Curcumin as a Potential Therapeutic Agent for Mitigating Carbon Monoxide Poisoning: Evidence from an Experimental Rat Study.

BACKGROUND Carbon monoxide (CO) is a poisonous gas and causes tissue damage through oxidative stress. We aimed to investigate the protective value of curcumin in CO poisoning. MATERIAL AND METHODS Twenty-four female Spraque Dawley rats were divided into 4 subgroups: controls (n=6), curcumin group (n=6), CO group (n=6), and curcumin+CO group (n=6). The experimental group was exposed to 3 L/min of CO gas at 3000 ppm. Curcumin was administered intraperitoneally at a dosage of 50 mg/kg. Hippocampal tissues were removed and separated for biochemical and immunohistochemical analysis. Tissue malondialdehyde (MDA) levels, nitric oxide (NO) levels, and superoxide dismutase (SOD) and catalase (CAT) activities were assayed spectrophotometrically, and serum asymmetric dimethylarginine (ADMA) were measured using the ELISA technique. Tissue Bcl-2 levels were detected by the immunohistochemistry method. RESULTS Tissue CAT and SOD activities and NO levels were significantly lower, and MDA and serum ADMA levels were higher in the CO group than in the control group (P<0.001). The curcumin+CO group had higher CAT activities (P=0.007) and lower MDA than the CO group (P<0.001) and higher ADMA levels than the control group (P=0.023). However, there was no significant difference observed for tissue SOD activity or NO levels between these 2 groups. In the curcumin+CO group, the Bcl-2 level was higher than that in the CO group (P=0.017). CONCLUSIONS The positive effect of curcumin on CAT activities, together with suppression of MDA levels, has shown that curcumin may have a protective effect against CO poisoning.

Evaluation of endothelial glycocalyx injury biomarkers in feline hemotropic mycoplasmosis.

The present study aimed to investigate endothelial glycocalyx (eGCx) damage in cats with feline hemotropic mycoplasmosis caused by Mycoplasma haemofelis using selected biomarkers and to determine the diagnostic and prognostic significance of these biomarkers. The study included 25 cats with feline hemotropic mycoplasmosis and 10 healthy cats. Clinical examination, blood gas analysis, complete blood count, and biochemical analysis were performed. Hemotropic mycoplasmosis diagnosed by microscopic examination and molecularly confirmed by PCR targeting the Mycoplasma haemofelis 16s rRNA gene. To evaluate endothelial glycocalyx damage, syndecan-1, endothelin-1 (ET-1), asymmetric dimethylarginine (ADMA), and vascular endothelial growth factor-A (VEGF-A) concentrations were measured using cat-specific commercial ELISA kits. Of the cats with feline hemotropic mycoplasmosis, 14 (56%) survived and 11 (44%) died. While syndecan-1 and ET-1 concentrations were significantly higher in cats with hemotropic mycoplasmosis compared to the control group (p < 0.001), no statistically significant difference was found for ADMA and VEGF-A concentrations (p > 0.05). Endothelial glycocalyx biomarkers showed significant correlations with each other and with hematological parameters (p < 0.01). The results of the ROC analysis showed that ET-1 with area under the curve (AUC) of 0.821 (p < 0.01) and VEGF-A with AUC of 0.805 (p < 0.010) were found to be significant prognostic indicators. In conclusion, this study demonstrated that serum syndecan-1 and ET-1 can be used as diagnostic and serum ET-1 and VEGF-A as prognostic biomarkers in cats with hemotropic mycoplasmosis. Our results indicate the development of eGCx damage in feline hemotropic mycoplasmosis and suggest that glycocalyx disruption may contribute to the pathogenesis of the disease.

A PRMT5-ZNF326 axis mediates innate immune activation upon replication stress.

DNA replication stress (RS) is a widespread phenomenon in carcinogenesis, causing genomic instability and extensive chromatin alterations. DNA damage leads to activation of innate immune signaling, but little is known about transcriptional regulators mediating such signaling upon RS. Using a chemical screen, we identified protein arginine methyltransferase 5 (PRMT5) as a key mediator of RS-dependent induction of interferon-stimulated genes (ISGs). This response is also associated with reactivation of endogenous retroviruses (ERVs). Using quantitative mass spectrometry, we identify proteins with PRMT5-dependent symmetric dimethylarginine (SDMA) modification induced upon RS. Among these, we show that PRMT5 targets and modulates the activity of ZNF326, a zinc finger protein essential for ISG response. Our data demonstrate a role for PRMT5-mediated SDMA in the context of RS-induced transcriptional induction, affecting physiological homeostasis and cancer therapy.

Revealing novel biomarkers for diagnosing chronic kidney disease in pediatric patients.

Pediatric chronic kidney disease (CKD) is a clinical condition characterized by progressive renal function deterioration. CKD diagnosis is based on glomerular filtration rate, but its reliability is limited, especially at the early stages. New potential biomarkers (citrulline (CIT), symmetric dimethylarginine (SDMA), S-adenosylmethionine (SAM), n-butyrylcarnitine (nC4), cis-4-decenoylcarnitine, sphingosine-1-phosphate and bilirubin) in addition to creatinine (CNN) have been proposed for early diagnosis. To verify the clinical value of these biomarkers we performed a comprehensive targeted metabolomics study on a representative cohort of CKD and healthy pediatric patients. Sixty-seven children with CKD and forty-five healthy children have been enrolled in the study. Targeted metabolomics based on liquid chromatography-triple quadrupole mass spectrometry has been used for serum and plasma samples analysis. Univariate data analysis showed statistically significant differences (p < 0.05) in the concentration of CNN, CIT, SDMA, and nC4 among healthy and CKD pediatric patients. The predictive ability of the proposed biomarkers was also confirmed through specificity and sensitivity expressed in Receiver Operating Characteristic curves (AUC = 0.909). In the group of early CKD pediatric patients, AUC of 0.831 was obtained, improving the diagnostic reliability of CNN alone. Moreover, the models built on combined CIT, nC4, SDMA, and CNN allowed to distinguish CKD patients from healthy control regardless of blood matrix type (serum or plasma). Our data demonstrate potential biomarkers in the diagnosis of early CKD stages.

A combined approach of lauroyl arginine ethyl ester hydrochloride and kojic acid in mitigating fresh-cut potato deterioration.

The combinational effects of kojic acid and lauroyl arginine ethyl ester hydrochloride (ELAH) on fresh-cut potatoes were investigated. Kojic acid of 0.6% (w/w) effectively inhibited the browning of fresh-cut potatoes and displayed antimicrobial capacity. The color difference value of samples was decreased from 175 to 26 by kojic acid. In contrast, ELAH could not effectively bind with the active sites of tyrosinase and catechol oxidase at molecular level. Although 0.5% (w/w) of ELAH prominently inhibited the microbial growth, it promoted the browning of samples. However, combining kojic acid and ELAH effectively inhibited the browning of samples and microbial growth during the storage and the color difference value of samples was decreased to 52. This amount of kojic acid inhibited enzyme activities toward phenolic compounds. The results indicated that combination of kojic acid and ELAH could provide a potential strategy to extend the shelf life of fresh-cut products.

Arginine methylation of ALKBH5 by PRMT6 promotes breast tumorigenesis via LDHA-mediated glycolysis.

ALKBH5 is a master regulator of N6-methyladenosine (m6A) modification, which plays a crucial role in many biological processes. Here, we show that ALKBH5 is required for breast tumor growth. Interestingly, PRMT6 directly methylates ALKBH5 at R283, which subsequently promotes breast tumor growth. Furthermore, arginine methylation of ALKBH5 by PRMT6 increases LDHA RNA stability via m6A demethylation, leading to increased aerobic glycolysis. Moreover, PRMT6-mediated ALKBH5 arginine methylation is confirmed in PRMT6-knockout mice. Collectively, these findings identify a PRMT6-ALKBH5-LDHA signaling axis as a novel target for the treatment of breast cancer.

Asymmetric dimethylarginine (ADMA) is associated with reduced myocardial mechano-energetic efficiency in hypertensive subjects.

BACKGROUND AND AIMS: Our prior study showed that endothelial dysfunction contributed to reduced myocardial mechano-energetics efficiency (MEEi) independently of several confounders. Reduced activity of endothelial nitric oxide synthase may be due to increased levels of the endogenous inhibitor asymmetric dimethylarginine (ADMA). The impact of ADMA on myocardial MEEi has not been determined yet. This study aims to investigate the association between plasma ADMA levels and MEEi in drug-naïve hypertensive individuals. METHODS AND RESULTS: 63 hypertensive individuals participating in the CATAnzaro MEtabolic RIsk factors (CATAMERI) study were included. All participants underwent to an echocardiogram for myocardial MEEi measurement. ADMA plasma concentrations were measured by high-performance liquid chromatography. A multivariate linear regression analysis was conducted to investigate the independent association between ADMA levels and MEEi. In a univariate analysis, ADMA levels were significantly associated with myocardial MEEi (r = 0.438; P < 0.001). In a multivariate regression analysis, plasma ADMA levels were associated to decreased myocardial MEEi (ß = 0.458, P < 0.001) independently of well-established cardiovascular risk factors including age, sex, BMI, waist circumference, smoking status, total cholesterol and HDL, triglycerides, glucose tolerance status, and HOMA-IR index of insulin resistance. CONCLUSIONS: ADMA may contribute to reduced myocardial MEEi by reducing nitric oxide bioavailability.

N-acetylcysteine and Hydroxychloroquine Ameliorate ADMA-Induced Fetal Growth Restriction in Mice via Regulating Oxidative Stress and Autophagy.

Fetal growth restriction (FGR) seriously threatens perinatal health. The main cause of FGR is placental malperfusion, but the specific mechanism is still unclear, and there is no effective treatment for FGR. We constructed a FGR mouse model by adding exogenous asymmetric dimethylarginine (ADMA) through in vivo experiments and found that ADMA could cause placental dysplasia and induce the occurrence of FGR. Compared with the control group, reactive oxygen species (ROS) production in the placenta was increased in mice with FGR, and the expression of autophagy-related proteins p-AKT/AKT, p-mTOR/mTOR, and P62 was significantly decreased, while the expression of Beclin-1 and LC3-II was significantly increased in the FGR group. Furthermore, ADMA had a favorable effect in promoting the formation of autophagosomes. Hydroxychloroquine (HCQ) and N-acetylcysteine (NAC) improved ADMA-induced disorders of placental development and alleviated ADMA-induced FGR. This study found that ADMA could cause excessive autophagy of trophoblasts by increasing the level of oxidative stress, ultimately leading to the occurrence of FGR, and HCQ and NAC had therapeutic effects on ADMA-induced FGR.

Direct thrombin inhibitors fail to reverse the negative effects of heparin on lung growth and function after murine left pneumonectomy.

Neonates with congenital diaphragmatic hernia (CDH) frequently require cardiopulmonary bypass and systemic anticoagulation. We previously demonstrated that even subtherapeutic heparin impairs lung growth and function in a murine model of compensatory lung growth (CLG). The direct thrombin inhibitors (DTIs) bivalirudin and argatroban preserved growth in this model. Although DTIs are increasingly used for systemic anticoagulation clinically, patients with CDH may still receive heparin. In this experiment, lung endothelial cell proliferation was assessed following treatment with heparin-alone or mixed with increasing concentrations of bivalirudin or argatroban. The effects of subtherapeutic heparin with or without DTIs in the CLG model were also investigated. C57BL/6J mice underwent left pneumonectomy and subcutaneous implantation of osmotic pumps. Pumps were preloaded with normal saline, bivalirudin, or argatroban; treated animals received daily intraperitoneal low-dose heparin. In vitro, heparin-alone decreased endothelial cell proliferation and increased apoptosis. The effect of heparin on proliferation, but not apoptosis, was reversed by the addition of bivalirudin and argatroban. In vivo, low-dose heparin decreased lung volume compared with saline-treated controls. All three groups that received heparin demonstrated decreased lung function on pulmonary function testing and impaired exercise performance on treadmill tolerance testing. These findings correlated with decreases in alveolarization, vascularization, angiogenic signaling, and gene expression in the heparin-exposed groups. Together, these data suggest that bivalirudin and argatroban fail to reverse the inhibitory effects of subtherapeutic heparin on lung growth and function. Clinical studies on the impact of low-dose heparin with DTIs on CDH outcomes are warranted.NEW & NOTEWORTHY Infants with pulmonary hypoplasia frequently require cardiopulmonary bypass and systemic anticoagulation. We investigate the effects of simultaneous exposure to heparin and direct thrombin inhibitors (DTIs) on lung growth and pulmonary function in a murine model of compensatory lung growth (CGL). Our data suggest that DTIs fail to reverse the inhibitory effects of subtherapeutic heparin on lung growth and function. Clinical studies on the impact of heparin with DTIs on clinical outcomes are thus warranted.

The relationship between reduced choroidal thickness due to high plasma asymmetrical dimethylarginine level and increased severity of diabetic retinopathy / Altos níveis de dimetil-arginina assimétrica no plasma podem aumentar a gravidade da retinopatia diabética através da redução da espessura da coroide

ABSTRACT Purpose: To evaluate the relationship between subfoveal choroidal thickness and plasma asymmetrical dimethylarginine level and the severity of diabetic retinopathy in patients with type 2 diabetes mellitus. Methods: A total of 68 cases, including 15 patients without diabetic retinopathy, 17 patients with nonproliferative diabetic retinopathy, 16 patients with type 2 diabetes mellitus and proliferative diabetic retinopathy, and 20 healthy patients (control group), were enrolled in this study. Subfoveal choroidal thickness was measured manually using the enhanced depth imaging optical coherence tomography scanning program, and plasma asymmetrical dimethylarginine level was measured using a commercial micro enzyme-linked immunosorbent assay kit. Results: The subfoveal choroidal thickness values and plasma asymmetrical dimethylarginine levels were significantly different between the four groups (p<0.001 and p<0.001). The subfoveal choroidal thickness values were significantly lower in the proliferative diabetic retinopathy group than in the other three groups (no diabetic retinopathy, nonproliferative diabetic retinopathy, and control groups; p<0.001, p=0.045, and p<0.001, respectively). The plasma asymmetrical dimethylarginine levels were significantly higher in the proliferative diabetic retinopathy group than in the other three groups (p<0.001, p<0.04, and p<0.001, respectively). In addition, a significant negative correlation was also found between plasma asymmetrical dimethylarginine level and subfoveal choroidal thickness (p<0.001, r=-0.479). Conclusion: Asymmetrical dimethylarginine is an important marker of endothelial dysfunction and endogenous endothelial nitric oxide synthase inhibitor. The severity of diabetic retinopathy was related to increased plasma asymmetrical dimethylarginine level and reduced subfoveal choroidal thickness in type 2 diabetic patients with diabetic retinopathy.

RESUMO Objetivo: Avaliar a relação da espessura subfoveal da coroide e dos níveis plasmáticos de dimetil-arginina assimétrica com a gravidade da retinopatia diabética em pacientes com diabetes mellitus tipo 2. Métodos: Foram incluídos 68 casos, compreendendo 15 pacientes sem retinopatia diabética, 17 pacientes com retinopatia diabética não proliferativa, 16 pacientes com retinopatia diabética proliferativa, e 20 casos saudáveis (grupo de controle). A espessura subfoveal da coroide foi medida manualmente, usando o programa de varredura com tomografia computadorizada óptica com imagem profunda aprimorada, e os níveis plasmáticos de dimetil-arginina assimétrica foram medidos usando um kit microELISA comercial. Resultados: Os valores da espessura subfoveal da coroide e os níveis plasmáticos de dimetil-arginina assimétrica foram significativamente diferentes nos quatro grupos (p<0,001 para ambos os parâmetros). Os valores da espessura subfoveal da coroide foram significativamente menores no grupo com retinopatia diabética proliferativa do que nos outros três grupos (sem retinopatia diabética, retinopatia diabética não proliferativa e grupo de controle, com p<0,001, p=0,045 e p<0,001, respectivamente). Já os níveis plasmáticos de dimetil-arginina assimétrica foram significativamente maiores no grupo com retinopatia diabética proliferativa do que nos outros três grupos (p<0,001, p=0,04 e p<0,001, respectivamente). Além disso, também foi encontrada uma correlação negativa significativa entre os níveis plasmáticos de dimetil-arginina assimétrica e a espessura subfoveal da coroide (p<0,001, r=-0,479). Conclusão: A dimetil-arginina assimétrica é um importante marcador de disfunção endotelial e um inibidor endógeno da óxido nítrico sintase. Foi encontrada uma relação da gravidade da retinopatia diabética e de níveis elevados de dimetil-arginina assimétrica no plasma com a redução da espessura subfoveal da coroide em pacientes diabéticos tipo 2 com retinopatia diabética.

The antitumor activity and pharmacokinetics research of PPD-Arg (Tos) using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

In this study, a new compound PPD-Arg (Tos) (PAT), an arginine derivative of 20(s)-PPD, was synthesized via Fmoc-Arg (Tos)-OH and 20(s)-PPD. The pharmacokinetic properties in rats, in vitro cytotoxicity, and cell apoptosis rates of protopanaxadiol (PPD) and PAT were determined. A sensitive bioanalytical method for pharmacokinetics using ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry was developed and validated. The result showed that the Tmax and t1/2 of PAT were significantly enhanced, indicating a long-lasting effect in vivo. Compared to the PPD group, the PAT group showed higher bioavailability. PAT also exhibited higher antitumor efficacy than PPD against three cancer cells, especially the strongest inhibitory activity against Huh-7, even more potent than the positive control of paclitaxel. Therefore, the apoptosis assay based on annexin V/propidium iodide-combined staining against Huh-7 further demonstrated that PAT could induce apoptosis of Huh-7 cells. Better pharmacokinetic properties and antitumor efficacy of the arginine derivative of 20(s)-PPD were important. These findings could provide references for further clinical research on amino acid derivatives of PPD as antitumor agents.

The Association Between Uric Acid and Symmetric Dimethylarginine Levels in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis.

BACKGROUND: Uric acid (UA) levels are associated with increased risk of cardiovascular events and mortality in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. In a study with a population of healthy young adults and HD there was a correlation between high blood uric acid levels and blood symmetric dimethylarginine (SDMA) level. However, in CAPD population, there are still conflicting data on the mechanism of increased risks related to uric acid levels. This study aimed to assess the association between uric acid levels and SDMA in the subjects undergoing CAPD. METHODS: This was a cross - sectional study conducted in all the adults who underwent CAPD for at least three months in tertiary hospital in Jakarta, Indonesia. Subjects already on uric lowering therapy, pregnant or lactating women, and those with a history of malignancy were excluded. Uric acid and SDMA level were measured at the same time patients controlled to outpatient clinic. Bivariate analysis was performed using the Mann - Whitney test and multivariate analysis performed using logistic regression test. RESULTS: A total of 55 subjects were included. The median level of UA was 7.30 + 1.59 mg/dl and 33 subjects (60%) had UA levels of 7 mg/dl or higher. The median SDMA level was 633.73 + 231.54 ng/mL. Subjects with UA levels > 7 mg/dl had significantly higher SDMA levels compared to subjects with UA levels < 7 mg/dl (721.58 + 220.57 vs 501.95 + 182; P < 0.001). The cut - off value of SDMA 536 ng/mL was obtained from the receiver operating characteristic (ROC) curve with sensitivity 81.8%, specificity 63.6%, PPV 77.78% and NPV 73.68%. After fully adjusted with the confounders, the determinant factors in this study were diabetes mellitus (OR: 7.844; CI95%: 1.899 - 32.395: P value: 0.004) and dyslipidemia (OR: 6.440; CI95%: 1.483 - 27.970; P value: 0.013) as risk factors. CONCLUSION: In CAPD patients, UA levels above 7 mg/dl were associated with increased SDMA levels. This study demonstrates the determinant factors regarding association between UA level and SDMA in CAPD patients were diabetes mellitus and dyslipidemia. The cut - off value of SDMA above 536 ng/mL were significant to increased risk of cardiovascular events.

A short review of ciraparantag in perspective of the currently available anticoagulant reversal agents.

Despite the improved safety-profile of direct oral anticoagulants (DOACs), bleeding complications remain an important side effect of anticoagulant treatment. Although anticoagulant-specific antidotes are available, an universal anticoagulant reversal agent in case of life-threatening bleeding or emergency surgery is not yet available. Ciraparantag, a synthetic small molecule that inactivates heparins and DOAC, is a promising new reversal agent that has been investigated in phase 2 trials. In this short review we provide an overview of the preclinical and clinical evidence of ciraparantag, and compare strengths and weaknesses of ciraparantag and the currently available anticoagulant reversal strategies.

Extracellular 5'-methylthioadenosine inhibits intracellular symmetric dimethylarginine protein methylation of FUSE-binding proteins.

Methylthioadenosine phosphorylase (MTAP) is a key enzyme in the methionine salvage pathway that converts the polyamine synthesis byproduct 5'-deoxy-5'-methylthioadenosine (MTA) into methionine. Inactivation of MTAP, often by homozygous deletion, is found in both solid and hematologic malignancies and is one of the most frequently observed genetic alterations in human cancer. Previous work established that MTAP-deleted cells accumulate MTA and contain decreased amounts of proteins with symmetric dimethylarginine (sDMA). These findings led to the hypothesis that accumulation of intracellular MTA inhibits the protein arginine methylase (PRMT5) responsible for bulk protein sDMAylation. Here, we confirm that MTAP-deleted cells have increased MTA accumulation and reduced protein sDMAylation. However, we also show that addition of extracellular MTA can cause a dramatic reduction of the steady-state levels of sDMA-containing proteins in MTAP+ cells, even though no sustained increase in intracellular MTA is found because of catabolism of MTA by MTAP. We determined that inhibition of protein sDMAylation by MTA occurs within 48 h, is reversible, and is specific. In addition, we have identified two enhancer-binding proteins, FUBP1 and FUBP3, that are differentially sDMAylated in response to MTAP and MTA. These proteins work via the far upstream element site located upstream of Myc and other promoters. Using a transcription reporter construct containing the far upstream element site, we demonstrate that MTA addition can reduce transcription, suggesting that the reduction in FUBP1 and FUBP3 sDMAylation has functional consequences. Overall, our findings show that extracellular MTA can inhibit protein sDMAylation and that this inhibition can affect FUBP function.

Arginyl-fructosyl-glucose from red ginseng alleviates TGF-ß1-induced epithelial-mesenchymal transition of renal tubular epithelial cells.

This study aims to explore the effect and mechanism of arginyl-fructosyl-glucose (AFG) on TGF-ß1-induced epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells. HK-2 cells were induced by TGF-ß1 and then co-cultured with AFG at different concentrations (0, 25, 50, and 100 µmol/l) for 48 h. The morphology of HK-2 cells was observed under an inverted microscope and the expressions of α-SMA, Vimentin, and E-cadherin were assessed by qRT-PCR, Western blot, and immunofluorescence. The mRNA expressions of ERK and STAT3 were also examined by qRT-PCR, and the protein levels of ERK, STAT3, p-ERK, and p-STAT3 were measured by Western blot. Finally, CCK-8 and transwell assays were used to detect cell proliferation and invasion. TGF-ß1 treatment significantly induced EMT in HK-2 cells. The expressions of p-ERK and p-STAT3 were signally increased after TGF-ß1 induction, while Mogrol treatment inhibited p-ERK, p-STAT3, α-SMA, and Vimentin expression levels, enhanced E-cadherin expression, and suppressed cell proliferation and invasion. AFG exposure could also inhibit p-ERK, p-STAT3, α-SMA, and Vimentin expressions, promote E-cadherin expression, and markedly inhibit HK-2 cell proliferation and invasion. AFG inhibited TGF-ß1-induced EMT of renal tubular epithelial cells by regulating phosphorylation of ERK and STAT3.

Enhanced protein aggregation suppressor activity of N-acetyl-l-arginine for agitation-induced aggregation with silicone oil and its impact on innate immune responses.

Previously, N-acetyl-l-arginine (NALA) suppressed the aggregation of intravenous immunoglobulins (IVIG) more effectively and with a minimum decrease in transition temperature (Tm) than arginine monohydrochloride. In this study, we performed a comparative study with etanercept (commercial product: Enbrel®), where 25 mM arginine monohydrochloride (arginine) was added to the prefilled syringe. The biophysical properties were investigated using differential scanning calorimetry (DSC), dynamic light scattering (DLS), size-exclusion chromatography (SEC), and flow-imaging microscopy (FI). NALA retained the transition temperature of etanercept better than arginine, where arginine significantly reduced the Tm by increasing its concentration. End-over-end rotation was applied to each formulation for 5 days to accelerate protein aggregation and subvisible particle formation. Higher monomeric content was retained with NALA with a decrease in particle level. Higher aggregation onset temperature (Tagg) was detected for etanercept with NALA than arginine. The results of this comparative study were consistent with previous study, suggesting that NALA could be a better excipient for liquid protein formulations. Agitated IVIG and etanercept were injected into C57BL/6J female mice to observe immunogenic response after 24 h. In the presence of silicone oil, NALA dramatically reduced IL-1 expression, implying that decreased aggregation was related to reduced immunogenicity of both etanercept and IVIG.

DDAH1/ADMA Regulates Adiponectin Resistance in Cerebral Ischemia via the ROS/FOXO1/APR1 Pathway.

Dimethylarginine dimethylaminohydrolase 1 (DDAH1) protects against cerebral ischemia injury via regulating the level of asymmetric dimethylarginine (ADMA). This study is aimed at exploring the effect of adiponectin resistance on ADMA-induced neuronal loss in ischemic stroke (IS) and the underlying mechanism. DDAH1 knockout (DDAH1-/-) and wild-type (DDAH1+/+) rats underwent middle cerebral artery occlusion/reperfusion (MCAO/R). Plasma and brain adiponectin levels and the expressions of adiponectin receptor 1 (APR1), adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1), adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated AMPK were determined after 24 h, 3 days, and 7 days. Neurological behavior, infarct volume, and adiponectin signaling were evaluated using adiponectin peptide or AdipoRon. The levels of reactive oxygen species (ROS) and Forkhead box O1 (FOXO1) (a transcription factor for APR1) were also assessed. An oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in primary neurons. DDAH1 was overexpressed in neurons, after which FOXO1 expression, ROS production, adiponectin resistance, and cell viability were detected. DDAH1-/- rats showed no significant difference in adiponectin level in either plasma or brain after MCAO/R in DDAH1+/+ rats, but downregulated APR1 expression and suppressed adiponectin signaling were observed. AdipoRon, but not adiponectin peptide, attenuated the neurological deficits and adiponectin resistance in DDAH1-/- rats. ROS accumulation and phosphorylated FOXO1 expression also increased with DDAH1 depletion. Following DDAH1 overexpression, decreased cell viability and inhibited adiponectin signaling induced by OGD/R were alleviated in primary neurons, accompanied by reduced ROS production and phosphorylated FOXO1 expression. Our study elucidated that in IS, DDAH1 protected against adiponectin resistance in IS via the ROS/FOXO1/APR1 pathway.

Evaluation of renal injury and function biomarkers, including symmetric dimethylarginine (SDMA), in the rat passive Heymann nephritis (PHN) model.

Symmetric dimethylarginine (SDMA) is a serum biomarker of excretory renal function which consistently correlates with glomerular filtration rate (GFR) across multiple species including rats, dogs, and humans. In human and veterinary clinical settings SDMA demonstrates enhanced sensitivity for detection of declining renal function as compared to other serum biomarkers, but application in preclinical study designs thus far has been limited. The purpose of this study was to determine the performance of serum SDMA in a rat passive Heyman nephritis model of glomerulopathy. In addition to SDMA other biomarkers of excretory renal function were measured including serum creatinine (sCr), blood urea nitrogen (BUN), and cystatin C along with creatinine clearance. Urinary renal biomarkers including microalbumin (µALB), clusterin (CLU), cystatin C, kidney injury marker-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin (OPN) were also measured. PHN was induced using commercial sheep anti-Fx1A serum. Tissue, serum, and urine were collected from groups of control and anti-Fx1A-treated animals for biomarker evaluation, hematology, urinalysis, serum biochemistry, and histologic examination of kidney. Over the course of a 28-day study, concentrations of the urinary biomarkers µALB, CLU, cystatin C, NGAL, KIM-1 and the serum biomarker cystatin C increased significantly in anti-Fx1A-treated rats as compared to controls but no significant increase in serum SDMA, sCr, BUN, or creatinine clearance were noted in anti-Fx1A-treated rats. Given lack of direct GFR measurement or significant change in the renal function biomarkers sCr, BUN, and creatinine clearance, it is unclear if GFR differed significantly between control and anti-Fx1A-treated rats in this study, though urinary biomarkers and histopathologic findings supported renal injury in anti-Fx1A-treated rats over the time course investigated. This study is among the first to investigate serum SDMA in a rat model relevant to preclinical safety assessment and serves to inform future experimental designs and biomarker selection when evaluation of glomerular injury is of priority.