Involvement of Lipophagy and Chaperone-Mediated Autophagy in the Pathogenesis of Non-Alcoholic Fatty Liver Disease by Regulation of Lipid Droplets.

Non-alcoholic fatty liver disease (NAFLD) is defined as the accumulation of lipids in the form of lipid droplets in more than 5% of hepatocytes. It is regarded as a range of diverse pathologies, including simple steatosis and steatohepatitis. The structural characteristics of lipid droplets, along with their protein composition, mainly including perilipins, have been implicated in the etiology of the disease. These proteins have garnered increasing attention as a pivotal regulator since their levels and distinct expression appear to be associated with the progression from simple steatosis to steatohepatitis. Perilipins are target proteins of chaperone-mediated autophagy, and their degradation is a prerequisite for lipolysis and lipophagy to access the lipid core. Both lipophagy and chaperone-mediated autophagy have significant implications on the development of the disease, as evidenced by their upregulation during the initial phases of simple steatosis and their subsequent downregulation once steatosis is established. On the contrary, during steatohepatitis, the process of chaperone-mediated autophagy is enhanced, although lipophagy remains suppressed. Evidently, the reduced levels of autophagic pathways observed in simple steatosis serve as a defensive mechanism against lipotoxicity. Conversely, in steatohepatitis, chaperone-mediated autophagy fails to compensate for the continuous generation of small lipid droplets and thus cannot protect hepatocytes from lipotoxicity.

The Role of Oxidative Stress and Cellular Senescence in the Pathogenesis of Metabolic Associated Fatty Liver Disease and Related Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) represents a worryingly increasing cause of malignancy-related mortality, while Metabolic Associated Fatty Liver Disease (MAFLD) is going to become its most common cause in the next decade. Understanding the complex underlying pathophysiology of MAFLD-related HCC can provide opportunities for successful targeted therapies. Of particular interest in this sequela of hepatopathology is cellular senescence, a complex process characterised by cellular cycle arrest initiated by a variety of endogenous and exogenous cell stressors. A key biological process in establishing and maintaining senescence is oxidative stress, which is present in multiple cellular compartments of steatotic hepatocytes. Oxidative stress-induced cellular senescence can change hepatocyte function and metabolism, and alter, in a paracrine manner, the hepatic microenvironment, enabling disease progression from simple steatosis to inflammation and fibrosis, as well as HCC. The duration of senescence and the cell types it affects can tilt the scale from a tumour-protective self-restricting phenotype to the creator of an oncogenic hepatic milieu. A deeper understanding of the mechanism of the disease can guide the selection of the most appropriate senotherapeutic agent, as well as the optimal timing and cell type targeting for effectively combating HCC.

Association between CD8+ Tumor Infiltrating Lymphocytes and the Clinical Outcome of Patients with Operable Breast Cancer Treated with Adjuvant Dose-Dense Chemotherapy-A 10 Year Follow-Up Report of a Hellenic Cooperative Oncology Group Observational Study.

Tumor-infiltrating lymphocytes (TILs) contribute to breast cancer (BC) prognosis. We investigated the prognostic impact of CD8+ TILs in patients with early breast cancer treated with adjuvant chemotherapy in a large observational clinical trial. Along with a 10 year follow-up, considering the efficacy and safety, we report the results of the translational part of our study. We examined the patients' tumors for total (t), stromal (s), and intratumoral (i) CD8 lymphocyte density (counts/mm2) on tissue-microarray cores. The impact of CD8+ TILs counts on DFS and OS, and its correlation with breast cancer subtypes and standard clinicopathological parameters, were investigated, along with efficacy and safety data. Among the 928 eligible patients, 627 had available CD8+ data. Of which, 24.9% had a high expression of sCD8, iCD8, and total CD8, which were correlated with higher Ki67, TILs density, ER/PgR negativity, and higher histological grade. The 5year DFS and OS rates were 86.1% and 91.4%, respectively. Patients with high iCD8 and tCD8 had longer DFS and OS compared to those with low counts/mm2 (DFS: HR = 0.58, p = 0.011 and HR = 0.65, p = 0.034 and OS: HR = 0.63, p = 0.043 and HR = 0.58, p = 0.020, respectively). Upon adjustment for clinicopathological parameters, iCD8 and tCD8 retained their favorable prognostic significance for DFS and OS, whereas high sCD8 was only prognostic for DFS. Menopausal status, tumor size, and nodal status retained their prognostic significance in all examined multivariate models. CD8+ TILs, and especially their intratumoral subset, represent a potential favorable prognostic factor in early BC.

The Role of Macroautophagy and Chaperone-Mediated Autophagy in the Pathogenesis and Management of Hepatocellular Carcinoma.

Hepatocarcinogenesis is a long process with a complex pathophysiology. The current therapeutic options for HCC management, during the advanced stage, provide short-term survival ranging from 10-14 months. Autophagy acts as a double-edged sword during this process. Recently, two main autophagic pathways have emerged to play critical roles during hepatic oncogenesis, macroautophagy and chaperone-mediated autophagy. Mounting evidence suggests that upregulation of macroautophagy plays a crucial role during the early stages of carcinogenesis as a tumor suppressor mechanism; however, it has been also implicated in later stages promoting survival of cancer cells. Nonetheless, chaperone-mediated autophagy has been elucidated as a tumor-promoting mechanism contributing to cancer cell survival. Moreover, the autophagy pathway seems to have a complex role during the metastatic stage, while induction of autophagy has been implicated as a potential mechanism of chemoresistance of HCC cells. The present review provides an update on the role of autophagy pathways in the development of HCC and data on how the modulation of the autophagic pathway could contribute to the most effective management of HCC.

Autophagy and Exosomes: Cross-Regulated Pathways Playing Major Roles in Hepatic Stellate Cells Activation and Liver Fibrosis.

Chronic liver injury, regardless of the underlying disease, results in gradual alteration of the physiological hepatic architecture and in excessive production of extracellular matrix, eventually leading to cirrhosis Liver cellular architecture consists of different cell populations, among which hepatic stellate cells (HSCs) have been found to play a major role in the fibrotic process. Under normal conditions, HSCs serve as the main storage site for vitamin A, however, pathological stimuli lead to their transdifferentiation into myofibroblast cells, with autophagy being the key regulator of their activation, through lipophagy of their lipid droplets. Nevertheless, the role of autophagy in liver fibrosis is multifaceted, as increased autophagic levels have been associated with alleviation of the fibrotic process. In addition, it has been found that HSCs receive paracrine stimuli from neighboring cells, such as injured hepatocytes, Kupffer cells, sinusoidal endothelial cells, which promote liver fibrosis. These stimuli have been found to be transmitted via exosomes, which are incorporated by HSCs and can either be degraded through lysosomes or be secreted back into the extracellular space via fusion with the plasma membrane. Furthermore, it has been demonstrated that autophagy and exosomes may be concomitantly or reciprocally regulated, depending on the cellular conditions. Given that increased levels of autophagy are required to activate HSCs, it is important to investigate whether autophagy levels decrease at later stages of hepatic stellate cell activation, leading to increased release of exosomes and further propagation of hepatic fibrosis.

Decreased DNA Disruption in the Porcine Neocortex with Erythromycin Preconditioning during Prolonged Hypothermic Circulatory Arrest: Evidence for Neuroprotection.

BACKGROUND AND AIM OF THE STUDY: We have previously reported that the neocortex is selectively vulnerable to injury in an acute porcine model of hypothermic circulatory arrest (HCA) at 18°C. In view of recent evidence showing that pharmacologic preconditioning with a single dose of erythromycin induces tolerance against transient global cerebral ischemia in rats, we hypothesized that erythromycin would reduce the number of apoptotic neurons in the neocortex in an acute porcine model of HCA at 18°C. METHODS: Fourteen piglets underwent 75 min of HCA at 18°C following pretreatment with erythromycin (25 mg/kg, IV) (n = 8) or vehicle (Normal Saline 0.9%) (n = 6), applied 12 hr before arrest. Three served as normal controls. After gradual rewarming to a temperature of 36°C, treatment animals were sacrificed and brains were perfusion-fixed and cryopreserved. Neuronal apoptosis after HCA was observed morphologically with hematoxylin and eosin staining, and characterized by in situ DNA fragmentation using terminal deoxynucleotidyl-transferase-mediated biotin-dUTP nick end-labeling (TUNEL) histochemistry. RESULTS: Pre-ischemic conditioning with a single dose of the antibiotic erythromycin reduced neuronal apoptosis in the neocortex of the porcine brain. TUNEL-positive cells indicating DNA fragmentation and neuronal injury were significantly greater in the neocortex of animals treated with 18°C HCA (2.55 ± 1.17) compared to animals undergoing HCA after erythromycin preconditioning (1.76 ± 0.91) (p ≤ 0.001). CONCLUSIONS: These results suggest that cerebral protection during HCA may be achieved with erythromycin pharmacological preconditioning in the porcine model.

Modernization of an anatomy class: From conceptualization to implementation. A case for integrated multimodal-multidisciplinary teaching.

It has become increasingly apparent that no single method for teaching anatomy is able to provide supremacy over another. In an effort to consolidate and enhance learning, a modernized anatomy curriculum was devised by attempting to take advantage of and maximize the benefits from different teaching methods. Both the more traditional approaches to anatomy teaching, as well as modern, innovative educational programs were embraced in a multimodal system implemented over a decade. In this effort, traditional teaching with lectures and dissection was supplemented with models, imaging, computer-assisted learning, problem-based learning through clinical cases, surface anatomy, clinical correlation lectures, peer teaching and team-based learning. Here, we review current thinking in medical education and present our transition from a passive, didactic, highly detailed anatomy course of the past, to a more interactive, as well as functionally and clinically relevant anatomy curriculum over the course of a decade.