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Increasing evidence suggests that the accumulations of reactive oxygen species (ROS), β-amyloid (Aβ), and neuroinflammation are crucial pathological hallmarks for the onset of Alzheimer's disease (AD), yet there are few effective treatment strategies. Therefore, design of nanomaterials capable of simultaneously elimination of ROS and inhibition of Aβ aggregation and neuroinflammation is urgently needed for AD treatment. Herein, we designed human serum albumin (HSA)-embedded ultrasmall copper nanoclusters (CuNCs@HSA) via an HSA-mediated fabrication strategy. The as-prepared CuNCs@HSA exhibited outstanding multiple enzyme-like properties, including superoxide dismutase (>5000 U/mg), catalase, and glutathione peroxidase activities as well as hydroxyl radicals scavenging ability. Besides, CuNCs@HSA prominently inhibited Aβ fibrillization, and its inhibitory potency was 2.5-fold higher than native HSA. Moreover, CuNCs@HSA could significantly increase the viability of Aβ-treated cells from 60 % to over 96 % at 40 μg/mL and mitigate Aβ-induced oxidative stresses. The secretion of neuroinflammatory cytokines by lipopolysaccharide-induced BV-2 cells, including tumor necrosis factor-α and interleukin-6, was alleviated by CuNCs@HSA. In vivo studies manifested that CuNCs@HSA effectively suppressed the formation of plaques in transgenic C. elegans, reduced ROS levels, and extended C. elegans lifespan by 5 d. This work, using HSA as a template to mediate the fabrication of copper nanoclusters with robust ROS scavenging capability, exhibited promising potentials in inhibiting Aβ aggregation and neuroinflammation for AD treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The elderly frequently present impaired blood-brain barrier which is closely associated with various neurodegenerative diseases. However, how the albumin, the most abundant protein in the plasma, leaking through the disrupted BBB, contributes to the neuropathology remains poorly understood. We here demonstrated that mouse serum albumin-activated microglia induced astrocytes to A1 phenotype to remarkably increase levels of Elovl1, an astrocytic synthase for very long-chain saturated fatty acids, significantly promoting VLSFAs secretion and causing neuronal lippoapoptosis through endoplasmic reticulum stress response pathway. Moreover, MSA-activated microglia triggered remarkable tau phosphorylation at multiple sites through NLRP3 inflammasome pathway. Intracerebroventricular injection of MSA into the brains of C57BL/6J mice to a similar concentration as in patient brains induced neuronal apoptosis, neuroinflammation, increased tau phosphorylation, and decreased the spatial learning and memory abilities, while Elovl1 knockdown significantly prevented the deleterious effect of MSA. Overall, our study here revealed that MSA induced tau phosphorylation and neuron apoptosis based on MSA-activated microglia and astrocytes, respectively, showing the critical roles of MSA in initiating the occurrence of tauopathies and cognitive decline, and providing potential therapeutic targets for MSA-induced neuropathology in multiple neurodegenerative disorders., (© 2024. The Author(s).)

The understanding that humans are exposed to a low level of toxic metals and metalloids in their lifetime has resulted in a shift in scientific and regulatory perspectives from the traditional evaluation of single metal toxicity to complex mixtures, relevant to real-life exposure. Therefore, the aim of this study was to examine the impact of real-life, 90-days exposure to mixture of toxic metal(oid)s, Cd, Pb, Ni, Cr, As and Hg, on the nuclear factor erythroid 2-related factor 2 and hemoxygenase-1 (Nrf2/HO-1) signalling and redox status by assessing total sulfhydryl groups (SH), glutathione (GSH), superoxide dismutase activity (SOD), malondialdehyde (MDA), and ischemia modified albumin (IMA) in the liver and kidney of Wistar rats. Animals (20 males and 20 females) were randomized in 2 control and 6 treated groups that received by oral gavage mixture of metal(oid)s solutions in doses that reflect blood metal(oid) levels determined in previous human biomonitoring study as benchmark dose (F/M _BMD), median (F/M _MED), and 95th percentile (F/M _95). Our results have shown that metal(oid)s mixture impaired the activation of the Nrf2/HO-1 pathway in the kidney and liver of male rats and kidney of female rats, followed by depletion of GSH levels in males. Additionally, in males elevated levels of IMA in the liver were observed, while in both genders increased MDA levels were observed in the kidney. Interestingly, the effects were more pronounced in male than in female rats. This study is among the first that examined hepato-renal toxic mechanisms of real-life metal mixture exposure, while our results might be of immense importance for assessing the risk of exposure to mixtures of toxic substances., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Introduction and Objective: Lipopolysaccharide (LPS) has been associated with myocardial inflammation, oxidative stress, apoptosis, and cardiac dysfunction, as well as death by causing sepsis. In this study, we investigated the effect of irbesartan (IRB), an angiotensin receptor antagonist, on cardiotoxicity caused by LPS., Methods: The experiment involved 24 Wistar albino rats divided into three groups of eight: control, LPS (5 mg/kg), and LPS (5 mg/kg)+IRB (3 mg/kg). Parameters including total oxidative status, total antioxidant status, oxidative stress index, and ischemia-modified albumin were measured to assess oxidative stress in heart tissues and serum. Serum CK, CK-MB, and LDH levels were measured spectrophotometrically. RT-qPCR was used to detect the mRNA expression levels of Bcl-2, BAX, p53, caspase-3, and sirtuin 1. Tissues taken from the heart and aorta were examined by immunohistochemistry and histopathology., Results: While there was an increase in the parameters indicating heart damage, oxidative stress, and apoptosis in the group given LPS, there was an improvement in all parameters and heart damage in the group treated with IRB., Conclusion: As a result of our study, we determined that IRB has an ameliorating effect on myocardial damage caused by oxidative stress and apoptosis developed by the LPS-induced sepsis model., (Copyright © 2023 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)

Cancer is one of the world's major causes of death. The aim of this study is to examine the acute effects of resveratrol on testicular toxicity, oxidative stress, and apoptosis caused by MTX, which is widely used in the treatment of many diseases, especially cancer, histochemically, immunohistochemically, and biochemical methods using different parameters. A total of 32 Wistar albino male rats were randomly divided into 4 groups: control, resveratrol (RES), MTX, and MTX + RES, with 8 animals in each group. At the end of the experiment, tissue and blood samples were taken, and histochemical, immunohistochemical, and biochemical parameters were examined. In this study, where parameters were compared for the first time, total thiol (TT) and native thiol (NT) are the highest in the RES group, disulfide (DS), and ischemia-modified albumin (IMA) are the highest in the MTX group. Total oxidant status (TOS) and oxidative stress index (OSI) are the highest in the MTX group, and total antioxidant status (TAS) is the highest in the RES group. Separation and deterioration in the tunica albuginea, congestion and edema in the interstitial region, vacuolization in the seminiferous epithelium, and spermatogenic serial cells spilling into the lumen without completing their maturation were observed. When examined in terms of histochemical, immunohistochemical, and biochemical examinations, our study revealed that resveratrol has positive effects on methotrexate-induced acute testicular damage, oxidative stress, and apoptosis., (© 2023. The Author(s), under exclusive licence to Society for Reproductive Investigation.)

This study aimed to examine the biological effects of blood plasma exchange in liver tissues of aged and young rats using machine learning methods and spectrochemical and histopathological approaches. Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM) were the machine learning algorithms employed. Young plasma was given to old male rats (24 months), while old plasma was given to young male rats (5 weeks) for thirty days. LDA (95.83-100%) and SVM (87.5-91.67%) detected significant qualitative changes in liver biomolecules. In old rats, young plasma infusion increased the length of fatty acids, triglyceride, lipid carbonyl, and glycogen levels. Nucleic acid concentration, phosphorylation, and carbonylation rates of proteins were also increased, whereas a decrease in protein concentration was measured. Aged plasma decreased protein carbonylation, triglyceride, and lipid carbonyl levels. Young plasma infusion improved hepatic fibrosis and cellular degeneration and reduced hepatic microvesicular steatosis in aged rats. Otherwise, old plasma infusion in young rats caused disrupted cellular organization, steatosis, and increased fibrosis. Young plasma administration increased liver glycogen accumulation and serum albumin levels. Aged plasma infusion raised serum ALT levels while diminished ALP concentrations in young rats, suggesting possible liver dysfunction. Young plasma increased serum albumin levels in old rats. The study concluded that young plasma infusion might be associated with declined liver damage and fibrosis in aged rats, while aged plasma infusion negatively impacted liver health in young rats. These results imply that young blood plasma holds potential as a rejuvenation therapy for liver health and function., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Serum albumin (SA), one of the most abundant proteins in blood plasma, plays essential roles in all living processes and has been used in various biomedical applications. Biomaterials fabricated from SAs (human SA, bovine SA, and ovalbumin) exhibit proper microstructure and hydrophilicity as well as remarkable biocompatibility; this makes them ideal for use in bone regeneration. This review provides a comprehensive overview of the structure, physicochemical properties, and biological features of SAs. SAs can be used to generate a wide array of biomaterials for bone repair because of their flexible structure and diverse functions, which enables us to control structure and morphology as well as modulate the biological responses with host tissue. This review summarizes the material categories, forms, and fabrication methods of SA in bone repair. Finally, concerns for future studies in biomedical fields with SA-derived biomaterials are discussed.

Blood-brain barrier dysfunction (BBBD) and accumulation of senescent astrocytes occur during brain aging and contribute to neuroinflammation and disease. Here, we explored the relationship between these two age-related events, hypothesizing that chronic hippocampal exposure to the blood-borne protein serum albumin could induce stress-induced premature senescence (SIPS) in astrocytes via transforming growth factor beta 1 (TGFβ) signaling. We found that 1 week of albumin exposure significantly increased TGFβ signaling and senescence marker expression in cultured rat hippocampal astrocytes. These changes were preventable by pharmacological inhibition of the type I TGFβ receptor (TGFβR) ALK5. To study these effects in vivo, we utilized an animal model of BBBD in which albumin was continuously infused into the lateral ventricles of adult mice. Consistent with our in vitro results, 1 week of albumin infusion significantly increased TGFβ signaling activation and the burden of senescent astrocytes in hippocampal tissue. Pharmacological inhibition of ALK5 TGFβR or conditional genetic knockdown of astrocytic TGFβR prior to albumin infusion was sufficient to prevent albumin-induced astrocyte senescence. Together, these results establish a link between TGFβ signaling activation and astrocyte senescence and suggest that prolonged exposure to serum albumin due to BBBD can trigger these phenotypic changes., (© 2022 The Authors. Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.)

The use of cisplatin is severely limited by the risk of developing cardiovascular complications. Sinapic acid may reduce cisplatin's side effects. The anti oxidant, anti-inflammatory, and peroxynitrite-scavenging properties of sinapic acid could provide protection against the cardiotoxicity caused by cisplatin. To induce toxicity in rats, cisplatin was administered for a period of 5 weeks. Animal electrocardiograms were obtained after cisplatin toxicity had taken effect. Blood samples and heart tissues were then harvested from the anesthetized animals. The ELISA technique was used to evaluate the level of proinflammatory cytokines and oxidative and nitrosative stress indicators in the heart tissue and serum. A real-time PCR was used to analyze GPX4 and NF-κB expression in the heart tissue. Hematoxylin-eosin and Masson's trichrome were also utilized. Electrocardiograms data showed an increase in QRS and QT intervals. Biochemically, cisplatin increased oxidative, nitrosative, and proinflammatory cytokine levels. Animals exposed to cisplatin had histopathological findings in the heart tissue, according to the results of histological assessment. Sinapic acid reduced TNF-alpha, interleukin-6, malondialdehyde, and ischemia-modified albumin. Sinapic acid also reduced oxidative and nitrosative stress. Furthermore, Sinapic acid restored lengthy QT and QRS. Cisplatin-treated rats had higher NF-κB activation than controls. This effect was successfully inhibited by sinapic acid. Histopathologically, tissues treated with sinapic acid were less damaged than tissues treated with cisplatin. In conclusion, our results suggest that sinapic acid exhibited a protective effect against the cardiotoxicity induced by cisplatin. These effects may be caused by the overexpression of GPX4 and the downregulation of NF-KB, as well as antioxidant and anti-inflammatory properties., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Diabetes mellitus is associated with the development of carbonyl-oxidative stress (COS) and an increased risk of a cerebral hemorrhage. Vitamin D3 is considered an additional drug to have an impact on COS and proteolysis in the extracellular matrix., Objective: The study aimed to evaluate the impact of D3 on the COS-markers and matrix metalloproteinases MMP2/MMP9 activity after acute intracerebral hemorrhage (ICH) in rats with experimental type 2 diabetes mellitus (Т2DM) compared to metformin (Met)., Methods: T2DM was induced in rats via the intraperitoneal injection of streptozotocin (STZ) and nicotinamide (NA), ICH - by microinjection of bacterial collagenase into the striatum. Rats were randomized into five groups: 1 - intact animals (n = 8), 2 - T2DM (n = 9); 3 - T2DM+ICH (n = 7); 4 - T2DM+ICH+Met (n = 7); 5 - T2DM+ICH+D3 (n = 7). Blood glucose, glycated hemoglobin, and oral glucose tolerance test (OGTT) were assessed using commercial kits. Advanced oxidation protein products (AOPP), protein carbonyls (PC370/430), and ischemia-modified albumin (IMA) were measured by spectrophotometry, advanced glycation end products (AGEs) by quantitative fluorescence, and matrix metalloproteinases MMP2/9 by gelatin zymography., Results: D3 does not significantly affect the glucose level and OGTT in rats with T2DM+ICH. However, it reduces AOPP, PC, and AGEs, thus reducing the COS index. In contrast, the activity of proMMP9 increases after D3 administration. These effects of D3 have been reported to be stronger and sometimes opposite to those of metformin., Conclusion: D3 supplementation may decrease the negative consequences of a cerebral hemorrhage in T2DM by reducing COS and preventing the accumulation of COS-modified proteins in the brain by regulating the expression and activity of MMP9., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Among one of the common hereditary causes of chronic kidney disease is autosomal-dominant polycystic kidney disease (ADPKD), and its incidence rate is reported as one between 500 and 1.000 individuals. The most common complications of ADPKD are hypertension (HT) and end-stage renal disease (ESRD). HT occurring in the early stage of ADPKD leads to deteriorations in renal function., Aims: It was aimed to investigate the ischemia-modified albumin (IMA) levels and the effect of renin-angiotensin-aldosterone system (RAAS) blockers on serum IMA levels in patients with ADPKD., Methods: One hundred and fifteen patients were included as ADPKD (n = 50), HT (n = 35), and healthy control (HC) groups (n = 30). Patients with ADPKD and HT were divided into two subgroups as RAAS blocker-users and non-users., Results: Serum IMA levels were detected as 0.42 (0.17-0.80) in ADPKD and 0.28 (0.04-0.51) in HT and 0.36 (0.22-0.56) in HC groups as absorbance units (ABSU), and the highest serum IMA level was seen in Group ADPKD. Serum IMA levels were 0.33 ± 0.14 in RAAS blocker-users and 0.41 ± 0.11 ABSU in non-users with ADPKD. Serum IMA levels were witnessed to be significantly lower in RAAS blocker-users in Groups ADPKD (p = 0.038) and HT (p = 0.004), compared to non-users. Given basal and 6-month values of those with ADPKD, the levels of serum IMA within 6 months were significantly lower (p = 0.002)., Conclusions: We consider that serum IM levels should be assessed in oxidative stress (OS)-related conditions, such as ADPKD, and RAAS blockers may be effective in reducing serum IMA levels in ADPKD and HT patients., (© 2022. The Author(s), under exclusive licence to Royal Academy of Medicine in Ireland.)

Tetrandrine (Tet), a compound found in a traditional Chinese medicine, presents the protective effect for kidney function. Our study is aimed at clarifying the efficacy and underlying mechanism of Tet on podocyte injury. In this study, podocyte injury was induced in rats with adriamycin (ADR), and MPC5 podocytes were constructed with TRPC6 overexpression. We found that Tet treatment reduced the levels of proteinuria, serum creatinine, and blood urea nitrogen and increased plasma albumin levels in ADR-induced rats. Tet reduced intracellular Ca 2+ influx and apoptosis in MPC5 podocytes overexpressing TRPC6. Tet downregulated the expression of renal TRPC6, RhoA, and ROCK1 and upregulated the expression of synaptopodin; meanwhile, it reduced calcineurin activity in vivo and in vitro . In conclusion, Tet protects against podocyte by affecting TRPC6 and its downstream RhoA/ROCK1 signaling pathway., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2022 Lichan Mao et al.)

Objectives: This study investigated the effect of dexmedetomidine on the oxidant-antioxidant (thiol/disulphide) balance., Methods: A total of 24 rats were divided into four groups. The renal arteries in groups IR (ischaemia/reperfusion) and IR + D (ischaemia/reperfusion + dexmedetomidine) were clamped for 45 min and reperfused for 180 min. Groups D (Dexmedetomidine) and IR + D were administered 100 μg/kg dexmedetomidine. Oxidant-antioxidant (thiol/disulphide) levels were measured. Kidney tissue was examined histopathologically., Results: No statistically difference was found between the groups in terms of thiol-disulphide averages, while IMA, TOS and thiol-disulphide results showed a minimal decrease in Group IR + D compared to Group IR ( p  > 0.05). Tubular lesions and necrosis were found in 26-50% of tubules in Group IR. Tubular damage and necrosis in Group IR + D declined to 5-25% ., Conclusions: No statistically difference was found in the study where OSI index, thiol/disulphide balance and IMA were measured together as biochemical values.

Background: The proteinuria remission in hepatitis B virus-associated glomerulonephritis (HBV-GN) patients with massive proteinuria treated with antiviral therapy was low. Tacrolimus (TAC) is effective in primary nephropathy and can inhibit HBV infection by inhibiting HBV binding to sodium taurocholate cotransporting polypeptide on liver cells. This study evaluated the efficacy and safety of TAC combined with ETV compared with entecavir (ETV) monotherapy in HBV-GN., Methods: Patients diagnosed with HBV-GN were recruited for this prospective, randomized, controlled, multicenter, single-blinded study in China. Patients were given TAC and ETV therapy (the TAC+ETV group) or placebo and ETV therapy (the ETV group) for 26 weeks. The efficacy endpoints included proteinuria remission, including complete and partial remission (CR and PR), the change of 24-hour proteinuria (24 h UP) and HBV DNA titer. The safety endpoints were the incidence of HBV virologic breakthrough and adverse events., Results: There were 14 patients in the TAC+ETV group and 17 patients in the ETV group. In the intention-to-treat analyses, 64.3% (9/14) of patients in the TAC+ETV group and 58.8% (10/17) in the ETV group achieved PR or CR at 26 weeks (P=0.38). At week 14, 42.9% (6/14) and 41.2% (7/17) of patients in the TAC+ETV group and the ETV group, respectively, achieved PR or CR (P=0.23). At week 26, the 24 h UP had decreased by 2.63±6.33 g from baseline in the TAC+ETV group and 1.42±4.34 g in the ETV group (P=0.55). The serum albumin increased by 11.1±7.30 g/L from baseline in the TAC+ETV group and 3.81±5.09 g/L in the ETV group (P<0.001). Log10 HBV DNA decreased by 1.49±2.04 from baseline in the TAC+ETV group and 2.47±2.08 in the ETV group (P=0.37); 28.6% (4/14) patients had HBV DNA virologic breakthrough in the ETV group, while none in the TAC+ETV group (P=0.29)., Conclusions: In adult HBV-GN patients, TAC and ETV combination therapy may significantly improve serum albumin levels without increasing the risk of HBV reactivation compared with entecavir monotherapy., Trial Registration: ClinicalTrials.gov Identifier NCT03062813.

Background: A low level of serum magnesium ion (Mg 2+ ) is associated with type 2 diabetes mellitus (T2D). However, the molecular mechanism of Mg 2+ deficiency has not been fully clarified. The current study sought to assesses the effect of reactive oxygen species on the expression of Mg 2+ channels and miRNA., Methods: The expression of Mg 2+ channels and miRNA were examined by real-time polymerase chain reaction. Intracellular Mg 2+ concentration was measured by Magnesium Green fluorescence measurement., Results: The mRNA level of transient receptor potential melastatin 6 (TRPM6), which functions as Mg 2+ influx channel in the distal convoluted tubule (DCT) of the kidney, was decreased by glycated albumin (GA), but not by insulin in rat renal tubule-derived NRK-52E cells. The mRNA levels of TRPM7, a homologue of TRPM6, and CNNM2, a Mg 2+ efflux transporter located at the basolateral membrane of DCT, were changed by neither GA nor insulin. The generation of reactive oxygen species (ROS) was increased by GA. Hydrogen peroxide (H 2 O 2 ) dose-dependently decreased TRPM6 mRNA, but it inversely increased the reporter activity of TRPM6. H 2 O 2 accelerated the degradation of TRPM6 mRNA in actinomycin D assay without affecting TRPM7 and CNNM2 mRNA expressions. Nine miRNAs were considered as candidates for the regulator of stability of TRPM6 mRNA. Among them, miR-24-3p expression was increased by H 2 O 2 . The H 2 O 2 -induced reduction of TRPM6 mRNA was rescued by miR-24-3p siRNA. Magnesium Green fluorescence measurement showed that Mg 2+ influx is suppressed by H 2 O 2 , which was rescued by an antioxidant and miR-24-3p siRNA., Conclusions: We suggest that GA decreases TRPM6 expression mediated by the elevation of ROS and miR-24-3p in renal tubular epithelial cells of T2D.

Objective: The influx of immune cells and serum proteins from the periphery into the brain due to a dysfunctional blood-brain barrier (BBB) has been proposed to contribute to the pathogenesis of seizures in various forms of epilepsy and encephalitis. We evaluated the pathophysiological impact of activated peripheral blood mononuclear cells (PBMCs) and serum albumin on neuronal excitability in an in vitro brain preparation., Methods: A condition of mild endothelial activation induced by arterial perfusion of lipopolysaccharide (LPS) was induced in the whole brain preparation of guinea pigs maintained in vitro by arterial perfusion. We analyzed the effects of co-perfusion of human recombinant serum albumin with human PBMCs activated with concanavalin A on neuronal excitability, BBB permeability (measured by FITC-albumin extravasation), and microglial activation., Results: Bioplex analysis in supernatants of concanavalin A-stimulated PBMCs revealed increased levels of several inflammatory mediators, in particular interleukin (IL)-1β, tumor necrosis factor (TNF)-α, interferon (INF)-γ, IL-6, IL-10, IL-17A, and MIP3α. LPS and human albumin arterially co-perfused with either concanavalin A-activated PBMCs or the cytokine-enriched supernatant of activated PBMCs (1) modulated calcium-calmodulin-dependent protein kinase II at excitatory synapses, (2) enhanced BBB permeability, (3) induced microglial activation, and (4) promoted seizure-like events. Separate perfusions of either nonactivated PBMCs or concanavalin A-activated PBMCs without LPS/human albumin (hALB) failed to induce inflammatory and excitability changes., Significance: Activated peripheral immune cells, such as PBMCs, and the extravasation of serum proteins in a condition of BBB impairment contribute to seizure generation., (© 2021 International League Against Epilepsy.)

Objective: Rheumatoid arthritis (RA) is a major autoimmune disease that causes synovitis and joint damage. Although clinical trials have been performed using interleukin-10 (IL-10), an antiinflammatory cytokine, as a potential treatment of RA, the therapeutic effects of IL-10 have been limited, potentially due to insufficient residence in lymphoid organs, where antigen recognition primarily occurs. This study was undertaken to engineer an IL-10-serum albumin (SA) fusion protein and evaluate its effects in 2 murine models of RA., Methods: SA-fused IL-10 (SA-IL-10) was recombinantly expressed. Mice with collagen antibody-induced arthritis (n = 4-7 per group) or collagen-induced arthritis (n = 9-15 per group) were injected intravenously with wild-type IL-10 or SA-IL-10, and the retention of SA-IL-10 in the lymph nodes (LNs), immune cell composition in the paws, and therapeutic effect of SA-IL-10 on mice with arthritis were assessed., Results: SA fusion to IL-10 led to enhanced accumulation in the mouse LNs compared with unmodified IL-10. Intravenous SA-IL-10 treatment restored immune cell composition in the paws to a normal status, elevated the frequency of suppressive alternatively activated macrophages, reduced IL-17A levels in the paw-draining LN, and protected joint morphology. Intravenous SA-IL-10 treatment showed similar efficacy as treatment with an anti-tumor necrosis factor antibody. SA-IL-10 was equally effective when administered intravenously, locally, or subcutaneously, which is a benefit for clinical translation of this molecule., Conclusion: SA fusion to IL-10 is a simple but effective engineering strategy for RA therapy and has potential for clinical translation., (© 2020, American College of Rheumatology.)

In a recent report by the Centers for Disease Control and Prevention (CDC), multidrug resistant (MDR) Acinetobacter baumannii is a pathogen described as an "urgent threat." Infection with this bacterium manifests as different diseases such as community and nosocomial pneumonia, bloodstream infections, endocarditis, infections of the urinary tract, wound infections, burn infections, skin and soft tissue infections, and meningitis. In particular, nosocomial meningitis, an unwelcome complication of neurosurgery caused by extensively-drug resistant (XDR) A. baumannii, is extremely challenging to manage. Therefore, understanding how A. baumannii adapts to different host environments, such as cerebrospinal fluid (CSF) that may trigger changes in expression of virulence factors that are associated with the successful establishment and progress of this infection is necessary. The present in-vitro work describes, the genetic changes that occur during A. baumannii infiltration into CSF and displays A. baumannii's expansive versatility to persist in a nutrient limited environment while enhancing several virulence factors to survive and persist. While a hypervirulent A. baumannii strain did not show changes in its transcriptome when incubated in the presence of CSF, a low-virulence isolate showed significant differences in gene expression and phenotypic traits. Exposure to 4% CSF caused increased expression of virulence factors such as fimbriae, pilins, and iron chelators, and other virulence determinants that was confirmed in various model systems. Furthermore, although CSF's presence did not enhance bacterial growth, an increase of expression of genes encoding transcription, translation, and the ATP synthesis machinery was observed. This work also explores A. baumannii's response to an essential component, human serum albumin (HSA), within CSF to trigger the differential expression of genes associated with its pathoadaptibility in this environment.

Purpose: To explore the feasibility of constructing tissue-engineered vascularised oral mucosa-like structures with rabbit ACVM-0.25% HLC-I scaffold and human gingival fibroblasts (HGFs), human gingival epithelial cells (HGECs) and vascular endothelial-like cells (VEC-like cells)., Method: Haematoxylin and Eosin (H&E) staining, immunohistochemical, immunofluorescence, 5-ethynyl-2'-deoxyuridine (EdU) staining and scanning electron microscope (SEM) were performed to detect the growth status of cells on the scaffold complex. After the scaffold complex implanted into nude mice for 28 days, tissues were harvested to observe the cell viability and morphology by the same method as above. Additionally, biomechanical experiments were used to assess the stability of composite scaffold., Results: Immunofluorescence and Immunohistochemistry showed positive expression of Vimentin, S100A 4 and CK, and the induced VEC-like cells had the ability to form tubule-like structures. In vitro observation results showed that HGFs, HGECs and VEC-like had good compatibility with ACVM-0.25% HLC-I and could be layered and grow in the scaffold. After implanted, the mice had no immune rejection and no obvious scar repair on the body surface. The biomfechanical test results showed that the composite scaffold has strong stability., Conclusion: The tissue-engineered vascularised complexes constructed by HGFs, HGECs, VEC-like cells and ACVM-0.25% HLC-I has good biocompatibility and considerable strength.

Twitching motility-mediated biofilm expansion occurs via coordinated, multi-cellular collective behaviour to allow bacteria to actively expand across surfaces. Type-IV pili (T4P) are cell-associated virulence factors which mediate twitching motility via rounds of extension, surface attachment and retraction. The Chp chemosensory system is thought to respond to environmental signals to regulate the biogenesis, assembly and twitching motility function of T4P. In other well characterised chemosensory systems, methyl-accepting chemotaxis proteins (MCPs) feed environmental signals through a CheW adapter protein to the histidine kinase CheA to modulate motility. The Pseudomonas aeruginosa Chp system has an MCP PilJ and two CheW adapter proteins, PilI and ChpC, that likely interact with the histidine kinase ChpA to feed environmental signals into the system. In the current study we show that ChpC is involved in the response to host-derived signals serum albumin, mucin and oligopeptides. We demonstrate that these signals stimulate an increase in twitching motility, as well as in levels of 3'-5'-cyclic adenosine monophosphate (cAMP) and surface-assembled T4P. Interestingly, our data shows that changes in cAMP and surface piliation levels are independent of ChpC but that the twitching motility response to these environmental signals requires ChpC. Furthermore, we show that protease activity is required for the twitching motility response of P. aeruginosa to environmental signals. Based upon our data we propose a model whereby ChpC feeds these environmental signals into the Chp system, potentially via PilJ or another MCP, to control twitching motility. PilJ and PilI then modulate T4P surface levels to allow the cell to continue to undergo twitching motility. Our study is the first to link environmental signals to the Chp chemosensory system and refines our understanding of how this system controls twitching motility-mediated biofilm expansion in P. aeruginosa .

The apelin receptor is a potential target in the treatment of heart failure and pulmonary arterial hypertension where levels of endogenous apelin peptides are reduced but significant receptor levels remain. Our aim was to characterise the pharmacology of a modified peptide agonist, MM202, designed to have high affinity for the apelin receptor and resistance to peptidase degradation and linked to an anti-serum albumin domain antibody (AlbudAb) to extend half-life in the blood. In competition, binding experiments in human heart MM202-AlbudAb (pK i  = 9.39 ± 0.09) bound with similar high affinity as the endogenous peptides [Pyr 1 ]apelin-13 (pK i  = 8.83 ± 0.06) and apelin-17 (pK i  = 9.57 ± 0.08). [Pyr 1 ]apelin-13 was tenfold more potent in the cAMP (pD 2  = 9.52 ± 0.05) compared to the β-arrestin (pD 2  = 8.53 ± 0.03) assay, whereas apelin-17 (pD 2  = 10.31 ± 0.28; pD 2  = 10.15 ± 0.13, respectively) and MM202-AlbudAb (pD 2  = 9.15 ± 0.12; pD 2  = 9.26 ± 0.03, respectively) were equipotent in both assays, with MM202-AlbudAb tenfold less potent than apelin-17. MM202-AlbudAb bound to immobilised human serum albumin with high affinity (pK D  = 9.02). In anaesthetised, male Sprague Dawley rats, MM202-AlbudAb (5 nmol, n = 15) significantly reduced left ventricular systolic pressure by 6.61 ± 1.46 mm Hg and systolic arterial pressure by 14.12 ± 3.35 mm Hg and significantly increased cardiac contractility by 533 ± 170 mm Hg/s, cardiac output by 1277 ± 190 RVU/min, stroke volume by 3.09 ± 0.47 RVU and heart rate by 4.64 ± 2.24 bpm. This study demonstrates that conjugating an apelin mimetic peptide to the AlbudAb structure retains receptor and in vivo activity and may be a new strategy for development of apelin peptides as therapeutic agents., (© 2019 The Authors. Basic & Clinical Pharmacology & Toxicology published by John Wiley & Sons Ltd on behalf of Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

The cytokine platelet factor 4 (PF4) enhances differentiation and cell viability of different stem cells lines in vitro. This study investigated whether PF4 addition to customary pig embryo semi-defined culture media can improve their developmental outcome (Experiment 1) and ultimately replace the need for bovine serum albumin (BSA, Experiment 2). Experiment 1 added PF4 (100-1000 ng/mL, 0 = control) to NCSU-23 with 0.4 mg/mL BSA culturing 3430 presumptive zygotes. Experiment 2 added PF4 (100-1000 ng/mL, 0 = Control-PVA) to a BSA-free medium (NCSU-23 with 0.3 mg/mL PVA) culturing 3820 presumptive zygotes. Zygote culture in NCSU-23 with 0.4 mg/mL BSA was used as overall control. All groups of Experiment 1 displayed similar rates of day 2-cleavage (range: 65.0 ± 10.9 to 70.0 ± 5.8%); of day 7-blastocyst rates (range: 46.6 ± 10.0 to 56.4 ± 8.2%) and of total day 7-blastocyst efficiency (range: 32.3 ± 8.3 to 37.2 ± 7.3%). Addition of PF4 did not affect total cell numbers of day 7 blastocysts (range: 44.1 ± 23.2 to 50.5 ± 26.4). In Experiment 2, PF4 accelerated embryo development, increasing (P < 0.01) blastocyst yield compared to 0-PF4, and blastocyst formation by day 5 adding PF4 100-500 ng/mL (range: 29.9 ± 7.8 to 31.8 ± 5.5%; P < 0.05) compared with BSA-control (17.2 ± 8.2%) and PF4 1000 ng/mL (15.5 ± 7.9%); showing similar blastocyst rates (range: 42.0 ± 11.5 to 49.3 ± 10.0%), total efficiency (28.0 ± 8.2 to 32.3 ± 7.1%) total cell numbers (range: 42.6 ± 19.3 to 45.7 ± 23.9) as BSA-controls. In conclusion, although PF4 did not show additive improvement under usual semi-defined, BSA-supplemented embryo media, it successfully replaced BSA sustaining porcine blastocyst production in chemically defined conditions., Competing Interests: Declaration of competing interest None of the authors have any conflicts of interest to declare., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In response to extreme environmental conditions, Bactrian camels with largest population in China have evolved with the unique and extraordinary stress-tolerant mechanism in the bodies, in which the most abundantly secreted serum albumins contribute to an important role in diverse physiological activities such as maintaining osmotic pressure and transporting endogenous/exogenous molecules. In this study, we have for the first time purified Chinese Bactrian camel serum albumins (CSA) aimed at exploring their biomedical application. The mass spectrometric as well as structural analysis of CSA have revealed the sequence consensus and alpha-helix abundant structures among its heterologous proteins. Using desolvation methods, CSA-based nanoparticles have been prepared to encapsulate two substrate molecules including Doxorubicin (Dox) and hemin, which confers the versatility of nanocomposite. As drug delivery matrix, the Dox-loaded CSA nanoparticles displayed sustained release behaviors of DOX with the decreased cytotoxicity detected by both CCK-8 assay and real-time cell analysis. The CSA-hemin nanoparticles exhibited superior catalytic activities in the oxidation of Orange II comparable with horse radish peroxidase following a ping-pong mechanism. Furthermore, the constructed CSA-hemin nanoparticles were applied for the spectroscopic detection of H 2 O 2 resulting in a wide linear calibration curve ranging from 5 to 400 μM with a detection limit of 3.32 μM., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The purpose of the present study was to investigate the effect of advanced glycated albumin (AGE-alb) on pyroptosis of macrophages and the underlying molecular mechanisms. RAW264.7 macrophages were treated with AGE-alb (1, 2, 4 and 6 g/L) and control albumin (C-alb, 4 g/L) for 24 h, or preincubated with MCC950 (1 μmol/L) for 1 h and then treated with AGE-alb (4 g/L) for 24 h. Cell viability and caspase-1 activity were measured by MTT and assay kits, respectively. Lactate dehydrogenase (LDH) activity and the levels of interleukin-1β (IL-1β) and IL-18 in media were detected. Cell death degree was evaluated by TUNEL and Hoechst 33342/PI staining. The protein levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), procaspase-1 and cleaved caspase-1 were assessed by Western blot. The results showed that AGE-alb treatment caused obvious decrease in cell viability and increases in LDH leakage and the percentages of TUNEL- or PI-positive cells in a concentration-dependent manner. Additionally, AGE-alb promoted IL-1β and IL-18 secretion, upregulated NLRP3 expression, and increased caspase-1 activity especially at the dose of 4 and 6 g/L. However, MCC950 (an NLRP3 inhibitor) pretreatment inhibited significantly the decrease in cell viability and the increases in LDH leakage and percentages of TUNEL- or PI-positive cells induced by AGE-alb. Furthermore, MCC950 attenuated obviously AGE-alb-induced IL-1β and IL-18 secretion and caspase-1 activation. These results indicate that AGE-alb may induce macrophage pyroptosis, and the mechanism is at least partially by activating NLRP3-caspase-1 pathway.

Human serum albumin (HSA) is the most abundant circulating protein in the body and presents an extensive range of biological functions. As such, it is prone to undergo post-translational modifications (PTMs). The non-enzymatic early glycation of HSA, one of the several PTMs undergone by HSA, arises from the addition of reducing sugars to amine group residues, thus modifying the structure of HSA. These changes may affect HSA functions impairing its biological activity, finally leading to cell damage. The aim of this study was to quantitate glycated-HSA (GA) levels in the plasma of heart failure (HF) patients and to evaluate the biological effects of GA on HL-1 cardiomyocytes. Plasma GA content from HF patients and healthy subjects was measured by direct infusion electrospray ionization mass spectrometry (ESI-MS). Results pointed out a significant increase of GA in HF patients with respect to the control group (p < 0.05). Additionally, after stimulation with GA, proteomic analysis of HL-1 secreted proteins showed the modulation of several proteins involved, among other processes, in the response to stress. Further, stimulated cells showed a rapid increase in ROS generation, higher mRNA levels of the inflammatory cytokine interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), and higher levels of the oxidative 4-HNE-protein adducts and carbonylated proteins. Our findings show that plasma GA is increased in HF patients. Further, GA exerts pro-inflammatory and pro-oxidant effects on cardiomyocytes, which suggest a causal role in the etiopathogenesis of HF., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To assess the difference between endothelial cells from tissues preserved in media supplemented with fetal bovine serum (FBS) and recombinant human serum albumin (rHSA)., Methods: In a donor-matched study, 48 tissues were preserved for 28 days at 31°C in Cornea Max and Cornea Syn supplemented with FBS and rHSA, respectively. Endothelial cells were visualized by 2 masked observers before and after preservation. Endothelial cell density (ECD) and the number of iatrogenic folds were counted manually. Alizarin red staining and tight junction protein (Zonula Occludens-1) were used to assess cell morphology (hexagonality and polymorphism). Intraobserver and interobserver cell counts were recorded and analyzed. Wilcoxon and one-way analysis of variance tests were used, where P < 0.05 was deemed statistically significantly different., Results: Significant amount of iatrogenic folds were observed in the tissues supplemented with FBS compared with rHSA postpreservation (P = 0.0007). Approximately 69% and 71% hexagonal cells (P = 0.0303) and 29% and 26% polymorphic cells (P = 0.0234) were observed in the FBS and rHSA groups, respectively. Postpreservation, operator 1 counted 1766 cells/mm in FBS and 1864 cells/mm in rHSA. Operator 2 counted 1702 cells/mm in FBS and 1858 cells/mm in rHSA. ECD counts from FBS (interoperator) were statistically significant (P = 0.0429). However, significance was not observed in the ECD counts (interoperator) from the rHSA-preserved tissues (P = 0.8738)., Conclusions: rHSA-supplemented media allow better visualization of the corneal endothelial cells. This reduces the rate of discard observed due to counting errors. Use of rHSA improves the current standard of care and reduces the use of animal-derived products.

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is commonly used to model Parkinson's disease (PD) as it specifically damages the nigrostriatal dopaminergic pathway. Recent studies in mice have, however, provided evidence that MPTP also compromises the integrity of the brain's vasculature. Photobiomodulation (PBM), the irradiation of tissue with low-intensity red light, mitigates MPTP-induced loss of dopaminergic neurons in the midbrain, but whether PBM also mitigates MPTP-induced damage to the cerebrovasculature has not been investigated. This study aimed to characterize the time course of cerebrovascular disruption following MPTP exposure and to determine whether PBM can mitigate this disruption. Young adult male C57BL/6 mice were injected with 80 mg/kg MPTP or isotonic saline and perfused with fluorescein isothiocyanate FITC-labelled albumin at various time points post-injection. By 7 days post-injection, there was substantial and significant leakage of FITC-labelled albumin into both the substantia nigra pars compacta (SNc; p < 0.0001) and the caudate-putamen complex (CPu; p ≤ 0.0003); this leakage partly subsided by 14 days post-injection. Mice that were injected with MPTP and treated with daily transcranial PBM (670 nm, 50 mW/cm 2 , 3 min/day), commencing 24 hours after MPTP injection, showed significantly less leakage of FITC-labelled albumin in both the SNc ( p < 0.0001) and CPu ( p = 0.0003) than sham-treated MPTP mice, with levels of leakage that were not significantly different from saline-injected controls. In summary, this study confirms that MPTP damages the brain's vasculature, delineates the time course of leakage induced by MPTP out to 14 days post-injection, and provides the first direct evidence that PBM can mitigate this leakage. These findings provide new understanding of the use of the MPTP mouse model as an experimental tool and highlight the potential of PBM as a therapeutic tool for reducing vascular dysfunction in neurological conditions., Competing Interests: The authors declare no conflict of interest.

This study sought to clarify the role and underlying mechanisms of human serum albumin (HSA) therapy in global cerebral ischemia/reperfusion (GCI/R)-induced brain damage in rats. Five groups of adult male Wistar rats (n = 12 per group) were created as follows: sham operation (Sham), global cerebral ischemia/reperfusion (GCI/R), HSA treatment (GCI/R + HSA), Dickkopf-1 (DDK1) treatment (GCI/R + DDK1), and DDK1 plus HSA treatment (GCI/R + DKK1 + HSA). The GCI/R injury model was created using the modified Pusinelli four-vessel occlusion method. After 24 h, rats were evaluated using neurological scoring, Nissl staining, and brain tissue water content. The mRNA expression of Wnt, GSK3β, and β-Catenin in the brain were detected by quantitative real time polymerase chain reaction. The protein expression of β-Catenin and GSK-3β were investigated by western blot and immunohistochemical analysis in the presence and absence of the Wnt/β-Catenin antagonist, DKK-1. Complex I activity and ROS content were also measured. After 24 h of reperfusion, the behavior score and brain tissue water content in the GCI/R + HSA group were lower than that in the GCI/R group. In addition, the degree of neuronal injury was significantly reduced in the GCI/R + HSA group (P < 0.05). The ROS content was significantly decreased and Complex I activity was markedly raised in the GCI/R + HSA group compared to the GCI/R group (P < 0.05). Further, GSK-3β expression in the GCI/R + HSA group was lower than that in the GCI/R group, while the Wnt and β-catenin expression were increased. These effects were reversed by DKK1. Taken together, we showed that HSA attenuates GCI/R-induced brain damage and may be neuroprotective via regulation of the Wnt/β-catenin/ROS signaling pathway., (Copyright © 2019 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Factor IX (FIX) binds to collagen IV (Col4) in the subendothelial basement membrane. In hemophilia B, this FIX-Col4 interaction reduces the plasma recovery of infused FIX and plays a role in hemostasis. Studies examining the recovery of infused BeneFix (FIX WT ) in null (cross-reactive material negative, CRM - ) hemophilia B mice suggest the concentration of Col4 readily available for binding FIX is ∼405 nM with a 95% confidence interval of 374 to 436 nM. Thus, the vascular cache of FIX bound to Col4 is several-fold the FIX level measured in plasma. In a mouse model of prophylactic therapy (testing hemostasis by saphenous vein bleeding 7 days after infusion of 150 IU/kg FIX), FIX WT and the increased half-life FIXs Alprolix (FIX FC ) and Idelvion (FIX Alb ) produce comparable hemostatic results in CRM - mice. In bleeding CRM - hemophilia B mice, the times to first clot at a saphenous vein injury site after the infusions of the FIX agents are significantly different, at FIX WT < FIX FC < FIX Alb Dysfunctional forms of FIX, however, circulate in the majority of patients with hemophilia B (CRM + ). In the mouse prophylactic therapy model, none of the FIX products improves hemostasis in CRM + mice expressing a dysfunctional FIX, FIX R333Q , that nevertheless competes with infused FIX for Col4 binding and potentially other processes involving FIX. The results in this mouse model of CRM + hemophilia B demonstrate that the endogenous expression of a dysfunctional FIX can deleteriously affect the hemostatic response to prophylactic therapy., (© 2019 by The American Society of Hematology.)

Binding of antigen to IgE-high affinity FcεRI complexes on mast cells and basophils results in the release of preformed mediators such as histamine and de novo synthesis of cytokines causing allergic reactions. Src-like adapter protein (SLAP) functions co-operatively with c-Cbl to negatively regulate signaling downstream of the T cell receptor, B cell receptor, and receptor tyrosine kinases (RTK). Here, we investigated the role of SLAP in FcεRI-mediated mast cell signaling, using bone marrow derived mast cells (BMMCs) from SLAP knock out (SLAP KO) mice. Mature SLAP-KO BMMCs displayed significantly enhanced antigen induced degranulation and synthesis of IL-6, TNFα, and MCP-1 compared to wild type (WT) BMMCs. In addition, SLAP KO mice displayed an enhanced passive cutaneous anaphylaxis response. In agreement with a negative regulatory role, SLAP KO BMMCs showed enhanced FcεRI-mediated signaling to downstream effector kinases, Syk, Erk, and Akt. Recombinant GST-SLAP protein binds to the FcεRIβ chain and to the Cbl-b in mast cell lysates, suggesting a role in FcεRI down regulation. In addition, the ubiquitination of FcεRIγ chain and antigen mediated down regulation of FcεRI is impaired in SLAP KO BMMCs compared to the wild type. In line with these findings, stimulation of peripheral blood human basophils with FcεRIα antibody, or a clinically relevant allergen, resulted in increased SLAP expression. Together, these results indicate that SLAP is a dynamic regulator of IgE-FcεRI signaling, limiting allergic responses.

De novo expression of CD44 in glomerular parietal epithelial cells (PECs) leads to a prosclerotic and migratory PEC phenotype in glomerulosclerosis. However, the regulatory mechanisms underlying CD44 expression by activated PECs remain largely unknown. This study was performed to examine the mediators responsible for CD44 induction in glomerular PECs in association with diabetes. CD44 expression and localization were evaluated in the glomeruli of Zucker diabetic rat kidneys and primary cultured PECs upon albumin stimulation. Real-time polymerase chain reaction confirmed an albuminuria-associated upregulation of the CD44 gene in the glomeruli of diabetic rats. Immunostaining analysis of diabetic kidneys further revealed an increase in CD44 in hypertrophic PECs, which often contain albumin-positive vesicles. Losartan treatment significantly attenuated albuminuria and lowered CD44 protein levels in the diabetic kidneys. In primary cultured rat PECs, rat serum albumin (0.25-1 mg/ml) caused a dose-dependent upregulation of CD44, claudin-1, and megalin protein expression, which was accompanied by an activation of extracellular signal-regulated kinase1/2 (ERK1/2) signaling. Albumin-induced CD44 and claudin-1 expression were greatly suppressed in the presence of the ERK1/2 inhibitor, U0126. In addition, knockdown of megalin by small interfering RNA interference in PECs resulted in a significant reduction of albumin-induced CD44 and claudin-1 proteins. Taken together, our results demonstrate that albumin induces CD44 expression by PECs via the activation of the ERK signaling pathway, which is partially mediated by endocytic receptor megalin., (© 2018 Wiley Periodicals, Inc.)

Hepatocellular carcinoma (HCC) ranks fifth in occurrence and second in mortality of all cancers. The development of effective therapies for HCC is urgently needed. Anticancer drugs targeted to the liver-specific asialoglycoprotein receptors (ASGPRs) are viewed as a promising potential treatment for HCC. ASGPRs facilitate the recognition and endocytosis of molecules, and possibly vehicles with galactose end groups, by the liver. In this study, bovine serum albumin (BSA) was conjugated with lactose using a thermal treatment. The formation of lactosylated BSA (BSA-Lac) was confirmed by a change of the chemical structure, increased molecular mass, and Ricinus communis lectin recognition. Subsequently, the low-crosslinking BSA-Lac nanoparticles (LC BSA-Lac NPs) and high-crosslinking BSA-Lac nanoparticles (HC BSA-Lac NPs) were synthesized. These nanoparticles presented spherical shapes with a size distribution of 560 ± 18.0 nm and 539 ± 9.0 nm, as well as an estimated surface charge of -26 ± 0.15 mV and -24 ± 0.45 mV, respectively. Both BSA-Lac NPs were selectively recognized by ASGPRs as shown by biorecognition, competition, and inhibition assays using an in vitro model of HCC. This justifies pursuing the strategy of using BSA-Lac NPs as potential drug nanovehicles with selective direction toward hepatocellular carcinoma.

Serum albumin-coated bone allografts (BoneAlbumin) have successfully supported bone regeneration in various experimental models by activating endogenous progenitors. However, the effect of tissue aging, linked to declining stem cell function, has yet to be explicitly examined within the context of BoneAlbumin's regenerative capacity. Stem cell function was tested with an in vitro attachment assay, which showed that albumin coating increases stem cell attachment on demineralized bone surfaces in an aging cell population. Bone regeneration was investigated in vivo by creating critical size bone defects on the parietal bones of aging female rats. Demineralized bone matrices with and without serum albumin coating were used to fill the defects. Bone regeneration was determined by measuring the density and the size of the remaining bone defect with computed tomography (CT). Microcomputed tomography (MicroCT) and mechanical testing were performed on the parietal bone explants. In vivo CT and ex vivo microCT measurements showed better regeneration with albumin-coated grafts. Additionally, the albumin-coated group showed a twofold increase in peak fracture force compared with uncoated allografts. In the present study, serum albumin-coated demineralized bone matrices successfully supported faster and functionally superior bone regeneration in aging rats. Because stem cell function, a key contributor of bone remodelling, decreases with age and serum albumin is an effective activator of endogenous progenitor cells, this method could be an effective and safe adjuvant in bone regeneration of aging adult and osteo-compromised populations., (© 2019 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.)

The formation of neutrophil extracellular traps (NETs) is an immune defense mechanism of neutrophilic granulocytes. Moreover, it is also involved in the pathogenesis of autoimmune, inflammatory, and neoplastic diseases. For that reason, the process of NET formation (NETosis) is subject of intense ongoing research. In vitro approaches to quantify NET formation are commonly used and involve neutrophil stimulation with various activators such as phorbol 12-myristate 13-acetate (PMA), lipopolysaccharides (LPS), or calcium ionophores (CaI). However, the experimental conditions of these experiments, particularly the media and media supplements employed by different research groups, vary considerably, rendering comparisons of results difficult. Here, we present the first standardized investigation of the influence of different media supplements on NET formation in vitro . The addition of heat-inactivated (hi) fetal calf serum (FCS), 0.5% human serum albumin (HSA), or 0.5% bovine serum albumin (BSA) efficiently prevented NET formation of human neutrophils following stimulation with LPS and CaI, but not after stimulation with PMA. Thus, serum components such as HSA, BSA and hiFCS (at concentrations typically found in the literature) inhibit NET formation to different degrees, depending on the NETosis inducer used. In contrast, in murine neutrophils, NETosis was inhibited by FCS and BSA, regardless of the inducer employed. This shows that mouse and human neutrophils have different susceptibilities toward the inhibition of NETosis by albumin or serum components. Furthermore, we provide experimental evidence that albumin inhibits NETosis by scavenging activators such as LPS. We also put our results into the context of media supplements most commonly used in NET research. In experiments with human neutrophils, either FCS (0.5-10%), heat-inactivated (hiFCS, 0.1-10%) or human serum albumin (HSA, 0.05-2%) was commonly added to the medium. For murine neutrophils, serum-free medium was used in most cases for stimulation with LPS and CaI, reflecting the different sensitivities of human and murine neutrophils to media supplements. Thus, the choice of media supplements greatly determines the outcome of experiments on NET-formation, which must be taken into account in NETosis research.

Podocyte injury is closely related to proteinuria and the progression of chronic kidney disease (CKD). Currently, there is no conclusive understanding about the mechanisms involved in albumin overload and podocyte apoptosis response. In this study, we sought to explore the ways by which intracellular albumin can mediate podocyte apoptosis. Here, immortalized mouse podocytes were treated with bovine serum albumin (BSA) at different times and concentrations, in the presence or absence of SB203580 (0.1 µM, inhibitor of mitogen-activated-protein kinase - p38MAPK). Using immunofluorescence images, flow cytometry and immunoblotting, we observed a time-dependent intracellular accumulation of fluorescent albumin-FITC-BSA, followed by concentration-and time-dependent effect of intracellular albumin overload on podocyte apoptosis, which was mediated by increased expression of the chaperone glucose-regulated-protein 78 (GRP 78) and phosphorylated inositol-requiring enzyme 1 alpha (pIRE1-α), as well as protein kinase C delta (PKC-δ), p38MAPK and cleaved caspase 12 expression. SB203580 prevented the cleavage of caspase 12 and the albumin-mediated podocyte apoptosis. These results suggest that intracellular albumin overload is associated with endoplasmic reticulum (ER) stress and upregulation of PKC-δ/p38MAPK/caspase 12 pathway, which may be a target for future therapeutic of albumin-induced podocyte apoptosis.

Background: Chemokines play a critical role in orchestrating the distribution and trafficking of neutrophils in homeostasis and disease., Results: The CXCR4/CXCL12 chemokine axis has been identified as a central regulator of these processes., Conclusion: In this review, we focus on the role of CXCR4/CXCL12 chemokine axis in regulating neutrophil release from the bone marrow and the trafficking of senescent neutrophils back to the bone marrow for clearance under homeostasis and disease. We also discuss the role of CXCR4 in fine-tuning neutrophil responses in the context of inflammation., (© 2018 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

Background: Dextran-70 is a more potent plasma volume expander than albumin but use has been hampered because of its antithrombotic properties. However, also albumin has antithrombotic properties and little is known about relative effects of these two colloids on coagulation in vivo when controlling for differences in efficacy as plasma volume expanders., Aim: Compare effects of dextran-70 and albumin on coagulation at a dose resulting in equal plasma volume expansion., Methods: Guinea pigs were subjected to a 25 mL/kg hemorrhage during 20 min and randomized to resuscitation with either 6% dextran-70 at a dose of 15 mL/kg or 5% albumin at a dose of 25 mL/kg (n = 14 in each group) during 30 min starting 1 h of shock. Blood samples were collected at the completion of resuscitation and at 4 h. Plasma volume was measured using I-albumin and the effect on coagulation was evaluated using whole blood thrombelastography (TEG), measurement of plasma fibrinogen and von Willebrand factor (vWF) concentrations and vWF glycoprotein 1b (GP1b) A activity., Results: Plasma volumes after resuscitation were similar in the groups at both time points. Dextran-70 resulted in a transient prolongation of TEG clot amplification time (K) at the completion of resuscitation compared with albumin. TEG clot initiation (R) and strength (MA) did not differ between the treatments at any of the time points. Albumin reduced vWF concentrations to a larger extent than dextran at both time points, whereas no difference in vWF GP1bA activity or in plasma fibrinogen and could be detected., Conclusion: In equipotent doses with regard to plasma volume expansion, dextran-70 transiently prolongs clot amplification time more than albumin whereas dextran-70 reduces plasma vWF concentrations less than albumin.

Aim: To explore the potential of albumin nanoparticles for oral drug delivery., Methods: Sub-150 nm human serum albumin nanoparticles were fabricated via a desolvation technique. Nanoparticle cell uptake and epithelial translocation were tested in Caco-2 monolayers, while comparing with albumin solution., Results: Data suggest epithelial transcytosis of albumin, applied in solution form, via neonatal Fc receptor. Cell uptake of albumin nanoparticles demonstrated behaviors indicating a different cell uptake pathway compared with albumin solution. Importantly, application of equivalent concentrations of albumin solution or nanoparticles resulted in higher epithelial transport capacity of the latter, suggesting improvement of intestinal delivery via nanoformulation., Conclusion: This study highlights for the first time that simply fabricated, nontoxic human serum albumin nanoparticles may find application in oral drug delivery.

Sulphonylurea drugs stimulate insulin secretion from pancreatic β-cells primarily by inhibiting ATP sensitive potassium (KATP) channels in the β-cell membrane. The effective sulphonylurea concentration at its site of action is significantly attenuated by binding to serum albumin, which makes it difficult to compare in vitro and in vivo data. We therefore measured the ability of gliclazide and glibenclamide to inhibit KATP channels and stimulate insulin secretion in the presence of serum albumin. We used this data, together with estimates of free drug concentrations from binding studies, to predict the extent of sulphonylurea inhibition of KATP channels at therapeutic concentrations in vivo. KATP currents from mouse pancreatic β-cells and Xenopus oocytes were measured using the patch-clamp technique. Gliclazide and glibenclamide binding to human plasma were determined in spiked plasma samples using an ultrafiltration-mass spectrometry approach. Bovine serum albumin (60g/l) produced a mild, non-significant reduction of gliclazide block of KATP currents in pancreatic β-cells and Xenopus oocytes. In contrast, glibenclamide inhibition of recombinant KATP channels was dramatically suppressed by albumin (predicted free drug concentration <0.1%). Insulin secretion was also reduced. Free concentrations of gliclazide and glibenclamide in the presence of human plasma measured in binding experiments were 15% and 0.05%, respectively. Our data suggest the free concentration of glibenclamide in plasma is too low to account for the drug's therapeutic effect. In contrast, the free gliclazide concentration in plasma is high enough to close KATP channels and stimulate insulin secretion., Competing Interests: The authors have declared that no competing interests exist.

The inefficiency of recombinant tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-based clinical regimens has been dominantly attributed to the short half-life of TRAIL. Affinity-controlled release using endogenous long-acting proteins, such as IgG and albumin, as carriers is extremely attractive for improving the pharmacokinetics of TRAIL. Up to now, it is unclear whether IgG-binding is efficient for affinity-controlled release of TRAIL. Methods: An IgG-binding affibody, IgBD, was genetically fused to the N-terminus of TRAIL to produce IgBD-TRAIL.The IgG-binding ability, cytotoxicity, serum half-life, and in vivo antitumor effect of IgBD-TRAIL were compared with that of TRAIL. In addition, an albumin-binding affibody, ABD, was fused to TRAIL to produce ABD-TRAIL. The cytototoxicity, serum half-life, and antitumor effect of IgBD-TRAIL and ABD-TRAIL were compared. Results: IgBD fusion endowed TRAIL with high affinity (nM) for IgG without interference with its cytotoxicity. The serum half-life of IgBD-TRAIL is 50-60 times longer than that of TRAIL and the tumor uptake of IgBD-TRAIL at 8-24 h post-injection was 4-7-fold that of TRAIL. In vivo antitumor effect of IgBD-TRAIL was at least 10 times greater than that of TRAIL. Owing to the high affinity (nM) for albumin, the serum half-life of ABD-TRAIL was 80-90 times greater than that of TRAIL. However, after binding to albumin, the cytotoxicity of ABD-TRAIL was reduced more than 10 times. In contrast, binding to IgG had little impact on the cytotoxicity of IgBD-TRAIL. Consequently, intravenously injected IgBD-TRAIL showed antitumor effects superior to those of ABD-TRAIL. Conclusions: Endogenous long-acting proteins, particularly IgG-based affinity-controlled release, prolonged the serum half-life as well as significantly enhanced the antitumor effect of TRAIL. IgBD-mediated endogenous IgG binding might be a novel approach for the affinity-controlled release of other protein drugs., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

The purpose of this study was to investigate whether activating transcription factor 6 (ATF6), a sensor to endoplasmic reticulum stress (ERS), would mediate advanced glycated albumin (AGE-alb)-induced macrophage apoptosis and to elucidate the possible molecular mechanisms. RAW264.7 macrophages were cultured in vitro and treated with AGE-alb (2, 4 and 6 g/L), normal control albumin or tunicamycin (TM, 4 mg/L) for 24 h. ATF6 small interfering RNA (siRNA) was transfected to RAW264.7 cells by Lipofectamine 2000. Cell viability and apoptosis were determined by MTT method and Annexin V-FITC/propidium iodide apoptosis detection kit, respectively. The activities of lactate dehydrogenase (LDH) in medium and caspase-3 in cells were measured by corresponding detection kits. ATF6 nuclear translocation was detected by Western blot and immunofluorescence cytochemistry. Protein and mRNA levels of C/EBP homologous protein (CHOP, a key-signaling component of ERS-induced apoptosis) were detected by Western blot and real-time fluorescence quantitative PCR, respectively. The results showed that similar to TM, AGE-alb increased the expression of CHOP at both the protein and mRNA levels in a concentration dependent manner. ATF6, as a factor that positively regulates CHOP expression, was activated by AGE-alb in a concentration dependent manner. siRNA-mediated knockdown of ATF6 significantly inhibited AGE-alb-induced macrophage injury, as indicated by the increased cell viability and the decreased LDH release, apoptosis and caspase-3 activation. Additionally, ATF6 siRNA attenuated AGE-alb-induced CHOP upregulation at both the protein and mRNA levels. These results suggest that ATF6 and its downstream molecule CHOP are involved in AGE-alb-induced macrophage apoptosis.

Glucose, in the presence of reactive oxygen species (ROS), acts as an as an oxidative agent and drives deleterious processes in Diabetes Mellitus. We have studied the mechanism and the toxicological effects of glucose-dependent glycoxidation reactions driven by copper and ROS, using a model peptide based on the exposed sequence of Human Serum Albumin (HSA) and containing a lysine residue susceptible to copper complexation. The main products of these reactions are Advanced Glycation End-products (AGEs). Carboxymethyl lysine and pyrraline condensed on the model peptide, generating a Modified Peptide (MP). These products were isolated, purified, and tested on cultured motor neuron cells. We observed DNA damage, enhancement of membrane roughness, and formation of domes. We evaluated nuclear abnormalities by the cytokinesis-blocked micronucleus assay and we measured cytostatic and cytotoxic effects, chromosomal breakage, nuclear abnormalities, and cell death. AGEs formed by glycoxidation caused large micronucleus aberrations, apoptosis, and large-scale nuclear abnormalities, even at low concentrations., (Copyright © 2017. Published by Elsevier B.V.)

A diabetic vasculature is detrimental to cardiovascular health through the actions of advanced glycation end products (AGEs) on endothelial cells and platelets. Platelets activated by AGEs agonize endothelial responses promoting cardiovascular disease (CVD) development. While it has been established that AGEs can alter platelet functions, little is known about the specific platelet pathways that AGEs modify. Therefore, we evaluated the effects of AGEs on specific salient platelet pathways related to CVDs and whether the effects that AGEs elicit are dependent on glycation extent. To accomplish our objective, platelets were incubated with reversibly or irreversibly glycated albumin. A time course for adhesion and aggregation agonist receptor expression was assessed. Optical platelet aggregometry was used to confirm the functional activity of platelets after AGE exposure. In general, platelets subjected to glycated albumin had a significantly enhanced adhesion and aggregation potential. Furthermore, we observed an enhancement in dense body secretion and intracellular calcium concentration. This was especially prevalent for platelets exposed to irreversibly glycated albumin. Additionally, functional aggregation correlated well with receptor expression, suggesting that AGE-induced altered receptor sensitivity translated to altered platelet functions. Our findings indicate that under diabetic vascular conditions platelets become more susceptible to activation and aggregation due to an overall enhanced receptor expression, which may act to promote CVD development.

Human serum albumin (HSA) and interleukin-1 receptor antagonist (IL1Ra) fusion protein is a potential long-acting drug in the treatment of type 2 diabetes. Previously, the expression level of HSA/IL1Ra in Pichia pastoris was successfully improved by increasing the gene copy number and coexpression with chaperone (protein disulfide isomerase) in our laboratory. However, the overexpression strain resulted in low production of high- cell-density fermentation. In this study, the culture medium was optimized in both flask and fermenter, and the optimum culture medium notably increased the productivity and stability of HSA/IL1Ra. To further improve the expression, response surface methodology was used to further optimize the culture condition through modeling three selected parameters (induction pH, induction temperature [T], and maximum methanol feed rate [V m ]). The maximum yield of HSA/IL1Ra reached 1.1 g/L (10-fold higher than original fermentation condition) under the optimized culture condition (pH 7.0, T = 29 ℃ and V m = 4.82 mL/L/H) in a 5-L fermenter. In addition, the degradation position of HSA/IL1Ra during fermentation was determined to be K571, serving as a potential target for genetic modification strategies to reduce the degradation. Finally, the in vivo activity study showed that HSA/IL1Ra maintained the therapeutic effect of IL1Ra in type 2 diabetes model rats meanwhile reducing the frequency of administration., (© 2016 International Union of Biochemistry and Molecular Biology, Inc.)

Albumin is the most abundant plasma protein. Critical illness is often associated with altered, predominately decreased, serum albumin levels. This hypoalbuminaemia is usually corrected by administration of exogenous albumin. This study aimed to track the concentration-dependent influence of albumin on blood coagulation in vitro. Whole blood (WB) samples from 25 volunteers were prepared to contain low (19.3 ± 7.7 g/L), physiological (45.2 ± 7.8 g/L), and high (67.5 ± 18.1 g/L) levels of albumin. Haemostatic profiling was performed using a platelet function analyzer (PFA) 200, impedance aggregometry, a Cone and Platelet analyzer (CPA), calibrated automated thrombogram, and thrombelastometry (TEM). Platelet aggregation-associated ATP release was assessed via HPLC analysis. In the low albumin group, when compared to the physiological albumin group, we found: i) shortened PFA 200-derived closure times indicating increased primary haemostasis; ii) increased impedance aggregometry-derived amplitudes, slopes, ATP release, as well as CPA-derived average size indicating improved platelet aggregation; iii) increased TEM-derived maximum clot firmness and alpha angles indicating enhanced clot formation. TEM measurements indicated impaired clot formation in the high albumin group compared with the physiological albumin group. Thus, albumin exerted significant anticoagulant action. Therefore, low albumin levels, often present in cancer or critically ill patients, might contribute to the frequently occurring venous thromboembolism.

Diabetes and obesity are strongly associated with increased levels of circulating advanced glycation end products (AGEs) and reactive oxygen species (ROS). These two molecular phenomena affect the physiology of adipose tissue, a biological driver of the metabolic syndrome, leading to an inflammatory profile and insulin resistance, which could contribute to obesity/diabetes-associated complications, such as cardiovascular diseases. Herein, we investigated the impact of AGEs on mitochondrial bioenergetics in murine preadipocyte cells (3T3-L1) and cellular redox homeostasis. We show that incubation of preadipocytes with AGEs stimulates mitochondrial activity and respiration while inducing oxidative stress. This AGE-induced intracellular ROS production was blocked by diphenylene iodonium, an NAD(P)H oxidase inhibitor. In parallel, antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase) were found to be activated upon AGE treatment. Our results suggest that AGE-induced oxidative stress is generated by NAD(P)H oxidase and leads to a cellular proliferation arrest associated with enhanced mitochondrial metabolism and biogenesis, and with increased levels of ROS-detoxifying enzymes, as well. These new data show how AGEs may be involved in hyperglycemia-induced oxidative damage in preadipocytes and their potential links to diabetes progression. © 2017 BioFactors, 43(4):577-592, 2017., (© 2017 International Union of Biochemistry and Molecular Biology.)

Oxidative stress aggravates renal fibrosis, a pathway involved in almost all forms of chronic kidney disease (CKD). However, the underlying mechanism involved in the pathogenesis of renal oxidative stress has not been completely elucidated. In this study, we explored the role and mechanism of hypochlorite-modified albumin (HOCl-alb) in mediating oxidative stress and fibrotic response in a remnant-kidney rat model. Five-sixths nephrectomy (5/6 NX) was performed on the rats and then the animals were randomly assigned to intravenous treatment with either vehicle alone, or HOCl-rat serum albumin (RSA) in the presence or absence of SS-31 (administered intraperitoneally). A sham-operation control group was set up concurrently. Compared with the control group, 5/6 NX animals displayed marked mitochondrial (mt) dysfunction, as evidenced by decrease of mitochondrial membrane potential (MMP), ATP production, mtDNA copy number alterations and manganese superoxide dismutase (MnSOD) activity, release of cytochrome C (Cyto C) from mitochondria to the cytoplasm, and increase of mitochondrial reactive oxygen species in renal tissues. They also displayed increased levels of HOCl-alb in both plasma and renal tissues. These changes were accompanied by accumulation of extracellular matrix, worsened proteinuria, deteriorated renal function, and a marked increase of macrophage infiltration along with up-regulation of monocyte chemoattractant protein (MCP)-1 and transforming growth factor (TGF)-β1 expression. HOCl-alb challenge further exacerbated the above biological effects in 5/6 NX animals, but these adverse effects were prevented by administration of SS-31, a mitochondrial targeted antioxidant peptide. These data suggest that accumulation of HOCl-alb may promote renal inflammation and fibrosis, probably related to mitochondrial oxidative stress and dysfunction and that the mitochondrial targeted peptide SS-31 might be a novel therapy for renal fibrosis and chronic renal failure (CRF)., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aggregation of amyloid β-proteins (Aβ) induced by Cu 2+ is a crucial element in the pathogenesis of Alzheimer's disease (AD), and cerebral acidosis is a common complication of AD. Under mildly acidic conditions, Cu 2+ -Aβ species have higher tendency to generate neurotoxic aggregates. Hence it is of significance to develop potent agents that inhibit Cu 2+ -mediated Aβ aggregation under a mildly acidic condition. Herein we synthesized acidulated human serum albumin (A-HSA) to mitigate Cu 2+ -mediated Aβ 42 aggregation and cytotoxicity at pH6.6. Extensive experiments showed that A-HSA altered the pathway of Cu 2+ -mediated Aβ 42 aggregation and protected SH-SY5Y cells from cytotoxicity and oxidative damage induced by Cu 2+ -Aβ 42 species. Equimolar A-HSA increased cell viability from 52% to 91% as compared to Cu 2+ -Aβ 42 -treated group. Stopped-flow fluorescence analysis revealed that A-HSA changed the Cu 2+ -Aβ 42 coordination mode from component I to II on the second timescale at pH6.6, which avoided the formation of aggregation-prone Cu 2+ -Aβ 42 aggregates. The findings revealed that the more negative charges on A-HSA surface could stabilize the protonated form of the adjacent histidine residues of Aβ 42 . Hence, component I, which is necessary to form toxic aggregates, became unstable in the presence of A-HSA. On the other hand, hydrophobic binding and electrostatic repulsion could work simultaneously on the bound Aβ 42 on A-HSA surface. The two opposite forces stretched Aβ 42 conformations, which inhibited the formation of toxic Cu 2+ -Aβ 42 aggregates. Thus, A-HSA worked as a bifunctional inhibitor against Cu 2+ -mediated Aβ 42 aggregation and cytotoxicity under a mildly acidic condition., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Tobacco smoke exposure is the principal cause of lung tissue destruction, which in turn results in emphysema that leads into shortness of breath. Liver growth factor (LGF, a cell and tissue regenerating factor with therapeutic activity in several organs) has antifibrotic and antioxidant properties that could be useful to promote lung tissue regenerating capacity in damaged lungs. The current study has examined differences in metabolite profiles (fingerprints) of plasma from mice (strain C57BL/6J, susceptible to develop emphysema) exposed to tobacco smoke during six months. One group of mice received a treatment with Liver Growth Factor (LGF) after emphysema was established, whereas the other group did not receive the treatment. Age and sex-matched mice not exposed to smoke were also maintained with or without treatment as controls. Metabolic fingerprints (untargeted analysis) of plasma after protein precipitation were obtained by LC-QTOF-MS. The signals were processed and a large number of possible metabolites were found (23944). Multivariate data analysis provided models that highlighted the differences between control and smoke exposed mice in both conditions. Accurate masses of features (possible compounds) representing significant differences were searched using online public databases. Lipid mediators, related to intracellular signaling in inflammation, were found among the metabolites putatively identified as markers of the different conditions and among them, sphingosine, sphingosine 1-phosphate and lysophospholipids point at the relevance of such metabolites in the regulation of the processes related to tissue regeneration mediated by LGF. These results also suggest that metabolomic fingerprinting could potentially guide the characterization of relevant metabolites leading the regeneration of lungs in emphysema disease., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Albumin is a major plasma protein that has become ubiquitous in regenerative medicine research. As such, many studies have examined its structure and advantageous properties. However, a systematic and comprehensive understanding of albumin's role, capabilities and therapeutic potential still eludes the field. In the present work, we review how albumin is applied in tissue engineering, including cell culture and storage, in vitro fertilization and transplantation. Furthermore, we discuss how albumin's physiological role extends beyond a carrier for metal ions, fatty acids, pharmacons and growth factors. Albumin acts as a bacteriostatic coating that simultaneously promotes attachment and proliferation of eukaryotic cells. These properties with the combination of free radical scavenging, neutrophil activation and as a buffer molecule already make the albumin protein beneficial in healing processes supporting functional tissue remodeling. Nevertheless, recent data revealed that albumin can be synthesized by osteoblasts and its local concentration is raised after bone trauma. Interestingly, by increasing the local albumin concentration in vivo, faster bone healing is achieved, possibly because albumin recruits endogenous stem cells and promotes the growth of new bone. These data also suggest an active role of albumin, even though a specific receptor has not yet been identified. Together, this discussion sheds light on why the extravascular use of the albumin molecule is in the scope of scientific investigations and why it should be considered as a local therapeutic agent in regenerative medicine. © 2016 BioFactors, 43(3):315-330, 2017., (© 2016 International Union of Biochemistry and Molecular Biology.)