Hippocampal Memory Recovery After Acute Stress: A Behavioral, Morphological and Molecular Study

Indexación: Scopus.Laboratory of Neuroplasticity and Neurogenetics, Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile, 2Laboratorio Farmacología del Comportamiento, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile, 3Department of Kinesiology, Faculty of Health Sciences, Universidad Católica del Maule, Talca, Chile, 4Facultad de Psicología, Universidad de Talca, Talca, Chile, 5Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile, 6Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.This study was supported by the following grants: Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT) 1120528 (JLF), Fondo Central de Investigación, Universidad de Chile ENL025/16 (JLF).Several studies have shown that a single exposure to stress may improve or impair learning and memory processes, depending on the timing in which the stress event occurs with relation to the acquisition phase. However, to date there is no information about the molecular changes that occur at the synapse during the stress-induced memory modification and after a recovery period. In particular, there are no studies that have evaluated—at the same time—the temporality of stress and stress recovery period in hippocampal short-term memory and the effects on dendritic spine morphology, along with variations in N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits. The aim of our study was to take a multidimensional approach to investigate concomitant behavioral, morphological and molecular changes induced by a single restraint stress exposure (2.5 h) and a recovery period of 6 and 24 h in rats. We found that acute stress elicited a reduced preference to explore an object placed in a novel position (a hippocampal-dependent task). These changes were accompanied by increased activity of LIM kinase I (LIMK; an actin-remodeling protein) and increased levels of NR2A subunits of NMDA receptors. After 6 h of recovery from stress, rats showed similar preference to explore an object placed in a novel or familiar position, but density of immature spines increased in secondary CA1 apical dendrites, along with a transient rise in GluA2 AMPA receptor subunits. After 24 h of recovery from stress, the animals showed a preference to explore an object placed in a novel position, which was accompanied by a normalization of NMDA and AMPA receptor subunits to control values. Our data suggest that acute stress produces reversible molecular and behavioral changes 24 h after stress, allowing a full reestablishment of hippocampal-related memory. Further studies need to be conducted to deepen our understanding of these changes and their reciprocal interactions.Adaptive stress responses are a promising avenue to develop interventions aiming at restoring hippocampal function impaired by repetitive stress exposure. © 2018 Aguayo, Tejos-Bravo, Díaz-Véliz, Pacheco, García-Rojo, Corrales, Olave, Aliaga, Ulloa, Avalos, Román-Albasini, Rojas and Fiedler.https://www.frontiersin.org/articles/10.3389/fnmol.2018.00283/ful

Involved margins after lumpectomy for breast cancer: Always to be re-excised?

Background: The oncologic benefit of upfront re-excision of involved margins after breast-conserving surgery in the context of current multimodal clinical management of breast cancer is unclear. The aim of the present study was to assess the 5-years locoregional recurrence (LRR)-free and distant metastases (DM)-free survival probabilities in patients not undergoing re-excision of positive margins after lumpectomy for breast cancer. Methods: A cohort of 104 patients with positive margins not undergoing re-excision was matched by propensity score with a cohort of 2006 control patients with clear margins after breast-conserving surgery, treated between 2008 and 2018. A multivariate survival analysis was performed accounting for all variables related to LRR and DM, including adjuvant treatments. Results: After adjusting for potential confounders, avoiding to re-excise a positive margin after lumpectomy had no effect on 5-years LRR-free survival probability (HR 0.98, 95%CI 0.36-2.67, p = 0.96) or 5-years DM-free survival probability (HR 0.37, 95%CI 0.08-1.61, p = 0.18). No correlation was found between occurrence of LRR and number of involved margins (HR 1.28, 95%CI 0.10-12.4, Log-rank p = 0.83), or extension of infiltrating disease (HR 1.21, 95%CI 0.20-7.40, Log-rank p = 0.83), but a trend toward higher LRR probability was found for invasive ductal (HR 6.92, 95%CI 0.7-68.8, Log-rank p = 0.10) and invasive lobular cancer (HR 12.95, 95%CI 0.79-213.6, Log-rank p = 0.07) on positive margins. Conclusions: In the era of multimodal treatment of breast cancer and accurate strategies to reduce the probability of residual disease in the post-lumpectomy cavity, re-excision of positive margins might be omitted in selected patients with low-risk breast cancers

Fast quantification of extracellular vesicles levels in early breast cancer patients by Single Molecule Detection Array (SiMoA)

Purpose: Preliminary reports suggest that extracellular vesicles (EVs) might be a promising biomarker for breast cancer (BC). However, the quantification of plasmatic levels of EVs is a complex task. To overcome these limitations, we developed a new, fast, and easy to use assay for the quantification of EVs directly in plasma based on the use of Single-Molecule Array (SiMoA). Methods: By using SiMoA to identify CD9+/CD63+ EVs, we analyzed plasma samples of 181 subjects (95 BC and 86 healthy controls, HC). A calibration curve, made of a serial dilution of lyophilized standards from human plasma, was used in each run to ensure the obtainment of quantitative results from the assay. In a subgroup of patients, EVs concentrations were estimated in plasma before and after 30 days from cancer surgery. Additional information on the size of EVs were also acquired using a Nanosight system to obtain a clearer understanding of the mechanism underlying the releases of EVs associated with the presence of cancer. Results: The measured levels of EVs resulted significantly higher in BC patients (median values 1179.1 ng/μl vs 613.0 ng/μl, p < 0.0001). ROC curve was used to define the optimal cut-off level of the test at 1034.5 ng/μl with an AUC of 0.75 [95% CI 0.68–0.82]. EVs plasmatic concentrations significantly decreased after cancer surgery compared to baseline values (p = 0.014). No correlation was found between EVs concentration and clinical features of BC. Conclusion: SiMoA assay allows plasmatic EVs levels detection directly without any prior processing. EVs levels are significantly higher in BC patients and significantly decreases after cancer surgery

Raman spectroscopy reveals that biochemical composition of breast microcalcifications correlates with histopathologic features

Breast microcalcifications are a common mammographic finding. Microcalcifications are considered suspicious signs of breast cancer and a breast biopsy is required, however, cancer is diagnosed in only a few patients. Reducing unnecessary biopsies and rapid characterization of breast microcalcifications are unmet clinical needs. In this study, 473 microcalcifications detected on breast biopsy specimens from 56 patients were characterized entirely by Raman mapping and confirmed by X-ray scattering. Microcalcifications from malignant samples were generally more homogeneous, more crystalline, and characterized by a less substituted crystal lattice compared with benign samples. There were significant differences in Raman features corresponding to the phosphate and carbonate bands between the benign and malignant groups. In addition to the heterogeneous composition, the presence of whitlockite specifically emerged as marker of benignity in benign microcalcifications. The whole Raman signature of each microcalcification was then used to build a classification model that distinguishes microcalcifications according to their overall biochemical composition. After validation, microcalcifications found in benign and malignant samples were correctly recognized with 93.5% sensitivity and 80.6% specificity. Finally, microcalcifications identified in malignant biopsies, but located outside the lesion, reported malignant features in 65% of in situ and 98% of invasive cancer cases, respectively, suggesting that the local microenvironment influences microcalcification features. This study confirms that the composition and structural features of microcalcifications correlate with breast pathology and indicates new diagnostic potentialities based on microcalcifications assessment. Significance: Raman spectroscopy could be a quick and accurate diagnostic tool to precisely characterize and distinguish benign from malignant breast microcalcifications detected on mammography

Development of a novel nomogram-based online tool to predict axillary status after neoadjuvant chemotherapy in cN+ breast cancer: A multicentre study on 1,950 patients

Background: Type of axillary surgery in breast cancer (BC) patients who convert from cN + to ycN0 after neoadjuvant chemotherapy (NAC) is still debated. The aim of the present study was to develop and validate a preoperative predictive nomogram to select those patients with a low risk of residual axillary disease after NAC, in whom axillary surgery could be minimized. Patients and methods: 1950 clinically node-positive BC patients from 11 Breast Units, treated by NAC and subsequent surgery, were included from 2005 to 2020. Patients were divided in two groups: those who achieved nodal pCR vs. those with residual nodal disease after NAC. The cohort was divided into training and validation set with a geographic separation criterion. The outcome was to identify independent predictors of axillary pathologic complete response (pCR). Results: Independent predictive factors associated to nodal pCR were axillary clinical complete response (cCR) after NAC (OR 3.11, p < 0.0001), ER-/HER2+ (OR 3.26, p < 0.0001) or ER+/HER2+ (OR 2.26, p = 0.0002) or ER-/HER2- (OR 1.89, p = 0.009) BC, breast cCR (OR 2.48, p < 0.0001), Ki67 > 14% (OR 0.52, p = 0.0005), and tumor grading G2 (OR 0.35, p = 0.002) or G3 (OR 0.29, p = 0.0003). The nomogram showed a sensitivity of 71% and a specificity of 73% (AUC 0.77, 95%CI 0.75\u20130.80). After external validation the accuracy of the nomogram was confirmed. Conclusion: The accuracy makes this freely-available, nomogram-based online tool useful to predict nodal pCR after NAC, translating the concept of tailored axillary surgery also in this setting of patients

Low neutrophil-to-lymphocyte ratio and pan-immune-inflammation-value predict nodal pathologic complete response in 1274 breast cancer patients treated with neoadjuvant chemotherapy: a multicenter analysis

Background: Systemic inflammatory markers draw great interest as potential blood-based prognostic factors in several oncological settings. Objectives: The aim of this study is to evaluate whether neutrophil-to-lymphocyte ratio (NLR) and pan-immune-inflammation value (PIV) predict nodal pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in node-positive (cN+) breast cancer (BC) patients. Design: Clinically, cN+ BC patients undergoing NAC followed by breast and axillary surgery were enrolled in a multicentric study from 11 Breast Units. Methods: Pretreatment blood counts were collected for the analysis and used to calculate NLR and PIV. Logistic regression analyses were performed to evaluate independent predictors of nodal pCR. Results: A total of 1274 cN+ BC patients were included. Nodal pCR was achieved in 586 (46%) patients. At multivariate analysis, low NLR [odds ratio (OR) = 0.71; 95% CI, 0.51–0.98; p = 0.04] and low PIV (OR = 0.63; 95% CI, 0.44–0.90; p = 0.01) were independently predictive of increased likelihood of nodal pCR. A sub-analysis on cN1 patients (n = 1075) confirmed the statistical significance of these variables. PIV was significantly associated with axillary pCR in estrogen receptor (ER)−/human epidermal growth factor receptor 2 (HER2)+ (OR = 0.31; 95% CI, 0.12–0.83; p = 0.02) and ER−/HER2− (OR = 0.41; 95% CI, 0.17–0.97; p = 0.04) BC patients. Conclusion: This study found that low NLR and PIV levels predict axillary pCR in patients with BC undergoing NAC. Registration: Eudract number NCT05798806

Antidepressant-relevant behavioral and synaptic molecular effects of long-term fasudil treatment in chronically stressed male rats

Several lines of evidence suggest that antidepressant drugs may act by modulating neuroplasticity pathways in key brain areas like the hippocampus. We have reported that chronic treatment with fasudil, a Rho-associated protein kinase inhibitor, prevents both chronic stress-induced depressive-like behavior and morphological changes in CA1 area. Here, we examined the ability of fasudil to (i) prevent stress-altered behaviors, (ii) influence the levels/phosphorylation of glutamatergic receptors and (iii) modulate signaling pathways relevant to antidepressant actions. 89 adult male Sprague-Dawley rats received intraperitoneal fasudil injections (10 mg/kg/day) or saline vehicle for 18 days. Some of these animals were daily restraint-stressed from day 5–18 (2.5 h/day). 24 hr after treatments, rats were either evaluated for behavioral tests (active avoidance, anxiety-like behavior and object location) or euthanized for western blot analyses of hippocampal whole extract and synaptoneurosome-enriched fractions. We report that fasudil prevents stress-induced impairments in active avoidance, anxiety-like behavior and novel location preference, with no effect in unstressed rats. Chronic stress reduced phosphorylations of ERK-2 and CREB, and decreased levels of GluA1 and GluN2A in whole hippocampus, without any effect of fasudil. However, fasudil decreased synaptic GluA1 Ser831 phosphorylation in stressed animals. Additionally, fasudil prevented stress-decreased phosphorylation of GSK-3β at Ser9, in parallel with an activation of the mTORC1/4E-BP1 axis, both in hippocampal synaptoneurosomes, suggesting the activation of the AKT pathway. Our study provides evidence that chronic fasudil treatment prevents chronic stress-altered behaviors, which correlated with molecular modifications of antidepressant-relevant signaling pathways in hippocampal synaptoneurosomes