Stat3 mediates LIF‐induced protection of astrocytes against toxic ROS by upregulating the UPC2 mRNA pool

Reactive oxygen species (ROS) have been implicated in various types of CNS damage, including stroke. We used a cultured astrocyte model to explore mechanisms of survival of CNS cells following ROS damage. We found that pretreatment with leukemia inhibitory factor (LIF) preserves astrocytes exposed to toxic levels of t‐BHP by inhibiting an increase in intracellular ROS following t‐BHP treatment. Astrocytes lacking functional Stat3 did not benefit from the pro‐survival or antioxidant effects of LIF. Inhibition of mitochondrial uncoupling protein 2 (UCP2) using a chemical inhibitor or siRNA abrogates the prosurvival effects of LIF, indicating a critical role for UCP2 in modulation of mitochondrial ROS production in survival following ROS exposure. LIF treatment of astrocytes results in increased UCP2 mRNA that is accompanied by an increase in Stat3 binding to the UCP2 promoter region. Although treatment with LIF alone did not increase UCP2 protein, a combination of LIF treatment and ROS stress led to increased UCP2 protein levels. We conclude that LIF protects astrocytes from ROS‐induced death by increasing UCP2 mRNA, allowing cells to respond to ROS stress by rapidly producing UCP2 protein that ultimately decreases endogenous mitochondrial ROS production. GLIA 2014;62:159–170     

Glutamate Excitotoxicity Activates the MAPK/ERK Signaling Pathway and Induces the Survival of Rat Hippocampal Neurons In Vivo

Current knowledge concerning the molecular mechanisms of the cellular response to excitotoxic insults in neurodegenerative diseases is insufficient. Although glutamate (Glu) has been widely studied as the main excitatory neurotransmitter and principal excitotoxic agent, the neuroprotective response enacted by neurons is not yet completely understood. Some of the molecular participants have been revealed, but the signaling pathways involved in this protective response are just beginning to be identified. Here, we demonstrate in vivo that, in response to the cell damage and death induced by Glu excitotoxicity, neurons orchestrate a survival response through the extracellular signal-regulated kinase (ERK) signaling pathway by increasing ERK expression in the rat hippocampal (CA1) region, allowing increased neuronal survival. In addition, this protective response is specifically reversed by U0126, an ERK inhibitor, which promotes cell death only when it is administered together with Glu. Our findings demonstrate that the ERK signaling pathway has a neuroprotective role in the response to Glu-induced excitotoxicity in hippocampal neurons. Therefore, the ERK signaling pathway may be activated as a cellular response to excitotoxic injury to prevent damage and neural loss, representing a novel therapeutic target in the treatment of neurodegenerative diseases.     

Longitudinal features of stir bright signal in FSHD1

Introduction: Magnetic resonance imaging of muscle shows short tau‐inversion recovery (STIR) brightness in autosomal dominant facioscapulohumeral muscular dystrophy (FSHD1) suggestive of active inflammation/injury. We measured the longitudinal stability/progression of this potential disease biomarker. Methods: Nine subjects underwent calf MRI imaging over 2 years. Two radiologists evaluated qualitative muscle changes. Results: In 3/9 subjects, calf muscles demonstrated moderate/severe STIR hyperintensity at Time 1 that had progressed to fatty replacement 2 years later (Time 2). In the remaining subjects, moderate/severe muscle STIR abnormalities, when present, were consistent between exams. Mild STIR+ elevations had roughly similar patterns between exams. Conclusions: Moderate/severe STIR hyperintensities often foreshadow fatty replacement over a 2‐year interval. Whether longer time courses are required to observe muscle degeneration and fatty replacement in some subjects remains to be explored. Muscle Nerve 49 : 257–260, 2014     

Molecular Mechanisms Underlying the Nephroprotective Effects of PACAP in Diabetes

Diabetic nephropathy is the leading cause of end-stage renal failure and accounts for 30–40 % of patients entering renal transplant programmes. The nephroprotective effects of the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP38) against diabetes have been shown previously, but the molecular mechanisms responsible for these effects remain unknown. In the present study, we showed that PACAP treatment counteracted the diabetes-induced increase in the level of the proapoptotic pp38MAPK and cleaved caspase-3 and also decreased the p60 subunit of NFκB. The examined antiapoptotic factors, including pAkt and pERK1/2, showed a slight increase in the diabetic kidneys, while PACAP treatment resulted in a notable elevation of these proteins. PCR and Western blot revealed the downregulation of fibrotic markers, like collagen IV and TGF-β1 in the kidney. PACAP treatment resulted in increased expression of the antioxidant glutathione. We conclude that the nephroprotective effect of PACAP in diabetes is, at least partly, due to its antiapoptotic, antifibrotic and antioxidative effect in addition to the previously described antiinflammatory effect.     

High Serum Levels of Vascular Endothelial Growth Factor-A and Transforming Growth Factor-β1 Before Neoadjuvant Chemoradiotherapy Predict Poor Outcomes in Patients with Esophageal Squamous Cell Carcinoma Receiving Combined Modality Therapy

Background and Purpose

This study was aimed at using proximity ligation assay (PLA) followed by enzyme-linked immunosorbent assay (ELISA) to identify serum biomarkers that predict treatment response and survival for patients with esophageal squamous cell carcinoma (ESCC) undergoing neoadjuvant concurrent chemoradiotherapy (CCRT) followed by esophagectomy.

Methods

Seventy-nine patients with ESCC receiving CCRT of taxane-based/5-fluorouracil-based chemotherapy and 40 Gy followed by surgery were enrolled. Serum samples were collected before and <1 month after CCRT. Fifteen biomarkers were analyzed using PLA. Biomarkers significantly correlating with pathological response/survival were verified by ELISA. Associations of the serum level of biomarkers and clinical factors with pathological response, disease-free survival (DFS), and overall survival (OS) were evaluated by analysis of variance and log-rank tests.

Results

Thirty patients had complete response (38 %), 37 had microscopic residual disease (47 %), and 12 had macroscopic residual disease (15 %). With a median follow-up of 52.8 months, the median DFS was 43 months. Among the 15 biomarkers screened by PLA, vascular endothelial growth factor (VEGF)-A and transforming growth factor (TGF)-β1 were significantly associated with pathological response and/or DFS. These biomarkers were further analyzed by ELISA to confirm initial biomarker findings by PLA. After ELISA of these two markers, only VEGF-A levels were significantly correlated with pathological response. On multivariate analysis, patients with combined high pre-CCRT VEGF-A and TGF-β1 levels (greater than or equal to the median), independent of pathological response, had significantly worse DFS (11 months vs. median not reached; p = 0.007) and OS (16 vs. 46 months; p = 0.07).

Conclusions

Pre-CCRT serum VEGF-A and TGF-β1 levels may be used to predict pathological response and survivals for ESCC patients receiving combined-modality therapy.     

Roadmap for the development of the University of North Carolina at Chapel Hill Genitourinary OncoLogy Database—UNC GOLD

BackgroundThe management of genitourinary malignancies requires a multidisciplinary care team composed of urologists, medical oncologists, and radiation oncologists. A genitourinary (GU) oncology clinical database is an invaluable resource for patient care and research. Although electronic medical records provide a single web-based record used for clinical care, billing, and scheduling, information is typically stored in a discipline-specific manner and data extraction is often not applicable to a research setting. A GU oncology database may be used for the development of multidisciplinary treatment plans, analysis of disease-specific practice patterns, and identification of patients for research studies. Despite the potential utility, there are many important considerations that must be addressed when developing and implementing a discipline-specific database.Methods and materialsThe creation of the GU oncology database including prostate, bladder, and kidney cancers with the identification of necessary variables was facilitated by meetings of stakeholders in medical oncology, urology, and radiation oncology at the University of North Carolina (UNC) at Chapel Hill with a template data dictionary provided by the Department of Urologic Surgery at Vanderbilt University Medical Center. Utilizing Research Electronic Data Capture (REDCap, version 4.14.5), the UNC Genitourinary OncoLogy Database (UNC GOLD) was designed and implemented.ResultsThe process of designing and implementing a discipline-specific clinical database requires many important considerations. The primary consideration is determining the relationship between the database and the Institutional Review Board (IRB) given the potential applications for both clinical and research uses. Several other necessary steps include ensuring information technology security and federal regulation compliance; determination of a core complete dataset; creation of standard operating procedures; standardizing entry of free text fields; use of data exports, queries, and de-identification strategies; inclusion of individual investigators' data; and strategies for prioritizing specific projects and data entry.ConclusionsA discipline-specific database requires a buy-in from all stakeholders, meticulous development, and data entry resources to generate a unique platform for housing information that may be used for clinical care and research with IRB approval. The steps and issues identified in the development of UNC GOLD provide a process map for others interested in developing a GU oncology database.     

Does Resident Experience Affect Outcomes in Complex Abdominal Surgery? Pancreaticoduodenectomy as an Example

Objectives

Understanding the factors contributing to improved postoperative patient outcomes remains paramount. For complex abdominal operations such as pancreaticoduodenectomy (PD), the influence of provider and hospital volume on surgical outcomes has been described. The impact of resident experience is less well understood.

Methods

We reviewed perioperative outcomes after PD at a single high-volume center between 2006 and 2012. Resident participation and outcomes were collected in a prospectively maintained database. Resident experience was defined as postgraduate year (PGY) and number of PDs performed.

Results

Forty-three residents and four attending surgeons completed 686 PDs. The overall complication rate was 44 %; PD-specific complications (defined as pancreatic fistula, delayed gastric emptying, intraabdominal abscess, wound infection, and bile leak) occurred in 28 % of patients. The overall complication rates were similar when comparing PGY 4 to PGY 5 residents (55.3 vs. 43.0 %; p?>?0.05). On univariate analysis, there was a difference in PD-specific complications seen between a PGY 4 as compared to a PGY 5 resident (44 vs. 27 %, respectively; p?=?0.016). However, this was not statistically significant when adjusted for attending surgeon. Logistic regression demonstrated that as residents perform more cases, PD-specific complications decrease (OR?=?0.97; p?<?0.01). For a resident's first PD case, the predicted probability of a PD-specific complication is 27 %; this rate decreases to 19 % by resident case number 15.

Conclusions

Complex cases, such as PD, provide unparalleled learning opportunities and remain an important component of surgical training. We highlight the impact of resident involvement in complex abdominal operations, demonstrating for the first time that as residents build experience with PD, patient outcomes improve. This is consistent with volume–outcome relationships for attending physicians and high-volume hospitals. Maximizing resident repetitive exposure to complex procedures benefits both the patient and the trainee.