Inflammasome Activation in Human Macrophages Induced by a LDL (-) Mimetic Peptide

A novel regulator of NLRP3 inflammasome: Peptides

The NLRP3 inflammasome plays a crucial role as a critical regulator of the immune response and has been implicated in the pathogenesis of numerous diseases. Peptides, known for their remarkable potency, selectivity, and low toxicity, have been extensively employed in disease treatment. Recent research has unveiled the potential of peptides in modulating the activity of the NLRP3 inflammasome. This review begins by examining the structure of the NLRP3 inflammasome, encompassing NLRP3, ASC, and Caspase-1, along with the three activation pathways: canonical, non-canonical, and alternative. Subsequently, we provide a comprehensive summary of peptide modulators targeting the NLRP3 inflammasome and elucidate their underlying mechanisms. The efficacy of these modulators has been validated through in vitro and in vivo experiments on NLRP3 inflammasome regulation. Furthermore, we conduct sequence alignment of the identified peptides and investigate their binding sites on the NLRP3 protein. This work is a foundational exploration for advancing peptides as potential therapeutic agents for NLRP3-related diseases.

The Oxidized Lipoproteins In Vivo: Its Diversity and Behavior in the Human Circulation

A high concentration of low-density lipoproteins (LDLs) in circulation has been well-known as a major risk factor for cardiovascular diseases. The presence of oxidized LDLs (oxLDLs) in atherosclerotic lesions and circulation was demonstrated using anti-oxLDL monoclonal antibodies. The so-called “oxLDL hypothesis”, as a mechanism for atherosclerosis development, has been attracting attention for decades. However, the oxLDL has been considered a hypothetical particle since the oxLDL present in vivo has not been fully characterized. Several chemically modified LDLs have been proposed to mimic oxLDLs. Some of the subfractions of LDL, especially Lp(a) and electronegative LDL, have been characterized as oxLDL candidates as oxidized phospholipids that stimulate vascular cells. Oxidized high-density lipoprotein (oxHDL) and oxLDL were discovered immunologically in vivo. Recently, an oxLDL-oxHDL complex was found in human plasma, suggesting the involvement of HDLs in the oxidative modification of lipoproteins in vivo. In this review, we summarize our understanding of oxidized lipoproteins and propose a novel standpoint to understand the oxidized lipoproteins present in vivo.

Formation and Cellular Impact of Cholesterol Crystals in Health and Disease

Cholesterol crystals (CCs) were first discovered in atherosclerotic plaque tissue in the early 1900 and have since been observed and implicated in many diseases and conditions, including myocardial infarction, abdominal aortic aneurism, kidney disease, ocular diseases, and even central nervous system anomalies. Despite the widespread involvement of CCs in many pathologies, the mechanisms involved in their formation and their role in various diseases are still not fully understood. Current knowledge concerning the formation of CCs, as well as the molecular pathways activated upon cellular exposure to CCs, will be explored in this review. As CC formation is tightly associated with lipid metabolism, the role of cellular lipid homeostasis in the formation of CCs is highlighted, including the role of lysosomes. In addition, cellular pathways and processes known to be affected by CCs are described. In particular, CC-induced activation of the inflammasome and production of reactive oxygen species, along with the role of CCs in complement-mediated inflammation is discussed. Moreover, the clinical manifestation of embolized CCs is described with a focus on renal and skin diseases associated with CC embolism. Lastly, potential therapeutic measures that target either the formation of CCs or their impact on different cell types and tissues are highlighted.