Pharmacokinetics of aspirin: evaluating shortcomings in the literature.

INTRODUCTION: Aspirin is known for its therapeutic benefits in preventing strokes and relieving pain. However, it is toxic to some individuals, and the biological mechanisms causing toxicity are unknown. Limited literature is available on the role of glycine conjugation as the principal pathway in aspirin detoxification. Previous studies have quantified this two-step enzyme reaction as a singular enzymatic process. Consequently, the individual contributions of these enzymes to the kinetics remain unclear. AREAS COVERED: This review summarized the available information on the pharmacokinetics and detoxification of aspirin by the glycine conjugation pathway. Literature searches were conducted using Google Scholar and the academic journal databases accessible through the North-West University Library. Furthermore, the factors affecting interindividual variation in aspirin metabolism and what is known regarding aspirin toxicity were discussed. EXPERT OPINION: The greatest drawback in understanding the pharmacokinetics of aspirin is the limited information available on the substrate preference of the xenobiotic ligase (ACSM) responsible for activating salicylate to salicyl-CoA. Furthermore, previous pharmacokinetic studies did not consider the contribution of other substrates from the diet or genetic variants, to the detoxification rate of glycine conjugation. Impaired glycine conjugation might contribute to adverse health effects seen in Reye's syndrome and cancer.

Stearoyl-CoA desaturase 1 is targeted by EBV-encoded miR-BART20-5p and regulates cell autophagy, proliferation, and migration in EBV-associated gastric cancer.

Epstein-Barr virus (EBV) is the first human oncogenic virus known to express microRNAs (miRNAs), which are closely associated with the development of various tumors, including nasopharyngeal and gastric cancers. Stearoyl-CoA Desaturase 1 (SCD1) is a key enzyme in fatty acid synthesis, highly expressed in numerous tumors, promoting tumor growth and metastasis, making it a potential therapeutic target. In this study, we found that SCD1 expression in EBV-associated gastric cancer (EBVaGC) was significantly lower than in EBV-negative gastric cancer (EBVnGC) at both cellular and tissue levels. In addition, EBV-miR-BART20-5p targets the 3'-UTR of SCD1, downregulating its expression. Moreover, overexpression of SCD1 in EBVaGC cells promoted cell migration and proliferation while inhibiting autophagy. These results suggest that EBV-encoded miRNA-BART20-5p may contribute to EBVaGC progression by targeting SCD1.

Deciphering structural variation upon biotinylation of biotin carboxyl carrier protein domain in Streptococcus pneumoniae.

Streptococcus pneumoniae is a leading cause of community-acquired pneumonia and is responsible for acute invasive and non-invasive infections. Fight against pneumococcus is currently hampered by insufficient vaccine coverage and rising antimicrobial resistance, making the research necessary on novel drug targets. High-throughput mutagenesis has shown that acetyl-CoA carboxylase (ACC) is an essential enzyme in S. pneumoniae which converts acetyl-CoA to malonyl-CoA, a key step in fatty acid biosynthesis. ACC has four subunits; Biotin carboxyl carrier protein (BCCP), Biotin carboxylase (BC), Carboxyl transferase subunit α and ß. Biotinylation of S. pneumoniae BCCP (SpBCCP) is required for the activation of ACC complex. In this study, we have biophysically characterized the apo- and holo- biotinylating domain SpBCCP80. We have performed 2D and 3D NMR experiments to analyze the changes in amino acid residues upon biotinylation of SpBCCP80. Further, we used NMR backbone chemical shift assignment data for bioinformatical analyses to determine the secondary and tertiary structure of proteins. We observed major changes in AMKVM motif and thumb region of SpBCCP80 upon biotinylation. Overall, this work provides structural insight into the apo- to holo- conversion of SpBCCP80 which can be further used as a drug target against S. pneumoniae.

Comparison of Statin With Ezetimibe Combination Therapy Versus Statin Monotherapy for Primary Prevention in Middle-Aged Adults.

BACKGROUND AND OBJECTIVES: Lipid lowering therapy is essential to reduce the risk of major cardiovascular events; however, limited evidence exists regarding the use of statin with ezetimibe as primary prevention strategy for middle-aged adults. We aimed to investigate the impact of single pill combination therapy on clinical outcomes in relatively healthy middle-aged patients when compared with statin monotherapy. METHODS: Using the Korean National Health Insurance Service database, a propensity score match analysis was performed for baseline characteristics of 92,156 patients categorized into combination therapy (n=46,078) and statin monotherapy (n=46,078) groups. Primary outcome was composite outcomes, including death, coronary artery disease, and ischemic stroke. And secondary outcome was all-cause death. The mean follow-up duration was 2.9±0.3 years. RESULTS: The 3-year composite outcomes of all-cause death, coronary artery disease, and ischemic stroke demonstrated no significant difference between the 2 groups (10.3% vs. 10.1%; hazard ratio (HR), 1.022; 95% confidence interval [CI], 0.980-1.064; p=0.309). Meanwhile, the 3-year all-cause death rate was lower in the combination therapy group than in the statin monotherapy group (0.2% vs. 0.4%; p<0.001), with a significant HR of 0.595 (95% CI, 0.460-0.769; p<0.001). Single pill combination therapy exhibited consistently lower mortality rates across various subgroups. CONCLUSIONS: Compared to the statin monotherapy, the combination therapy for primary prevention showed no difference in composite outcomes but may reduce mortality risk in relatively healthy middle-aged patients. However, since the study was observational, further randomized clinical trials are needed to confirm these findings.

Global lysine succinylation analysis unveils post-translational regulation effect on phenylpropanoid metabolism remodeling during Lonicera japonica flower development.

Lonicera japonica plays a significant role in traditional Chinese medicine and as a food source, making it a focus of studies on protein succinylation and its potential role in regulating secondary metabolism during flower development. This study aimed to clarify the regulatory mechanism of protein succinylation on phenylpropanoid-related phenotypic changes by conducting a global lysine succinylation proteomic analysis across different flowering stages. A total of 586 lysine succinylated peptides in 303 proteins were identified during early and late floral stages. Functional enrichment analysis revealed that succinylated proteins primarily participated in the tricarboxylic acid (TCA) cycle, amino acid metabolism, and secondary metabolism. The abundance of succinylated aspartate transaminase (AT), 4-coumarate-CoA ligase (4CL), and phenylalanine N-hydroxylase (CYP79A2) in phenylpropanoid metabolism varied during flower development. In vitro experiments demonstrated that succinylation increased AT activity while inhibited 4CL activity. Decreased levels of total flavonoids and phenolic acids indicated significant alterations in phenylpropanoid metabolism during later floral stages. These results suggest that succinylation of TCA cycle proteins not only influences flower development but also, together with AT-4CL-CYP79A2 co-succinylation, redirects phenylpropanoid metabolism during flower development in L. japonica.

Statins enhance extracellular release of hepatitis C virus particles through ERK5 activation.

Statins, such as lovastatin, have been known to inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Statins were reported to moderately suppress hepatitis C virus (HCV) replication in cultured cells harboring HCV RNA replicons. We report here using an HCV cell culture (HCVcc) system that high concentrations of lovastatin (5-20 µg/mL) markedly enhanced the release of HCV infectious particles (virion) in the culture supernatants by up to 40 times, without enhancing HCV RNA replication, HCV protein synthesis, or HCV virion assembly in the cells. We also found that lovastatin increased the phosphorylation (activation) level of extracellular-signal-regulated kinase 5 (ERK5) in both the infected and uninfected cells in a dose-dependent manner. The lovastatin-mediated increase of HCV virion release was partially reversed by selective ERK5 inhibitors, BIX02189 and XMD8-92, or by ERK5 knockdown using small interfering RNA (siRNA). Moreover, we demonstrated that other cholesterol-lowering statins, but not dehydrolovastatin that is incapable of inhibiting HMG-CoA reductase and activating ERK5, enhanced HCV virion release to the same extent as observed with lovastatin. These results collectively suggest that statins markedly enhance HCV virion release from infected cells through HMG-CoA reductase inhibition and ERK5 activation.

The Effects of Long-Term High Fat and/or High Sugar Feeding on Sources of Postprandial Hepatic Glycogen and Triglyceride Synthesis in Mice.

BACKGROUND: In MASLD (formerly called NAFLD) mouse models, oversupply of dietary fat and sugar is more lipogenic than either nutrient alone. Fatty acids suppress de novo lipogenesis (DNL) from sugars, while DNL inhibits fatty acid oxidation. How such factors interact to impact hepatic triglyceride levels are incompletely understood. METHODS: Using deuterated water, we measured DNL in mice fed 18-weeks with standard chow (SC), SC supplemented with 55/45-fructose/glucose in the drinking water at 30% (w/v) (HS), high-fat chow (HF), and HF with HS supplementation (HFHS). Liver glycogen levels and its sources were also measured. For HS and HFHS mice, pentose phosphate (PP) fluxes and fructose contributions to DNL and glycogen were measured using [U-13C]fructose. RESULTS: The lipogenic diets caused significantly higher liver triglyceride levels compared to SC. DNL rates were suppressed in HF compared to SC and were partially restored in HFHS but supplied a minority of the additional triglyceride in HFHS compared to HF. Fructose contributed a significantly greater fraction of newly synthesized saturated fatty acids compared to oleic acid in both HS and HFHS. Glycogen levels were not different between diets, but significant differences in Direct and Indirect pathway contributions to glycogen synthesis were found. PP fluxes were similar in HS and HFHS mice and were insufficient to account for DNL reducing equivalents. CONCLUSIONS: Despite amplifying the lipogenic effects of fat, the fact that sugar-activated DNL per se barely contributes suggests that its role is likely more relevant in the inhibition of fatty acid oxidation. Fructose promotes lipogenesis of saturated over unsaturated fatty acids and contributes to maintenance of glycogen levels. PP fluxes associated with sugar conversion to fat account for a minor fraction of DNL reducing equivalents.

Biochemical Pattern of Methylmalonyl-CoA Epimerase Deficiency Identified in Newborn Screening: A Case Report.

Methylmalonyl-CoA epimerase enzyme (MCEE) is responsible for catalyzing the isomeric conversion between D- and L-methylmalonyl-CoA, an intermediate along the conversion of propionyl-CoA to succinyl-CoA. A dedicated test for MCEE deficiency is not included in the newborn screening (NBS) panels but it can be incidentally identified when investigating methylmalonic acidemia and propionic acidemia. Here, we report for the first time the biochemical description of a case detected by NBS. The NBS results showed increased levels of propionylcarnitine (C3) and 2-methylcitric acid (MCA), while methylmalonic acid (MMA) and homocysteine (Hcy) were within the reference limits. Confirmatory analyses revealed altered levels of metabolites, including MCA and MMA, suggesting a block in the propionate degradation pathway. The analysis of methylmalonic pathway genes by next-generation sequencing (NGS) allowed the identification of the known homozygous nonsense variation c.139C>T (p.R47X) in exon 2 of the MCE gene. Conclusions: Elevated concentrations of C3 with a slight increase in MCA and normal MMA and Hcy during NBS should prompt the consideration of MCEE deficiency in differential diagnosis. Increased MMA levels may be negligible at NBS as they may reach relevant values beyond the first days of life and thus could be identified only in confirmatory analyses.

Suppression of RCAN1 alleviated lipid accumulation and mitochondrial fission in diabetic cardiomyopathy.

BACKGROUND: Although metabolic disturbance is a characteristic of diabetic cardiomyopathy (DbCM), the detailed pathogenesis of DbCM remains unknown. METHODS: We used a heart transplantation (HTx) cohort to explore the effect of diabetes mellitus on heart failure (HF) progression dependent of myocardium. Microscopic and ultramicroscopic pathology were used to depict the pathological features of human myocardium of DbCM. We performed targeted metabolomics to characterize the metabolic phenotype of human DbCM. Transcriptomics data were analyzed and weighted gene co-expression network analysis was performed to explore the potential upstream regulator for metabolic remodeling of DbCM. In vivo and in vitro experiments were further conducted to demonstrate the therapeutic effects and molecular mechanisms. RESULTS: DbCM promoted the progression of HF and increased death or HF-rehospitalization after HTx. Lipid accumulation and mitochondrial fission were the obvious pathological features of DbCM myocardium. The concentrations of C14:0-CoA and C16:1-CoA were significantly increased in the myocardium, and they were positively correlated with the accelerated HF progression and RCAN1 expression in DbCM patients. Knockdown of RCAN1 improved cardiac dysfunction, lipid accumulation, and mitochondrial fission in db/db mice. In vitro studies showed that RCAN1 knockdown improved mitochondrial dysfunction in DbCM cardiomyocytes via the RCAN1-p-Drp1 Ser616 axis. CONCLUSIONS: Diabetes is associated with faster progression of HF and causes poor prognosis after HTx, accompanied by metabolic remodeling in the myocardium. Accumulation of long chain acyl-CoA in the myocardium is the metabolic hallmark of human DbCM and is associated with more rapid disease progression for DbCM patients. Upregulation of RCAN1 in the myocardium is associated with the metabolic signatures of DbCM and RCAN1 is a potential therapeutic target for DbCM.

Kinetic characterization of the C-terminal domain of Malonyl-CoA reductase.

Malonyl-CoA reductase utilizes two equivalents of NADPH to catalyze the reduction of malonyl-CoA to 3-hydroxypropionic acid (3HP). This reaction is part of the carbon fixation pathway in the phototrophic bacterium Chloroflexus aurantiacus. The enzyme is composed of two domains. The C-terminal domain catalyzes the reduction of malonyl-CoA to malonic semialdehyde, while the N-terminal domain catalyzes the reduction of the aldehyde to 3HP. The two domains can be produced independently and retain their enzymatic activity. This report focuses on the kinetic characterization of the C-terminal domain. Initial velocity patterns and inhibition studies showed the kinetic mechanism is ordered with NADPH binding first followed by malonyl-CoA. Malonic semialdehyde is released first, while CoA and NADP+ are released randomly. Analogs of malonyl-CoA showed that the thioester carbon is reduced, while the carboxyl group is needed for proper positioning. The enzyme transfers the pro-S hydrogen of NADPH to malonyl-CoA and pH rate profiles revealed that a residue with a pKa value of about 8.8 must be protonated for activity. Kinetic isotope effects indicated that NADPH is not sticky (that is, NADPH dissociates from the enzyme faster than the rate of product formation) and product release is partially rate-limiting. Moreover, the mechanism is stepwise with the pH dependent step occurring before or after hydride transfer. The findings from this study will aid in the development of an eco-friendly biosynthesis of 3HP which is an industrial chemical used in the production of plastics and adhesives.

Effect of disclosing a polygenic risk score for coronary heart disease on adverse cardiovascular events: 10-year follow-up of the MI-GENES randomized clinical trial.

Background: The MI-GENES clinical trial (NCT01936675), in which participants at intermediate risk of coronary heart disease (CHD) were randomized to receive a Framingham risk score (FRSg, n=103), or an integrated risk score (IRSg, n=104) that additionally included a polygenic risk score (PRS), demonstrated that after 6 months, participants randomized to IRSg had higher statin initiation and lower low-density lipoprotein cholesterol (LDL-C). Objectives: In a post hoc 10-year follow-up analysis of the MI-GENES trial, we investigated whether disclosure of a PRS for CHD was associated with a reduction in adverse cardiovascular events. Methods: Participants were followed from randomization beginning in October 2013 until September 2023 to ascertain adverse cardiovascular events, testing for CHD, and changes in risk factors, by blinded review of electronic health records. The primary outcome was the time from randomization to the occurrence of the first major adverse cardiovascular event (MACE), defined as cardiovascular death, non-fatal myocardial infarction, coronary revascularization, and non-fatal stroke. Statistical analyses were conducted using Cox proportional hazards regression and linear mixed-effects models. Results: We followed all 203 participants who completed the MI-GENES trial, 100 in FRSg and 103 in IRSg (mean age at the end of follow-up: 68.2±5.2, 48% male). During a median follow-up of 9.5 years, 9 MACEs occurred in FRSg and 2 in IRSg (hazard ratio (HR), 0.20; 95% confidence interval (CI), 0.04 to 0.94; P=0.042). In FRSg, 47 (47%) underwent at least one test for CHD, compared to 30 (29%) in IRSg (HR, 0.51; 95% CI, 0.32 to 0.81; P=0.004). IRSg participants had a longer duration of statin therapy during the first four years post-randomization and a greater reduction in LDL-C for up to 3 years post-randomization. No significant differences between the two groups were observed for hemoglobin A1C, systolic and diastolic blood pressures, weight, and smoking cessation rate during follow-up. Conclusions: The disclosure of an IRS that included a PRS to individuals at intermediate risk for CHD was associated with a lower incidence of MACE after a decade of follow-up, likely due to a higher rate of initiation and longer duration of statin therapy, leading to lower LDL-C levels.

Multiple Acyl-CoA Dehydrogenase Deficiency: Phenotypic and Genetic Features of a Malaysian Cohort.

BACKGROUND AND PURPOSE: Multiple acyl-CoA dehydrogenase deficiency (MADD) is an inherited disorder of fatty acid oxidation that causes lipid storage myopathy (LSM). This is the first report on MADD that describes the phenotypic and genetic features of a Malaysian cohort. METHODS: Among the >2,500 patients in a local muscle biopsy database, patients with LSM were identified and their genomic DNA were extracted from muscle samples and peripheral blood. All 13 exons of the electron-transfer flavoprotein dehydrogenase gene (ETFDH) were subsequently sequenced. Fifty controls were included to determine the prevalence of identified mutations in the normal population. RESULTS: Fourteen (82%) of the 17 LSM patients had MADD with ETFDH mutations. Twelve (86%) were Chinese and two were Malay sisters. Other unrelated patients reported that they had no relevant family history. Nine (64%) were females. The median age at onset was 18.5 years (interquartile range=16-37 years). All 14 demonstrated proximal limb weakness, elevated serum creatine kinase levels, and myopathic changes in electromyography. Three patients experienced a metabolic crisis at their presentation. Sanger sequencing of ETFDH revealed nine different variants/mutations, one of which was novel: c.998A>G (p.Y333C) in exon 9. Notably, 12 (86%) patients, including the 2 Malay sisters, carried a common c.250G>A (p.A84T) variant, consistent with the hotspot mutation reported in southern China. All of the patients responded well to riboflavin therapy. CONCLUSIONS: Most of our Malaysian cohort with LSM had late-onset, riboflavin-responsive MADD with ETFDH mutations, and they demonstrated phenotypic and genetic features similar to those of cases reported in southern China. Furthermore, we report a novel ETFDH mutation and possibly the first ever MADD patients of Malay descent.

Intraperitoneally injected d11-11(12)-epoxyeicosatrienoic acid is rapidly incorporated and esterified within rat plasma and peripheral tissues but not the brain.

Epoxyeicosatrienoic acids (EpETrEs) are bioactive lipid mediators of arachidonic acid cytochrome P450 oxidation. In vivo, the free (unbound) form of EpETrEs regulate multiple processes including blood flow, angiogenesis and inflammation resolution. Free EpETrEs are thought to rapidly degrade via soluble epoxide hydrolase (sEH); yet, in many tissues, the majority of EpETrEs are esterified to complex lipids (e.g. phospholipids) suggesting that esterification may play a major role in regulating free, bioactive EpETrE levels. This hypothesis was tested by quantifying the metabolism of intraperitoneally injected free d11-11(12)-Epoxyeicosatrienoic acid (d11-11(12)-EpETrE) in male and female rats. Plasma and tissues (liver, adipose and brain) were obtained 3 to 4 min later and assayed for d11-11(12)-EpETrE and its sEH metabolite, d11-11,12-dihydroxyeicosatrienoic acid (d11-11,12-diHETrE) in both the free and esterified lipid fractions. In both males and females, the majority of injected tracer was recovered in liver followed by plasma and adipose. No tracer was detected in the brain, indicating that brain levels are maintained by endogenous synthesis from precursor fatty acids. In plasma, liver, and adipose, the majority (>54 %) of d11-11(12)-EpETrE was found esterified to phospholipids or neutral lipids (triglycerides and cholesteryl esters). sEH-derived d11-11,12-diHETrE was not detected in plasma or tissues, suggesting negligible conversion within the 3-4 min period post tracer injection. This study shows that esterification is the main pathway regulating free 11(12)-EpETrE levels in vivo.

Shi-pi-xiao-ji formula suppresses hepatocellular carcinoma by reducing cellular stiffness through upregulation of acetyl-coA acetyltransferase 1.

BACKGROUND: Previous studies have shown that the Shi-pi-xiao-ji (SPXJ) herbal decoction formula is effective in suppressing hepatocellular carcinoma (HCC), but the underlying mechanisms are not known. Therefore, this study investigated whether the antitumor effects of the SPXJ formula in treating HCC were mediated by acetyl-coA acetyltransferase 1 (ACAT1)-regulated cellular stiffness. Through a series of experiments, we concluded that SPXJ inhibits the progression of HCC by upregulating the expression level of ACAT1, lowering the level of cholesterol in the cell membrane, and altering the cellular stiffness, which provides a new idea for the research of traditional Chinese medicine against HCC. AIM: To investigate the anti-tumor effects of the SPXJ formula on the malignant progression of HCC. METHODS: HCC cells were cultured in vitro with SPXJ-containing serum prepared by injecting SPXJ formula into wild-type mice. The apoptotic rate and proliferative, invasive, and migratory abilities of control and SPXJ-treated HCC cells were compared. Atomic force microscopy was used to determine the cell surface morphology and the Young's modulus values of the control and SPXJ-treated HCC cells. Plasma membrane cholesterol levels in HCC cells were detected using the Amplex Red cholesterol detection kit. ACAT1 protein levels were estimated using western blotting. RESULTS: Compared with the vehicle group, SPXJ serum considerably reduced proliferation of HCC cells, increased stiffness and apoptosis of HCC cells, inhibited migration and invasion of HCC cells, decreased plasma membrane cholesterol levels, and upregulated ACAT1 protein levels. However, treatment of HCC cells with the water-soluble cholesterol promoted proliferation, migration, and invasion of HCC cells as well as decreased cell stiffness and plasma membrane cholesterol levels, but did not alter the apoptotic rate and ACAT1 protein expression levels compared with the vehicle control. CONCLUSION: SPXJ formula inhibited proliferation, invasion, and migration of HCC cells by decreasing plasma membrane cholesterol levels and altering cellular stiffness through upregulation of ACAT1 protein expression.

Intensive Versus Moderate Statin-Based Therapies in Patients With Mild Ischemic Stroke: A Prospective Multicenter Cohort Study.

BACKGROUND: Statins are widely used for treating patients with ischemic stroke at risk of secondary cerebrovascular events. It is unknown whether Asian populations benefit from more intensive statin-based therapy for stroke recurrence. Therefore, in the present study we evaluated the effectiveness and safety of high-dose and moderate-dose statins for patients who had experienced mild ischemic stroke during the acute period. METHODS AND RESULTS: This multicenter prospective study included patients with mild ischemic stroke who presented within 72 hours of symptom onset. The outcomes of patients in the high-intensity and moderate-intensity statin treatment groups were compared, with the main efficacy outcome being stroke recurrence and the primary safety end point being intracranial hemorrhage. The propensity score matching method was employed to control for imbalances in baseline variables. Subgroup analyses were conducted to evaluate group differences. In total, the data of 2950 patients were analyzed at 3 months, and the data of 2764 patients were analyzed at 12 months due to loss to follow-up. According to the multivariable Cox analyses adjusted for potential confounders, stroke recurrence occurred similarly in the high-intensity statin and moderate-intensity statin groups (3 months: adjusted hazard ratio [HR], 1.12 [95% CI, 0.85-1.49]; P=0.424; 12 months: adjusted HR, 1.08 [95% CI, 0.86-1.34]; P=0.519). High-intensity statin therapy was associated with an increased risk of intracranial hemorrhage (3 months: adjusted HR, 1.81 [95% CI, 1.00-3.25]; P=0.048; 12 months: adjusted HR, 1.86 [95% CI, 1.10-3.16]; P=0.021). The results from the propensity score-matched analyses were consistent with those from the Cox proportional hazards analysis. CONCLUSIONS: Compared with moderate-intensity statin therapy, high-dose statin therapy may not decrease the risk of mild, noncardiogenic ischemic stroke recurrence but may increase the risk of intracranial hemorrhage. REGISTRATION: URL: www.chictr.org.cn/. Unique Identifier: ChiCTR1900025214.

Hepatic stearoyl-CoA desaturase-1 deficiency induces fibrosis and hepatocellular carcinoma-related gene activation under a high carbohydrate low fat diet.

Stearoyl-CoA desaturase-1 (SCD1) is a pivotal enzyme in lipogenesis, which catalyzes the synthesis of monounsaturated fatty acids (MUFA) from saturated fatty acids, whose ablation downregulates lipid synthesis, preventing steatosis and obesity. Yet deletion of SCD1 promotes hepatic inflammation and endoplasmic reticulum stress, raising the question of whether hepatic SCD1 deficiency promotes further liver damage, including fibrosis. To delineate whether SCD1 deficiency predisposes the liver to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC), we employed in vivo SCD1 deficient global and liver-specific mouse models fed a high carbohydrate low-fat diet and in vitro established AML12 mouse cells. The absence of liver SCD1 remarkably increased the saturation of liver lipid species, as indicated by lipidomic analysis, and led to hepatic fibrosis. Consistently, SCD1 deficiency promoted hepatic gene expression related to fibrosis, cirrhosis, and HCC. Deletion of SCD1 increased the circulating levels of Osteopontin, known to be increased in fibrosis, and alpha-fetoprotein, often used as an early marker and a prognostic marker for patients with HCC. De novo lipogenesis or dietary supplementation of oleate, an SCD1-generated MUFA, restored the gene expression related to fibrosis, cirrhosis, and HCC. Although SCD1 deficient mice are protected against obesity and fatty liver, our results show that MUFA deprivation results in liver injury, including fibrosis, thus providing novel insights between MUFA insufficiency and pathways leading to fibrosis, cirrhosis, and HCC under lean non-steatotic conditions.

Two novel SUCLA2 variants cause mitochondrial DNA depletion syndrome, type 5 in two siblings.

Mitochondrial DNA depletion syndrome (MDS), characterized by succinate-CoA ligase deficiency and loss of mitochondrial DNA (mtDNA), is caused by specific variants in nuclear genes responsible for mtDNA maintenance. SUCLA2-related mitochondrial DNA depletion syndrome, type 5 (MTDPS-5), presents as a rare, severe early progressive encephalomyopathy. This report investigates a new family exhibiting clinical manifestations of MTDPS-5 and elucidates the genetic basis of this disorder. In two affected siblings, a novel maternally inherited nonsense variant [c.1234C>T (p.Arg412*)] in the SUCLA2 gene and a unique paternally inherited indel variant (g.48569263-48571020del1758insATGA) were identified. Additionally, the siblings exhibited blood mtDNA content lower than 33% compared to age-matched controls. These findings underscore the importance of assessing SUCLA2 variants in patients with severe early progressive encephalomyopathy, even in the absence of methylmalonic aciduria or mtDNA loss, thereby broaden the mutational spectrum of this gene.

Phenylalanine ammonia-lyases and 4-coumaric acid coenzyme A ligases in Chara braunii, Marchantia polymorpha, and Physcomitrium patens as extant model organisms for plant terrestrialization.

The conquest of land posed severe problems to plants which they had to cope with by adapting biosynthetic capacities. Adaptations to respond to UV irradiation, water loss, pathogen and herbivore defense, and the earth's pull were essential. Chemical compounds alleviating these problems can be synthesized by the phenylpropanoid pathway, the core of which are three enzymes: phenylalanine ammonia-lyase (PAL), cinnamic acid 4-hydroxylase, and 4-coumaric acid coenzyme A-ligase (4CL). The genomes of model organisms, Chara braunii as aquatic alga and the two bryophytes Physcomitrium patens and Marchantia polymorpha, were searched for sequences encoding PAL and 4CL and selected sequences heterologously expressed in Escherichia coli for biochemical characterization. Several possible isoforms were identified for both enzymes in Marchantia polymorpha and Physcomitrium patens, while only one or two isoforms could be retrieved for Chara braunii. Active forms of both enzymes were found in all three organisms, although the catalytic efficiencies varied in a wide range. l-Phenylalanine was accepted as best substrate by all PAL-like enzymes, despite annotations in some cases suggesting different activities. The substrate spectrum of 4CLs was more diverse, but caffeic and/or 4-coumaric acids generally were the best-accepted substrates. Our investigations show that PAL and 4CL, important enzymes for the formation of phenolic compounds, are present and active in extant charophytes and bryophytes as model organisms for the conquest of land.

Clinical, biochemical and genetic characteristics and long-term follow-up of five patients with malonyl-CoA decarboxylase deficiency.

BACKGROUND: Malonyl-CoA decarboxylase (MLYCD) deficiency, also known as malonic aciduria (MAD), is a rare autosomal recessive inherited metabolic defect. In this study, we aimed to investigate the clinical and molecular features of five patients with MAD in order to increase clinicians' awareness of the disease. METHODS: Sanger sequencing was used to detect and genetically analyze the MLYCD variations in the preexisting patients and their parents. RESULTS: Five patients with MAD (5 months to 9.6 years old; two males and three females) rarely exhibited metabolic decompensation episodes or seizures. All patients exhibited varying degrees of developmental delay and hypotonia. Our study expands the spectrum of variants of the MLYCD gene. MLYCD gene variations were detected in all five patients, and five new variants were identified: c.60delG (p.Arg21Glyfs*52), c.928C > T (p.Arg310*), c.1293G > T (p.Trp431Cys), c.721T > C (p.Ser241Pro), and Exons 4-5 deletion. Additionally, there is no correlation between various genotypes and phenotypes. CONCLUSION: A high-medium-chain triglyceride and low-long-chain triglyceride diet supplemented with L-carnitine was effective in most patients and may improve cardiomyopathy and muscle weakness. Newborn screening may aid in the early diagnosis, treatment, and prognosis of this rare disorder.