[Pharmacokinetic and pharmacodynamic synergism between neuropeptides and lithium in the neurotrophic and neuroprotective action of cerebrolysin].

OBJECTIVE: To study the synergism between neuropeptides and lithium ions. MATERIAL AND METHODS: An experimental model of stroke (chronic bilateral occlusion of the common carotid arteries in rats), neuronal culture studies, histomorphological analyses, determination of micronutrient profile of brain substrates were used. RESULTS: A complex of experimental studies revealed that the effect of cerebrolysin is influenced by the synergism between lithium ions and the neuropeptide contentof this drug. Pharmacokinetic synergism promotes the accumulation of lithium in brain tissues during cerebrolysin treatment. The existence of the pharmacokinetic synergism is evident from the potentiation of neuroprotective effects of the drug under the action of lithium ions established in the model of stroke. CONCLUSION: Lithium ions potentiate neuroprotective effects of cerebrolysin.

New labeled derivatives of the neuroprotective peptide colivelin: synthesis, characterization, and first in vitro and in vivo applications.

Colivelin (CL), first reported in 2005, is the most potent member of the humanin family of neuroprotective peptides with in vitro and in vivo rescuing action against insults associated with Alzheimer's disease (AD). The objective of the present work is the design, synthesis and characterization of specific CL derivatives that can be used as molecular probes in the investigation of the unknown mechanism of CL action. Within this framework, three CL derivatives bearing suitable tags, i.e., the fluorescent moiety FITC, the streptavidin-counterpart biotinyl-group, and the (99m)Tc-radiometal chelating unit dimethylGly-Ser-Cys, were developed and subsequently applied in biological evaluation experiments. Specifically, the FITC-labeled derivative of CL was used in confocal microscopy, where specific binding at the periphery of F11 cells was observed; the biotin-labeled derivative of CL was used in an in-house developed ELISA-type assay, where specific and concentration-dependent binding with the ß-amyloid peptide of AD was shown; finally, the (99m)Tc-radiolabeled derivative of CL was used in in vivo biodistribution studies in healthy Swiss Albino mice, where 0.58% of the radioactivity administered was measured in the mouse brain 2min after injection. The above first successful applications of the CL probes demonstrate their potential to contribute in the field of neuroprotective peptides.

Zfyve9a regulates the proliferation of hepatic cells during zebrafish embryogenesis.

Zfyve9 is a FYVE domain protein first identified as a binding partner for SMAD2/3. In vitro studies indicate that it can function either positively or negatively in the TGF-beta signaling pathway depending on the cell lines used. However, the in vivo function of this protein remains to be investigated. We first analyzed the tissue distribution of zebrafish zfyve9a by in situ hybridization. To investigate the in vivo function of this gene, we performed morpholino mediated loss-of-function assays. We analyzed the expression patterns of liver (cp and fabp10a), pancreas (trypsin and insulin) or gut (fabp2) specific markers to determine whether the formation of these organs is affected by zfyve9a knockdown. We determined the specification of hepatoblast in the zfyve9a morphants (prox1a) and investigated the proliferation and survival of hepatic cells in the morphants by P-H3 staining and TUNEL assay respectively. We report here that zfyve9a is enriched in the zebrafish embryonic liver and required for hepatogenesis. Morpholino mediated knockdown of zfyve9a inhibits the formation of liver by day 4 while the other endoderm-derived organs appear unaffected. We demonstrated that the specification of hepatoblasts is normal in the zfyve9a morphants; however, the proliferation rate of these cells is reduced. Thus, our results reveal the liver-specific function of zfyve9a during early embryogenesis and indicate that the zfyve9a mediated signal is essential for the proliferation of hepatic cells during the expansion of liver bud.

Pharmacokinetics and tissue distribution of humanin and its analogues in male rodents.

Humanin (HN) is a novel 24-amino acid mitochondrial-derived peptide that has demonstrated diverse cytoprotective effects, including an emerging role in diabetes. The purpose of this study was to examine the pharmacokinetics of humanin analogues, which show great potential as therapeutic agents (HNG and the non-IGFBP-3 binding, HNGF6A). 11-week-old male IGFBP-3(-/-) and wild type (WT) mice were divided into 3 groups: WT mice treated with HNG, WT mice treated with HNGF6A, and IGFBP-3(-/-) mice treated with HNG. Plasma was obtained from mice following ip injection with HN analogues, and HN levels were measured with ELISA. WT mice treated with HNGF6A and IGFBP-3(-/-) mice treated with HNG displayed a longer half-life of HN compared with WT mice treated with HNG. Following HNG injection, both IGF-1 and IGFBP-3 levels decreased over time. Adult male Sprague Dawley rats were also ip injected with HNG, and HN levels were measured in various tissues (plasma, liver, heart, and brain) by ELISA. The half-life of HN was found to be longer in rats compared with mice. In rats, HN levels were found to be highest in plasma, present in liver, and undetectable in brain or heart. The current study provides evidence of HN and IGFBP-3 association in the circulation and suggests that native HN may modulate the distribution of IGF-1 and IGFBP-3. The results also demonstrate varying kinetic profiles of HN analogues and interspecies variation in rodents. Sustainable levels of circulating HN measured in plasma underline the potential value of HN analogues as a new therapeutic intervention in the treatment of diabetes.

Amelioration of neurodegenerative diseases by cell death-induced cytoplasmic delivery of humanin.

Inhibition of the early intracellular event that triggers neurodegenerative cascades and reversal of neuronal cell death are essential for effective treatment of Alzheimer's disease (AD). In this study, a novel therapeutic for AD, a transducible humanin with an extended caspase-3 cleavage sequence (tHN-C3), was developed and showed multiple mechanisms of therapeutic action. These included targeted delivery of anti-apoptotic protein humanin through the blood-brain barrier (BBB) to neuronal cells, specific inhibition of caspase-3 activation to inhibit the early triggering of AD progression, and delivery of humanin into the cytoplasm of neuronal cells undergoing apoptosis where it exerts its anti-apoptotic functions effectively. The tHN-C3 prevented neuronal cell death induced by H2O2, or soluble Aß42, via Bax binding. In animal models of AD induced by amyloid beta, in Tg2576 mice, and in the rat middle cerebral artery occlusion model of stroke, tHN-C3 effectively prevented neuronal cell death, inflammatory cell infiltration into the brain, and improved cognitive memory. The therapeutic effectiveness of tHN-C3 was comparable to that of Aricept, a clinically approved drug for AD treatment. Therefore, tHN-C3 may be a new remedy with multiple therapeutic functions targeting the early and late stages of neurodegeneration in AD and other brain injuries.

Protective effects of transduced Tat-DJ-1 protein against oxidative stress and ischemic brain injury.

Reactive oxygen species (ROS) contribute to the development of a number of neuronal diseases including ischemia. DJ-1, also known to PARK7, plays an important role in transcriptional regulation, acting as molecular chaperone and antioxidant. In the present study, we investigated whether DJ-1 protein shows a protective effect against oxidative stress-induced neuronal cell death in vitro and in ischemic animal models in vivo. To explore DJ-1 protein's potential role in protecting against ischemic cell death, we constructed cell permeable Tat-DJ-1 fusion proteins. Tat-DJ-1 protein efficiently transduced into neuronal cells in a doseand time-dependent manner. Transduced Tat-DJ-1 protein increased cell survival against hydrogen peroxide (H2O2) toxicity and also reduced intracellular ROS. In addition, Tat-DJ-1 protein inhibited DNA fragmentation induced by H2O2. Furthermore, in animal models, immunohistochemical analysis revealed that Tat-DJ-1 protein prevented neuronal cell death induced by transient forebrain ischemia in the CA1 region of the hippocampus. These results demonstrate that transduced Tat-DJ-1 protein protects against cell death in vitro and in vivo, suggesting that the transduction of Tat-DJ-1 may be useful as a therapeutic agent for ischemic injuries related to oxidative stress.

A novel small Odorranalectin-bearing cubosomes: preparation, brain delivery and pharmacodynamic study on amyloid-ß25₋35-treated rats following intranasal administration.

Because of the immunogenicity and toxicity in vivo of large molecules such as lectins, the application of these molecules is remarkably restricted in drug delivery systems. In this study, to improve the brain drug delivery and reduce the immunogenicity of traditional lectin modified delivery system, Odorranalectin (OL, 1700 Da), a novel non-immunogenic small peptide, was selected to establish an OL-modified cubosomes (Cubs) system. The streptavidin (SA)-conjugated Cubs were prepared by incorporating maleimide-PEG-oleate and taking advantage of its thiol group binding reactivity to conjugate with 2-iminothiolane thiolated SA; mono-biotinylated OL was then coupled with the SA-modified Cubs. The OL-decorated Cubs (OL-Cubs) devised via a non-covalent SA-biotin "bridge" made it easy to conjugate OL and determine the number of ligands on the surface of the Cubs using sensitive chemiluminescent detection. Retention of the bio-recognitive activity of OL after covalent coupling was verified by hemagglutination testing. Nose-to-brain delivery characteristic of OL-Cubs was investigated by in vivo fluorescent biodistribution using coumarin-6 as a marker. The relative uptake of coumarin carried by OL-Cubs was 1.66- to 3.46-fold in brain tissues compared to that incorporated in the Cubs. Besides, Gly14-Humanin (S14G-HN) as a model peptide drug was loaded into cubosomes and evaluated for its pharmacodynamics on Alzheimer's disease (AD) rats following intranasal administration by Morris water maze test and acetylcholinesterase activity determination. The results suggested that OL functionalization enhanced the therapeutic effects of S14G-HN-loaded cubosomes on AD. Thus, OL-Cubs might offer a novel effective and noninvasive system for brain drug delivery, especially for peptides and proteins.

Systemic delivery of NEMO binding domain/IKKγ inhibitory peptide to young mdx mice improves dystrophic skeletal muscle histopathology.

The activation of nuclear factor κB (NF-κB) contributes to muscle degeneration that results from dystrophin deficiency in human Duchenne muscular dystrophy (DMD) and in the mdx mouse. In dystrophic muscle, NF-κB participates in inflammation and failure of muscle regeneration. Peptides containing the NF-κB Essential Modulator (NEMO) binding domain (NBD) disrupt the IκB kinase complex, thus blocking NF-κB activation. The NBD peptide, which is linked to a protein transduction domain to achieve in vivo peptide delivery to muscle tissue, was systemically delivered to mdx mice for 4 or 7 weeks to study NF-κB activation, histological changes in hind limb and diaphragm muscle and ex vivo function of diaphragm muscle. Decreased NF-κB activation, decreased necrosis and increased regeneration were observed in hind limb and diaphragm muscle in mdx mice treated systemically with NBD peptide, as compared to control mdx mice. NBD peptide treatment resulted in improved generation of specific force and greater resistance to lengthening activations in diaphragm muscle ex vivo. Together these data support the potential of NBD peptides for the treatment of DMD by modulating dystrophic pathways in muscle that are downstream of dystrophin deficiency.

A novel peptide, colivelin, prevents alcohol-induced apoptosis in fetal brain of C57BL/6 mice: signaling pathway investigations.

Fetal alcohol exposure is known to induce cell death through apoptosis. We found that colivelin (CLN), a novel peptide with the sequence SALLRSIPAPAGASRLLLLTGEIDLP, prevents this apoptosis. Our initial experiment revealed that CLN enhanced the viability of primary cortical neurons exposed to alcohol. We then used a mouse model of fetal alcohol exposure to identify the intracellular mechanisms underlying these neuroprotective effects. On embryonic day 7 (E7), weight-matched pregnant females were assigned to the following groups: (1) ethanol liquid diet 25% (4.49% v/v) ethanol derived calories; (2) pair-fed control; (3) normal chow; (4) ethanol liquid diet combined with administration (i.p.) of CLN (20 microg/20 g body weight); and (5) pair-fed combined with administration (i.p.) of CLN (20 microg/20 g body weight). On E13, fetal brains were collected and assayed for TdT-mediated dUTP nick end labeling staining, caspase-3 colorimetric assay, enzyme-linked immunosorbent assay, and Meso scale discovery electrochemiluminescence. CLN blocked the alcohol-induced decline in brain weight and prevented alcohol-induced: apoptosis, activation of caspase-3 and increases of cytosolic cytochrome c, and decreases of mitochondrial cytochrome c Analysis of proteins in the upstream signaling pathway revealed that CLN down-regulated the phosphorylation of the c-Jun N-terminal kinase. Moreover, CLN prevented alcohol-induced reduction in phosphorylation of BAD protein. Thus, CLN appears to act directly on upstream signaling proteins to prevent alcohol-induced apoptosis. Further assessment of these proteins and their signaling mechanisms is likely to enhance development of neuroprotective therapies.

Intranasal drug targeting of hypocretin-1 (orexin-A) to the central nervous system.

The blood-brain barrier (BBB) limits the distribution of systemically administered therapeutics to the central nervous system (CNS). Intranasal delivery is a noninvasive method that targets drugs to the brain and spinal cord along olfactory and trigeminal neural pathways, bypassing the BBB and minimizing systemic exposure and side effects. To assess intranasal drug targeting of a neuropeptide (hypocretin-1, HC) to the CNS, pharmacokinetics in blood, CNS tissues, and peripheral tissues were compared after intranasal and intravenous infusion to anesthetized rats. Despite a 10-fold lower blood concentration of HC with intranasal administration, both routes resulted in similar brain concentrations. Tissue-to-blood concentration ratios after intranasal administration were significantly greater in all brain regions over 2 h compared to intravenous administration, with the highest ratios in the trigeminal nerve (14-fold) and olfactory bulbs (9-fold). Intranasal delivery increased drug targeting to the brain and spinal cord 5- to 8-fold. Approximately 80% of the area under the brain concentration-time curve following intranasal administration was due to direct transport from the nasal passages. Intranasal delivery rapidly targets HC to the CNS with minimal systemic exposure, most of which reaches the brain intact by mechanisms not involving distribution from the blood and/or cerebrospinal fluid.

Novel vasoconstrictor formulation to enhance intranasal targeting of neuropeptide therapeutics to the central nervous system.

The intranasal route of drug administration is noninvasive, convenient, and rapidly targets therapeutics to the central nervous system (CNS) using olfactory and trigeminal neural pathways connecting the nasal passages to the brain. The purpose of this research was to enhance intranasal drug targeting to the CNS by incorporating a vasoconstrictor [phenylephrine (PHE)] into nasal formulations containing therapeutic neuropeptides [hypocretin-1 (HC) or the dipeptide L-Tyr-D-Arg (D-KTP)]. Concentrations in CNS tissues, peripheral tissues, and blood were determined at 30 min following intravenous or intranasal administration of (125)I-labeled neuropeptides with and without PHE. Compared with intranasal controls, inclusion of 1% PHE in nasal formulations significantly reduced absorption into the blood for HC (65% reduction) and D-KTP (56% reduction), whereas it significantly increased deposition into the olfactory epithelium by approximately 3-fold for both. PHE (1%) significantly increased delivery to the olfactory bulbs for HC (2.1-fold) and D-KTP (3.0-fold), whereas it significantly reduced concentrations in the trigeminal nerve for HC (65% reduction) and D-KTP (39% reduction) and in most remaining brain regions by approximately 50% for both. The dramatic reduction in blood concentrations with PHE contributed to brain-to-blood concentration ratios that were significantly increased for HC throughout the brain (1.6-6.8-fold) compared with intranasal controls. For D-KTP, 1% PHE significantly increased ratios only in the olfactory bulbs (5.3-fold). With a 5% PHE formulation, D-KTP ratios were significantly increased to additional brain areas (1.5-16-fold). Vasoconstrictor nasal formulations may have particular relevance for CNS therapeutics with adverse side effects where it would be advantageous to limit systemic exposure.

Nasal Colivelin treatment ameliorates memory impairment related to Alzheimer's disease.

Humanin (HN) and its derivatives, such as Colivelin (CLN), suppress neuronal death induced by insults related to Alzheimer's disease (AD) by activating STAT3 in vitro. They also ameliorate functional memory impairment of mice induced by anticholinergic drugs or soluble toxic amyloid-beta (Abeta) in vivo when either is directly administered into the cerebral ventricle or intraperitoneally injected. However, the mechanism underlying the in vivo effect remains uncharacterized. In addition, from the standpoint of clinical application, drug delivery methods that are less invasive and specific to the central nervous system (CNS) should be developed. In this study, we show that intranasally (i.n.) administered CLN can be successfully transferred to CNS via the olfactory bulb. Using several behavioral tests, we have demonstrated that i.n. administered CLN ameliorates memory impairment of AD models in a dose-responsive manner. Attenuation of AD-related memory impairment by HN derivatives such as CLN appears to be correlated with an increase in STAT3 phosphorylation levels in the septohippocampal region, suggesting that anti-AD activities of HN derivatives may be mediated by activation of STAT3 in vivo as they are in vitro. We further demonstrate that CLN treatment inhibits an Abeta induced decrease in the number of choline acetyltransferase (ChAT)-positive neurons in the medial septum. Combined with the finding that HN derivatives upregulate mRNA expression of neuronal ChAT and vesicular acetylcholine transporter (VAChT) in vitro, it is assumed that CLN may ameliorate memory impairment of AD models by supporting cholinergic neurotransmission, which is at least partly mediated by STAT3-mediated transcriptional upregulation of ChAT and VAChT.

A-770041, a novel and selective small-molecule inhibitor of Lck, prevents heart allograft rejection.

Lck, one of eight members of the Src family of tyrosine kinases, is activated after T cell stimulation and is required for T-cell proliferation and interleukin (IL)-2 production. Inhibition of Lck has been a target to prevent lymphocyte activation and acute rejection. Here, we report the pharmacologic characterization of 1-methyl-1H-indole-2-carboxylic acid (4-{1-[4-(4-acetyl-piperazin-l-yl)-cyclohexyl]-4-amino-1H-pyrazolo[3,4-d]pyrimidin-3-yl}-2-methoxy-phenyl)-amide (A-770041), an orally bioavailable pyrazolo[3,4-d]pyrimidine with increased selectivity for Lck compared with previously reported compounds. A-770041 is a 147 nM inhibitor of Lck (1 mM ATP) and is 300-fold selective against Fyn, the other Src family kinase involved in T-cell signaling. Concanavalin A-stimulated IL-2 production in whole blood is inhibited by A-770041 with an EC50 of approximately 80 nM. A-770041 is orally bioavailable (F = 34.1 +/- 7.2% at 10 mg/kg) and has a t(1/2) of 4.1 +/- 0.1 h. Concanavalin A-induced IL-2 production in vivo is inhibited by oral administration of A-770041 (in vivo EC50 = 78 +/- 28 nM). Doses of A-770041 at or above 10 mg/kg/day prevent rejection of hearts transplanted heterotopically in rats from Brown Norway donors to Lewis recipients across a major histocompatibility barrier for least 65 days. Grafts from animals treated with 20 mg/kg/day A-770041 or 10 mg/day Cyclosporin A had minimal microvascular changes or multifocal mononuclear infiltrates. However, mineralization in myocytes from the grafts from A-770041-treated animals was less than animals treated with Cyclosporin A. Lck inhibition is an attractive target to prevent acute rejection.

Small molecules with EGFR-TK inhibitor activity.

Specific and reversible EGFR tyrosine kinase inhibitors (TKI) such as gefitinib and erlotinib are clinically active in advanced or metastatic NSCLC and both are approved in various countries for the treatment of patients that failed prior chemotherapy. Erlotinib has also prolonged survival in pancreatic cancer patients when added to gemcitabine and regulatory approval in this disease is being sought. Additional promising activity has been seen in other tumor types, such as ovarian cancer or head and neck malignancies, and phase III trials in these malignancies are ongoing or planned. Despite these successes, these agents have exhibited anecdotal or modest activity when used as single agents in unselected patients with various other tumor types. We have learned that the clinical development of these agents is far from simple and we need to better understand biological and clinical criteria for patient selection and how to best use the different available agents. The recent discovery of EGFR mutations and the potential identification of other markers that might predict patient response could help to optimize the use of these agents in the future. Irreversible EGFR inhibitors, dual EGF/HER2 and pan-ErbB receptor inhibitors may have greater antitumor activity although the tolerance of these compounds compared to specific EGFR TKIs needs further characterization. HER2 specific TKIs are also in development. Lapatinib, a dual EGFR/HER2 TK inhibitors, is particularly promising in breast cancer. Newer agents, such as BMS-599626, have recently entered into the clinic. In addition to the use of these agents as single agents, many clinical studies are addressing the role of combining them with hormonal agents, biological agents or chemotherapy.

Pharmacokinetic profile of orexin A and effects on plasma insulin and glucagon in the rat.

Orexin A (OXA) is found in the central nervous system (CNS) and in the gut. Peripheral administration of OXA to rats results in an inhibition of fasting motility. Plasma OXA increases during fasting and central administration of OXA increases food intake. The aim of the present study was to assess the pharmacokinetic profile of OXA and the effect of intravenously (i.v.) administered OXA on plasma concentrations of insulin and glucagon concentrations. Rats were given OXA i.v. (100 pmol kg(-1) min(-1)) for time periods of 0, 10, 20, 30 min and for 10, 20, 30 min after ceasing a 30-min infusion. After each time period, rats were then sacrificed and blood obtained. OXA was also administered at increasing doses (0, 100, 300 and 500 pmol kg(-1) min(-1)) for 30 min and blood was obtained. Plasma OXA, insulin and glucagon levels were measured using commercially available radioimmunoassay (RIA) kits. The plasma half-life of OXA was 27.1+/-9.5 min. Stepwise increasing infusion rates of OXA confirmed a linear concentration-time curve and thus first-order kinetics. Its volume of distribution indicated no binding to peripheral tissues. Plasma glucagon decreased during infusion of OXA, while insulin was unaffected. Plasma OXA was raised fourfold after food intake. Thus, OXA has a longer plasma half-life than many other peptides found in the gut. This needs to be taken into account when assessing effects of OXA on biological parameters after peripheral administration.