Biodistribution and brain permeability of the extracellular domain of neuregulin-1-β1

Neuregulin-1 (NRG1) belongs to a large family of growth and differentiation factors with a key role in the development and maintenance of the brain. Genetic association of NRG1 within brain disorders such as Alzheimer’s disease, schizophrenia and neuroprotective properties of certain NRG1 isoforms have led to a variety of studies in corresponding disease models. In the present work, we investigated NRG1 with regard to its peripheral and central biodistribution after systemic application.We first-time radiolabeled the entire biologically active extracellular domain of NRG1 isotype-β1 (NRG1-β1 ECD; aa 2–246) with iodine-125 and administered it peripherally to healthy adult C57Bl6 mice. Blood kinetics and relative organ distribution of ¹²⁵I-labeled NRG1-β1 ECD were determined. The blood level of NRG1-β1 ECD peaked within the first hour after intraperitoneal (i.p.) application. The brain-blood ratios of ¹²⁵I-labeled NRG1-β1 ECD were time-dependently 150–370% higher compared to the brain impermeable control, ¹³¹I-labeled bovine serum albumin. Autoradiographs of brain slices demonstrated that ¹²⁵I-labeled NRG1-β1 ECD accumulated in several regions of the brain e.g. frontal cortex, striatum and ventral midbrain containing the substantia nigra. In addition we found histochemical and biochemical evidence that phosphorylation of the NRG1 prototype receptor ErbB4 was increased in these regions after systemic application of NRG1-β1 ECD.Our data suggest that NRG1-β1 ECD passes the blood–brain barrier and activates cerebral ErbB4 receptors.     

Engagement of PSGL-1 enhances β2-integrin-involved adhesion of neutrophils to recombinant ICAM-1

AIM: The interactions of selectins and their ligands initiate the process of leukocyte migrating into inflamed tissue. P-selectin glycoprotein ligand 1 (PSGL-1) is the best characterized ligand of selectins, and has been demonstrated to mediate the adhesion of leukocytes to all three selectins in vivo. PSGL-1 not only functions as an anchor molecule to capture the leukocytes to the activated endothelial cells by its interaction with selectins, but also transduces the signals to activate leukocytes. Our present work aimed to investigate the mechanism by which PSGL-1-mediated signal activates neutrophils and enhances the adhesion to the endothelial cells. METHODS: We detected the effects of the engagement of PSGL-1 with monoclonal antibodies (mAb) or P-selectin on the adhesion of neutrophils to the recombinant intercellular adhesion molecule-1 (ICAM-1), and on the expression of beta(2)-integrin. Additionally, the role of cytoskeleton in these process was studied by using inhibitor cytochalasin B. RESULTS: The engagement of PSGL-1 increased the expression of beta(2)-integrin on the surface of neutrophils and enhanced the adhesion of neutrophils to the recombinant ICAM-1. mAb against CD18 impaired the adhesion of PSGL-1-engaged neutrophils to ICAM-1. Moreover, the inhibitor cytochalasin B largely blocked the increase of CD18 expression as well as the adhesion of PSGL-1-engaged neutrophils to ICAM-1. CONCLUSION: The PSGL-1-transduced signals can enhance beta(2)-integrin-involved adhesion of neutrophils to the recombinant ICAM-1, and this process depends on the dynamics of cytoskeleton.     

Influence of silybin on biophysical properties of phospholipid bilayers1／

AIM: Silybin (silibinin) is major biologically active flavonolignan extracted from milk thistle (Sylibum marianum). Its biological activities include hepato-protection, anticancer properties, and antioxidant- and membrane-stabilizing functions. Although membranes are postulated to be one of the cellular targets for silybin, little is known about its interaction with phospholipid bilayers. METHODS: In the present work, the interactions of silybin with phosphatidylcholine bilayers were studied in detail using fluorescence spectroscopy, microcalorimetry and electron spin resonance techniques. RESULTS: The results showed that silybin interacted with the surface of lipid bilayers. It affected the generalized polarization of the fluorescent probe Prodan, while not influencing the more deeply located Laurdan. Silybin lowered the main phospholipid phase transition temperature as judged by microcalorimetry, and caused the immobilization of spin probe Tempo-palmitate located on the surface of membranes. The mobility of spin probes 5- and 16-doxyl stearic acid was not affected by silybin. Silybin-induced quenching of 1,6-diphenyl-1,3,5-hexatriene fluorescence indicated that some flavonoid molecules partitioned into the hydrophobic region of membranes, which did not change significantly the biophysical properties of the deeper membrane regions. CONCLUSION: Such a behavior of silybin in membranes is in accordance with its postulated biological functions and neglectable side effects of therapies using silybin.     

Synthesis of N1-Retinoyi-5-fluorouracil

Although 5-fluorouracil is one of the most widelyused cytotoxic drugs in the treatment of solid tumors inmany organs, it has a severe drawback in its serious side-effects (e.g. gastrointestinal and bone marrow toxicity)and the properties (e.g. low lipophilicity) leading tovarious delivery problems. The low lipophilicity of 5-fluorouracil may be a predominant factor for its poorbiomembrane permeability.     

Synthesis of N_1-Retinoyl-5-fluorouracil

Introduction Although 5-fluorouracil is one of the most widely used cytotoxic drugs in the treatment of solid tumors in many organs, it has a severe drawback in its serious side-effects (e.g. gastrointestinal and bone marrow toxicity) and the properties (e.g. low lipophilicity) leading to various delivery problems. The low lipophilicity of 5-fluorouracil may be a predominant factor for its poor biomembrane permeability. Hence it can hardly reach the brain tissue through the blood-brain barrie…     

Immunomodulating activity of analogs of noninflammatory fragment 163–171 of human interleukin-1β

The synthetic nonapeptide Val–Gln–Gly–Glu–Glu–Ser–Asn–Asp–Lys corresponding to the amino acid sequence 163–171 of human interleukin-1β (IL-1β) has been reported to retain considerable immunostimulatory activity of the native protein without the induction of the inflammatory or pyrogenic responses. Two lipophilic derivatives of this nonapeptide, one having a lauroyl residue (1) and the other having a palmitoyl residue (2) at the N-terminus of the peptide, and a more stable analog carrying d-Val residue at position 1 of the peptide (3) were synthesized with a view to find out if these structural modifications had a favorable effect on in vitro mouse thymocyte proliferation and IL-1 dependent inhibition of A375 cells. We have found that analogs (1) and (2) are active in both the tests like the parent nonapeptide. The lipophilic analog (2) is in fact, effective at a lower dose as compared to the parent nonapeptide in mouse thymocyte proliferation assay. Although the analog (3) has the ability to inhibit A375 cells, it does not stimulate mouse thymocyte proliferation in vitro. The IL-1β fragment (163–171) and the analog (2) were further compared for their effects on pyrogenicity, blood glucose level, acute phase response and radioprotection. Unlike IL-1β, its fragment (163–171) and the analog (2) do not induce pyrogenicity and any of the acute phase related changes such as the increase in C-reactive protein and hypoglycemia following their administration in Balb/c mice. We have found that 40% of animals treated with analog (2) survive more than 21 days after lethal irradiation as compared to 20% survivors in groups treated with recombinant IL-1β or its nonapeptide fragment (163–171), under conditions when all the control animals died within 10 days. This study may help in designing small peptides which may be more effective and stable.     

Up-regulation of microRNA-93 inhibits TGF-β1-induced EMT and renal fibrogenesis by down-regulation of Orai1

TGF-β1-induced excessive deposition of ECM and EMT process of tubular epithelial cells play critical roles in the development and progression of fibrosis in diabetic nephropathy (DN). Orai1 has been demonstrated to be involved in TGF-β1-induced EMT via TGF-β/Smad3 pathway. We are aimed to explore the effects of miR-93 on TGF-β1-induced EMT process in HK2 cells. In this study, our data showed that miR-93 was dramatically decreased in renal tissues of patients with DN and TGF-β1-stimulated HK2 cells. Moreover, the decreased level of miR-93 was closely associated with the increased expression of Orai1. Overexpression of miR-93 decreased Orai1 expression, and then suppressed TGF-β1-mediated EMT and fibrogenesis. Next, we predicted that the Orai1 was a potential target gene of miR-93, and demonstrated that miR-93 could directly target Orai1. SiRNA targeting Orai1 was sufficient to suppress TGF-β1-induced EMT and fibrogenesis in HK2 cells. Furthermore, Overexpression of Orai1 partially reversed the protective effect of miR-93 overexpression on TGF-β1-mediated EMT and fibrogenesis in HK2 cells. Taken together, Orai1 and miR-93 significantly impact on the progression of TGF-β1-mediated EMT and fibrogenesis in HK2 cells, and they may represent novel targets for the prevention strategies of fibrosis in the context of DN.     

Summary of anti-inflammatory and antiviral effects of IFIT1北大核心CSCD

IFIT1是一种高度诱导的具有四肽重复序列的干扰素刺激基因家族(ISGs)成员,主要存在于细胞质,其表达受干扰素(IFN)、多种病毒和某些病原体相关分子模式的调节,具有抗病毒、抗炎等作用。IFIT1的抗病毒作用可通过多种机制和途径发挥,同时部分病毒也进化出独特的机制逃避宿主IFIT1的限制作用,从而对抗机体抗病毒免疫。在许多炎症性疾病中,IFIT1也显示出其独特的抗炎作用。该文就IFIT1的抗炎和抗病毒作用与相关机制作一综述,为进一步研究相关疾病的治疗提供新的靶点和思路。     

Loss of selectivity of so-called selective α1-adrenoceptor agonists after phenoxybenzamine

Summary This study examined the nature of -adrenoceptor subtype involved in pressor responses to so-called selective ₁-adrenoceptor agonists after treatment with phenoxybenzamine in vivo. The influence of prazosin (0.1 mg/kg) and of yohimbine (1 mg/kg) on the dose-response curves for cirazoline in the pithed rat, and for phenylephrine in the anaesthetized dog were compared, after various doses of phenoxybenzamine.In the pithed rat, after 0.05 mg/kg phenoxybenzamine, prazosin caused a displacement of the dose-response curve of cirazoline to the right which was much larger than that caused by yohimbine; after 0.3 mg/kg phenoxybenzamine, prazosin and yohimbine caused about equal displacements; after 1 mg/kg phenoxybenzamine, yohimbine caused a marked displacement, while prazosin was without effect.In the anaesthetized dog, after 1 mg/kg phenoxybenzamine, prazosin and yohimbine produced about equal rightward shifts of the dose-response curve for phenylephrine. However, after 3 mg/kg phenoxybenzamine the rightward shift of the dose-response curve for phenylephrine was much larger after yohimbine than after prazosin. In the anaesthetized dog, verapamil (1 mg/kg) caused a small and parallel rightward shift of the dose-response curve for phenylephrine before phenoxybenzamine and a large and nonparallel one after phenoxybenzamine (3 mg/kg); the effect of verapamil on responses to the selective ₂-adrenoceptor agonist UK-14,304 (before and after phenoxybenzamine) were similar to those on responses to phenylephrine after phenoxybenzamine.It is concluded that after 1 mg/kg phenoxybenzamine in the pithed rat or after 3 mg/kg phenoxybenzamine in the anaesthetized dog, the responses to the so-called selective ₁-adrenoceptor agonists cirazoline and phenylephrine, respectively, are predominantly or totally ₂-adrenoceptor-mediated. This explains why, after inactivation of ₁-adrenoceptors by phenoxybenzamine, the so-called selective ₁- and ₂-adrenoceptor agonists are equally antagonized by calcium entry blockers.This work was supported by grants from INIC (Instituto Nacional de Investigação Cientifica): FmP₁ and FMP₃ Send offprint requests to S. Guimarães at the above address     

Identification of Inhibitors of NOD1-Induced Nuclear Factor-κB Activation

NOD1 (nucleotide-binding oligomerization domain 1) protein is a member of the NLR (NACHT and leucine rich repeat domain containing proteins) protein family, which plays a key role in innate immunity as a sensor of specific microbial components derived from bacterial peptidoglycans and induction of inflammatory responses. Mutations in NOD proteins have been associated with various inflammatory diseases that affect NF-κB (nuclear factor κB) activity, a major signaling pathway involved in apoptosis, inflammation, and immune response. A luciferase-based reporter gene assay was utilized in a high-throughput screening program conducted under the NIH-sponsored Molecular Libraries Probe Production Center Network program to identify the active scaffolds. Herein, we report the chemical synthesis, structure-activity relationship studies, downstream counterscreens, secondary assay data, and pharmacological profiling of the 2-aminobenzimidazole lead (compound 1c, ML130) as a potent and selective inhibitor of NOD1-induced NF-κB activation.     

The mechanism of ginsenosides Rg1 and Rb1 promoting neurotransmitters release

The root of Panax ginseng C. A. Meyer （Araliaceae） has been extensively used in traditional oriental medicine for prevention and treatment of aging - related disorders for over 2000 years. To study the mechanism of ginsennsides Rgl and Rb1 promoting neurotransmitters release , the amount of amino acids released from cell culture were measured by high performance liquid chromatography （HPLC）. Effects of Rg1 and Rbl on the phosphorylation of synapsins were detected with immunofluorescent staining and western blotting. Accumulating evidence suggests that ginsenosides such as Rgl and Rbl, which are the pharmacologically active ingredients of ginseng, modulate neurotransmission. Synapsins are abundant phosphoproteins essential for regulating neurotransmitter release. All synapsins contain a short amino - terminal domain A that is highly conserved and phosphorylated by cAMP- dependent protein kinase （PKA） , which plays a main role in regulating neurotransmitter release. In this study, we found that both Rgl and Rbl could increase glutamate releasing within physiological concentration. However, glutamate quantity was decreased by pre - incubating with PKA Inhibitor H89. When Rg1 joining again, glutamate quantity remained elevation as before, but Rb1 could not achieve it.     

Roles of phosphoinositide-dependent kinase-1 in α1B-adrenoceptor phosphorylation and desensitization

The role of phosphoinositide-dependent protein kinase-1 (PDK-1) activity on α(1B)-adrenoceptor phosphorylation and function was explored using pharmacological inhibitors and expression of a dominant-negative mutant of this enzyme. Noradrenaline-, phorbol myristate acetate-, lysophosphatidic acid- and epidermal growth factor-mediated α(1B)-adrenoceptor phosphorylation were markedly reduced by the two inhibitors used: UCN-01 [(7-hydroxystaurosporine; (3R*,8S*, 9R*, 10R*,12R*)-2,3,9,10,11,12-hexahydro-3-hydroxy-9-methoxy-8-methyl-10-(methylamino)-8,12-epoxy-1H, 8H-2,7b,12a-triazadibenzo[a,g]-cyclonona[cde]triden-1-one)] and OSU-03012 [(2-amino-N-[4-[5-(2-phenanthrenyl)-3-trifluoromethyl)-1H-pyrazol-1-yl]phenyl]-acetamide)]. A similar effect was observed in cells expressing a PDK-1 dominant-negative mutant. Phosphorylated PDK-1 (S241) and protein kinase C α (T497) were associated with cell membranes in the basal state which increased in response to the hormonal stimuli mentioned previously. UCN-01 essentially abolished phospho-PDK-1 membrane-association and markedly attenuated that of protein kinase C α. Consistent with the findings, UCN-01 reduced lysophosphatidic acid- and epidermal growth factor-induced α(1B-)adrenoceptor desensitization. Our data suggest that PDK-1 plays a permissive role in α(1B)-adrenoceptor desensitization and phosphorylation and participates in the formation of signaling complexes, which delicately modulate receptor function and regulation.     

Effect of TJN-331 on anti-Thy1 nephritis in rats via inhibition of transforming growth factor-β1 production

This study was performed to examine the effects of the antifibrotic agents TJN-331 and tranilast on mesangial expansion in a rat model of anti-Thy1 nephritis. We first investigated the effects of TJN-331 and tranilast on mesangial expansion induced by anti-Thy1 serum in rats, and determined the counts of glomerular cells and proliferative cell nuclear antigen (PCNA)-positive cells. The effects of TJN-331 and tranilast on production of transforming growth factor-β1 (TGF-β1) by isolated glomeruli incubated for 48 h were then examined. The TGF-β1 staining score, the number of TGF-β1-positive cells and the TGF-β1 receptor-positive area in the anti-Thy1 nephritis model were also measured using immunohistochemistry. TJN-331 administered from day 1 (the day after anti-Thy1 serum injection) blocked an increase in mesangial matrix accumulation on days 4 and 8, compared to untreated anti-Thy1 nephritic rats. TJN-331 also inhibited both the increase in the number of glomerular cells on day 8 and the decrease in this cell count on day 2 observed in untreated nephritic rats, and TJN-331 and tranilast inhibited an increase in PCNA-positive cells in the glomerular cross section on days 4 and 8. Both TJN-331 and tranilast inhibited increases in the TGF-β1 protein content from nephritic glomeruli, the TGF-β1-positive area, and the number of TGF-β1-positive cells/cross section in anti-Thy1 nephritic glomeruli. These results suggest that TJN-331 and tranilast prevent expansion of the mesangial area by suppression of TGF-β1 secretion from inflamed glomeruli.     

Angiotensin 1 – 7 stimulation of platelet recovery

Introduction: Thrombocytopenia is an abnormally low number of platelets in the blood resulting from either too few platelets being produced or existing platelets being destroyed. Severe thrombocytopenia leads to excessive bleeding and can be the result of numerous medical conditions or a side effect of medications or treatments. Although platelet transfusions are typically administered to correct thrombocytopenia, transfusions represent a temporary and unsustainable solution. As there is a limited supply of platelet units available for transfusion, along with the significant financial cost and risk of infection, investigation to uncover mechanisms that boost platelet production may have important clinical and therapeutic implications. Treatment with angiotensin 1 – 7 (A(1 – 7)) has been shown in a preclinical and clinical evaluations to have a positive effect on platelet recovery.

Areas covered: The authors provide an overview of the current treatment options available for platelet recovery and highlight the need for alternatives. Following on, the authors discuss the use of A(1 – 7) as a potential therapeutic option for platelet recovery, including its safety and efficacy.

Expert opinion: Current evidence provides a good basis for continued research and evaluation of the benefits of A(1 – 7) treatment in stimulating platelet recovery following myelosuppression. A(1 – 7) therapy has the potential to make a significant contribution to healthcare by providing standalone and additive treatments to address unmet medical needs and life-threatening diseases by utilizing the regenerative arm of the renin–angiotensin system.     

Structure-based development of potent and selective type-Ⅱ kinase inhibitors of RIPK1

Receptor-interacting serine/threonine-protein kinase 1(RIPK1) functions as a key regulator in inflammation and cell death and is involved in mediating a variety of inflammatory or degenerative diseases. A number of allosteric RIPK1 inhibitors(RIPK1i) have been developed, and some of them have already advanced into clinical evaluation. Recently, selective RIPK1i that interact with both the allosteric pocket and the ATP-binding site of RIPK1 have started to emerge. Here, we report the rational dev...     

Role and mechanism of NR1D1 in proliferation and migration of vascular adventitial fibroblasts北大核心CSCD

Aim To explore the role and mechanism of nuclear receptor subfamily 1,group D,member 1(NR1D1)in the proliferation and migration of mouse adventitial fibroblasts(AFs). Methods Primary AFs isolated from C57BL/6J mice were cultured. Adenovirus carrying Nr1d1 gene was used to overexpress NR1D1 in AFs. The expression of β-catenin was restored by SKL2001. Proliferating cell nuclear antigen(Ki-67)immunofluorescence staining and CCK-8 staining were used to determine cell proliferation,and scratch test was used to determine cell migration. qPCR was used to determine the mRNA level of Nr1d1. Western blot was used to determine the protein levels of NR1D1 and β-catenin. To investigate the role of NR1D1 in intimal hyperplasia,20 male wild type C57BL/6J mice were randomly divided into sham group,carotid artery endothelial injury,sham+SR9009(NR1D1 agonist)group and carotid artery endothelial injury+SR9009(n=5 in each group). They were treated with DMSO or SR9009(100 mg·kg-1·d-1)via intraperitoneal injection for 14 days after operation,respectively. The degree of carotid intimal hyperplasia was measured by HE staining 28 days after operation. Results NR1D1 overexpression significantly reduced the percentage of Ki-67-positive cells(P<0.01),total cell number(P<0.01)and slowed down the rate of wound-healing(P<0.01). NR1D1 overexpression significantly inhibited the expression of β-catenin(P<0.05). After the expression of β-catenin was restored by SKL2001,the inhibitory effects of NR1D1 overexpression on the proliferation and migration of AFs were abolished(P<0.01). Enhanced activity of NR1D1 significantly ameliorated intimal hyperplasia after carotid endothelial injury(P<0.01). Conclusion NR1D1 may inhibit the proliferation and migration of AFs via suppressing the expression of β-catenin. © 2023 Publication Centre of Anhui Medical University. All rights reserved.     

Binding of perazine to α1-acid glycoprotein

Summary The high-affinity binding of perazine to human serum-protein (non-albumin binding) was previously investigated by gel-chromatography. The immunoelectrophoretic identification of the binding agent as ₁-acid glycoprotein is described here. It was demonstrated by equilibrium dialysis that the average free fraction of³H-perazine added to 22 sera from patients before neuroleptic treatment was 3.67±0.42%, and that there was a significant correlation between the ₁-acid glycoprotein content and the free fraction in these serum samples. This result is in accordance with what others have found for impramine. It is suggested that the nature of this binding should be studied in more detail, since specific binding to ₁-acid glycoprotein may be related to the receptor binding of perazine and possibly other drugs.A preliminary summary of the present findings appeared in Naunyn-Schmiedebergs Arch Pharmacol 307 (Suppl) R 70 (1979)