Saverio Cinti
Nov 1, 2005; 46:2347-2355
Research Articles

Cholesterol/sphingolipid-rich membrane domains, known as lipid rafts or membrane rafts, play a critical role in the compartmentalization of signaling pathways. Physical segregation of proteins in lipid rafts may modulate the accessibility of proteins to regulatory or effector molecules. Thus, lipid rafts serve as sorting platforms and hubs for signal transduction proteins. Cancer cells contain higher levels of intracellular cholesterol and lipid rafts than their normal non-tumorigenic counterparts. Many signal transduction processes involved in cancer development (insulin-like growth factor system and phosphatidylinositol 3-kinase-AKT) and metastasis [cluster of differentiation (CD)44] are dependent on or modulated by lipid rafts. Additional proteins playing an important role in several malignant cancers (e.g., transmembrane glycoprotein mucin 1) are also being detected in association with lipid rafts, suggesting a major role of lipid rafts in tumor progression. Conversely, lipid rafts also serve as scaffolds for the recruitment and clustering of Fas/CD95 death receptors and downstream signaling molecules leading to cell death-promoting raft platforms. The partition of death receptors and downstream signaling molecules in aggregated lipid rafts has led to the formation of the so-called cluster of apoptotic signaling molecule-enriched rafts, or CASMER, which leads to apoptosis amplification and can be pharmacologically modulated. These death-promoting rafts can be viewed as a linchpin from which apoptotic signals are launched. In this review, we discuss the involvement of lipid rafts in major signaling processes in cancer cells, including cell survival, cell death, and metastasis, and we consider the potential of lipid raft modulation as a promising target in cancer therapy.

The linear ubiquitin assembly complex (LUBAC) is an essential component of the innate and adaptive immune system. Modification of cellular substrates with linear polyubiquitin chains is a key regulatory step in signal transduction that impacts cell death and inflammatory signaling downstream of various innate immunity receptors. Loss-of-function mutations in the LUBAC components HOIP and HOIL-1 yield a systemic autoinflammatory disease in humans, whereas their genetic ablation is embryonically lethal in mice. Deficiency of the LUBAC adaptor protein Sharpin results in a multi-organ inflammatory disease in mice characterized by chronic proliferative dermatitis (cpdm), which is propagated by TNFR1-induced and RIPK1-mediated keratinocyte cell death. We have previously shown that caspase-1 and -11 promoted the dermatitis pathology of cpdm mice and mediated cell death in the skin. Here, we describe a reciprocal regulation of caspase-1 and LUBAC activities in keratinocytes. We show that LUBAC interacted with caspase-1 via HOIP and modified its CARD domain with linear polyubiquitin and that depletion of HOIP or Sharpin resulted in heightened caspase-1 activation and cell death in response to inflammasome activation, unlike what is observed in macrophages. Reciprocally, caspase-1, as well as caspase-8, regulated LUBAC activity by proteolytically processing HOIP at Asp-348 and Asp-387 during the execution of cell death. HOIP processing impeded substrate ubiquitination in the NF-κB pathway and resulted in enhanced apoptosis. These results highlight a regulatory mechanism underlying efficient apoptosis in keratinocytes and provide further evidence of a cross-talk between inflammatory and cell death pathways.

(JAMA Network) Death certificate data were used to compare the rate of opioid-related deaths in the US among cancer survivors with that of the general population from 2006 through 2016. Whether opioid-associated deaths in cancer survivors, who are often prescribed opioids for cancer-related pain, are rising at the same rate as in the general population is unknown.

(Anglia Ruskin University) A new study has found an association between low average levels of vitamin D and high numbers of COVID-19 cases and mortality rates across 20 European countries.

(Rutgers University) A Rutgers engineer has created a mathematical model that accurately estimates the death toll linked to the COVID-19 pandemic in the United States and could be used around the world.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with very limited therapeutic options. We have recently shown that the combined inhibition of EGFR and ROCK in TNBC cells results in cell death, however, the underlying mechanisms remain unclear. To investigate this, here we applied a mass spectrometry-based proteomic approach to identify proteins altered on single and combination treatments. Our proteomic data revealed autophagy as the major molecular mechanism implicated in the cells' response to combinatorial treatment. We here show that EGFR inhibition by gefitinib treatment alone induces autophagy, a cellular recycling process that acts as a cytoprotective response for TNBC cells. However, combined inhibition of EGFR and ROCK leads to autophagy blockade and accumulation of autophagic vacuoles. Our data show impaired autophagosome clearance as a likely cause of antitumor activity. We propose that the inhibition of the autophagic flux on combinatorial treatment is attributed to the major cytoskeletal changes induced on ROCK inhibition, given the essential role the cytoskeleton plays throughout the various steps of the autophagy process.

It turns out that even death needs the internet.

This week host Matt Egan is joined by producer Chris to talk about the recent batch of new Pebble devices and the smartwatch market. Staff writer at PC Advisor Lewis Painter joins in to talk about the death of the hoverboard (13:00). Finally, regular podder David Price comes on to talk about Appl...oh Twitter, specifically changes to the character limit and the sad loss of the @ (24:00).  

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Cholesterol/sphingolipid-rich membrane domains, known as lipid rafts or membrane rafts, play a critical role in the compartmentalization of signaling pathways. Physical segregation of proteins in lipid rafts may modulate the accessibility of proteins to regulatory or effector molecules. Thus, lipid rafts serve as sorting platforms and hubs for signal transduction proteins. Cancer cells contain higher levels of intracellular cholesterol and lipid rafts than their normal non-tumorigenic counterparts. Many signal transduction processes involved in cancer development (insulin-like growth factor system and phosphatidylinositol 3-kinase-AKT) and metastasis [cluster of differentiation (CD)44] are dependent on or modulated by lipid rafts. Additional proteins playing an important role in several malignant cancers (e.g., transmembrane glycoprotein mucin 1) are also being detected in association with lipid rafts, suggesting a major role of lipid rafts in tumor progression. Conversely, lipid rafts also serve as scaffolds for the recruitment and clustering of Fas/CD95 death receptors and downstream signaling molecules leading to cell death-promoting raft platforms. The partition of death receptors and downstream signaling molecules in aggregated lipid rafts has led to the formation of the so-called cluster of apoptotic signaling molecule-enriched rafts, or CASMER, which leads to apoptosis amplification and can be pharmacologically modulated. These death-promoting rafts can be viewed as a linchpin from which apoptotic signals are launched. In this review, we discuss the involvement of lipid rafts in major signaling processes in cancer cells, including cell survival, cell death, and metastasis, and we consider the potential of lipid raft modulation as a promising target in cancer therapy.

Clinical studies have shown a link between hyperuricemia (HU) and diabetes, while the exact effect of soluble serum urate on glucose metabolism remains elusive. This study aims to characterize the glucose metabolic phenotypes and investigate the underlying molecular mechanisms using a novel spontaneous HU mouse model in which the Uricase (Uox) gene is absent. In an attempt to study the role of HU in glycometabolism, we implemented external stimulation on Uox-knockout (KO) and wild-type (WT) males with a high-fat diet (HFD) and/or injections of multiple low-dose streptozotocin (MLD-STZ) to provoke the potential role of urate. Notably, while Uox-KO mice developed glucose intolerance in the basal condition, no mice spontaneously developed diabetes, even with aging. HFD-fed Uox-KO mice manifested similar insulin sensitivity compared with WT controls. HU augmented the existing glycometabolism abnormality induced by MLD-STZ and eventually led to diabetes, as evidenced by the increased random glucose. Reduced β-cell masses and increased terminal deoxynucleotidyl TUNEL-positive β-cells suggested that HU-mediated diabetes was cell death dependent. However, urate-lowering treatment (ULT) cannot ameliorate the diabetes incidence or reverse β-cell apoptosis with significance. ULT displayed a significant therapeutic effect of HU-crystal– associated kidney injury and tubulointerstitial damage in diabetes. Moreover, we present transcriptomic analysis of isolated islets, using Uox-KO versus WT mice and streptozotocin-induced diabetic WT (STZ-WT) versus diabetic Uox-KO (STZ-KO) mice. Shared differentially expressed genes of HU primacy revealed Stk17β is a possible target gene in HU-related β-cell death. Together, this study suggests that HU accelerates but does not cause diabetes by inhibiting islet β-cell survival.

Diabetes occurs due to a loss of functional β-cells, resulting from β-cell death and dysfunction. Lactogens protect rodent and human β-cells in vitro and in vivo against triggers of β-cell cytotoxicity relevant to diabetes, many of which converge onto a common pathway, endoplasmic reticulum (ER) stress. However, whether lactogens modulate the ER stress pathway is unknown. This study examines if lactogens can protect β-cells against ER stress and mitigate diabetes incidence in Akita mice, a rodent model of ER stress-induced diabetes, akin to neonatal diabetes in humans. We show that lactogens protect INS1 cells, primary rodent and human β-cells in vitro against two distinct ER stressors, tunicamycin and thapsigargin, through activation of the JAK2/STAT5 pathway. Lactogens mitigate expression of pro-apoptotic molecules in the ER stress pathway that are induced by chronic ER stress in INS1 cells and rodent islets. Transgenic expression of placental lactogen in β-cells of Akita mice drastically reduces the severe hyperglycemia, diabetes incidence, hypoinsulinemia, β-cell death, and loss of β-cell mass observed in Akita littermates. These are the first studies in any cell type demonstrating lactogens modulate the ER stress pathway, causing enhanced β-cell survival and reduced diabetes incidence in the face of chronic ER stress.

Marc Y. Donath
Dec 1, 2005; 54:S108-S113
Section III: Inflammation and beta-Cell Death

Miriam Cnop
Dec 1, 2005; 54:S97-S107
Section III: Inflammation and beta-Cell Death

The current orthodoxy is that home is the best and preferred place of death for most people, but in this podcast, Kristian Pollock a sociologist from Nottingham University questions these assumptions and calls for greater attention to improving the experience of dying in hospital and elsewhere. Read the full...

Medical error is not included on death certificates or in rankings of cause of death. Martin Makary, professor of surgery at Johns Hopkins University School of Medicine, joins us to explain why we don't measure medical error, and why it is so important that we start. Read the full analysis: http://www.bmj.com/content/353/bmj.i2139

Scott Murray, professor of primary palliative care at the University of Edinburgh, has written, and talked in this podcast before, about the benefits of early palliative care - and today he’s back to explain how illness trajectory, and the pattern of decline at the end of life, affects 4 main areas of wellness - physical, social, psychological and...

Findings from a range of prospective cohort studies based around the world indicate that higher intelligence in children is related to a lower risk of all cause mortality in adulthood - and now a new study, published on bmj.com, is trying to dig into that association further, with a whole population cohort and data on cause specific...

This week the Trump administration has banned the sale of flavoured vapes in the USA. The reason for that is the sudden rash of cases of pulmonary disease, including deaths, linked to vaping. The mechanism by which vaping may be causing damage to the lungs is as yet unclear, and our understanding is hampered by the heterogeneous nature of the...

For the next few months Talk Evidence is going to focus on the new corona virus pandemic. There is an enormous amount of uncertainty about the disease, what the symptoms are, fatality rate, treatment options, things we shouldn't be doing. We're going to try to get away from the headlines and talk about what we need to know - to hopefully give...

Christophe Bonny
Jan 1, 2001; 50:77-82
Islet Studies

Miriam Cnop
Dec 1, 2005; 54:S97-S107
Section III: Inflammation and beta-Cell Death

PORT AU PRINCE, Haiti, CMC – The Ministry of Public Health has confirmed that a 20-year-old man has become the seventh person in Haiti to die of the coronavirus (COVID-19). It is urging the population to follow restriction measures, including...

HAMILTON, Bermuda, CMC –  Bermuda recorded its seventh COVID-19 death on Saturday as Finance Minister Curtis Dickinson announced that he would need to rewrite this year’s budget because of the battering from the global...

A rise in mortality is a price worth paying to restart the US economy, President Trump has said, as many states flout advice from scientists and reopen beaches, cinemas, or hair salons while new...

Samy Suissa
Jan 1, 2018; 41:6-10
Perspectives in Care

More than two months after Ahmaud Arbery was fatally shot while jogging near Brunswick, Georgia police arrested two men for the shooting, authorities said.

Authorities have charged a fourth person connected to the shooting death of a Flint, Mich., security guard who was killed after confronting a customer who entered a store without a state-mandated facemask.

There are no major changes coming to Britain's current coronavirus lockdown orders anytime soon, a government official said Friday as health officials reported 626 more deaths from COVID-19.

South Dakota Gov. Kristi Noem has ordered two Sioux tribes to remove checkpoints designed to curb the coronavirus on tribal lands.

Irl B. Hirsch
Apr 1, 2002; 20:
Editorials

A dystopian science fiction bordering on reality and fantasy, each page accompanied by a high-quality illustration -- Australian authors.

Tohoku Earthquake and Tsunami, Japan, 2011.

Death -- Philosophy.

Australian fiction.

Ability -- United States.

Vaccination -- History.