We have previously demonstrated that Stat3 regulates lysosomal mediated-programmed cell death (LM-PCD) during mouse mammary gland involution in vivo. However, the mechanism that controls the release of lysosomal cathepsins to initiate cell death in this context has not been elucidated. We show here that Stat3 regulates the formation of large lysosomal vacuoles that contain triglyceride. Furthermore, we demonstrate that milk fat globules (MFGs) are toxic to epithelial cells and that, when applied to purified lysosomes, the MFG hydrolysate oleic acid potently induces lysosomal leakiness. Additionally, uptake of secreted MFGs coated in butyrophilin 1A1 is diminished in Stat3 ablated mammary glands while loss of the phagocytosis bridging molecule MFG-E8 results in reduced leakage of cathepsins in vivo. We propose that Stat3 regulates LM-PCD in mouse mammary gland by switching cellular function from secretion to uptake of MFGs. Thereafter, perturbation of lysosomal vesicle membranes by high levels of free fatty acids results in controlled leakage of cathepsins culminating in cell death.

No abstract

Schizophrenia is a debilitating psychiatric disorder and patients experience significant comorbidity, especially cognitive and psychosocial deficits, already at the onset of disease. Previous research suggests that treatment during the earlier stages of disease reduces disease burden, and that a longer time of untreated psychosis has a negative impact on treatment outcomes. A targeted literature review was conducted to gain insight into the definitions currently used to describe patients with a recent diagnosis of schizophrenia in the early course of disease (‘early’ schizophrenia). A total of 483 relevant English-language publications of clinical guidelines and studies were identified for inclusion after searches of MEDLINE, MEDLINE In-Process, relevant clinical trial databases and Google for records published between January 2005 and October 2015. The extracted data revealed a wide variety of terminology and definitions used to describe patients with ‘early’ or ‘recent-onset’ schizophrenia, with no apparent consensus. The most commonly used criteria to define patients with early schizophrenia included experience of their first episode of schizophrenia or disease duration of less than 1, 2 or 5 years. These varied definitions likely result in substantial disparities of patient populations between studies and variable population heterogeneity. Better agreement on the definition of early schizophrenia could aid interpretation and comparison of studies in this patient population and consensus on definitions should allow for better identification and management of schizophrenia patients in the early course of their disease.

Background: Schizophrenia is a heterogeneous disorder with a burden that can vary greatly depending on the severity and the duration. Previous research has suggested that patients in the earlier stages of schizophrenia (typically first-episode schizophrenia) benefit from effective early treatment, however, a comprehensive review of the burden specifically in this population has not been undertaken. A systematic literature review was therefore conducted to characterize the clinical, economic, and humanistic burden, as reported in naturalistic studies of schizophrenia populations specifically at an early stage of disease in comparison with healthy controls, patients with chronic schizophrenia, and patients with other psychiatric disorders.

Mammary gland involution involves a process that includes one of the most dramatic examples of cell death in an adult mammalian organism. We have previously shown that Stat3 regulates a lysosomal pathway of cell death in the first 48 hours of involution and induces lysosome leakiness in mammary epithelial cells. Interestingly, Stat3 is associated also with the striking induction of autophagy which occurs concomitantly with cell death, presumably as a transient survival mechanism. The PI3 Kinase regulatory subunits p55α and p50α are dramatically and specifically upregulated at the transcriptional level by Stat3 at the onset of involution. We show here that ablation of either Stat3 or p55α/p50α in vivo affects autophagy during involution. We used two different cell culture models, normal mammary epithelial cells and mouse embryonic fibroblasts, to further investigate the role of p55α/p50α in autophagy regulation. Our results demonstrate a direct role for p55α/p50α as inhibitors of autophagy mediated by p85α. Thus Stat3 and its downstream targets p55α/p50α are key regulators of the balance between autophagy and cell death in vivo.