Identification of Four Mouse FcRn Splice Variants and FcRn-Specific Vesicles.

Research into the neonatal Fc receptor (FcRn) has increased dramatically ever since Simister and Mostov first purified a rat version of the receptor. Over the years, FcRn has been shown to function not only as a receptor that transfers immunity from mother to fetus but also performs an array of different functions that include transport and recycling of immunoglobulins and albumin in the adult. Due to its important cellular roles, several clinical trials have been designed to either inhibit/enhance FcRn function or develop of non-invasive therapeutic delivery system such as fusion of drugs to IgG Fc or albumin to enhance delivery inside the cells. Here, we report the accidental identification of several FcRn alternatively spliced variants in both mouse and human cells. The four new mouse splice variants are capable of binding immunoglobulins' Fc and Fab portions. In addition, we have identified FcRn-specific vesicles in which immunoglobulins and albumin can be stored and that are involved in the endosomal-lysosomal system. The complexity of FcRn functions offers significant potential to design and develop novel and targeted therapeutics.

Particulate polycyclic aromatic hydrocarbons and metals, DNA methylation and DNA methyltransferase among middle-school students in China.

The main components of particulate matter (PM) had been reported to change DNA methylation levels. However, the mixed effect of PM and its constituents on DNA methylation and the underlying mechanism in children has not been well characterized. To investigate the association between single or mixture exposures and global DNA methylation or DNA methyltransferases (DNMTs), 273 children were recruited (110 in low-exposed area and 163 in high-exposed area) in China. Serum benzo[a]pyridin-7,8-dihydroglycol-9, 10-epoxide (BPDE)-albumin adduct and urinary metals were determined as exposure markers. The global DNA methylation (% 5mC) and the mRNA expression of DNMT1, and DNMT3A were measured. The linear regression, quantile-based g-computation (QGC), and mediation analyses were performed to investigate the effects of individual and mixture exposure. We found that significantly lower levels of % 5mC (P < 0.001) and the mRNA expression of DNMT3A in high-PM exposed group (P = 0.031). After adjustment for age, gender, BMI z-score, detecting status of urinary cotinine, serum folate, and white blood cells, urinary arsenic (As) was negatively correlated with the % 5mC. One IQR increase in urinary As (19.97 µmol/mol creatinine) was associated with a 11.06 % decrease in % 5mC (P = 0.026). Serum BPDE-albumin adduct and urinary cadmium (Cd) were negatively correlated with the levels of DNMT1 and DNMT3A (P < 0.05). Mixture exposure was negatively associated with expression of DNMT3A in QGC analysis (ß: -0.19, P < 0.001). Mixture exposure was significantly associated with decreased % 5mC in the children with non-detected cotinine or normal serum folate (P < 0.05), which the most contributors were PAHs and As. The mediated effect of hypomethylation through DNMT1 or DNMT3A pathway was not observed. Our findings indicated that individual and mixture exposure PAHs and metal components had negative associations with global DNA methylation and decreased DNMT3A expression significantly in school-age individuals.

Seminal extracellular vesicles alter porcine in vitro fertilization outcome by modulating sperm metabolism.

Porcine seminal plasma (SP) is loaded with a heterogeneous population of extracellular vesicles (sEVs) that modulate several reproductive-related processes. This study investigated the effect of two sEV subsets, small (S-sEVs) and large (L-sEVs), on porcine in vitro fertilization (IVF). The sEVs were isolated from nine SP pools (five ejaculates/pool) using a size-exclusion chromatography-based procedure and characterized for quantity (total protein), morphology (cryogenic electron microscopy), size distribution (dynamic light scattering), purity and EV-protein markers (flow cytometry; albumin, CD81, HSP90ß). The characterization confirmed the existence of two subsets of high purity (low albumin content) sEVs that differed in size (S- and L-sEVs). In vitro fertilization was performed with in vitro matured oocytes and frozen-thawed spermatozoa and the IVF medium was supplemented during gamete coincubation (1 h at 38.5 °C, 5 % CO2 in a humidified atmosphere) with three different concentrations of each sEV subset: 0 (control, without sEVs), 0.1, and 0.2 mg/mL. The first experiment showed that sEVs, regardless of subset and concentration, decreased penetration rates and total IVF efficiency (P < 0.0001). In a subsequent experiment, it was shown that sEVs, regardless of subset and concentration, impaired the ability of spermatozoa to bind to the zona pellucida of oocytes (P < 0.0001). The following experiment showed that sEVs, regardless of the subset, bound to frozen-thawed sperm but not to in vitro matured oocytes, indicating that sEVs would affect sperm functionality but not oocyte functionality. The lack of effect on oocytes was confirmed by incubating sEVs with oocytes prior to IVF, achieving sperm-zona pellucida binding results similar to those of control. In the last experiment, conducted under IVF conditions, sperm functionality was analyzed in terms of tyrosine phosphorylation, acrosome integrity and metabolism. The sEVs, regardless of the subset, did not affect sperm tyrosine phosphorylation or acrosome integrity, but did influence sperm metabolism by decreasing sperm ATP production under capacitating conditions. In conclusion, this study demonstrated that the presence of sEVs on IVF medium impairs IVF outcomes, most likely by altering sperm metabolism.

Cloflucarban Illuminates Specificity and Context-Dependent Activation of the PINK1-Parkin Pathway by Mitochondrial Complex Inhibition.

The PTEN-induced kinase 1 (PINK1)-Parkin pathway plays a vital role in maintaining a healthy pool of mitochondria in higher eukaryotic cells. While the downstream components of this pathway are well understood, the upstream triggers remain less explored. In this study, we conducted an extensive analysis of inhibitors targeting various mitochondrial electron transport chain (ETC) complexes to investigate their potential as activators of the PINK1-Parkin pathway. We identified cloflucarban, an antibacterial compound, as a novel pathway activator that simultaneously inhibits mitochondrial complexes III and V, and V. RNA interference (RNAi) confirmed that the dual inhibition of these complexes activates the PINK1-Parkin pathway. Intriguingly, we discovered that albumin, specifically bovine serum albumin (BSA) and human serum albumin (HSA) commonly present in culture media, can hinder carbonyl cyanide m-chlorophenyl hydrazone (CCCP)-induced pathway activation. However, cloflucarban's efficacy remains unaffected by albumin, highlighting its reliability for studying the PINK1-Parkin pathway. This study provides insights into the activation of the upstream PINK1-Parkin pathway and underscores the influence of culture conditions on research outcomes. Cloflucarban emerges as a promising tool for investigating mitochondrial quality control and neurodegenerative diseases.

Metabolic Tumor Volume as Significant Predictor for Chemotherapy Containing PD-L1 Blocker in Extensive Stage Small Cell Lung Cancer.

BACKGROUND/AIM: Chemo-immunotherapy, including the programmed death ligand 1 (PD-L1) antibody, is an effective treatment for patients with extensive-stage small-cell lung cancer (ES-SCLC). However, no biomarker has been established for the prediction of chemo-immunotherapy. Therefore, we investigated the potential of 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) as a predictive marker. PATIENTS AND METHODS: Forty-six patients with ES-SCLC who received 18F-FDG-PET immediately before combined platinum-based chemotherapy with PD-L1 blockade as a first-line treatment were eligible, and the maximum standard uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on 18F-FDG uptake were evaluated. RESULTS: PD-L1 and tumor infiltrative lymphocytes (TILs) were immunohistochemically analyzed in 36 of the 46 patients. A high MTV was significantly associated with poor performance status and low albumin levels, and there was a significant association between low albumin and high TLG. Univariate analysis identified sex, Brinkman index, and MTV as significant predictors of progression-free survival (PFS), and sex, SUVmax, MTV, and TLG as significant factors of overall survival (OS). Multivariate analysis revealed that sex, Brinkman index, and MTV were independent prognostic factors for PFS, and sex, SUVmax, MTV, and TLG were significant predictors of OS. SUVmax was significantly higher in patients with positive PD-L1 expression than in those with negative expression but was not significantly different between positive and negative TILs. Moreover, the levels of MTV and TLG were not closely associated with the levels of PD-L1 and TILs. CONCLUSION: MTV or TLG metabolic tumor activity is suitable for the prediction of chemo-immunotherapy outcomes in patients with ES-SCLC.

The Prolonged Activation of the p65 Subunit of the NF-Kappa-B Nuclear Factor Sustains the Persistent Effect of Advanced Glycation End Products on Inflammatory Sensitization in Macrophages.

Advanced glycation end products (AGEs) prime macrophages for lipopolysaccharide (LPS)-induced inflammation. We investigated the persistence of cellular AGE-sensitization to LPS, considering the nuclear content of p50 and p65 nuclear factor kappa B (NFKB) subunits and the expression of inflammatory genes. Macrophages treated with control (C) or AGE-albumin were rested for varying intervals in medium alone before being incubated with LPS. Comparisons were made using one-way ANOVA or Student t-test (n = 6). AGE-albumin primed macrophages for increased responsiveness to LPS, resulting in elevated levels of TNF, IL-6, and IL-1beta (1.5%, 9.4%, and 5.6%, respectively), compared to C-albumin. TNF, IL-6, and IL-1 beta secretion persisted for up to 24 h even after the removal of AGE-albumin (area under the curve greater by 1.6, 16, and 5.2 times, respectively). The expressions of Il6 and RelA were higher 8 h after albumin removal, and Il6 and Abca1 were higher 24 h after albumin removal. The nuclear content of p50 remained similar, but p65 showed a sustained increase (2.9 times) for up to 24 h in AGE-albumin-treated cells. The prolonged activation of the p65 subunit of NFKB contributes to the persistent effect of AGEs on macrophage inflammatory priming, which could be targeted for therapies to prevent complications based on the AGE-RAGE-NFKB axis.

Characterization of diseased primary human hepatocytes in an all-human cell-based triculture system.

Liver diseases, including NAFLD, are a growing worldwide health concern. Currently, there is a lack of suitable in vitro models that sustain basic primary human hepatocyte (PHH) morphology and functionality while supporting presentation of disease-associated phenotypic characteristics such as lipid accumulation and inflammasome activation. In TruVivo, an all-human triculture system (hTCS), basic metabolic functions were characterized in PHHs isolated from normal or diseased livers during two-weeks of culture. Decreases in albumin and urea levels and CYP3A4 activity were seen in diseased-origin PHHs compared to normal PHHs along with higher CYP2E1 expression. Positive expression of the macrophage markers CD68 and CD163 were seen in the diseased PHH preparations. Elevated levels of the pro-inflammatory cytokines IL-6 and MCP-1 and the fibrotic markers CK-18 and TGF-ß were also measured. Gene expression of FASN, PCK1, and G6PC in the diseased PHHs was decreased compared to the normal PHHs. Further characterization revealed differences in lipogenesis and accumulation of intracellular lipids in normal and diseased PHHs when cultured with oleic acid and high glucose. TruVivo represents a promising new platform to study lipogenic mechanisms in normal and diseased populations due to the preservation of phenotypic differences over a prolonged culture period.

Prefeeding of Clarias gariepinus with Spirulina platensis counteracts petroleum hydrocarbons-induced hepato- and nephrotoxicity.

Petroleum aromatic hydrocarbons are considered one of the most dangerous aquatic pollutants due to their widespread across water bodies, persistence, and extension to the food chain. To our knowledge, there hasn't been any research investigating the hepatorenoprotective effects of Spirulina platensis (SP) against toxicity induced by these environmental toxicants in fish. Thus, we decided to explore its potential safeguarding against benzene and toluene exposure in adult Clarias gariepinus. To achieve this objective, fish were divided into five groups (60 per group; 20 per replicate). The first group served as a control. The second and third groups were intoxicated with benzene and toluene at doses of 0.762 and 26.614 ng/L, respectively for 15 days. The fourth and fifth groups (SP + benzene and SP + toluene, respectively) were challenged with benzene and toluene as previously mentioned following dietary inclusion of SP at a dose of 5 g/kg diet for 30 days. The marked increase in liver metabolizing enzymes, glucose, total protein, albumin, globulin, albumin/globulin ratio, and creatinine confirmed the hepato- and nephrotoxic impacts of benzene and toluene. These outcomes were coupled with cytopathological affections and excessive collagen deposition. The incorporation of SP in ration formulation, on the contrary, restored the previously mentioned toxicological profile due to its antioxidant and cytoprotective attributes. Regardless of SP intervention, the renal tissues still displayed histo-architectural lesions, because of insufficient dose and timeframe. Additional research will be required to identify the ideal SP remediation regimen.

Altered platelet-megakaryocyte endocytosis and trafficking of albumin and fibrinogen in RUNX1 haplodeficiency.

ABSTRACT: Platelet α-granules have numerous proteins, some synthesized by megakaryocytes (MK) and others not synthesized but incorporated by endocytosis, an incompletely understood process in platelets/MK. Germ line RUNX1 haplodeficiency, referred to as familial platelet defect with predisposition to myeloid malignancies (FPDMMs), is associated with thrombocytopenia, platelet dysfunction, and granule deficiencies. In previous studies, we found that platelet albumin, fibrinogen, and immunoglobulin G (IgG) were decreased in a patient with FPDMM. We now show that platelet endocytosis of fluorescent-labeled albumin, fibrinogen, and IgG is decreased in the patient and his daughter with FPDMM. In megakaryocytic human erythroleukemia (HEL) cells, small interfering RNA RUNX1 knockdown (KD) increased uptake of these proteins over 24 hours compared with control cells, with increases in caveolin-1 and flotillin-1 (2 independent regulators of clathrin-independent endocytosis), LAMP2 (a lysosomal marker), RAB11 (a marker of recycling endosomes), and IFITM3. Caveolin-1 downregulation in RUNX1-deficient HEL cells abrogated the increased uptake of albumin, but not fibrinogen. Albumin, but not fibrinogen, partially colocalized with caveolin-1. RUNX1 KD resulted in increased colocalization of albumin with flotillin and fibrinogen with RAB11, suggesting altered trafficking of both proteins. The increased uptake of albumin and fibrinogen, as well as levels of caveolin-1, flotillin-1, LAMP2, and IFITM3, were recapitulated by short hairpin RNA RUNX1 KD in CD34+-derived MK. To our knowledge, these studies provide first evidence that platelet endocytosis of albumin and fibrinogen is impaired in some patients with RUNX1-haplodeficiency and suggest that megakaryocytes have enhanced endocytosis with defective trafficking, leading to loss of these proteins by distinct mechanisms. This study provides new insights into mechanisms governing endocytosis and α-granule deficiencies in RUNX1-haplodeficiency.

ANGPT2/CAV1 regulates albumin transcytosis of glomerular endothelial cells under high glucose exposure and is impaired by losartan / ANGPT2/CAV1 regula la transcitosis de la albúmina de las células endoteliales glomerulares bajo exposición a hiperglucemia, alterándose con la intervención de losartan

Background Microalbuminuria is a common clinical symptom that manifests in the early stages of diabetic kidney disease (DKD) and is also the main feature of glomerular endothelial cells (GECs) injury. There is increasing evidence that the transcytosis of albumin across GECs is closely related to the formation of albuminuria. Our previous studies have shown that angiopoietin 2 (ANGPT2) can inhibit albumin transcytosis across renal tubular epithelial cells by activating caveolin 1 (CAV1) phosphorylation during high glucose (HG) exposure. The role of ANGPT2 in albumin transcytosis across GECs remains unclear. Losartan significantly reduces albuminuria, but the mechanism has not been clarified. Methods We established an in vitro albumin transcytosis model to investigate the change in albumin transcytosis across human renal glomerular endothelial cells (hrGECs) under normal glucose (NG), high glucose (HG) and losartan intervention. We knocked down ANGPT2 and CAV1 to evaluate their roles in albumin transcytosis across hrGECs and verified the relationship between them. In vivo, DKD mouse models were established and treated with different doses of losartan. Immunohistochemistry and Western blot were used to detect the expression of ANGPT2 and CAV1. Results In vitro, the transcytosis of albumin across hrGECs was significantly increased under high glucose stimulation, and losartan inhibited this process. The expression of ANGPT2 and CAV1 were both increased in hrGECs under HG conditions and losartan intervention reduced the expression of them. Moreover, ANGPT2 downregulation reduced albumin transcytosis in hrGECs by regulating CAV1 expression. In vivo, the expression of ANGPT2 and CAV1 in the glomerulus was both increased significantly in DKD mice. Compared with DKD mice, losartan treatment reduced albuminuria and decreased the expression of ANGPT2 and CAV1 in a dose-dependent manner (AU)

Antecedentes La microalbuminuria es un síntoma clínico común que se manifiesta en las fases tempranas de la enfermedad renal diabética (ERD), y también es característica del daño de las células endoteliales glomerulares (GEC). Existe evidencia creciente en cuanto a que la transcitosis de la albúmina a través de las GEC está estrechamente relacionada con la formación de albuminuria. Nuestros estudios previos reflejaron que angiopoyetina 2 (ANGPT2) puede inhibir la transcitosis de la albúmina a través de las células epiteliales tubulares renales activando la fosforilación de caveolina 1 (CAV1) durante la exposición a hiperglucemia (HG). El rol de ANGPT2 en la transcitosis de la albúmina a través de las GEC resulta incierto. Losartan reduce considerablemente la albuminuria, aunque no se ha esclarecido el mecanismo. Métodos Establecimos un modelo in vitro de transcitosis de la albúmina para investigar el cambio de dicho mecanismo a través de las células endoteliales glomerulares renales humanas (hrGEC) en condiciones de glucosa normal (GN), hiperglucemia (HG) e intervención de losartan. Realizamos breakdown de ANGPT2 y CAV1 para evaluar sus roles en la transcitosis de la albúmina a través de las hrGEC, y verificamos la relación entre ellas. Se establecieron modelos in vivo de ratones con ERD, tratados con diferentes dosis de losartan. Se utilizaron pruebas de inmunohistoquímica e inmunotransferencia para detectar la expresión de ANGPT2 y CAV1. Resultados In vitro, la transcitosis de la albúmina a través de hrGEC se incrementó considerablemente en condiciones de estimulación de la hiperglucemia, inhibiendo losartan este proceso. La expresión de ANGPT2 y CAV1 se incrementó en las hrGEC en condiciones de HG, reduciendo la intervención de losartan la expresión de ambas (AU)

Assessing the effects of tempol on renal fibrosis, inflammation, and oxidative stress in a high-salt diet combined with 5/6 nephrectomy rat model: utilizing oxidized albumin as a biomarker.

BACKGROUND: Oxidative stress has been implicated in the pathogenesis of chronic kidney disease (CKD), prompting the exploration of antioxidants as a potential therapeutic avenue for mitigating disease progression. This study aims to investigate the beneficial impact of Tempol on the progression of CKD in a rat model utilizing oxidized albumin as a biomarker. METHODS: After four weeks of treatment, metabolic parameters, including body weight, left ventricle residual weight, kidney weight, urine volume, and water and food intake, were measured. Systolic blood pressure, urinary protein, oxidized albumin level, serum creatinine (Scr), blood urea nitrogen (BUN), 8-OHdG, TGF-ß1, and micro-albumin were also assessed. Renal fibrosis was evaluated through histological and biochemical assays. P65-NF-κB was quantified using an immunofluorescence test, while Smad3, P65-NF-κB, and Collagen I were measured using western blot. TNF-α, IL-6, MCP-1, TGF-ß1, Smad3, and P65-NF-κB were analyzed by RT-qPCR. RESULTS: Rats in the high-salt diet group exhibited impaired renal function, characterized by elevated levels of blood urea nitrogen, serum creatinine, 8-OHdG, urine albumin, and tubulointerstitial damage, along with reduced body weight. However, these effects were significantly ameliorated by Tempol administration. In the high-salt diet group, blood pressure, urinary protein, and oxidized albumin levels were notably higher compared to the normal diet group, but Tempol administration in the treatment group reversed these effects. Rats in the high-salt diet group also displayed increased levels of proinflammatory factors (TNF-α, IL-6, MCP1) and profibrotic factors (NF-κB activation, Collagen I), elevated expression of NADPH oxidation-related subunits (P65), and activation of the TGF-ß1/Smad3 signaling pathway. Tempol treatment inhibited NF-κB-mediated inflammation and TGF-ß1/Smad3-induced renal fibrosis signaling pathway activation. CONCLUSION: These findings suggest that Tempol may hold therapeutic potential for preventing and treating rats undergoing 5/6 nephrectomy. Further research is warranted to elucidate the mechanisms underlying Tempol's protective effects and its potential clinical applications. Besides, there is a discernible positive relationship between oxidized albumin and other biomarkers, such as 8-OHG, urinary protein levels, mALB, Scr, BUN, and TGF-ß1 in a High-salt diet combined with 5/6 nephrectomy rat model. These findings suggest the potential utility of oxidized albumin as a sensitive indicator for oxidative stress assessment.

Effects of topical application of resveratrol on tight junction barrier and antimicrobial compound production in lactating goat mammary glands.

In mammary glands, the formation of less-permeable tight junctions (TJs) and the production of antimicrobial compounds like lactoferrin and defensins are important for preventing mastitis. Resveratrol, a polyphenol contained in red grapes, is known to protect mammary epithelial cells (MECs) from oxidative stress; however, oral administration of resveratrol causes a decrease in certain biological processes through conjugation and metabolic conversion. In this study, we determined the beneficial effects of resveratrol on TJs and antimicrobial compounds in cultured goat MECs by adding it to the medium, and in lactating goat mammary glands by topical application for percutaneous absorption. TJ barrier function was evaluated by transepithelial resistance and expression or localization pattern of claudins for culture model in vitro and by somatic cell count, Na+, albumin, and IgG in milk for topical application in vivo. Concentrations of antimicrobial compounds and cytokines were measured using ELISA. Activation of STAT3 was evaluated by Western blotting. Resveratrol strengthened TJ barrier function by upregulating claudin-3 in cultured MECs and topical application to udders reduced somatic cell count, Na+, albumin, and IgG in milk. Resveratrol increased ß-defensin and S100A7 levels in cultured MECs and milk. In addition, resveratrol down-regulated cytokine production and STAT3 pathway. These findings suggest that the topical application of resveratrol to udders may be effective in preventing mastitis.

Hepatoprotective effect of methanol fruit extract of Punica granatum L in highly active antiretroviral therapy-induced toxicity in Wistar rats.

Prolonged use of Highly Active Antiretroviral Therapy (HAART) has been linked to toxicity, particularly hepatotoxicity. There are few effective drugs for HAART patients that promote hepatic cell regeneration and prevent liver injury. Therefore, the purpose of this study was to investigate the hepato-protective activity of Methanol fruit extract of Punica granatum (MFEPG) in HAART-administered rats. Thirty rats weighing between 150-200 g were randomly divided into six groups and each group comprised of five rats. Distilled water was given to the rats in group one. Only HAART was given to the rats in group two. MFEPG at doses of 100 and 400 mg/kg was given to the rats in groups three and four. MFEPG dosages of 100 and 400 mg/kg along with HAART were given to the rats in groups five and six, respectively. All treatments were via oral gavage daily for 40 days. Under halothane anesthesia, all rats were sacrificed on day 41. Liver tissues were utilized for lipid peroxidation marker; Malondialdehyde (MDA), antioxidant enzymes; Superoxide dismutase (SOD) and Catalase (CAT) and histological evaluation, while blood samples were examined for biochemical parameters (AST, ALT, ALP, Total cholesterol, Total protein, and Albumin). The HAART-treated group exhibited a significantly higher amount of the lipid peroxidation end product; MDA, and significantly lower levels of antioxidant enzymes; SOD, and CAT. Liver enzymes and total cholesterol were significantly increased with a significant reduction in Total protein and Albumin levels in the HAART-treated group. Conversely, the liver function biomarkers were returned to normal levels in the HAART and MFEPG-treated groups. Histopathological studies revealed that when HAART-exposed rats were treated with MFEPG, both the biochemical and histological results significantly improved. Thus, the antioxidant activity of MFEPG provides protection against HAART-induced liver oxidative damage. More research is needed to determine the safety of using MFEPG in humans.

Cathepsin B Processing Is Required for the In Vivo Efficacy of Albumin-Drug Conjugates.

Targeted drug delivery approaches that selectively and preferentially deliver therapeutic agents to specific tissues are of great interest for safer and more effective pharmaceutical treatments. We investigated whether cathepsin B cleavage of a valine-citrulline [VC(S)]-containing linker is required for the release of monomethyl auristatin E (MMAE) from albumin-drug conjugates. In this study, we used an engineered version of human serum albumin, Veltis High Binder II (HBII), which has enhanced binding to the neonatal Fc (fragment crystallizable) receptor (FcRn) to improve drug release upon binding and FcRn-mediated recycling. The linker-payload was conjugated to cysteine 34 of albumin using a carbonylacrylic (caa) reagent which produced homogeneous and plasma stable conjugates that retained FcRn binding. Two caa-linker-MMAE reagents were synthesized─one with a cleavable [VC(S)] linker and one with a noncleavable [VC(R)] linker─to question whether protease-mediated cleavage is needed for MMAE release. Our findings demonstrate that cathepsin B is required to achieve efficient and selective antitumor activity. The conjugates equipped with the cleavable [VC(S)] linker had potent antitumor activity in vivo facilitated by the release of free MMAE upon FcRn binding and internalization. In addition to the pronounced antitumor activity of the albumin conjugates in vivo, we also demonstrated their preferable tumor biodistribution and biocompatibility with no associated toxicity or side effects. These results suggest that the use of engineered albumins with high FcRn binding combined with protease cleavable linkers is an efficient strategy to target delivery of drugs to solid tumors.

Tangshen formula improves diabetic nephropathy in STZ-induced diabetes rats fed with hyper-methionine by regulating the methylation status of kidney.

BACKGROUND: The objective of this study was to examine and analyze differential methylation profiles in order to investigate the influence of hyper-methioninemia (HM) on the development of diabetic nephropathy (DN). Male Wistar rats, aged eight weeks and weighing 250-300 g, were randomly assigned into four groups: a control group (Healthy, n = 8), streptozocin-induced rats (STZ group, n = 8), HM + STZ group (n = 8), and the Tangshen Formula (TSF) treatment group (TSF group, n = 8). Blood glucose levels and other metabolic indicators were monitored before treatment and at four-week intervals until 12 weeks. Total DNA was extracted from the aforementioned groups, and DNA methylation landscapes were analyzed via reduced representative bisulfite sequencing. RESULTS: Both the STZ group and HM + STZ group exhibited increased blood glucose levels and urinary albumin/creatinine ratios in comparison with the control group. Notably, the HM + STZ group exhibited a markedly elevated urinary albumin/creatinine ratio (411.90 ± 88.86 mg/g) compared to the STZ group (238.41 ± 62.52 mg/g). TSF-treated rats demonstrated substantial reductions in both blood glucose levels and urinary albumin/creatinine ratios in comparison with the HM + STZ group. In-depth analysis of DNA methylation profiles revealed 797 genes with potential therapeutic effects related to TSF, among which approximately 2.3% had been previously reported as homologous genes. CONCLUSION: While HM exacerbates DN through altered methylation patterns at specific CpG sites, TSF holds promise as a viable treatment for DN by restoring abnormal methylation levels. The identification of specific genes provides valuable insights into the underlying mechanisms of DN pathogenesis and offers potential therapeutic targets for further investigation.

Mac-2-Binding Protein Glycosylation Isomer to Albumin Ratio Predicts Bacterial Infections in Cirrhotic Patients.

INTRODUCTION: Mac-2-binding protein glycosylation isomer (M2BPGi) is a novel biomarker for liver fibrosis, but little is known about its role in cirrhosis-associated clinical outcomes. This study aimed to investigate the predictive role of M2BPGi in cirrhosis-associated complications. METHODS: One hundred and forty-nine cirrhotic patients were retrospectively enrolled. Patients were followed up for 1 year, and cirrhosis-associated clinical events were recorded. Receiver operating characteristic curve (ROC) analysis was used to establish the values of the predictive models for cirrhotic outcomes, and Cox proportional hazards regression models were used to identify predictors of clinical outcomes. RESULTS: Sixty (40.3%) patients experienced cirrhosis-associated clinical events and had higher M2BPGi levels compared to those without events (8.7 vs. 5.1 cutoff index, p < 0.001). The most common cirrhosis-associated complications were bacterial infections (24.2%). On ROC analysis, M2BPGi to albumin ratio (M2BPGi/albumin) had comparable discriminant abilities for all cirrhosis-associated events (area under the ROC curve [AUC] = 0.74) compared with M2BPGi, Child-Pugh, model for end-stage liver disease, albumin-bilirubin scores, and neutrophil-to-lymphocyte ratio and was superior to M2BPGi alone for all bacterial infectious events (AUC = 0.80). Cox regression analysis revealed that the M2BPGi/albumin, but not M2BPGi alone, independently predicted all cirrhosis-associated events (hazard ratio [HR] = 1.34, p = 0.038) and all bacterial infectious events (HR = 1.51, p = 0.011) within 1 year. However, M2BPGi/albumin did not predict other cirrhotic complications and transplant-free survival. DISCUSSION/CONCLUSION: M2BPGi/albumin might serve as a potential prognostic indicator for patients with cirrhosis, particularly for predicting bacterial infections.

Introducing the Dynamic Well-Stirred Model for Predicting Hepatic Clearance and Extraction Ratio.

The well-stirred model (WSM) incorporating the fraction of unbound drug (fu) to account for the effect of plasma binding on intrinsic clearance has been widely used for predicting hepatic clearance under the assumption that drug protein binding reaches equilibrium instantaneously. Our theoretical analysis reveals that the effect of protein binding on intrinsic clearance is better accounted for with the dynamic free fraction (fD), a measure of drug protein binding affinity, which leads to a putative dynamic well-stirred model (dWSM) without the instantaneous equilibrium assumption. Using recombinant CYP3A4 as the in vitro clearance system, we demonstrate that the binding effect of albumin on the intrinsic clearance of both highly bound midazolam and highly free verapamil is fully corrected by their corresponding fD values, respectively. On the other hand, fu only corrects the binding effect of albumin on the intrinsic clearance of verapamil, and yields severe over-correction of the intrinsic clearance of midazolam. The results suggest that the traditional WSM is suitable for highly free drugs like verapamil but not necessarily for highly bound drugs such as midazolam due to the violation of the instantaneous equilibrium assumption or under-estimating the true free drug concentration. In comparison, the dWSM incorporating fD holds true as long as drug elimination follows steady-state kinetics, and hence, it is more broadly applicable to drugs with different protein binding characteristics. Here we demonstrate with 36 diverse drugs, that the dWSM significantly improves the accuracy of predicting human hepatic clearance and liver extraction ratio from in vitro microsomal clearance data, highlighting the importance of drug plasma protein binding kinetics in addressing the under-prediction of hepatic clearance by the WSM.

Iron-related markers of inflammation in horses with colic.

The aim of the study was to compare and correlate levels of ferritin, transferrin, iron and APPs in healthy horses and those surgically treated for strangulating colic. On admission, measurements of inflammatory markers related to iron and total protein, fibrinogen, albumin, haptoglobin and ceruloplasmin were made. The study comprised 22 horses, divided into a control group (CG) of healthy horses (n = 10) and horses with surgically treated acute abdomen (n = 12), obstruction group (OG). The OG was subdivided according to the affected intestinal segment (small vs. large) and according to outcome (survivors vs. non survivors). The OG had higher haptoglobin (34.8±14.2 mg/dL vs 20.8±7.21 mg/dL) and transferrin (487±161 mg/dL vs 369±71.4 mg/dL) values and lower iron (96.9±65 µg/dL vs 218±105 µg/dL) values than the CG. The OG horses with large intestine obstruction had lower values of transferrin (374.6±130 mg/dL) than horses with small intestinal obstruction (598.6±98.9 mg/dL). There was no difference in outcome between horses with large and small intestinal obstruction. Ferritin levels were moderately correlated with total protein (r = 0.594; P = 0.042) and albumin (r = 0.584; P = 0.046) in OG. In the multivariate exploratory analysis, fibrinogen levels were higher in animals that did not survive. In conclusion, haptoglobin, transferrin and iron were useful inflammatory markers for colic in horses. The correlation of ferritin with other APPs shows a possible role of ferritin as an APP in horses. Fibrinogen levels are higher in horses with greater risk of death from strangulating obstructions.

Association between haemoglobin, albumin, lymphocytes, and platelets and mortality in patients with heart failure.

AIMS: The combination of haemoglobin, albumin, lymphocytes, and platelets (HALP) is a new metric used to assess patient prognosis in many diseases. This study aimed to assess the relationship between HALP and short- and long-term mortality in patients with heart failure. METHODS AND RESULTS: This retrospective cohort study included adult patients with heart failure who were hospitalized between 2019 and 2021. The primary outcomes were 1-month mortality and 1-year mortality. The multivariable logistic regression analysis was used to evaluate the association between HALP and the risk of mortality. Stratified analyses were conducted based on New York Heart Association functional classification (NYHA) stage (II/III, IV) and left ventricular ejection fraction (LVEF, <50%, ≥50%). The area under the receiver operating characteristic curve (AUC) was used to evaluate the ability of HALP, prognostic nutritional index (PNI), C-reactive protein (CRP), and the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC-HF) risk score in predicting mortality in patients with heart failure. A total of 730 patients with heart failure were included, of whom 61 (8.36%) died within 1 month and 77 (10.55%) died within 1 year. High HALP scores were associated with a reduced risk of 1-month mortality (odds ratio (OR) = 0.978, 95% confidence interval (CI): 0.963-0.992, P = 0.003) and 1-year mortality (OR = 0.987, 95% CI: 0.977-0.997, P = 0.009) in patients with heart failure. In patients with different NYHA stages or LVEF levels, high HALP scores were correlated with a reduced risk of 1-year mortality in patients with NYHA stage II/III (OR = 0.978, 95% CI: 0.957-1.000, P = 0.045) or LVEF ≥50% (OR = 0.970, 95% CI: 0.945-0.996, P = 0.024). The AUC for HALP, PNI, CRP, and MAGGIC-HF to predict 1-year mortality in patients with heart failure were 0.677 (95% CI: 0.619-0.735), 0.666 (95% CI: 0.608-0.723), 0.638 (95% CI: 0.572-0.704), and 0.654 (95% CI: 0.591-0.717), respectively. CONCLUSIONS: HALP may be a potential marker for predicting mortality in patients with heart failure. Further exploration based on HALP may yield better clinical predictors of prognosis in patients with heart failure.

Early detection of liver injuries by the Serum enhanced binding test sensitive to albumin post-transcriptional modifications.

Early and sensitive biomarkers of liver dysfunction and drug-induced liver injury (DILI) are still needed, both for patient care and drug development. We developed the Serum Enhanced Binding (SEB) test to reveal post-transcriptional modifications (PTMs) of human serum albumin resulting from hepatocyte dysfunctions and further evaluated its performance in an animal model. The SEB test consists in spiking serum ex-vivo with ligands having specific binding sites related to the most relevant albumin PTMs and measuring their unbound fraction. To explore the hypothesis that albumin PTMs occur early during liver injury and can also be detected by the SEB test, we induced hepatotoxicity in male albino Wistar rats by administering high daily doses of ethanol and CCl4 over several days. Blood was collected for characterization and quantification of albumin isoforms by high-resolution mass spectrometry, for classical biochemical analyses as well as to apply the SEB test. In the exposed rats, the appearance of albumin isoforms paralleled the positivity of the SEB test ligands and histological injuries. These were observed as early as D3 in the Ethanol and CCl4 groups, whereas the classical liver tests (ALT, AST, PAL) significantly increased only at D7. The behavior of several ligands was supported by structural and molecular simulation analysis. The SEB test and albumin isoforms revealed hepatocyte damage early, before the current biochemical biomarkers. The SEB test should be easier to implement in the clinics than albumin isoform profiling.