Adverse drug reactions of statin therapy in China from 1989 to 2019: a national database analysis.

BACKGROUND: The baseline incidence of the adverse events of statin therapy varies between countries. Notably, Chinese patients seem more susceptible to myopathy induced by simvastatin. OBJECTIVES: This research studies the adverse drug reactions (ADRs) of statin therapy in China by analysing trial-based data from the Anti-hyperlipidaemic Drug Database built by the China National Medical Products Administration Information Centre. METHODS: All clinical trials involving statin therapy (including simvastatin, atorvastatin, fluvastatin, lovastatin, pravastatin and rosuvastatin) in China from 1989 to 2019 were screened. In total, 569 clinical studies with 37 828 patients were selected from 2650 clinical trials in the database. RESULTS: Among the reported cases with ADRs (2822/37 828; 7.460%), gastrointestinal symptoms were the most common (1491/37 828; 3.942%), followed by liver disease (486/37 828; 1.285%), muscle symptoms (444/37 828; 1.174%) and neurological symptoms (247/37 828; 0.653%). Pravastatin (231/1988; 11.620%) caused the most common gastrointestinal side effects, followed by fluvastatin (333/3094; 10.763%). The least likely to cause gastrointestinal irritation was rosuvastatin (82/1846; 4.442%). CONCLUSION: In Chinese clinical trials, gastrointestinal symptoms were the most common ADR of statin use for hyperlipidaemia and other cardiovascular diseases.

Comparative decline of the protein profiles of nebulin in response to denervation in skeletal muscle.

The sliding filament model of the sarcomere was developed more than half a century ago. This model, consisting only of thin and thick filaments, has been efficacious in elucidating many, but not all, features of skeletal muscle. Work during the 1980s revealed the existence of two additional filaments: the giant filamentous proteins titin and nebulin. Nebulin, a giant myofibrillar protein, acts as a protein ruler to maintain the lattice arrays of thin filaments and plays a role in signal transduction and contractile regulation. However, the change of nebulin and its effect on thin filaments in denervation-induced atrophic muscle remains unclear. The purpose of this study is to examine the content and pattern of nebulin, myosin heavy chain (MHC), actin, and titin in innervated and denervated tibialis anterior (TA) muscles of rats using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), densitometry and electron microscopic (EM) analyses. The results revealed that denervation induced muscle atrophy is accompanied by decreased nebulin content in a time-dependent manner. For instant, the levels of nebulin in denervated muscles were markedly (P < 0.05) decreased, about 24.6% and 40.2% in comparison with innervated muscle after denervation of 28 and 56 days, respectively. The nebulin/MHC, nebulin/actin, and nebulin/titin ratios were decreased, suggesting a concomitant reduction of nebulin in denervated muscle. Moreover, a western blotting assay proved that nebulin declined faster than titin on 28 and 56 days of denervated muscle. In addition, EM study revealed that the disturbed arrangements of myofilaments and a disorganized contractile apparatus were also observed in denervated muscle. Overall, the present study provides evidence that nebulin is more sensitive to the effect of denervation than MHC, actin, and titin. Nebulin decline indeed resulted in disintegrate of thin filaments and shortening of sarcomeres.

YC-1, a potent antithrombotic agent, induces lipolysis through the PKA pathway in rat visceral fat cells.

This study investigated the effects of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), a soluble guanylyl cyclase (sGC) activator and potential antithrombotic agent, on lipolysis in isolated visceral fat cells of the rat. Visceral fat cells were isolated from epididymal fat pads of rats and treated with YC-1 at different doses and times. Glycerol release, and intracellular cAMP and cGMP levels were analyzed by specific kits. Moreover, several inhibitors or drugs were used to examine the signal transduction pathways of YC-1-induced lipolysis in adipocytes. Herein we report that YC-1 stimulated glycerol release in dose- and time-dependent manners. Intracellular cAMP and cGMP levels of adipocytes both increased in time-dependent manners, but elevation of the cGMP level was faster and higher than that of the cAMP level after YC-1 treatment. An sGC inhibitor (ODQ) inhibited YC-1-induced glycerol release, indicating the involvement of sGC in YC-1-induced lipolysis. Administration of insulin, an activator of type-3B phosphodiesterase (PDE-3B), attenuated YC-1-induced lipolysis, indicating that elevation of the cAMP level is an important step in the lipolytic effect of YC-1. In addition, YC-1-induced lipolysis was inhibited by a protein kinase A (PKA) inhibitor (KT5720) but not by a PKG inhibitor (KT5823), indicating that YC-1-induced lipolysis occurs through a PKA-dependent pathway. A Western blot analysis showed that extracellular signal-regulated kinase was not phosphorylated by YC-1 treatment. In conclusion, our results suggest that YC-1 might stimulate lipolysis via activation of sGC/cGMP and then activation of the cAMP/PKA signaling cascade in isolated rat visceral adipocytes.

Decline in titin content in rat skeletal muscle after denervation.

Titin, an elastic and giant myofibrillar protein, is responsible for generating passive tension and maintaining sarcomere structure in striated muscles. Several studies have reported attenuation of passive tension and disorganization of sarcomere in atrophic muscles, but the changes of titin have not been investigated after denervation. For this purpose, we used sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunofluorescent staining to examine titin in innervated and denervated tibialis anterior (TA) muscles of the rat. With increasing denervation time, we found a greater loss of titin than myosin heavy chain (MHC) and actin contents in atrophic TA muscle. The ratios of titin/MHC and titin/actin gradually decreased following denervation. In contrast, ratios of MHC/actin in the denervated groups showed no significant differences with the controls even at 56 days postdenervation. The ultrastructure of myofibrils also showed disturbed arrangements of myofilaments and a disorganized contractile apparatus in denervated muscle. Immunofluorescent staining displayed translocation of the titin epitope from the Z-line to the I-band, suggesting that the apparent cleavage of titin occurred near the Z-line region during the atrophying process. Our study provides evidence that titin is more sensitive to degradation than MHC and actin after denervation. Moreover, the titin decline results in the loss of titin-based sarcomeric integrity in atrophic muscle.

Detection of myofibrillar proteins using a step gradient minigel with an ambiguous interface.

Myosin heavy chain (MHC), actin, titin, and nebulin are four major myofibrillar proteins that interact with each other. However, it is difficult to analyze the four proteins simultaneously on the same minigel due to their broad range of molecular weights. Numerous gradient gels are normally used to detect these myofibrillar proteins. The conventional step gradient gel provides better separation of the four major proteins, but several proteins accumulate at the interfaces between different gradient layers. To eliminate the obvious interfaces, we employed a plastic syringe filled with 12 and 4% acrylamide solutions simultaneously and then established an improved step gradient minigel with an ambiguous interface. It was determined by blue dextran in-gel visualization and scanning densitometry that the acrylamide concentration at the ambiguous interface gradually changed. Coomassie blue staining and immunoblotting revealed that the four proteins were successfully separated and transferred for analysis. This gel system is simple to prepare and easy to use, and it is a reliable method for analyzing myofibrillar proteins or other protein mixtures with broad molecular masses.