Oxidized phospholipids exert a dual effect on bile acid-induced CCL2 expression in pancreatic acini

Bile Acids and Microbiota Interplay in Pancreatic Cancer

Evidence suggests the involvement of the microbiota, including oral, intra-tumoral and gut, in pancreatic cancer progression and response to therapy. The gut microbiota modulates the bile acid pool and is associated with maintaining host physiology. Studies have shown that the bile acid/gut microbiota axis is dysregulated in pancreatic cancer. Bile acid receptor expression and bile acid levels are dysregulated in pancreatic cancer as well. Studies have also shown that bile acids can cause pancreatic cell injury and facilitate cancer cell proliferation. The microbiota and its metabolites, including bile acids, are also altered in other conditions considered risk factors for pancreatic cancer development and can alter responses to chemotherapeutic treatments, thus affecting patient outcomes. Altogether, these findings suggest that the gut microbial and/or bile acid profiles could also serve as biomarkers for pancreatic cancer detection. This review will discuss the current knowledge on the interaction between gut microbiota interaction and bile acid metabolism in pancreatic cancer.

Phospholipid Membrane Transport and Associated Diseases

Phospholipids are the basic structure block of eukaryotic membranes, in both the outer and inner membranes, which delimit cell organelles. Phospholipids can also be damaged by oxidative stress produced by mitochondria, for instance, becoming oxidized phospholipids. These damaged phospholipids have been related to prevalent diseases such as atherosclerosis or non-alcoholic steatohepatitis (NASH) because they alter gene expression and induce cellular stress and apoptosis. One of the main sites of phospholipid synthesis is the endoplasmic reticulum (ER). ER association with other organelles through membrane contact sites (MCS) provides a close apposition for lipid transport. Additionally, an important advance in this small cytosolic gap are lipid transfer proteins (LTPs), which accelerate and modulate the distribution of phospholipids in other organelles. In this regard, LTPs can be established as an essential point within phospholipid circulation, as relevant data show impaired phospholipid transport when LTPs are defected. This review will focus on phospholipid function, metabolism, non-vesicular transport, and associated diseases.

Role of Bile Acids and Bile Salts in Acute Pancreatitis: From the Experimental to Clinical Studies

ABSTRACT

Acute pancreatitis (AP) is one of the most common gastroenterological disorders leading to hospitalization. It has long been debated whether biliary AP, about 30% to 50% of all cases, is induced by bile acids (BAs) when they reach the pancreas via reflux or via the systemic blood circulation.Besides their classical function in digestion, BAs have become an attractive research target because of their recently discovered property as signaling molecules. The underlying mechanisms of BAs have been investigated in various studies. Bile acids are internalized into acinar cells through specific G-protein-coupled BA receptor 1 and various transporters. They can further act via different receptors: the farnesoid X, ryanodine, and inositol triphosphate receptor. Bile acids induce a sustained Ca2+ influx from the endoplasmic reticulum and release of Ca2+ from acidic stores into the cytosol of acinar cells. The overload of intracellular Ca2+ results in mitochondrial depolarization and subsequent acinar cell necrosis. In addition, BAs have a biphasic effect on pancreatic ductal cells. A more detailed characterization of the mechanisms through which BAs contribute to the disease pathogenesis and severity will greatly improve our understanding of the underlying pathophysiology and may allow for the development of therapeutic and preventive strategies for gallstone-inducedAP.

The roles of PPARγ and its agonists in autoimmune diseases: A comprehensive review

Autoimmune diseases are common diseases of the immune system that are characterized by the loss of self-tolerance and the production of autoantibodies; the breakdown of immune tolerance and the prolonged inflammatory reaction are undisputedly core steps in the initiation and maintenance of autoimmunity. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors that belong to the nuclear hormone receptor family and act as ligand-activated transcription factors. There are three different isotypes of PPARs: PPARα, PPARγ, and PPARβ/δ. PPARγ is an established regulator of glucose homeostasis and lipid metabolism. Recent studies have demonstrated that PPARγ exhibits anti-inflammatory and anti-fibrotic effects in multiple disease models. PPARγ can also modulate the activation and polarization of macrophages, regulate the function of dendritic cells and mediate T cell survival, activation, and differentiation. In this review, we summarize the signaling pathways and biological functions of PPARγ and focus on how PPARγ and its agonists play protective roles in autoimmune diseases, including autoimmune thyroid diseases, multiple sclerosis, rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus, primary Sjogren syndrome and primary biliary cirrhosis.