehydrogenase (LDH)) and inflammation of lung. Blood were collected and parameters of inflammation (total cell numbers, interleukin-6 (IL-6), tumor necrosis factor (TNF-alpha)) and CRP were measured. The nickel levels in the blood were also determined. RESULTS: NiSO4 induced significant increases of leukocytes, neutrophil, TP contents and LDH activity in BALF (P < 0.05, P < 0.01). The level of TNF-alpha and IL-6 in BALF of NiSO4-treated rats increased significantly compared with those of the control group (P < 0.05). The level of TNF-alpha in blood of NiSO4-treated rats increased significantly compared with the control group. Concentrations of CRP in the serum were more higher in NiSO4-treated rats than the control group, but statistical significances were only seen in the highest dosage group (Ni 750 microg/kg). Nickel in serum of NiSO4-treated rats increased significantly in a dose-dependent manner. CONCLUSION: NiSO4 induced pulmonary and systemic inflammation effects in rats, suggested that NiSO4 may play an important role in the acute effects of PM2.5.