Novel substituted pyrazolone derivatives as AMP-activated protein kinase activators to inhibit lipid synthesis and reduce lipid accumulation in ob/ob mice

Chlormequat chloride induces hepatic steatosis by promoting mTOR/SREBP1 mediated lipogenesis via AMPK inhibition

Chlormequat chloride (CCC), a widely used plant growth regulator, is a choline analogue that has been shown to have endocrine-disrupting effects. Previous studies have shown that maternal exposure to CCC could induce hyperlipidemia and growth disruption in rat offspring. This study aims to further investigate the effects of peripubertal exposure to CCC on pubertal development and lipid homeostasis, as well as the underlying mechanisms. In vivo, male weanling rats were exposed to CCC (0, 20, 75 and 200 mg/kg bw/day) from post-natal day 21-60 via daily oral gavage. The results in rats showed that 75 mg/kg CCC treatment induced hepatic steatosis, predominantly microvesicular steatosis with a small amount of macrovesicular steatosis, in rat livers and 200 mg/kg CCC treatment induced liver damage including inflammatory infiltration, hepatic sinusoidal dilation and necrosis. In vitro, HepG2 cells were treated with CCC (0, 30, 60, 120, 240 and 480 μg/mL) for 24 h. And the results showed that CCC above 120 μg/mL induced an increase in triglyceride and neutral lipid levels of HepG2 cells. Mechanism exploration revealed that CCC treatment promoted the activation of mTOR/SREBP1 signalling pathway and inhibited activation of AMPK in both in vivo rat livers and in vitro HepG2 cells. Treatment with AMPK activator Acadesine (AICAR) could alleviate the lipid accumulation in HepG2 cells induced by CCC. Collectively, the present results indicate that CCC might induce hepatic steatosis by promoting mTOR/SREBP1 mediated lipogenesis via AMPK inhibition.

Identification of toll-like receptor 2 as a key regulator of neuronal apoptosis in vascular dementia by bioinformatics analysis and experimental validation

BACKGROUND

Vascular dementia (VaD), the second most prevalent type of dementia, lacks a well-defined cause and effective treatment. Our objective was to utilize bioinformatics analysis to discover the fundamental disease-causing genes and pathological mechanisms in individuals diagnosed with VaD.

METHODS

To identify potential pathogenic genes associated with VaD, we conducted weighted gene co-expression network analysis (WGCNA), differential expression analysis, and protein-protein interaction (PPI) analysis. The exploration of potential biological mechanisms involved the utilization of Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. Moreover, a bilateral common carotid artery stenosis (BCAS) mouse model of VaD was established, and the expression of the hub gene, its relationship with cognitive function and its potential pathogenic mechanism were verified by cognitive behavior tests, cerebral blood flow measurement, Western blotting, and immunofluorescence experiments.

RESULTS

This study identified 293 DEGs from the brain cortex of VaD patients and healthy controls, among these genes, the Toll-like receptor 2 (TLR2) gene was identified as hub gene, and it was associated with the apoptosis-related pathway PI3K/AKT.The BCAS model demonstrated that the use of TLR2 inhibitors greatly enhanced the cognitive function of the mice (p < 0.05). Additionally, there was a notable decrease in the number of apoptotic cells in the brain cortex of the mice (p < 0.01). Moreover, significant alterations in the levels of proteins related to the PI3K/AKT pathway and cleaved-caspase3 proteins were detected (p < 0.05).

CONCLUSIONS

TLR2 plays a role in the pathophysiology of VaD by enhancing the neuronal apoptotic pathway, suggesting it could be a promising therapeutic target.

TLR2 Mediates Microglial Activation and Contributes to Central Sensitization in a Recurrent Nitroglycerin-induced Chronic Migraine Model

Central sensitization is an important pathophysiological mechanism underlying chronic migraine (CM). Previous studies have shown that microglial activation and subsequent inflammation in the trigeminal nucleus caudalis (TNC) contribute to central sensitization. Toll-like receptor 2 (TLR2) is a receptor expressed on the membrane of microglia and participates in central sensitization in inflammatory and chronic pain; however, its role in CM is unclear. Therefore, this study investigated TLR2 involvement in CM in detail. Mice treated with recurrent nitroglycerin (NTG) were used as a CM model. Hyperalgesia was assessed using a 50% paw mechanical threshold and a 50% periorbital threshold on a Von Frey filament pain meter. Western blotting and immunofluorescence analyses were used to detect the expression of TLR2, microglia, c-fos and CGRP in TNC. The expression of inflammatory factors (IL-6, IL-1β、 IL-10、TNF-α and IFN-β1) was detected using quantitative real-time polymerase chain reaction (qRT-PCR). A selective TLR2 antagonist (C29) was systematically administered to observe its effect on hyperalgesia, microglia activation and the expression of c-fos, CGRP and inflammatory factors. Recurrent administration of NTG resulted in acute and chronic hypersensitivity, accompanied by upregulation of TLR2 expression and microglial activation in TNC. C29 partially inhibited pain hypersensitivity. C29 suppressed microglial activation induced by NTG administration. Inhibition of TLR2 reduced the expression of c-fos and CGRP in TNC after NTG treatment. C29 inhibited the expression of inflammatory mediators in TNC. These data showed that microglial TLR2 plays a critical role in the pathogenesis of CM by regulating microglial activation in TNC.

Pathological features of reinnervated skeletal muscles after crush injury of the sciatic nerve in ob/ob mice

INTRODUCTION/AIMS

Obesity is a factor contributing to suboptimal improvement of motor function in peripheral nerve disorders. In this study we aimed to evaluate the skeletal muscles during denervation and reinnervation after nerve crush injury in leptin-deficient (ob/ob) mice.

METHODS

Experiments were performed on the skeletal muscles of the hindlimbs in 20 male ob/ob mice and controls. Characteristics of the gastrocnemius muscles were evaluated by histological analysis, immunohistological analysis, and Sircol-collagen assay after measurement of body weight and wet weight of the skeletal muscles, and by walking track analysis. The sciatic nerve was denervated by crushing with smooth forceps and reinnervation was evaluated.

RESULTS

Gastrocnemius wet weight was significantly lower in the ob/ob mice than in the control mice. A smaller cross-sectional area of type II fibers and increase of type I fiber grouping of the skeletal muscles was demonstrated in the ob/ob mice. After nerve injury, motor function recovery was equal between the groups but the cross-sectional area of type II fibers was significantly smaller in the ob/ob mice than in control mice at 4 weeks. The denervated muscles showed an increase in collagen deposition in the interstitial space; predominant in the ob/ob mice after nerve injury.

DISCUSSION

The results of this study suggest that fibrosis in the skeletal muscle of obese patients after nerve injury is prominent, which may impair improvement of muscle function after treatment of peripheral nerve disorders.

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.

Pyrazolone structural motif in medicinal chemistry: Retrospect and prospect

The pyrazolone structural motif is a critical element of drugs aimed at different biological end-points. Medicinal chemistry researches have synthesized drug-like pyrazolone candidates with several medicinal features including antimicrobial, antitumor, CNS (central nervous system) effect, anti-inflammatory activities and so on. Meanwhile, SAR (Structure-Activity Relationship) investigations have drawn attentions among medicinal chemists, along with a plenty of analogues have been derived for multiple targets. In this review, we comprehensively summarize the biological activity and SAR for pyrazolone analogues, wishing to give an overall retrospect and prospect on the pyrazolone derivatives.

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The pyrazolone structural motif is a critical element of drugs aimed at different biological end-points.

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The pyrazolone analogues have been carried out to drug-like candidates with broad range of medicinal properties.

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This review wishes to give an overall retrospect and prospect on the pyrazolone derivatives.