Latamoxef dosing regimen adjustments and pharmaceutical care in pediatrics.

Latamoxef is a semi-synthetic, broad-spectrum oxacephem antibiotic used primarily to treat infectious diseases, but the adverse drug reactions, such as the risk of fatal bleeding, once caused physicians to use it less frequently. However, with the rise of antibiotic-resistant bacterial strains, latamoxef is being used again to treat infectious diseases, especially in pediatrics. The pharmacokinetic parameters of latamoxef are highly variable, given the changes in body composition, organ maturation, and development that occurs in pediatrics. Therefore, an appropriate dosing regimen is essential. Latamoxef dosing optimization in pediatrics should adequately account for current body weight, postnatal age, postmenstrual age, and different minimum inhibitory concentration (MIC) values. In addition, attention should also be paid to some of the adverse reactions associated with latamoxef, such as coagulation disorders and bleeding risks, disulfiram-like reactions, as well as hypersensitivity and anaphylactic shock. This review summarizes the dosing regimens and some key points of pharmaceutical care for latamoxef in pediatrics in order to provide a better reference for its application in clinical practice.

A pharmacovigilance study of association between proton-pump inhibitors and rhabdomyolysis event based on FAERS database.

BACKGROUND AND AIM: The association between proton-pump inhibitors (PPIs) and rhabdomyolysis were unclear. The aim of this study was to explore and systematically analyze the potential link between five PPIs and the rhabdomyolysis events using the FDA Adverse Event Reporting System (FAERS) database. METHODS: Suspected rhabdomyolysis events associated with PPIs were identified by data mining with the reporting odds ratio (ROR), proportional reporting ratio (PRR), the information component (IC), and Empirical Bayes Geometric Mean (EBGM). Demographic information, drug administration, and outcomes of PPI-induced rhabdomyolysis events were also analyzed. RESULTS: There were 3311 reports associated with PPI-induced rhabdomyolysis that were identified. After removing duplicates, 1899 cases were determined to contain complete patient demographic data. The average age was 65 ± 18 year and 57% were male. Omeprazole and pantoprazole had the same largest percentage of reports. Lansoprazole had the highest ROR index of 12.67, followed by esomeprazole (11.18), omeprazole (10.27), rabeprazole (10.06), and pantoprazole (9.24). PRR, IC, and EBGM showed similar patterns. This suggested that lansoprazole exhibited the strongest correlation with rhabdomyolysis. In rhabdomyolysis events, PPIs were mainly "concomitant" (>60%), and only a few cases were "primary suspects" (<15%). Rabeprazole showed the lowest death rate while lansoprazole showed the highest. CONCLUSIONS: The study suggested that significant rhabdomyolysis signals were associated with PPIs. Further research should be performed in drug safety evaluation for a more comprehensive association.

Visualizing Cardiolipin In Situ with HKCL-1M, a Highly Selective and Sensitive Fluorescent Probe.

Reliable probing of cardiolipin (CL) content in dynamic cellular milieux presents significant challenges and great opportunities for understanding mitochondria-related diseases, including cancer, neurodegeneration, and diabetes mellitus. In intact respiring cells, selectivity and sensitivity for CL detection are technically demanding due to structural similarities among phospholipids and compartmental secludedness of the inner mitochondrial membrane. Here, we report a novel "turn-on" fluorescent probe HKCL-1M for detecting CL in situ. HKCL-1M displays outstanding sensitivity and selectivity toward CL through specific noncovalent interactions. In live-cell imaging, its hydrolyzed product HKCL-1 efficiently retained itself in intact cells independent of mitochondrial membrane potential (Δψm). The probe robustly co-localizes with mitochondria and outperforms 10-N-nonyl acridine orange (NAO) and Δψm-dependent dyes with superior photostability and negligible phototoxicity. Our work thus opens up new opportunities for studying mitochondrial biology through efficient and reliable visualization of CL in situ.

Population Pharmacokinetics of Tacrolimus in Pediatric Patients With Umbilical Cord Blood Transplant.

Tacrolimus was frequently used in pediatric patients with umbilical cord blood transplant for the prevention of graft-versus-host disease. The aim of the present study was to evaluate the population pharmacokinetics of tacrolimus among pediatric patients with umbilical cord blood transplant and find potential influenced factors. A total of 275 concentrations from 13 pediatric patients were used to build a polulation pharmacokinetic model using a nonlinear mixed-effects modeling approach. The impact of demographic features, biological characteristics, and concomitant medications, including sex, age, body weight, postoperative day, white blood cell count, red blood cell count, hemoglobin, platelets, hematocrit, blood urea nitrogen, creatinine, aspartate transaminase, alanine transaminase, total bilirubin, albumin, and total protein were investigated. The pharmacokinetics of tacrolimus were best described by a 1-compartment model with first- and zero-order mixed absorption and first-order elimination. The clearance and volume of distribution of tacrolimus were 1.93 L/h and 75.1 L, respectively. A covariate analysis identified that postoperative day and co-administration with trimethoprim-sulfamethoxazole were significant covariates influencing clearance of tacrolimus. Frequent blood monitoring and dose adjustment might be needed with the prolongation of postoperative day and coadministration with trimethoprim-sulfamethoxazole.

Evaluating linezolid dose regimens against methicillin-resistant Staphylococcus aureus based on renal function in populations with different body weight.

WHAT IS KNOWN AND OBJECTIVE: Linezolid is an alternative first-line agent for MRSA pneumonia. This study assessed whether dose adjustments of linezolid against methicillin-resistant Staphylococcus aureus (MRSA) infections were needed based on renal function in populations with different body weight. METHODS: Monte Carlo simulations were conducted to evaluate renal function in relation to the probability of target attainment (PTA) in three population groups with different body weight. Area under the concentration time curve (AUC)/ minimum inhibitory concentration (MIC) ratio and percentage of time above the MIC (%T > MIC) were regarded as pharmacokinetic/pharmacodynamic targets. The PTA and cumulative fractions of response (CFR) were calculated to assess the efficacy. Regarding safety, trough plasma concentration (Cmin ) > 8 mg/L was used as target for toxicity. RESULTS AND DISCUSSION: Using AUC/MIC >100 as the target pharmacodynamic (PD) index, the CFR of linezolid at the standard dose (600 mg every 12 h [q12h]) were 57.01%, 93.22%, and 99.93% in patients with normal renal function, patients with renal dysfunction and low body weight patients with renal dysfunction, respectively. Using 100%T > MIC as the target PD index, all the CFR of three population groups were more than 90% at the standard dose. The percentages of Cmin > 8 mg/L at the standard dose of linezolid were 24.16%, 53.24%, and 90.10% in three population groups on day 7. WHAT IS NEW AND CONCLUSION: The risk of thrombocytopenia of linezolid was extremely higher in low body weight patients with renal impairment when receiving standard linezolid dose compared with patients with normal renal function. 450 mg q12h and 300 mg q12h might be effective and safe against MRSA infection in patients with renal dysfunction and low body weight patients with renal dysfunction, respectively.

The Role of MicroRNAs in Hyperlipidemia: From Pathogenesis to Therapeutical Application.

Hyperlipidemia is a common metabolic disorder with high morbidity and mortality, which brings heavy burden on social. Understanding its pathogenesis and finding its potential therapeutic targets are the focus of current research in this field. In recent years, an increasing number of studies have proved that miRNAs play vital roles in regulating lipid metabolism and were considered as promising therapeutic targets for hyperlipidemia and related diseases. It is demonstrated that miR-191, miR-222, miR-224, miR-27a, miR-378a-3p, miR-140-5p, miR-483, and miR-520d-5p were closely associated with the pathogenesis of hyperlipidemia. In this review, we provide brief overviews about advances in miRNAs in hyperlipidemia and its potential clinical application value.

Loss of Sam50 in hepatocytes induces cardiolipin-dependent mitochondrial membrane remodeling to trigger mtDNA release and liver injury.

BACKGROUND AND AIMS: Sam50, a key component of the sorting and assembly machinery (SAM) complex, is also involved in bridging mitochondrial outer-membrane and inner-membrane contacts. However, the physiological and pathological functions of Sam50 remain largely unknown. APPROACH AND RESULTS: Here we show that Sam50 interacts with MICOS (mitochondrial contact site and cristae organizing system) and ATAD3 (ATPase family AAA domain-containing protein 3) to form the Sam50-MICOS-ATAD3-mtDNA axis, which maintains mtDNA stability. Loss of Sam50 causes mitochondrial DNA (mtDNA) aggregation. Furthermore, Sam50 cooperates with Mic60 to bind to cardiolipin, maintaining the integrity of mitochondrial membranes. Sam50 depletion leads to cardiolipin externalization, which causes mitochondrial outer-membrane and inner-membrane (including crista membrane) remodeling, triggering Bax mitochondrial recruitment, mtDNA aggregation, and release. Physiologically, acetaminophen (an effective antipyretic and analgesic)-caused Sam50 reduction or Sam50 liver-specific knockout induces mtDNA release, leading to activation of the cGAS-STING pathway and liver inflammation in mice. Moreover, exogenous expression of Sam50 remarkably attenuates APAP-induced liver hepatoxicity. CONCLUSIONS: Our findings uncover the critical role of Sam50 in maintaining mitochondrial membrane integrity and mtDNA stability in hepatocytes and reveal that Sam50 depletion-induced cardiolipin externalization is a signal of mtDNA release and controls mtDNA-dependent innate immunity.

Association of lncRNA PVT1 Gene Polymorphisms with the Risk of Essential Hypertension in Chinese Population.

Vascular dysfunction and hyperlipidemia are essential risk factors contributing to essential hypertension (EH). The plasmacytoma variant translocation 1 (PVT1) is involved in modulating angiogenesis in tumor tissues and plays an important role in fat differentiation in the progress of obesity. Therefore, we selected two tagSNPs of PVT1 (rs10956390 and rs80177647) to investigate whether they are contributing to the risk of hypertension in Chinese patients. In total, 524 adult patients with EH and 439 matched healthy controls were enrolled for two central of China. Results. PVT1 rs10956390 and rs80177647 polymorphisms were genotyped by using TaqMan assay. PVT1 rs10956390 TT genotype was associated with a decreased risk of EH (OR = 0.561, 95% CI = 0.372-0.846, P = 0.006), while rs80177647 TA genotype was associated with an increased risk (OR = 2.236, 95% CI = 1.515-3.301, P < 0.001). Rs10956390 T allele was associated with lower triglyceride levels in the plasma both from healthy and EH donors. What is more, there is an association between rs10956390 polymorphism and HDL-C level, as well as LDL-C. Conclusion. PVT1 rs10956390 and rs80177647 polymorphisms may contribute to the risk of EH in Chinese population by regulating blood lipid levels.

SOCS3 Gene Polymorphism and Hypertension Susceptibility in Chinese Population: A Two-Center Case-Control Study.

Endothelial inflammation and vascular damage are essential risk factors contributing to hypertension. Suppressor of cytokine signaling 3 (SOCS3) is involved in the regulation of multiple inflammatory pathways. A large number of studies have shown that the anti-inflammatory effect of SOCS3 in hypertension, obesity, and allergic reactions has brought more insights into the inhibition of inflammation. Therefore, we selected a tagSNP of SOCS3 (rs8064821) to investigate whether they are contributing to the risk of hypertension in the Chinese population. In total, 532 patients with hypertension and 569 healthy controls were enrolled for two central of China. SOCS3 rs8064821 C>A polymorphism was genotyped using TaqMan assay. SOCS3 rs8064821 CA genotype was associated with an increased risk of hypertension (OR = 1.821, 95%CI = 1.276-2.600, P = 0.001). Rs8064821 A allele was associated with higher SOCS3 mRNA level in PBMCs from healthy donors. SOCS3 rs8064821 C>A polymorphism may contribute to the risk of hypertension in the Chinese population by regulating the expression of SOCS3.

MicroRNA-455-5p Contributes to Cholangiocarcinoma Growth and Mediates Galangin's Anti-Tumor Effects.

Fully understanding the mechanism of how Cholangiocarcinoma (CCA) development and discovering promising therapeutic drugs are important to improve patients' survival time. This study identifies that microRNA-455-5p (miR-455-5p) targets protein phosphatase 1 regulatory subunit 12A (PPP1R12A), an effect that represses mitogen-activated protein kinase (MAPK) and PI3K/AKT pathway activation, thereby controlling CCA cells survival and metastasis. Moreover, miR-455-5p expression is reduced in CCA tissues and negative correlation with PPP1R12A and PPP1R12A knockdown phenotypic mimics miR-455-5p' effects on CCA cells. Furthermore, we demonstrate that galangin inhibits CCA growth both in vitro and in vivo, which is associated with increased miR-455-5p and repressed PPP1R12A expression. In support, overexpression of miR-455-5p abrogates those galangin-mediated anti-CCA effects. These findings establish an essential role of miR-455-5p in CCA development and galangin may provide a potential therapeutic adjuvant agent for anti-CCA treatment.

Drug-drug interaction comparison between tacrolimus and phenobarbital in different formulations for paediatrics and adults.

To compare drug-drug interaction (DDI) between tacrolimus and different formulations of phenobarbital in paediatrics and adults.Physiologically based pharmacokinetics (PBPK) models were used to evaluate DDI between phenobarbital (oral (p.o.) and intravenous (i.v.) formulations) and tacrolimus in paediatrics and adults. All dosing regimens were maintained for 7 days.Compared to i.v. phenobarbital, p.o. phenobarbital could decrease pharmacokinetic (PK) parameters of tacrolimus much more in both paediatrics and adults. On day 7, the results showed that the ratio of Cmax for tacrolimus in the presence and absence of phenobarbital were 0.13 (p.o.) and 0.48 (i.v.), respectively, in paediatrics, while 0.54 (p.o.) and 0.73 (i.v.) in adults, respectively. The ratios of the area under the concentration-time curve (AUC) were 0.06 (p.o.) and 0.18 (i.v.) in paediatrics, while 0.46 (p.o.) and 0.53 (i.v.) in adults, respectively. PK parameters of tacrolimus decreased more significantly in paediatrics compared to adults.In paediatric, phenobarbital had a greater impact on PK of tacrolimus than that in adults. P.o. phenobarbital reduced PK parameters of tacrolimus even more than i.v. administration. In clinical practice, the concentration monitoring and dosage adjustment of tacrolimus should be emphasised when co-administrated with phenobarbital, especially in paediatric or in p.o. formulation.Key pointsThe results indicated that p.o. and i.v. phenobarbital both had a significant DDI with tacrolimus in paediatrics and adults.Phenobarbital had a greater impact on the PK of tacrolimus over time in paediatrics.P.o. administration of phenobarbital can reduce the PK parameters of tacrolimus more.

Effect of oxymatrine on liver gluconeogenesis is associated with the regulation of PEPCK and G6Pase expression and AKT phosphorylation.

An increase in liver gluconeogenesis is an important pathological phenomenon in type 2 diabetes mellitus (T2DM) and oxymatrine is an effective natural drug used for T2DM treatment. The present study aimed to explore the effect of oxymatrine on gluconeogenesis and elucidate the underlying mechanism. Male Sprague-Dawley rats were treated with a high-fat diet and streptozotocin for 4 weeks to induce T2DM, and HepG2 cells were treated with 55 mM glucose to simulate T2DM in vitro. T2DM rats were treated with oxymatrine (10 or 20 mg/kg weight) or metformin for 4 weeks, and HepG2 cells were treated with oxymatrine (0.1 or 1 µM), metformin (0.1 µM), or oxymatrine combined with MK-2206 (AKT inhibitor) for 24 h. Fasting blood glucose and insulin sensitivity of rats were measured to evaluate insulin resistance. Glucose production and uptake ability were measured to evaluate gluconeogenesis in HepG2 cells, and the expression of related genes was detected to explore the molecular mechanism. Additionally, the body weight, liver weight and liver index were measured and hematoxylin and eosin staining was performed to evaluate the effects of the disease. The fasting glucose levels of T2DM rats was 16.5 mmol/l, whereas in the control rats, it was 6.1 mmol/l. Decreased insulin sensitivity (K-value, 0.2), body weight loss (weight, 300 g), liver weight gain, liver index increase (value, 48) and morphological changes were observed in T2DM rats, accompanied by reduced AKT phosphorylation, and upregulated expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). High-glucose treatment significantly increased glucose production and decreased glucose uptake in HepG2 cells, concomitant with a decrease in AKT phosphorylation and increase of PEPCK and G6Pase expression. In vivo, oxymatrine dose-dependently increased the sensitivity of T2DM rats to insulin, increased AKT phosphorylation and decreased PEPCK and G6Pase expression in the liver, and reversed the liver morphological changes. In vitro, oxymatrine dose-dependently increased AKT phosphorylation and glucose uptake of HepG2 cells subjected to high-glucose treatment, which was accompanied by inhibition of the expression of the gluconeogenesis-related genes, PEPCK and G6Pase. MK-2206 significantly inhibited the protective effects of oxymatrine in high-glucose-treated cells. These data indicated that oxymatrine can effectively prevent insulin resistance and gluconeogenesis, and its mechanism may be at least partly associated with the regulation of PEPCK and G6Pase expression and AKT phosphorylation in the liver.

OMA1 reprograms metabolism under hypoxia to promote colorectal cancer development.

Many cancer cells maintain enhanced aerobic glycolysis due to irreversible defective mitochondrial oxidative phosphorylation (OXPHOS). This phenomenon, known as the Warburg effect, is recently challenged because most cancer cells maintain OXPHOS. However, how cancer cells coordinate glycolysis and OXPHOS remains largely unknown. Here, we demonstrate that OMA1, a stress-activated mitochondrial protease, promotes colorectal cancer development by driving metabolic reprogramming. OMA1 knockout suppresses colorectal cancer development in AOM/DSS and xenograft mice models of colorectal cancer. OMA1-OPA1 axis is activated by hypoxia, increasing mitochondrial ROS to stabilize HIF-1α, thereby promoting glycolysis in colorectal cancer cells. On the other hand, under hypoxia, OMA1 depletion promotes accumulation of NDUFB5, NDUFB6, NDUFA4, and COX4L1, supporting that OMA1 suppresses OXPHOS in colorectal cancer. Therefore, our findings support a role for OMA1 in coordination of glycolysis and OXPHOS to promote colorectal cancer development and highlight OMA1 as a potential target for colorectal cancer therapy.

Low expression of miR­532­3p contributes to cerebral ischemia/reperfusion oxidative stress injury by directly targeting NOX2.

NADPH oxidase 2 (NOX2) is a major subtype of NOX and is responsible for the generation of reactive oxygen species (ROS) in brain tissues. MicroRNAs (miRNAs/miRs) are important epigenetic regulators of NOX2. The present study aimed to identify the role of NOX2 miRNA­targets in ischemic stroke (IS). A rat cerebral ischemia/reperfusion (CI/R) injury model and a SH­SY5Y cell hypoxia/reoxygenation (H/R) model were used to simulate IS. Gene expression levels, ROS production and apoptosis in tissue or cells were determined, and bioinformatic analysis was conducted for target prediction of miRNA. In vitro experiments, including function­gain and luciferase activity assays, were also performed to assess the roles of miRNAs. The results indicated that NOX2 was significantly increased in brain tissues subjected to I/R and in SH­SY5Y cells subjected to H/R, while the expression of miR­532­3p (putative target of NOX2) was significantly decreased in brain tissues and plasma. Overexpression of miR­532­3p significantly suppressed NOX2 expression and ROS generation in SH­SY5Y cells subjected to H/R, as well as reduced the relative luciferase activity of cells transfected with a reporter gene plasmid. Collectively, these data indicated that miR­532­3p may be a target of NOX2 and a biomarker for CI/R injury. Thus, the present study may provide a novel target for drug development and IS therapy.

Galangin Inhibits Cholangiocarcinoma Cell Growth and Metastasis through Downregulation of MicroRNA-21 Expression.

Galangin, a natural flavonoid product derived from the root of galangal, is emerging as a promising anticancer agent against multiple cancers. Yet, whether it also has antitumor effects on cholangiocarcinoma (CCA) and the underlying mechanism is still unknown. Herein, we demonstrate that galangin exhibits multiple antitumor effects on CCA cells including decreases cell viability; inhibits proliferation, migration, and invasion; and induces apoptosis. Moreover, those phenotypic changes are associated with downregulated microRNA-21 (miR-21) expression. To support, overexpression of miR-21 blocks galangin-mediated antisurvival and metastasis effects on CCA cells. Mechanically, galangin increases the expression of phosphatase and tensin homolog (PTEN), a direct target of miR-21, resulting in decreased phosphorylation of AKT, a protein kinase which plays a critical role in controlling survival and apoptosis. In contrast, overexpression of miR-21 abrogates galangin-regulated PTEN expression and AKT phosphorylation. Taken together, these findings indicate that galangin inhibits CCA cell proliferation and metastasis and induces cell apoptosis through a miR-21-dependent manner, and galangin may provide a novel potential therapeutic adjuvant to treat CCA.

miR-652 protects rats from cerebral ischemia/reperfusion oxidative stress injury by directly targeting NOX2.

Ischemic stroke is a devastating central nervous disease associated with oxidative stress and NOX2 is the main source of ROS responsible for brain tissue. miRNAs are a class of negative regulator of genes in mammals and involves the pathogenesis of ischemic stroke. This study aims to observe the role of target miRNA(miR-652) of NOX2 in ischemic stroke. A rat cerebral ischemia/reperfusion (CI/R) injury model and an SH-SY5Y cell hypoxia/reoxygenation(H/R) model were used to simulate ischemic stroke, and corresponding gene expression, biochemical indicators and pathophysiological indicators were measured to observe the role of miR-652. NOX2 significantly increased in brain tissues subjected to I/R or in SH-SY5Y cells subjected to H/R, while the expression level of miR-652(potential target of NOX2) significantly decreased in both brain tissues and plasma. Overexpression of miR-652 significantly suppressed NOX2 expression and ROS generation in H/R treated SH-SY5Y cells and reduced the relative luciferase activity of cells transfected with plasmid NOX2-WT (reporter gene plasmid). MiR-652 agomir significantly decreased the expression of NOX2 and ROS generation in brain tissues of CIR rats, as well as tissue injury. These data indicated that miR-652 protected rats from cerebral ischemia reperfusion injury by directly targeting NOX2, is a novel target for ischemic stroke therapy.

Oxymatrine ameliorates insulin resistance in rats with type 2 diabetes by regulating the expression of KSRP, PETN, and AKT in the liver.

Insulin resistance plays a key role in the development and progression of type 2 diabetes mellitus (T2DM). Recent studies found that insulin resistance was associated with the dysfunction of KH-type splicing regulatory protein (KSRP) expression and AKT pathway, and that oxymatrine possesses an antidiabetic effect. The aim of the present study was to investigate whether the protection of oxymatrine against T2DM was associated with the modulation of the KSRP expression and AKT pathway. Sprague-Dawley rats were fed a high-fat diet and injected with streptozotocin intraperitoneally to induce T2DM, which led to an increase in blood glucose levels and insulin resistance, and a decrease in insulin sensitivity and glycogen synthesis concomitant with KSRP downregulation, PTEN upregulation, and AKT phosphorylation deficiency. The administration of oxymatrine decreased blood glucose levels and insulin resistance, increased insulin sensitivity, and improved glycogen synthesis in the liver of T2DM rats, through a reversal in the expression of KSRP, PTEN, and AKT. On the basis of these observations, we concluded that oxymatrine can protect T2DM rats from insulin resistance through the regulation of the KSRP, PETN, and AKT expression in the liver.

Role of ALK5/SMAD2/3 signaling in the regulation of NOX expression in cerebral ischemia/reperfusion injury.

Nicotinamide adenine dinucleotide phosphate oxidase (NOX)-derived reactive oxygen species (ROS) serve an important role in cerebral ischemia/reperfusion (I/R) injury. However, the mechanism by which ROS generation is regulated has not yet been fully elucidated. The present study aimed to explore the role of transforming growth factor-ß signaling in ROS generation. Sprague Dawley rats were subjected to I/R injury and PC-12 cells were transfected with small interfering RNA against activin receptor-like kinase (ALK)5 or hypoxia/reoxygenation (H/R). The results indicated that I/R or H/R significantly increased ALK5 expression, SMAD2/3 phosphorylation and NOX2/4 expression and activity, concomitant with ROS generation and apoptosis. In addition, ALK5 knockdown significantly reversed changes induced by H/R treatment in PC-12 cells. These results suggest that ALK5/SMAD2/3 signaling serves a key role in oxidative stress. To the best of our knowledge, this is the first study to demonstrate that ALK5/SMAD2/3 activation is associated with the regulation of NOX2/4 expression and exacerbates I/R injury.

Upregulation of NOX2 and NOX4 Mediated by TGF-ß Signaling Pathway Exacerbates Cerebral Ischemia/Reperfusion Oxidative Stress Injury.

BACKGROUND/AIMS: Ischemic stroke is still one of the leading debilitating diseases with high morbidity and mortality. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) play an important role in cerebral ischemia/reperfusion (I/R) injury. However, the mechanism underlying the regulation of ROS generation is still not fully elucidated. This study aims to explore the role of transforming growth beta (TGF-ß) signals in ROS generation. METHODS: Sprague-Dawley rats were subjected to I/R injury, and PC-12 cells were challenged by hypoxia/reoxygenation (H/R) and/or treated with activin receptor-like kinase (ALK5) inhibitor Sb505124 or siRNA against ALK5. Brain damage was evaluated using neurological scoring, triphenyl tetrazolium chloride staining, hematoxylin and eosin staining, infarct volume measurement, TUNEL staining, and caspase-3 activity measurement. Expression of TGF-ß and oxidative stress-related genes was analyzed by real-time polymerase chain reaction and Western blot; NOX activity and ROS level were measured using spectrophotometry and fluorescence microscopy, respectively. RESULTS: I/R contributed to severe brain damage (impaired neurological function, brain infarction, tissue edema, apoptosis), TGF-ß signaling activation (upregulation of ALK5, phosphorylation of SMAD2/3) and oxidative stress (upregulation of NOX2/4, rapid release of ROS [oxidative burst]). However, Sb505124 significantly reversed these alterations and protected rats against I/R injury. As in the animal results, H/R also contributed to TGF-ß signaling activation and oxidative stress. Likewise, the inhibition of ALK5 or ALK5 knockdown significantly reversed these alterations in PC-12 cells. Other than ALK5 knockdown, ALK5 inhibition had no effect on the expression of ALK5 in PC-12 cells. CONCLUSIONS: Our studies demonstrated that TGF-ß signaling activation is involved in the regulation of NOX2/NOX4 expression and exacerbates cerebral I/R injury.

mir-193 targets ALDH2 and contributes to toxic aldehyde accumulation and tyrosine hydroxylase dysfunction in cerebral ischemia/reperfusion injury.

MicroRNAs (miRNAs, miR) play a fundamental role in cerebral ischemia/reperfusion (I/R) injury. However, the role of miRNAs in toxic aldehyde and tyrosine accumulation is not fully elucidated. We constructed a cerebral I/R rat model and found that overexpression of miR-193 was associated with the accumulation of 4-Hydroxynonenal (4-HNE), Malondialdehyde (MDA), and tyrosine, and with the decrease of aldehyde dehydrogenase (ALDH2), tyrosine hydroxylase (TH), and dopamine. To unveil the molecular mechanism of the miR-193-mediated phenotype in I/R injury as described above, we performed bioinformatic analysis and found that ALDH2 was a potential target of miR-193. Through in vitro experiments (such as miR-193 mimic/inhibitor transfection, luciferase reporter gene plasmid transfection, and 4-HNE exposure) and in vivo infusion of miR-193 agomir, we demonstrated that miR-193 directly suppressed the expression of ALDH2 and led to toxic aldehyde accumulation, resulting in dysfunction of tyrosine hydroxylase. The present study suggests that the overexpression of miR-193 in a rat model exacerbated brain injury due to the following sequential process: targeted suppression of ALDH2, aldehyde accumulation, and tyrosine hydroxylase dysfunction, leading to tyrosine accumulation and insufficiency of dopamine synthesis.