A review of the current research on in vivo and in vitro detection for alpha-synuclein: a biomarker of Parkinson's disease.

Parkinson's disease is a health-threatening neurodegenerative disease of the elderly with clinical manifestations of motor and non-motor deficits such as tremor palsy and loss of smell. Alpha-synuclein (α-Syn) is the pathological basis of PD, it can abnormally aggregate into insoluble forms such as oligomers, fibrils, and plaques, causing degeneration of nigrostriatal dopaminergic neurons in the substantia nigra in the patient's brain and the formation of Lewy bodies (LBs) and Lewy neuritis (LN) inclusions. As a result, achieving α-Syn aggregate detection in the early stages of PD can effectively stop or delay the progression of the disease. In this paper, we provide a brief overview and analysis of the molecular structures and α-Syn in vivo and in vitro detection methods, such as mass spectrometry, antigen-antibody recognition, electrochemical sensors, and imaging techniques, intending to provide more technological support for detecting α-Syn early in the disease and intervening in the progression of Parkinson's disease.

Enantiomeric pairs of macrocyclic acylphloroglucinols from Syzygium szemaoense.

Two enantiomeric pairs of macrocyclic acylphloroglucinols (1a/1b and 2a/2b) with an unprecedented carbon skeleton featuring a bicyclo[12.3.1]octadecane core, together with an undescribed biogenetically related long-chain acylphloroglucinol (3), were isolated from Syzygium szemaoense. Their structures were fully established by spectroscopic method, X-ray crystallographic analysis, and ECD calculation. Compounds 1b and 2a/2b exhibited inhibition against death-associated protein kinase-related apoptosis inducing protein kinase 2 (DRAK2) and ATP citrate lyase (ACLY), respectively.

Punicalagin attenuates ventricular remodeling after acute myocardial infarction via regulating the NLRP3/caspase-1 pathway.

CONTEXT: Punicalagin has myocardial protection; the mechanism of punicalagin on ventricular remodeling (VR) after acute myocardial infarction (AMI) remains unclear. OBJECTIVE: These studies explore the role and mechanism of punicalagin in preventing and treating VR after AMI. MATERIALS AND METHODS: Molecular docking was used to predict the targets of punicalagin. After 2 weeks of AMI model, the SD rats were randomly divided into model, and punicalagin (200, 400 mg/kg, gavage) groups for 4 weeks. Thoracotomy with perforation but no ligature was performed on rats in control group. The protein expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3), apoptosis speck-like protein (ASC), caspase-1, gasdermin D (GSDMD), and GSDMD-N, the mRNA expression of NLRP3, caspase-1, GSDMD, interleukin-1ß (IL-1ß) and IL-18 were evaluated. RESULTS: Punicalagin had binding activities with NLRP3 (Vina score, -5.8), caspase-1 (Vina score, -6.7), and GSDMD (Vina score, -6.7). Punicalagin could improve cardiac function, alleviate cardiac pathological changes, minimize the excessive accumulation of collagen in the left ventricular myocardium (p < 0.01), and inhibit cardiomyocyte apoptosis (p < 0.01). Furthermore, punicalagin could inhibit the overexpression of NLRP3, caspase-1, and GSDMD via immunohistochemistry (p < 0.01). Punicalagin inhibited the protein levels of NLRP3, caspase-1, ASC, GSDMD, and GSDMD-N (p < 0.05, p < 0.01). Punicalagin reduced the mRNA expression of NLRP3, caspase-1, GSDMD, IL-1ß and IL-18 (p < 0.05, p < 0.01). CONCLUSIONS: Punicalagin may provide a useful treatment for the future myocardial protection.

Rhodomeroterpene alleviates macrophage infiltration and the inflammatory response in renal tissue to improve acute kidney injury.

Inflammation is broadly recognized as an important factor in the pathogenesis of acute kidney injury (AKI), but pharmacological approaches to alleviate inflammation in AKI have not been proved successful in clinical trials. Macrophage infiltration into renal tissue promotes inflammatory responses that contribute to the pathogenesis of AKI. Suppression of renal tissue inflammatory responses is postulated to improve renal injury of patients and animals. Rhodomeroterpene (RMT) is a novel meroterpenoid isolated from the Rhododendron genus that was shown to exert anti-inflammatory action in vivo or in vitro in this study. We investigated the treatment effects of RMT on LPS-induced sepsis and two different AKI models. The results showed that pretreatment with RMT (30 mg kg-1  d-1 , ip, for 3 days) significantly inhibited acute inflammatory responses in LPS-induced septic mice. In both renal ischemia-reperfusion injury (I/R) and sepsis-induced AKI models, RMT (30 mg kg-1  d-1 , ip, for 3 days) ameliorated renal function and injury and alleviated inflammation by reducing the infiltration of immune cells, including macrophages and neutrophils. Furthermore, our study demonstrated that RMT inhibits inflammatory responses in macrophages. The anti-inflammatory effects of RMT may be due to the inactivation of the IKK/NF-κB and PI3K/PDK1/Akt inflammatory signaling pathways in macrophages. Collectively, our findings indicate that RMT ameliorates renal injury and alleviates the renal inflammatory state in different AKI models, suggesting that RMT may be a potential agent for the treatment of AKI.

Quinoline alkaloids with anti-inflammatory activity from Zanthoxylum avicennae.

Zanthoxylum avicennae fruits were traditionally used to treat many inflammatory-related diseases, such as icterohepatitis, nephritis and colitis, which inspired us to explore the active chemicals and pharmacological activity. As a result, ten quinoline alkaloids, including six new ones, avicenines A-F (1-6), were isolated and structurally characterized by solid data. Compounds 1, 7 and 8 were identified as three pairs of enantiomers by chiral HPLC separation, of which 1 was an unusual 6/6/5/5-fused quinoline alkaloid bearing a unique cis-hexahydrofuro[3,2-b]furan moiety. The putative biosynthetic pathway for enantiomeric compounds was also proposed. In addition, compound 6 significantly suppressed the gene expression and secretion of pro-inflammatory cytokines IL-1ß and IL-6 in macrophages.

Mitochondria homeostasis: Biology and involvement in hepatic steatosis to NASH.

Mitochondrial biology and behavior are central to the physiology of liver. Multiple mitochondrial quality control mechanisms remodel mitochondrial homeostasis under physiological and pathological conditions. Mitochondrial dysfunction and damage induced by overnutrition lead to oxidative stress, inflammation, liver cell death, and collagen production, which advance hepatic steatosis to nonalcoholic steatohepatitis (NASH). Accumulating evidence suggests that specific interventions that target mitochondrial homeostasis, including energy metabolism, antioxidant effects, and mitochondrial quality control, have emerged as promising strategies for NASH treatment. However, clinical translation of these findings is challenging due to the complex and unclear mechanisms of mitochondrial homeostasis in the pathophysiology of NASH.

Distal mutation V486M disrupts the catalytic activity of DPP4 by affecting the flap of the propeller domain.

Dipeptidyl peptidase-4 (DPP4) plays a crucial role in regulating the bioactivity of glucagon-like peptide-1 (GLP-1) that enhances insulin secretion and pancreatic ß-cell proliferation, making it a therapeutic target for type 2 diabetes. Although the crystal structure of DPP4 has been determined, its structure-function mechanism is largely unknown. Here, we examined the biochemical properties of sporadic human DPP4 mutations distal from its catalytic site, among which V486M ablates DPP4 dimerization and causes loss of enzymatic activity. Unbiased molecular dynamics simulations revealed that the distal V486M mutation induces a local conformational collapse in a ß-propeller loop (residues 234-260, defined as the flap) and disrupts the dimerization of DPP4. The "open/closed" conformational transitions of the flap whereby capping the active site, are involved in the enzymatic activity of DPP4. Further site-directed mutagenesis guided by theoretical predictions verified the importance of the conformational dynamics of the flap for the enzymatic activity of DPP4. Therefore, the current studies that combined theoretical modeling and experimental identification, provide important insights into the biological function of DPP4 and allow for the evaluation of directed DPP4 genetic mutations before initiating clinical applications and drug development.

Mechanisms of Cd-Induced Cytotoxicity in Normal Human Skin Keratinocytes: Implication for Human Health.

Cadmium (Cd) is one of the toxic heavy metals found widely in the environment. Skin is an important target organ of Cd exposure. However, the adverse effects of Cd on human skin are still not well known. In this study, normal human skin keratinocytes (HaCaT cells) were studied for changes in cell viability, morphology, DNA damage, cycle, apoptosis, and the expression of endoplasmic reticulum (ER) stress-related genes (XBP-1, BiP, ATF-4, and CHOP) after exposure to Cd for 24 h. We found that Cd decreased cell viability in a concentration-dependent manner, with a median lethal concentration (LC50) of 11 µM. DNA damage induction was evidenced by upregulation of the level of γ-H2AX. Furthermore, Cd induced G0/G1 phase cell cycle arrest and apoptosis in a dose-dependent manner and upregulated the mRNA levels of ER stress biomarker genes (XBP-1, BiP, ATF4, and CHOP). Taken together, our results showed that Cd induced cytotoxicity and DNA damage in HaCaT cells, eventually resulting in cell cycle arrest in the G0/G1 phase and apoptosis. In addition, ER stress may be involved in Cd-induced HaCaT apoptosis. Our data imply the importance of reducing Cd pollution in the environment to reduce its adverse impacts on human skin.

Organophosphorus Flame Retardant TCPP Induces Cellular Senescence in Normal Human Skin Keratinocytes: Implication for Skin Aging.

Tris (1-chloro-2-propyl) phosphate (TCPP) is one of the most frequently detected organophosphorus flames in the environment. Continuous daily exposure to TCPP may harm human skin. However, little is known about the adverse effects of TCPP on human skin. In this study, we first evaluated the detrimental effects and tried to uncover the underlying mechanisms of TCPP on human skin keratinocytes (HaCaT) after 24 h exposure. We found that TCPP caused a concentration-dependent decrease in HaCaT cell viability after exposure to 1.56-400 µg/mL for 24 h, with an IC50 of 275 µg/mL. TCPP also promoted the generation of intracellular reactive oxygen species (ROS) and triggered DNA damage, evidenced by an increase of phosphorylated histone H2A.X (γH2A.X) in the nucleus. Furthermore, the cell cycle was arrested at the G1 phase at 100 µg/mL by upregulation of the mRNA expression of p53 and p21 and downregulation of cyclin D1 and CDK4 expression. Additionally, both the senescence-associated-ß-galactosidase activity and related proinflammatory cytokine IL-1ß and IL-6 were elevated, indicating that TCPP exposure caused cellular senescence may be through the p53-dependent DNA damage signal pathway in HaCaT cells. Taken together, our data suggest that flame-retardant exposure may be a key precipitating factor for human skin aging.

In vivo and in vitro protective effects of shengmai injection against doxorubicin-induced cardiotoxicity.

CONTEXT: Shengmai injection (SMI) has been used to treat heart failure. OBJECTIVE: This study determines the molecular mechanisms of SMI against cardiotoxicity caused by doxorubicin (DOX). MATERIALS AND METHODS: In vivo, DOX (15 mg/kg) was intraperitoneally injected in model, Dex (dexrazoxane), SMI-L (2.7 mL/kg), SMI-M (5.4 mL/kg), and SMI-H (10.8 mL/kg) for 7 consecutive days. Hematoxylin-eosin (HE) and Masson staining were used to evaluate histological changes, and cardiomyocyte apoptosis was identified using TdT-mediated dUTP nick-end labelling (TUNEL). Enzymatic indexes were determined. mRNA and protein expressions were analysed through RT-qPCR and Western blotting. In vitro, H9c2 cells were divided into control group, model group (2 mL 1 µM DOX), SMI group, ML385 group, and SMI + ML385 group, the intervention lasted for 24 h. mRNA and protein expressions were analysed. RESULTS: SMI markedly improved cardiac pathology, decreased cardiomyocyte apoptosis, increased creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), decreased superoxide dismutase (SOD). Compared with the model group, the protein expression of nuclear factor erythroid2-related factor 2 (Nrf2) (SMI-L: 2.42-fold, SMI-M: 2.67-fold, SMI-H: 3.07-fold) and haem oxygenase-1(HO-1) (SMI-L: 1.64-fold, SMI-M: 2.01-fold, SMI-H: 2.19-fold) was increased and the protein expression of kelch-like ECH-associated protein 1 (Keap1) (SMI-L: 0.90-fold, SMI-M: 0.77-fold, SMI-H: 0.66-fold) was decreased in SMI groups and Dex group in vivo. Additionally, SMI dramatically inhibited apoptosis, decreased CK, LDH and MDA levels, and enhanced SOD activity. Our results demonstrated that SMI reduced DOX-induced cardiotoxicity via activation of the Nrf2/Keap1 signalling pathway. CONCLUSIONS: This study revealed a new mechanism by which SMI alleviates DOX-induced 45 cardiomyopathy by modulating the Nrf2/Keap1 signal pathway.

Pyrazolone derivative C29 protects against HFD-induced obesity in mice via activation of AMPK in adipose tissue.

Beige adipocytes have been considered as a potential strategy in anti-obesity therapy because of its thermogenic capacity. AMP-activated protein kinase (AMPK) plays important roles in regulating adipose tissue function. C29 is a novel pyrazolone derivative with AMPK activity. In the current study, we investigated the role of C29 in the regulation of thermogenesis using differentiated adipocytes and diet-induced obese mice, and explored the mechanisms that might be involved in energy expenditure via adipocyte AMPK activation. We showed that treatment with C29 (2.5-10 µM) concentration-dependently increased thermogenesis in differentiated preadipocytes separated from inguinal white adipose tissue (iWAT), evidenced by increased expression levels of thermogenesis markers such as Ucp1, Pgc-1α, Dio2, Prdm16, Cox7a1, Cox8b, Elovl3, and Cidea, fatty acid oxidation (FAO) genes including Cpt1a, Lcad and Pparα, as well as beige-selective genes such as Cd137, Tmem26, Slc27a1, and Tbx1. In high-fat diet (HFD)-fed mice, oral administration of C29 (30 mg·kg-1·day-1) for 9 weeks alleviated HFD-induced obesity, promoted energy expenditure and modulated iWAT browning. However, these effects were not observed in adipose-specific AMPKα1/α2 knockout (AKO) mice following C29 administration. Together, this study demonstrates that C29 regulates energy balance via adipocyte AMPK. Our findings show that the discovery of AMPK activators that specifically target adipose tissue may have therapeutic potential for treating obesity-related metabolic diseases.

Sarsasapogenin improves adipose tissue inflammation and ameliorates insulin resistance in high-fat diet-fed C57BL/6J mice.

Insulin resistance is a major cause of type 2 diabetes and metabolic syndrome. Macrophage infiltration into obese adipose tissue promotes inflammatory responses that contribute to the pathogenesis of insulin resistance. Suppression of adipose tissue inflammatory responses is postulated to increase insulin sensitivity in obese patients and animals. Sarsasapogenin (ZGY) is one of the metabolites of timosaponin AIII in the gut, which has been shown to exert anti-inflammatory action. In this study, we investigated the effects of ZGY treatment on obesity-induced insulin resistance in mice. We showed that pretreatment with ZGY (80 mg·kg-1·d-1, ig, for 18 days) significantly inhibited acute adipose tissue inflammatory responses in LPS-treated mice. In high-fat diet (HFD)-fed obese mice, oral administration of ZGY (80 mg·kg-1·d-1, for 6 weeks) ameliorated insulin resistance and alleviated inflammation in adipose tissues by reducing the infiltration of macrophages. Furthermore, we demonstrated that ZGY not only directly inhibited inflammatory responses in macrophages and adipocytes, but also interrupts the crosstalk between macrophages and adipocytes in vitro, improving adipocyte insulin resistance. The insulin-sensitizing and anti-inflammatory effects of ZGY may result from inactivation of the IKK /NF-κB and JNK inflammatory signaling pathways in adipocytes. Collectively, our findings suggest that ZGY ameliorates insulin resistance and alleviates the adipose inflammatory state in HFD mice, suggesting that ZGY may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.

AMPK activator C24 inhibits hepatic lipogenesis and ameliorates dyslipidemia in HFHC diet-induced animal models.

Dyslipidemia is a chronic metabolic disease characterized by elevated levels of lipids in plasma. Recently, various studies demonstrate that the increased activity of adenosine 5'-monophosphate-activated protein kinase (AMPK) causes health benefits in energy regulation. Thus, great efforts have been made to develop AMPK activators as a metabolic syndrome treatment. In the present study, we investigated the effects of the AMPK activator C24 on dyslipidemia and the potential mechanisms. We showed that C24 (5-40 µM) dose-dependently increased the phosphorylation of AMPKα and acetyl-CoA carboxylase (ACC), and inhibited lipogenesis in HepG2 cells. Using compound C, an AMPK inhibitor, or hepatocytes isolated from liver tissue-specific AMPK knockout AMPKα1α2fl/fl;Alb-cre mice (AMPK LKO), we demonstrated that the lipogenesis inhibition of C24 was dependent on hepatic AMPK activation. In rabbits with high-fat and high-cholesterol diet-induced dyslipidemia, administration of C24 (20, 40, and 60 mg · kg-1· d-1, ig, for 4 weeks) dose-dependently decreased the content of TG, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) in plasma and played a role in protecting against hepatic dysfunction by decreasing lipid accumulation. A lipid-lowering effect was also observed in high-fat and high-cholesterol diet-fed hamsters. In conclusion, our results demonstrate that the small molecular AMPK activator C24 alleviates hyperlipidemia and represents a promising compound for the development of a lipid-lowering drug.

Two New Oleanane-Triterpenoid Saponins from Clinopodium gracile.

Two new oleanane-triterpenoid saponins, clinograsaponins A (1) and B (2), together with twelve known ones (3-14), were isolated from the whole herb of Clinopodium gracile (Bentham) Matsumura. Their structures were determined by spectroscopic analysis and chemical method. All the isolated compounds were evaluated for their activities against ATP-citrate lyase (ACLY) and nuclear factor kappa B (NF-κB).

Berberine derivatives with a long alkyl chain branched by hydroxyl group and methoxycarbonyl group at 9-position show improved anti-proliferation activity and membrane permeability in A549 cells.

Berberine (BBR) exhibits diverse bioactivities, including anticancer activity; but its poor druggability limits its applications. In this study, we designed and synthesized a series of 9-O position modified BBR derivatives aiming to improve its cell permeability and anticancer activity, utilizing a long alkyl chain branched by hydroxyl group and methoxycarbonyl group. Among these compounds, B10 showed 3.6-fold higher intracellular concentration than BBR, as well as 60-fold increased anti-proliferation activity against human lung cancer A549 cells compared with BBR. Treatment with B10 (1, 2 µM) induced apoptosis of A549 cells. Further investigations showed that B10 treatment dose-dependently affected mitochondrial functions, including oxygen consumption rate (OCR), mitochondrial membrane potential (MMP) and the morphology of mitochondria in A549 cells. Therefore, this work offers a new way for BBR structural modification through improving cell membrane permeability to affect mitochondrial functions and potential anti-tumor therapy in the future.

Maximumins A-D, Rearranged Labdane-Type Diterpenoids with Four Different Carbon Skeletons from Amomum maximum.

Four highly rearranged labdane-type diterpenoids, maximumins A-D (1-4) possessing different new carbon skeletons, together with a biosynthetically related known analog 5 were isolated from Amomum maximum. The structures of new compounds with absolute configurations were characterized by spectroscopic and computational approaches. The plausible biogenetic pathways for 1-4 were proposed. These compounds showed moderate to weak activities against nuclear factor kappa B (NF-κB).

Cinerols, Nitrogenous Meroterpenoids from the Marine Sponge Dysidea cinerea.

Eleven new nitrogenous meroterpenoids, cinerols A-K (1-11), were isolated from the marine sponge Dysidea cinerea collected in the South China Sea, and their structures were determined by detailed spectroscopic analysis. Cinerols A (1) and B (2) feature a rare 5H-pyrrolo[1,2a]benzimidazole moiety, while cinerols C-G (3-7) are examples of rare meroterpene benzoxazoles. The cinerols are noncytotoxic to human melanoma A375 cells at the concentration of 32 µM; however, selected cinerols exhibit moderate inhibitory activity against one or more of protein-tyrosine phosphatase 1B, ATP-citrate lyase, and SH2 domain-containing phosphatase-1 with IC50 values of 2.8-27 µM.

Sulfuretin protects hepatic cells through regulation of ROS levels and autophagic flux.

Palmitate (PA) exposure induces stress conditions featuring ROS accumulation and upregulation of p62 expression, resulting in autophagic flux blockage and cell apoptosis. Sulfuretin (Sul) is a natural product isolated from Rhus verniciflua Stokes; the cytoprotective effect of Sul on human hepatic L02 cells and mouse primary hepatocytes under PA-induced stress conditions was investigated in this study. Sul induced mitophagy by activation of p-TBK1 and LC3 and produced a concomitant decline in p62 expression. Autophagosome formation and mitophagy were assessed by the sensitive dual fluorescence reporter mCherry-EGFP-LC3B, and mitochondrial fragmentation was analyzed using MitoTracker Deep Red FM. A preliminary structure-activity relationship (SAR) for Sul was also investigated, and the phenolic hydroxyl group was found to be pivotal for maintaining the cytoprotective bioactivity of Sul. Furthermore, experiments using flow cytometry and western blots revealed that Sul reversed the cytotoxic effect stimulated by the autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ), and its cytoprotective effect was almost eliminated when the autophagy-related 5 (Atg5) gene was knocked down. These studies suggest that, in addition to its antioxidative effects, Sul stimulates mitophagy and restores impaired autophagic flux, thus protecting hepatic cells from apoptosis, and that Sul has potential future medical applications for hepatoprotection.

The Landscape of Histone Modifications in a High-Fat Diet-Induced Obese (DIO) Mouse Model.

Type 2 diabetes (T2D) is a major chronic healthcare concern worldwide. Emerging evidence suggests that a histone-modification-mediated epigenetic mechanism underlies T2D. Nevertheless, the dynamics of histone marks in T2D have not yet been carefully analyzed. Using a mass spectrometry-based label-free and chemical stable isotope labeling quantitative proteomic approach, we systematically profiled liver histone post-translational modifications (PTMs) in a prediabetic high-fat diet-induced obese (DIO) mouse model. We identified 170 histone marks, 30 of which were previously unknown. Interestingly, about 30% of the histone marks identified in DIO mouse liver belonged to a set of recently reported lysine acylation modifications, including propionylation, butyrylation, malonylation, and succinylation, suggesting possible roles of these newly identified histone acylations in diabetes and obesity. These histone marks were detected without prior affinity enrichment with an antibody, demonstrating that the histone acylation marks are present at reasonably high stoichiometry. Fifteen histone marks differed in abundance in DIO mouse liver compared with liver from chow-fed mice in label-free quantification, and six histone marks in stable isotope labeling quantification. Analysis of hepatic histone modifications from metformin-treated DIO mice revealed that metformin, a drug widely used for T2D, could reverse DIO-stimulated histone H3K36me2 in prediabetes, suggesting that this mark is likely associated with T2D development. Our study thus offers a comprehensive landscape of histone marks in a prediabetic mouse model, provides a resource for studying epigenetic functions of histone modifications in obesity and T2D, and suggest a new epigenetic mechanism for the physiological function of metformin.

[Flavonoids with PTP1B inhibition from Broussonetia papyrifera].

Eleven flavonoids were isolated from the twigs of Broussonetia papyrifera by column chromatography over silica gel,ODS,MCI gel,and Sephadex LH-20,as well as RP-HPLC.Their structures were identified by spectroscopic methods including NMR,MS,UV,and IR as broupapyrin A(1),5,7,3',4'-tetrahydroxy-3-methoxy-8-geranylflavone(2),8-prenylquercetin-3-methyl ether(3),broussonol D(4),broussoflavonol B(5),uralenol(6),broussonol E(7),8-(1,1-dimethylallyl)-5'-(3-methylbut-2-enyl)-3',4',5,7-tetrahydroxyflanvonol(8),broussoflavonol E(9),4,2',4'-trihydroxychalcone(10),and butein(11).Compound 1 is a new isoprenylated flavonol.Compounds 3,6,10,and 11 were obtained from the genus Broussonetia for the first time,and 4 and 7 were firstly discovered in B.papyrifera.Compounds 1-5 and 7-9 showed significant inhibitory effects on PTP1 B with IC50 values ranging from(0.83±0.30) to(4.66±0.83) µmol·L-1.