Mouse serum albumin induces neuronal apoptosis and tauopathies.

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.

Histochemical, Immunohistochemical, and Biochemical Investigation of the Effect of Resveratrol on Testicular Damage Caused by Methotrexate (MTX).

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.

Irbesartan has a curative effect on lipopolysaccharide-induced cardiotoxicity by antioxidant and antiapoptotic pathways.

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.

Age-related differences in response to plasma exchange in male rat liver tissues: insights from histopathological and machine-learning assisted spectrochemical analyses.

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.

Insight on Serum Albumin: From Structure and Biological Properties to Functional Biomaterials for Bone Repair.

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.

Impact of Vitamin D3 on Carbonyl-Oxidative Stress and Matrix Metalloproteinases after Acute Intracerebral Hemorrhage in Rats with Type 2 Diabetes Mellitus.

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.

Blood-brain barrier dysfunction promotes astrocyte senescence through albumin-induced TGFß signaling activation.

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 (TGFß) signaling. We found that 1 week of albumin exposure significantly increased TGFß signaling and senescence marker expression in cultured rat hippocampal astrocytes. These changes were preventable by pharmacological inhibition of the type I TGFß receptor (TGFßR) 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 TGFß signaling activation and the burden of senescent astrocytes in hippocampal tissue. Pharmacological inhibition of ALK5 TGFßR or conditional genetic knockdown of astrocytic TGFßR prior to albumin infusion was sufficient to prevent albumin-induced astrocyte senescence. Together, these results establish a link between TGFß signaling activation and astrocyte senescence and suggest that prolonged exposure to serum albumin due to BBBD can trigger these phenotypic changes.

Sinapic Acid Attenuated Cisplatin-Induced Cardiotoxicity by Inhibiting Oxidative Stress and Inflammation with GPX4-Mediated NF-kB Modulation.

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.

Tetrandrine Attenuates Podocyte Injury by Inhibiting TRPC6-Mediated RhoA/ROCK1 Pathway.

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 Ca2+ 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.

The efficacy and safety of tacrolimus and entecavir combination therapy in the treatment of hepatitis B virus-associated glomerulonephritis: a multi-center, placebo controlled, and single-blind randomized trial.

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.

The effects of the renin-angiotensin-aldosterone system blockers on serum ischemia-modified albumin levels in autosomal dominant polycystic kidney disease.

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.

Effects of dexmedetomidine on new oxidative stress markers on renal ischaemia-reperfusion injury in rats: thiol/disulphide homeostasis and the ischaemia-modified albumin.

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.

Reactive Oxygen Species Downregulate Transient Receptor Potential Melastatin 6 Expression Mediated by the Elevation of miR-24-3p in Renal Tubular Epithelial Cells.

BACKGROUND: A low level of serum magnesium ion (Mg2+) is associated with type 2 diabetes mellitus (T2D). However, the molecular mechanism of Mg2+ deficiency has not been fully clarified. The current study sought to assesses the effect of reactive oxygen species on the expression of Mg2+ channels and miRNA. METHODS: The expression of Mg2+ channels and miRNA were examined by real-time polymerase chain reaction. Intracellular Mg2+ concentration was measured by Magnesium Green fluorescence measurement. RESULTS: The mRNA level of transient receptor potential melastatin 6 (TRPM6), which functions as Mg2+ 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 Mg2+ 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 (H2O2) dose-dependently decreased TRPM6 mRNA, but it inversely increased the reporter activity of TRPM6. H2O2 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 H2O2. The H2O2-induced reduction of TRPM6 mRNA was rescued by miR-24-3p siRNA. Magnesium Green fluorescence measurement showed that Mg2+ influx is suppressed by H2O2, 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.

Peripheral blood mononuclear cell activation sustains seizure activity.

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)-1ß, 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.

Cerebrospinal fluid (CSF) augments metabolism and virulence expression factors in Acinetobacter baumannii.

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.

Suppression of Rheumatoid Arthritis by Enhanced Lymph Node Trafficking of Engineered Interleukin-10 in Murine Models.

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.

Study of tissue engineered vascularised oral mucosa-like structures based on ACVM-0.25% HLC-I scaffold in vitro and in vivo.

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, S100A4 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.

ChpC controls twitching motility-mediated expansion of Pseudomonas aeruginosa biofilms in response to serum albumin, mucin and oligopeptides.

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.

Bactrian camel serum albumins-based nanocomposite as versatile biocargo for drug delivery, biocatalysis and detection of hydrogen peroxide.

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 H2O2 resulting in a wide linear calibration curve ranging from 5 to 400 µM with a detection limit of 3.32 µM.

Apelin peptides linked to anti-serum albumin domain antibodies retain affinity in vitro and are efficacious receptor agonists in vivo.

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 (pKi  = 9.39 ± 0.09) bound with similar high affinity as the endogenous peptides [Pyr1 ]apelin-13 (pKi  = 8.83 ± 0.06) and apelin-17 (pKi  = 9.57 ± 0.08). [Pyr1 ]apelin-13 was tenfold more potent in the cAMP (pD2  = 9.52 ± 0.05) compared to the ß-arrestin (pD2  = 8.53 ± 0.03) assay, whereas apelin-17 (pD2  = 10.31 ± 0.28; pD2  = 10.15 ± 0.13, respectively) and MM202-AlbudAb (pD2  = 9.15 ± 0.12; pD2  = 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 (pKD  = 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.