The differential proteomic response to ischemic stroke in appalachian subjects treated with mechanical thrombectomy.

INTRODUCTION: The Appalachia region of North America is known to have significant health disparities, specifically, worse risk factors and outcomes for stroke. Appalachians are more likely to have comorbidities related to stroke, such as diabetes, obesity, and tobacco use, and are often less likely to have stroke interventions, such as mechanical thrombectomy (MT), for emergent large vessel occlusion (ELVO). As our Comprehensive Stroke Center directly serves stroke subjects from both Appalachian and non-Appalachian areas, inflammatory proteomic biomarkers were identified associated with stroke outcomes specific to subjects residing in Appalachia. METHODS: There were 81 subjects that met inclusion criteria for this study. These subjects underwent MT for ELVO, and carotid arterial blood samples acquired at time of intervention were sent for proteomic analysis. Samples were processed in accordance with the Blood And Clot Thrombectomy Registry And Collaboration (BACTRAC; clinicaltrials.gov; NCT03153683). Statistical analyses were utilized to examine whether relationships between protein expression and outcomes differed by Appalachian status for functional (NIH Stroke Scale; NIHSS and Modified Rankin Score; mRS), and cognitive outcomes (Montreal Cognitive Assessment; MoCA). RESULTS: No significant differences were found in demographic data or co-morbidities when comparing Appalachian to non-Appalachian subjects. However, time from stroke onset to treatment (last known normal) was significantly longer and edema volume significantly higher in patients from Appalachia. Further, when comparing Appalachian to non-Appalachian subjects, there were significant unadjusted differences in the NIHSS functional outcome. A comprehensive analysis of 184 proteins from Olink proteomic (92 Cardiometabolic and 92 Inflammation panels) showed that the association between protein expression outcomes significantly differed by Appalachian status for seven proteins for the NIHSS, two proteins for the MoCA, and three for the mRS. CONCLUSION: Our study utilizes an ELVO tissue bank and registry to investigate the intracranial/intravascular proteomic environment occurring at the time of thrombectomy. We found that patients presenting from Appalachian areas have different levels of proteomic expression at the time of MT when compared to patients presenting from non-Appalachian areas. These proteins differentially relate to stroke outcome and could be used as prognostic biomarkers, or as targets for novel therapies. The identification of a disparate proteomic response in Appalachian patients provides initial insight to the biological basis for health disparity. Nevertheless, further investigations through community-based studies are imperative to elucidate the underlying causes of this differential response.

CCR3 Expression in Relation to Delayed Microbleeds in a Rat Model of Large Vessel Occlusion.

Thirty percent of ischemic stroke patients develop vascular cognitive impairment and dementia (VCID) within 1 year of stroke onset. The expression of C-C motif chemokine receptor 3 (CCR3) is associated with endothelial dysfunction and memory impairment. CCR3 has been reported to increase after experimental stroke and in human stroke patients. Using an in vivo model of stroke, our study aims to link CCR3 expression with endothelial dysfunction in this rodent stroke model. Methods: 5-hour transient Middle Cerebral Artery Occlusion (5t-MCAO) or sham surgery was performed on rats and tissue collected at 3- and 30-days post-stroke. We measured the change in expression of CCR3 and its ligands in the venous blood before and after occlusion in the rat model.Immunohistochemistry was performed on consecutive coronal brain sections using Prussian blue to visualize microbleeds and DAB to visualize CCR3. Images were quantified using HALO. Results: Using linear regression, we found that increased expression of CCR3 and its ligands after stroke were positively correlated with infarct volume. CCR3 expression was significantly increased in the ipsilateral hemisphere at 30 days post 5t-MCAO. Prussian blue staining was significantly increased in ipsilateral sections at 30 days post-stroke. Immunostaining for CCR3 was primarily detected in endothelium in areas of Prussian blue staining. Conclusions: Our results demonstrate that CCR3 expression is associated with the presence of microbleeds at 30 days but not 3 days post-stroke in the ipsilateral hemisphere, and further supports the link between CCR3 and the endothelial dysfunction that is associated with VCID. CCR3 and its inflammatory pathway is a potential target for reducing endothelial dysfunction after ischemic stroke that may lead to VCID.

Adolescent- and adult-initiated alcohol exposure in mice differentially promotes tumorigenesis and metastasis of breast cancer.

BACKGROUND: Alcohol exposure increases the risk of breast cancer. Alcohol consumption by adolescents is a serious social and public health issue. This study investigated the impact of adolescent alcohol consumption on mammary tumorigenesis and progression and compared it to that of adult alcohol exposure in animal models. METHODS: Female adolescent (5 weeks) and adult (8 weeks) MMTV-Wnt1 mice were exposed to alcohol either chronically or acutely. For chronic alcohol exposure, animals were fed a liquid diet containing 6.7% ethanol for 23 weeks. For acute exposure, animals were treated with ethanol (2.5 g/kg, 25% w/v) via intraperitoneal (IP) injection for 15 days. RESULTS: In control animals, the tumor latency was 18.5 to 22 weeks. Both chronic and acute alcohol exposure in adolescent mice significantly shortened the tumor latency to 9.5 and 8.4 weeks, respectively. However, adult-initiated alcohol exposure had little effect on the tumor latency. Both adolescent- and adult-initiated alcohol exposure significantly increased lung metastasis. Adolescent-initiated alcohol exposure but not adult-initiated alcohol exposure increased the breast cancer stem cell population. Adolescent-initiated alcohol exposure significantly altered the proliferation of mammary epithelial cells, ductal growth, and the formation of terminal end buds in the mammary glands. Adolescent-initiated alcohol exposure but not adult-initiated alcohol exposure increased estradiol levels in the blood. Acute adolescent alcohol exposure also significantly increased blood progesterone levels. Furthermore, adolescent-initiated alcohol exposure activated PAK1 and p38γ MAPK, critical regulators of mammary tumorigenesis and aggressiveness, respectively, while adult-initiated alcohol exposure activated only p38γ MAPK. In addition, both adolescent and adult alcohol exposure significantly decreased the levels of a prognostic marker miR200b. CONCLUSIONS: Adolescent-initiated alcohol exposure enhanced both tumorigenesis and aggressiveness of mammary tumors, while adult-initiated alcohol exposure mainly promoted tumor metastasis. Thus, adolescent mice were more sensitive than adult mice in response to alcohol-induced tumor promotion.

Plasma protein alterations during human large vessel stroke: A controlled comparison study.

BACKGROUND: Stroke is a major cause of death and disability in the United States. Mechanical thrombectomy (MT) and tissue plasminogen activator are the current treatments for ischemic stroke, which have improved clinical outcomes. Despite these treatments, functional and cognitive deficits still occur demonstrating a need for predictive biomarkers for beneficial clinical outcomes which can be used as therapeutic targets for pharmacotherapy. The aim of this study compares the proteomic expression of systemic arterial blood collected at the time of MT to those from a matched cerebrovascular disease (CVD) control cohort. METHODS: The Blood And Clot Thrombectomy Registry And Collaboration (BACTRAC) (clinicaltrials.gov NCT03153683) collects and banks arterial blood, both distal and proximal to the thrombus, from ischemic stroke subjects undergoing MT. Arterial blood from patients undergoing a diagnostic angiogram was also collected and banked as CVD controls. Changes in cardiometabolic and inflammatory proteins between stroke and CVD controls were analyzed via Olink Proteomics. RESULTS: Proteins including ARTN, TWEAK, HGF, CCL28, FGF-5, CXCL9, TRANCE and GDNF were found to be decreased in stroke subjects when compared to CVD controls. CXCL1, CCL5, OSM, GP1BA, IL6, MMP-1, and CXCL5 were increased in stroke subjects when compared to CVD controls. These proteins were also significantly correlated to stroke outcome metrics such as NIHSS, infarct volume and MoCA scoring. CONCLUSION: Overall, acute stroke patients had an increase in inflammatory proteins with a decrease in trophic proteins systemically compared to matched CVD controls. Using our CVD controls, proteins of interest were directly compared to stroke patients with the same cerebrovascular risk factors instead of statistically controlling for comorbidities. The novel methodology of matching an arterial blood CVD control group to a stroke group, as well as controlling for age and comorbid status add to the literature on prognostic stroke biomarkers, which are specific targets for future therapeutics.

Influence of BMI on adenosine deaminase and stroke outcomes in mechanical thrombectomy subjects.

BACKGROUND: Emergent Large Vessel Occlusion (ELVO) strokes are ischemic vascular events for which novel biomarkers and therapies are needed. The purpose of this study is to investigate the role of Body Mass Index (BMI) on protein expression and signaling at the time of ELVO intervention. Additionally, we highlight the protein adenosine deaminase (ADA), which is a deaminating enzyme that degrades adenosine, which has been shown to be neuroprotective in ischemia. We investigate the relationship between ADA and BMI, stroke outcomes, and associated proteomic networks which might aid in personalizing prognosis and future treatment of ELVO stroke. METHODS: The Blood And Clot Thrombectomy And Collaboration (BACTRAC) study is a continually enrolling tissue bank (clinicaltrials.gov NCT03153683) and registry from stroke patients undergoing mechanical thrombectomy (MT). N â€‹= â€‹61 human carotid plasma samples were analyzed for inflammatory and cardiometabolic protein expression by Olink Proteomics. Statistical analyses used t-tests, linear, logistic, and robust regressions, to assess the relationship between BMI, proteomic expression, and stroke-related outcomes. RESULTS: The 61 subjects studied were broken into three categories: normal weight (BMI 18.5-24.9) which contained 19 subjects, overweight (BMI 25-30) which contained 25 subjects, and obese (BMI ≥30) which contained 17 subjects. Normal BMI group was a significantly older population (mean 76 years) when compared to overweight (mean 66 years) and obese (mean 61 years) with significance of p â€‹= â€‹0.041 and p â€‹= â€‹0.005, respectively. When compared to normal weight and overweight categories, the obese category had significantly higher levels of adenosine deaminase (ADA) expression (p â€‹= â€‹0.01 and p â€‹= â€‹0.039, respectively). Elevated levels of ADA were found to have a significant positive correlation with both infarct volume and edema volume (p â€‹= â€‹0.013 and p â€‹= â€‹0.041, respectively), and were associated with a more severe stroke (NIHSS on discharge) and greater stroke related disability (mRS on discharge) with significance of p â€‹= â€‹0.053 and p â€‹= â€‹0.032, respectively. CONCLUSIONS: When examined according to BMI, subjects undergoing MT for ELVO demonstrate significant differences in the expression of certain plasma proteins, including ADA. Levels of ADA were found to be significantly higher in the obese population when compared to normal or overweight groups. Increased levels of ADA in the obese group were predictive of increased infarct volume, edema volume, and worse NIHSS scores and mRS at discharge. These data provide novel biomarker candidates as well as treatment targets while increasing the personalization of stroke prognosis and treatment.

Smoking-Induced Sex Differences in Clinical Outcomes in Patients Undergoing Mechanical Thrombectomy for Stroke.

OBJECTIVE: Ischemic stroke is the fifth leading cause of death in the United States. Smoking accelerates the onset of stroke by 10 years. The effects of smoking status on percent change in National Institutes of Health Stroke Scale (NIHSS) score, infarct volume, and edema volume were examined following mechanical thrombectomy for large vessel occlusion in patients with acute ischemic stroke. METHODS: Subjects (N = 90; >18 years old) were divided into 3 groups based on smoking status: current smokers, previous smokers (defined as having quit >6 months before the ischemic event), and nonsmokers. Percent change in NIHSS score was defined as score at admission minus score at discharge divided by score at admission and was used as a predictor of functional outcome. Linear regression analysis was performed based on infarct or edema volume versus percent change in NIHSS score and separated by sex. RESULTS: Consistent with previous findings, smokers experienced a stroke 10 years earlier than nonsmokers (P = 0.004). Statistically significant linear regressions existed between infarct volume or edema volume in relation to worsening change in NIHSS score with female smokers only. Stroke-induced tissue damage, as measured by magnetic resonance imaging or computed tomography, was predictive of functional recovery only in female smokers. CONCLUSIONS: These findings are valuable for patient counseling, particularly for women, for smoking cessation.

MANF protects pancreatic acinar cells against alcohol-induced endoplasmic reticulum stress and cellular injury.

BACKGROUND/PURPOSE: Heavy alcohol drinking is associated with pancreatitis. Pancreatitis is initiated by the damage to the pancreatic acinar cells. The endoplasmic reticulum (ER) stress has been shown to play an important role in alcohol-induced pancreatic damage. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress-inducible protein. The aim of the study was to determine whether MANF can ameliorate alcohol-induced ER stress and cellular damages to pancreatic acinar cells. METHODS: Alcohol-induced damage to mouse pancreatic 266-6 acinar cells was determined by MTT and flow cytometry. MANF expression was downregulated by MANF siRNA using the Neon Transfection System. The overexpression of MANF was performed by the infection with the adenoviral vector carrying mouse MANF gene. The expression of ER stress markers was determined by immunoblotting and immunofluorescence. RESULTS: Alcohol caused ER stress, oxidative stress and induced apoptosis of 266-6 acinar cells. Recombinant human MANF alleviated alcohol-induced ER stress and cell death by inhibiting IRE1-caspase 12-caspase 3 apoptotic pathway. Overexpression of mouse MANF also protected cells against alcohol-induced apoptosis. In contrast, inhibiting MANF by siRNA exacerbated alcohol-induced cellular damage. CONCLUSIONS: MANF was protective against alcohol-induced ER stress and cellular injury in pancreatic acinar cells. The findings suggest a potential therapeutic value of MANF for alcoholic pancreatitis.

Chronic Voluntary Alcohol Drinking Causes Anxiety-like Behavior, Thiamine Deficiency, and Brain Damage of Female Crossed High Alcohol Preferring Mice.

The central nervous system is vulnerable to chronic alcohol abuse, and alcohol dependence is a chronically relapsing disorder which causes a variety of physical and mental disorders. Appropriate animal models are important for investigating the underlying cellular and molecular mechanisms. The crossed High Alcohol Preferring mice prefer alcohol to water when given free access. In the present study, we used female cHAP mice as a model of chronic voluntary drinking to evaluate the effects of alcohol on neurobehavioral and neuropathological changes. The female cHAP mice had free-choice access to 10% ethanol and water, while control mice had access to water alone at the age of 60-day-old. The mice were exposed to alcohol for 7 months then subjected to neurobehavioral tests including open field (OF), elevated plus maze (EPM), and Morris water maze (MWM). Results from OF and EPM tests suggested that chronic voluntary drinking caused anxiety-like behaviors. After behavior tests, mice were sacrificed, and brain tissues were processed for biochemical analyses. Alcohol altered the levels of several neurotransmitters and neurotrophic factors in the brain including gamma-Aminobutyric acid (GABA), corticotropin-releasing factor, cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor. Alcohol increased the expression of neuroinflammation markers including interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and C-C chemokine receptor 2 (CCR2). Alcohol also induced cleaved caspase-3 and glial fibrillary acidic protein, indicative of neurodegeneration and gliosis. In addition, alcohol inhibited the expression of thiamine transporters in the brain and reduced thiamine levels in the blood. Alcohol also caused oxidative stress and endoplasmic reticulum (ER) stress, and stimulated neurogenesis.

Proteomic changes in intracranial blood during human ischemic stroke.

BACKGROUND: Since 2015, mechanical thrombectomy has been the standard treatment for emergent large vessel occlusion ischemic stroke. OBJECTIVE: To investigate, using the previously published Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC) protocol (clinicaltrials.gov NCT03153683), how the protein expression of a patient's intracranial blood during ischemic stroke compares with the protein expression of their systemic arterial blood in order to better understand and treat stroke. METHODS: Plasma samples from 25 subjects underwent proteomic analysis, where intracranial protein expression was compared with systemic protein levels. Data including sex, comorbidities, infarct volume, and infarct time were included for each subject. RESULTS: A majority of important proteins had a lower expression in intracranial blood than in systemic arterial blood. Proteins with the most significant changes in expression were: endopeptidase at -0.26 (p<0.0001), phospholipid transfer protein (PLTP) at -0.26 (p=0.0005), uromodulin (UMOD) at -0.14 (p=0.002), ficolin-2 (FCN2) at -0.46 (p=0.005), C-C motif chemokine 19 (CCL19) at -0.51 (p<0.0001), C-C motif chemokine 20 (CCL20) at -0.40 (p<0.0001), fibroblast growth factor 21 at -0.37 (p=0.0002), and C-C motif chemokine (CCL23) at -0.43 (p=0.0003). CONCLUSIONS: Evaluation of proteomic changes in the intravascular space of a cerebral infarct in progress in human subjects suggested that changes in proteins such PLTP, fetuin-B (FETUB), and FCN2 may be involved in atherosclerotic changes, and chemokines such as CCL23 are known to play a role in the Th2 autoimmune response. These data provide a scientific springboard for identifying clinically relevant biomarkers for diagnosis/prognosis, and targets for much needed neuroprotective/neuroreparative pharmacotherapies.

Mesencephalic Astrocyte-Derived Neurotrophic Factor (MANF) Regulates Neurite Outgrowth Through the Activation of Akt/mTOR and Erk/mTOR Signaling Pathways.

Neurite outgrowth is essential for brain development and the recovery of brain injury and neurodegenerative diseases. In this study, we examined the role of the neurotrophic factor MANF in regulating neurite outgrowth. We generated MANF knockout (KO) neuro2a (N2a) cell lines using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and demonstrated that MANF KO N2a cells failed to grow neurites in response to RA stimulation. Using MANF siRNA, this finding was confirmed in human SH-SY5Y neuronal cell line. Nevertheless, MANF overexpression by adenovirus transduction or addition of MANF into culture media facilitated the growth of longer neurites in RA-treated N2a cells. MANF deficiency resulted in inhibition of Akt, Erk, mTOR, and P70S6, and impaired protein synthesis. MANF overexpression on the other hand facilitated the growth of longer neurites by activating Akt, Erk, mTOR, and P70S6. Pharmacological blockade of Akt, Erk or mTOR eliminated the promoting effect of MANF on neurite outgrowth. These findings suggest that MANF positively regulated neurite outgrowth by activating Akt/mTOR and Erk/mTOR signaling pathways.

Star-related lipid transfer protein 10 (STARD10): a novel key player in alcohol-induced breast cancer progression.

BACKGROUND: Ethanol abuse promotes breast cancer development, metastasis and recurrence stimulating mammary tumorigenesis by mechanisms that remain unclear. Normally, 35% of breast cancer is Erb-B2 Receptor Tyrosine Kinase 2 (ERBB2)-positive that predisposes to poor prognosis and relapse, while ethanol drinking leads to invasion of their ERBB2 positive cells triggering the phosphorylation status of mitogen-activated protein kinase. StAR-related lipid transfer protein 10 (STARD10) is a lipid transporter of phosphatidylcholine (PC) and phosphatidylethanolamine (PE); changes on membrane composition of PC and PE occur before the morphological tumorigenic events. Interestingly, STARD10 has been described to be highly expressed in 35-40% of ERBB2-positive breast cancers. In this study, we demonstrate that ethanol administration promotes STARD10 and ERBB2 expression that is significantly associated with increased cell malignancy and aggressiveness. MATERIAL AND METHODS: We investigated the effect of ethanol on STARD10-ERBB2 cross-talk in breast cancer cells, MMTV-neu transgenic mice and in clinical ERBB2-positive breast cancer specimens with Western Blotting and Real-time PCR. We also examined the effects of their knockdown and overexpression on transient transfected breast cancer cells using promoter activity, MTT, cell migration, calcium and membrane fluidity assays in vitro. RESULTS: Ethanol administration induces STARD10 and ERBB2 expression in vitro and in vivo. ERBB2 overexpression causes an increase in STARD10 expression, while overexpression of ERBB2's downstream targets, p65, c-MYC, c-FOS or c-JUN induces STARD10 promoter activity, correlative of enhanced ERBB2 function. Ethanol and STARD10-mediated cellular membrane fluidity and intracellular calcium concentration impact ERBB2 signaling pathway as evaluated by enhanced p65 nuclear translocation and binding to both ERBB2 and STARD10 promoters. CONCLUSION: Our finding proved that STARD10 and ERBB2 positively regulate each other's expression and function. Taken together, our data demonstrate that ethanol can modulate ERBB2's function in breast cancer via a novel interplay with STARD10.

Minocycline attenuates ethanol-induced cell death and microglial activation in the developing spinal cord.

Developmental exposure to ethanol may cause fetal alcohol spectrum disorders (FASD), and the immature central nervous system (CNS) is particularly vulnerable to ethanol. In addition to vulnerability in the developing brain, we previously showed that ethanol also caused neuroapoptosis, microglial activation, and neuroinflammation in the spinal cord. Minocycline is an antibiotic that inhibits microglial activation and alleviates neuroinflammation. We sought to determine whether minocycline could protect spinal cord neurons against ethanol-induced damage. In this study, we showed that minocycline significantly inhibited ethanol-induced caspase-3 activation, microglial activation, and the expression of pro-inflammatory cytokines in the developing spinal cord. Moreover, minocycline blocked ethanol-induced activation of glycogen synthase kinase 3 beta (GSK3ß), a key regulator of microglial activation. Meanwhile, minocycline significantly restored ethanol-induced inhibition of protein kinase B (AKT), mammalian target of the rapamycin (mTOR), and ERK1/2 signaling pathways, which were important pro-survival signaling pathways for neurons. Together, minocycline may attenuate ethanol-induced damage to the developing spinal cord by inhibiting microglial activation/neuroinflammation and by restoring the pro-survival signaling.

Role of p38γ MAPK in regulation of EMT and cancer stem cells.

p38γ is a member of p38 MAPK family which contains four isoforms p38α, p38ß, p38γ, and p38δ. p38γ MAPK has unique function and is less investigated. Recent studies revealed that p38γ MAPK may be involved in tumorigenesis and cancer aggressiveness. However, the underlying cellular/molecular mechanisms remain unclear. Epithelial-mesenchymal transition (EMT) is a process that epithelial cancer cells transform to facilitate the loss of epithelial features and gain of mesenchymal phenotype. EMT promotes cancer cell progression and metastasis, and is involved in the regulation of cancer stem cells (CSCs) which have self-renewal capacity and are resistant to chemotherapy and target therapy. We showed that p38γ MAPK significantly increased EMT in breast cancer cells; over-expression of p38γ MAPK enhanced EMT while its down-regulation inhibited EMT. Meanwhile, p38γ MAPK augmented CSC population while knock down of p38γ MAPK decreased CSC ratio in breast cancer cells. MicroRNA-200b (miR-200b) was down-stream of p38γ MAPK and inhibited by p38γ MAPK; miR-200b mimics blocked p38γ MAPK-induced EMT while miR-200b inhibitors promoted EMT. p38γ MAPK regulated miR-200b through inhibiting GATA3. p38γ MAPK induced GATA3 ubiquitination, leading to its proteasome-dependent degradation. Suz12, a Polycomb group protein, was down-stream of miR-200b and involved in miR-200b regulation of EMT. Thus, our study established an important role of p38γ MAPK in EMT and identified a novel signaling pathway for p38γ MAPK-mediated tumor promotion.

Effects of hexavalent chromium on mouse splenic T lymphocytes.

Hexavalent chromium [Cr(VI)] is widely used in various industrial processes and has been recognized as a carcinogen. As the first line of host defense system, the immune system can be a primary target of Cr(VI). T cell population represents a major arm of the immune system that plays a critical role in host anti-tumor immunity. Dysfunction of T cells, such as exhaustion under the persistent presence of tumor antigen, compromise host anti-tumor immunity resulting in oncogenesis. Previous studies have shown Cr(VI) exposure alters the phenotype of human peripheral blood lymphocytes. However, the mechanism of the alteration and whether such an alteration in immunity affects immunosurveillance and promotes carcinogenicity are not clear. Using a culture of mouse splenic T cells as an in vitro model system, the present study assessed the effects of Cr(VI) on T cells, as the first step in our investigation of the mechanism underlying Cr(VI)-inhibited immunosurveillance and carcinogenesis. Our results showed that Cr(VI) decreased the viability of CD4+ and CD8+ T cells and inhibited their activation, proliferation, cytokine release and cytolytic function.

M2 polarization of macrophages facilitates arsenic-induced cell transformation of lung epithelial cells.

The alterations in microenvironment upon chronic arsenic exposure may contribute to arsenic-induced lung carcinogenesis. Immune cells, such as macrophages, play an important role in mediating the microenvironment in the lungs. Macrophages carry out their functions after activation. There are two activation status for macrophages: classical (M1) or alternative (M2); the latter is associated with tumorigenesis. Our previous work showed that long-term arsenic exposure induces transformation of lung epithelial cells. However, the crosstalk between epithelial cells and macrophages upon arsenic exposure has not been investigated. In this study, using a co-culture system in which human lung epithelial cells are cultured with macrophages, we determined that long-term arsenic exposure polarizes macrophages towards M2 status through ROS generation. Co-culture with epithelial cells further enhanced the polarization of macrophages as well as transformation of epithelial cells, while blocking macrophage M2 polarization decreased the transformation. In addition, macrophage M2 polarization decreased autophagy activity, which may account for increased cell transformation of epithelial cells with co-culture of macrophages.

Thiamine deficiency induces endoplasmic reticulum stress and oxidative stress in human neurons derived from induced pluripotent stem cells.

Thiamine (vitamin B1) deficiency (TD) plays a major role in the etiology of Wernicke's encephalopathy (WE) which is a severe neurological disorder. TD induces selective neuronal cell death, neuroinflammation, endoplasmic reticulum (ER) stress and oxidative stress in the brain which are commonly observed in many aging-related neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and progressive supranuclear palsy (PSP). However, the underlying cellular and molecular mechanisms remain unclear. The progress in this line of research is hindered due to the lack of appropriate in vitro models. The neurons derived for the human induced pluripotent stem cells (hiPSCs) provide a relevant and powerful tool for the research in pharmaceutical and environmental neurotoxicity. In this study, we for the first time used human induced pluripotent stem cells (hiPSCs)-derived neurons (iCell neurons) to investigate the mechanisms of TD-induced neurodegeneration. We showed that TD caused a concentration- and duration-dependent death of iCell neurons. TD induced ER stress which was evident by the increase in ER stress markers, such as GRP78, XBP-1, CHOP, ATF-6, phosphorylated eIF2α, and cleaved caspase-12. TD also triggered oxidative stress which was shown by the increase in the expression 2,4-dinitrophenyl (DNP) and 4-hydroxynonenal (HNE). ER stress inhibitors (STF-083010 and salubrinal) and antioxidant N-acetyl cysteine (NAC) were effective in alleviating TD-induced death of iCell neurons, supporting the involvement of ER stress and oxidative stress. It establishes that the iCell neurons are a novel tool to investigate cellular and molecular mechanisms for TD-induced neurodegeneration.

AIM2 inflammasome mediates Arsenic-induced secretion of IL-1 ß and IL-18.

Chronic sterile inflammation has been implicated in the pathogenesis of many cancers, including skin cancer. Chronic arsenic exposure is closely associated with the development of skin cancer. However, there is a lack of understanding how arsenic induces chronic inflammation in the skin. Interleukin-1 family cytokines play a central role in regulating immune and inflammatory response. IL-1α, IL-1ß and IL-18 are three pro-inflammatory cytokines in IL-1 family. Their secretion, especially the secretion of IL-1ß and IL-18, is regulated by inflammasomes which are multi-protein complexes containing sensor proteins, adaptor protein and caspase-1. The data from current study show sub-chronic arsenic exposure activates AIM2 inflammasome which in turn activates caspase-1 and enhances the secretion of IL-1ß and IL-18 in HaCaT cells and the skin of BALB/c mice. In addition, arsenic-promoted activation of AIM2 inflammasome and increase of IL-1ß/IL-18 production are inhibited by PKR inhibitor in HaCaT cells or in the skin of PKR mutant mice, indicating a potential role of PKR in arsenic-induced sterile inflammation.

ErbB2 and p38γ MAPK mediate alcohol-induced increase in breast cancer stem cells and metastasis.

BACKGROUND: Both epidemiological and experimental studies suggest that excessive alcohol exposure increases the risk for breast cancer and enhances metastasis/recurrence. We have previously demonstrated that alcohol enhanced the migration/invasion of breast cancer cells and cancer cells overexpressing ErbB2/HER2 were more sensitive to alcohol exposure. However, the underlying mechanisms remain unclear. This study was designed to investigate the mechanisms underlying alcohol-enhanced aggressiveness of breast cancer. Cancer stem cells (CSCs) play a critical role in cancer metastasis and recurrence. METHODS: We evaluated the effect of chronic alcohol exposure on mammary tumor development/metastasis in MMTV-neu transgenic mice and investigated the cell signaling in response to alcohol exposure in breast cancer cells overexpressing ErbB2/HER2. RESULTS AND DISCUSSION: Chronic alcohol exposure increased breast cancer stem cell-like CSC population and enhanced the lung and colon metastasis in MMTV-neu transgenic mice. Alcohol exposure caused a drastic increase in CSC population and mammosphere formation in breast cancer cells overexpressing ErbB2/HER2. Alcohol exposure stimulated the phosphorylation of p38γ MAPK (p-p38γ) which was co-localized with phosphorylated ErbB2 and CSCs in the mammary tumor tissues. In vitro results confirmed that alcohol activated ErbB2/HER2 and selectively increased p-p38γ MAPK as well as the interaction between p38γ MAPK and its substrate, SAP97. However, alcohol did not affect the expression/phosphorylation of p38α/ß MAPKs. In breast cancer cell lines, high expression of ErbB2 and p-p38γ MAPK was generally correlated with more CSC population. Blocking ErbB2 signaling abolished heregulin ß1- and alcohol-stimulated p-p38γ MAPK and its association with SAP97. More importantly, p38γ MAPK siRNA significantly inhibited an alcohol-induced increase in CSC population, mammosphere formation and migration/invasion of breast cancer cells overexpressing ErbB2. CONCLUSIONS: p38γ MAPK is downstream of ErbB2 and plays an important role in alcohol-enhanced aggressiveness of breast cancer. Therefore, in addition to ErbB2/HER2, p38γ MAPK may be a potential target for the treatment of alcohol-enhanced cancer aggressiveness.

Chronic ethanol exposure enhances the aggressiveness of breast cancer: the role of p38γ.

Both epidemiological and experimental studies suggest that ethanol may enhance aggressiveness of breast cancer. We have previously demonstrated that short term exposure to ethanol (12-48 hours) increased migration/invasion in breast cancer cells overexpressing ErbB2, but not in breast cancer cells with low expression of ErbB2, such as MCF7, BT20 and T47D breast cancer cells. In this study, we showed that chronic ethanol exposure transformed breast cancer cells that were not responsive to short term ethanol treatment to a more aggressive phenotype. Chronic ethanol exposure (10 days - 2 months) at 100 (22 mM) or 200 mg/dl (44 mM) caused the scattering of MCF7, BT20 and T47D cell colonies in a 3-dimension culture system. Chronic ethanol exposure also increased colony formation in an anchorage-independent condition and stimulated cell invasion/migration. Chronic ethanol exposure increased cancer stem-like cell (CSC) population by more than 20 folds. Breast cancer cells exposed to ethanol in vitro displayed a much higher growth rate and metastasis in mice. Ethanol selectively activated p38γ MAPK and RhoC but not p38α/ß in a concentration-dependent manner. SP-MCF7 cells, a derivative of MCF7 cells which compose mainly CSC expressed high levels of phosphorylated p38γ MAPK. Knocking-down p38γ MAPK blocked ethanol-induced RhoC activation, cell scattering, invasion/migration and ethanol-increased CSC population. Furthermore, knocking-down p38γ MAPK mitigated ethanol-induced tumor growth and metastasis in mice. These results suggest that chronic ethanol exposure can enhance the aggressiveness of breast cancer by activating p38γ MAPK/RhoC pathway.

Role of MCP-1 in alcohol-induced aggressiveness of colorectal cancer cells.

Epidemiological studies demonstrate that alcohol consumption is associated with an increased risk of colorectal cancer (CRC). In addition to promoting carcinogenesis, alcohol may also accelerate the progression of existing CRC. We hypothesized that alcohol may enhance the aggressiveness of CRC. In this study, we investigated the effect of alcohol on the migration/invasion and metastasis of CRC. Alcohol increased the migration/invasion of colorectal cancer cells (DLD1, HCT116, HT29, and SW480) in a concentration-dependent manner. Among these colon cancer cell lines, HCT116 cells were most responsive while HT29 cells were the least responsive to ethanol-stimulated cell migration/invasion. These in vitro results were supported by animal studies which demonstrated that ethanol enhanced the metastasis of colorectal cancer cells to the liver and lung. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that plays an important role in regulating tumor microenvironment and metastasis. Alcohol increased the expression of MCP-1 and its receptor CCR2 at both protein and mRNA levels. The pattern of alcohol-induced alterations in MCP-1 expression was consistent with its effect on migration/invasion; HCT116 cells displayed the highest up-regulation of MCP-1/CCR2 in response to alcohol exposure. An antagonist of CCR2 blocked alcohol-stimulated migration. Alcohol caused an initial cytosolic accumulation of ß-catenin and its subsequent nuclear translocation by inhibiting GSK3ß activity. Alcohol stimulated the activity of MCP-1 gene promoter in a ß-catenin-dependent manner. Furthermore, knock-down of MCP-1/CCR2 or ß-catenin was sufficient to inhibit alcohol-induced cell migration/invasion. Together, these results suggested that alcohol may promote the metastasis of CRC through modulating GSK3ß/ß-catenin/MCP-1 pathway.