Curcumin promotes AApoAII amyloidosis and peroxisome proliferation in mice by activating the PPARα signaling pathway

Insights into the Structural Basis of Amyloid Resistance Provided by Cryo-EM Structures of AApoAII Amyloid Fibrils

Amyloid resistance is the inability or the reduced susceptibility of an organism to develop amyloidosis. In this study we have analysed the molecular basis of the resistance to systemic AApoAII amyloidosis, which arises from the formation of amyloid fibrils from apolipoprotein A-II (ApoA-II). The disease affects humans and animals, including SAMR1C mice that express the C allele of ApoA-II protein, whereas other mouse strains are resistant to development of amyloidosis due to the expression of other ApoA-II alleles, such as ApoA-IIF. Using cryo-electron microscopy, molecular dynamics simulations and other methods, we have determined the structures of pathogenic AApoAII amyloid fibrils from SAMR1C mice and analysed the structural effects of ApoA-IIF-specific mutational changes. Our data show that these changes render ApoA-IIF incompatible with the specific fibril morphologies, with which ApoA-II protein can become pathogenic in vivo.

Curcumin-loaded chitosan nanoparticles alleviate fenpropathrin-induced hepatotoxicity by regulating lipogenesis and pyroptosis in rats

In this study, the probable alleviative role of curcumin (CMN) (50 mg/kg b.wt) or curcumin-loaded chitosan nanoparticle (CLC-NP) (50 mg/kg b.wt) was assessed against the hepatotoxic effect of a widely used pyrethroid insecticide, fenpropathrin (FEN) (15 mg/kg b.wt) in rats in a 60-day experiment. The results revealed that CMN and CLC-NP significantly suppressed the FEN-induced increment in serum hepatic enzyme activities (ALT, AST, and ALP) and hyperbilirubinemia. Moreover, FEN-associated dyslipidemia, hepatic oxidative stress, and altered hepatic histology were significantly rescued by CMN and CLC-NP. Furthermore, the increased TNF-α and Caspase-3 immunoexpression in hepatic tissues of FEN-exposed rats was significantly reduced in CMN and CLC-NP-treated ones. FEN exposure significantly upregulated the pyroptosis-related genes, including GSDMD, Casp-1, Casp-3, Casp-8, IL-18, TNF-α, IL-1β, and NF-κB and altered the expression of lipogenesis-related genes including SREBP-1c, PPAR-α, MCP1, and FAS in the hepatic tissues. Nevertheless, the earlier disturbances in gene expression were corrected in CMN and CLC-NP-treated groups. Of note, compared to CMN, CLC-NP was more effective at inhibiting oxidative damage and controlling lipogenesis and pyroptosis in the hepatic tissues of FEN-exposed rats. Conclusively, the current study findings proved the superior and useful role of CLC-NP in combating pollutants associated with hepatic dysfunction.

APOA2: New Target for Molecular Hydrogen Therapy in Sepsis-Related Lung Injury Based on Proteomic and Genomic Analysis

Target biomarkers for H₂ at both the protein and genome levels are still unclear. In this study, quantitative proteomics acquired from a mouse model were first analyzed. At the same time, functional pathway analysis helped identify functional pathways at the protein level. Then, bioinformatics on mRNA sequencing data were conducted between sepsis and normal mouse models. Differential expressional genes with the closest relationship to disease status and development were identified through module correlation analysis. Then, common biomarkers in proteomics and transcriptomics were extracted as target biomarkers. Through analyzing expression quantitative trait locus (eQTL) and genome-wide association studies (GWAS), colocalization analysis on Apoa2 and sepsis phenotype was conducted by summary-data-based Mendelian randomization (SMR). Then, two-sample and drug-target, syndrome Mendelian randomization (MR) analyses were all conducted using the Twosample R package. For protein level, protein quantitative trait loci (pQTLs) of the target biomarker were also included in MR. Animal experiments helped validate these results. As a result, Apoa2 protein or mRNA was identified as a target biomarker for H₂ with a protective, causal relationship with sepsis. HDL and type 2 diabetes were proven to possess causal relationships with sepsis. The agitation and inhibition of Apoa2 were indicated to influence sepsis and related syndromes. In conclusion, we first proposed Apoa2 as a target for H₂ treatment.

Evaluation of nano-curcumin against inhaled paraquat-induced lung injury in rats

BACKGROUND

Acute lung injury (ALI) remains a significant source of morbidity and mortality in critically ill patients and currently there is no efficient therapy for this condition. The aim of this research was to evaluate the protective activity of nano-curcumin (nano-CU) as a natural anti-inflammatory and antioxidant agent, against inhaled paraquat (PQ)-induced lung injury.

METHODS

One group of rats was exposed to saline (control group, Ctrl) and six groups to PQ aerosol (54 mg/m³ on alternate days 8 times, each time for 30 min) treated with drinking water alone (group PQ), 2 and 8 mg/kg nano-CU (nano + CU(L) and nano + CU(H)), 5 mg/kg pioglitazone (PIO), nano-CU(L) + PIO or 0.03 mg/kg dexamethasone (Dexa) for 16 days after PQ exposure period. PIO and Dexa were intraperitoneal (ip) injected and nano-CU was administered orally (po), (6 rats in each group).

RESULTS

In the PQ group, total and differential WBC counts, malondialdehyde (MDA) in the bronchoalveolar lavage fluid (BALF), interferon gamma (INF-γ) and interleukin 10 (IL-10) levels in the lung tissues, lung pathological changes, and tracheal responsiveness were increased but the BALF thiol, catalase (CAT) and superoxide dismutase (SOD) levels were reduced. In treated groups with nano-CU(H) and PIO + nano-CU(L), all measured variables, in Dexa and nano-CU(L) treated groups, most variables and in the PIO group only a few variables were improved. The improvement of most variables in the PIO + nano-CU(L) group was significantly higher than in the PIO and nano-CU(L) groups alone.

CONCLUSIONS

Nano-CU ameliorated lung damage induced by inhaled PQ similar to dexa and a synergic effect between nano-CU and PIO was observed, suggesting, a possible PPAR-γ receptor-mediated effect of curcumin.

Renal function in aged C57BL/6J mice is impaired by deposition of age-related apolipoprotein A-II amyloid independent of kidney aging

Spontaneous and age-related amyloidosis has been reported in C57BL/6J mice; however, the biochemical characteristics of age-related amyloidosis remain unclear. Therefore, we herein investigated the age-related prevalence of amyloidosis, the types of amyloid fibril proteins, and the effects of amyloid deposition on renal function in C57BL/6J mice. The results obtained revealed a high incidence of amyloidosis in C57BL/6J mice originating from the Jackson laboratory as well as the deposition of large amounts of amyloid in the glomeruli of aged mice. We identified the amyloid fibril protein in C57BL/6J mice as wild-type apolipoprotein A-II. We induced renal amyloid deposition in 40-week-old mice, equivalent to that of spontaneous development in 80-week-old mice, to rule out the effects of aging, and revealed subsequent damage to kidney function by amyloid deposits. Furthermore, amyloid deposition in the mesangial region decreased podocyte density, compromised foot processes, and led to the accumulation of fibroblast growth factor 2 (FGF2) in glomeruli. Collectively, these results suggest that AApoAII deposition is a general pathology in aged C57BL/6J mice and is dependent on supplier colonies. Therefore, the effects of age-related amyloid deposition need to be considered in research on aging in mice.

Dietary Polyphenols Alleviate Autoimmune Liver Disease by Mediating the Intestinal Microenvironment: Challenges and Hopes

Autoimmune liver disease is a chronic liver disease caused by an overactive immune response in the liver that imposes a significant health and economic cost on society. Due to the side effects of existing medicinal medications, there is a trend toward seeking natural bioactive compounds as dietary supplements. Currently, dietary polyphenols have been proven to have the ability to mediate gut-liver immunity and control autoimmune liver disease through modulating the intestinal microenvironment. Based on the preceding, this Review covers the many forms of autoimmune liver illnesses, their pathophysiology, and the modulatory effects of polyphenols on immune disorders. Finally, we focus on how polyphenols interact with the intestinal milieu to improve autoimmune liver disease. In conclusion, we suggest that dietary polyphenols have the potential as gut-targeted modulators for the prevention and treatment of autoimmune liver disease and highlight new perspectives and critical issues for future pharmacological applications.

Impact of Phytochemicals on PPAR Receptors: Implications for Disease Treatments

Peroxisome proliferator-activated receptors (PPARs) are members of the ligand-dependent nuclear receptor family. PPARs have attracted wide attention as pharmacologic mediators to manage multiple diseases and their underlying signaling targets. They mediate a broad range of specific biological activities and multiple organ toxicity, including cellular differentiation, metabolic syndrome, cancer, atherosclerosis, neurodegeneration, cardiovascular diseases, and inflammation related to their up/downstream signaling pathways. Consequently, several types of selective PPAR ligands, such as fibrates and thiazolidinediones (TZDs), have been approved as their pharmacological agonists. Despite these advances, the use of PPAR agonists is known to cause adverse effects in various systems. Conversely, some naturally occurring PPAR agonists, including polyunsaturated fatty acids and natural endogenous PPAR agonists curcumin and resveratrol, have been introduced as safe agonists as a result of their clinical evidence or preclinical experiments. This review focuses on research on plant-derived active ingredients (natural phytochemicals) as potential safe and promising PPAR agonists. Moreover, it provides a comprehensive review and critique of the role of phytochemicals in PPARs-related diseases and provides an understanding of phytochemical-mediated PPAR-dependent and -independent cascades. The findings of this research will help to define the functions of phytochemicals as potent PPAR pharmacological agonists in underlying disease mechanisms and their related complications.

Apolipoprotein A-II, a Player in Multiple Processes and Diseases

Apolipoprotein A-II (apoA-II) is the second most abundant apolipoprotein in high-density lipoprotein (HDL) particles, playing an important role in lipid metabolism. Human and murine apoA-II proteins have dissimilar properties, partially because human apoA-II is dimeric whereas the murine homolog is a monomer, suggesting that the role of apoA-II may be quite different in humans and mice. As a component of HDL, apoA-II influences lipid metabolism, being directly or indirectly involved in vascular diseases. Clinical and epidemiological studies resulted in conflicting findings regarding the proatherogenic or atheroprotective role of apoA-II. Human apoA-II deficiency has little influence on lipoprotein levels with no obvious clinical consequences, while murine apoA-II deficiency causes HDL deficit in mice. In humans, an increased plasma apoA-II concentration causes hypertriglyceridemia and lowers HDL levels. This dyslipidemia leads to glucose intolerance, and the ensuing high blood glucose enhances apoA-II transcription, generating a vicious circle that may cause type 2 diabetes (T2D). ApoA-II is also used as a biomarker in various diseases, such as pancreatic cancer. Herein, we provide a review of the most recent findings regarding the roles of apoA-II and its functions in various physiological processes and disease states, such as cardiovascular disease, cancer, amyloidosis, hepatitis, insulin resistance, obesity, and T2D.