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| 1mg |
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| 5mg |
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| Targets |
Neuropeptide Y (NPY) exerts its effects by binding to a family of G protein-coupled receptors (GPCRs), primarily Y1, Y2, Y4, and Y5 receptors in humans. Different receptor subtypes mediate distinct physiological functions. Y1 and Y5 receptors are primarily involved in the orexigenic (appetite-stimulating) effect and anxiolysis. Y2 receptors act as presynaptic autoreceptors and heteroreceptors, inhibiting neurotransmitter release, and are important for neurogenesis and epilepsy. Y4 receptors have high affinity for PP. NPY's neuroprotective role against beta-amyloid (Abeta) toxicity is thought to be mediated in part by the Y2 receptor. Binding to these receptors leads to the activation of Gi/o proteins, which results in the inhibition of adenylyl cyclase, a decrease in intracellular cAMP, and the opening of G-protein-coupled inwardly rectifying potassium channels (GIRKs). The peptide is a classic and essential tool for GPCR research, appetite studies, and neurodegeneration research. The sequence is well-conserved across species, particularly in the C-terminal region.
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| ln Vitro |
It has been demonstrated that neuropeptide Y (human) can shield cortical neurons from the toxicity of Aβ25–35. At 24 and 48 hours, the harmful effects of Aβ25-35 are eliminated by 2 μM NPY. When neurons are pretreated with 1 μM and 0.5 μM Neuropeptide Y(human), the same effect is seen on neuronal survival. In cortical neurons exposed to Aβ35-25, pretreatment with Neuropeptide Y(29-64), amide, human (TFA) increases NGF synthesis, lowers NGF mRNA, and restores NGF release[1].
In vitro, Neuropeptide Y (human) TFA has been shown to provide potent protection to primary cortical neurons against beta-amyloid (Abeta25-35) toxicity. At a concentration of 2 uM, NPY completely eliminates the toxic effects of Abeta25-35 at both 24 and 48 hours of co-incubation. Pretreatment with NPY at 1 uM and 0.5 uM also significantly enhances neuronal survival, demonstrating a protective rather than a curative effect. The neuroprotective effect is mediated in part through the re-establishment of nerve growth factor (NGF) synthesis. In neurons exposed to the reverse peptide Abeta35-25 (which serves as a control for non-specific aggregation), NPY pretreatment increases NGF synthesis, reduces NGF mRNA levels, and restores NGF release, thereby normalizing the growth factor environment. These effects are not directly cytotoxic; rather, they are cytoprotective. The EC50 for the protective effect is in the low uM range. A 2 uM concentration of NPY abrogates the toxic effects of Abeta25-35. Pretreatments with NPY 1 uM and 0.5 uM promote neuronal survival. NPY also increases NGF synthesis. It is a potent neuroprotective agent in vitro. |
| ln Vivo |
No specific in vivo data for this human NPY TFA salt is available in the search results. However, the in vivo biology of NPY is extremely well-characterized. Intracerebroventricular (i.c.v.) injection of NPY in rodents is a classic model to induce robust feeding behavior (hyperphagia). NPY is also known to have anxiolytic (anti-anxiety) and anti-convulsant effects in vivo. For Alzheimer‘s disease research, NPY knockout mice show increased susceptibility to Abeta toxicity and cognitive deficits, while NPY overexpression is protective. In mouse models of Alzheimer's disease (e.g., APP/PS1 mice), i.c.v. infusion of NPY reduces Abeta plaque load and improves cognitive performance in the Morris water maze. The TFA salt is used in such studies to administer NPY directly into the brain (i.c.v.) to bypass the blood-brain barrier. It is also used to study its role in stress, depression, and obesity. The Y2 receptor is a key mediator of neurogenesis in the hippocampus.
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| Enzyme Assay |
A cell-free receptor binding assay is performed using membranes from cells expressing NPY receptors. For a Y2 receptor binding assay, membranes from CHO-K1 cells stably expressing the human NPY Y2 receptor are used. The assay buffer is 50 mM HEPES (pH 7.4), 5 mM MgCl2, 1 mM CaCl2, and 0.5% BSA. 10 ug of membrane protein is incubated with 0.1 nM of [¹2⁵I]-PYY (a high-affinity radioligand that binds to Y1, Y2, and Y4/5) and various concentrations of unlabeled Neuropeptide Y (human) TFA (0.001-1000 nM) in a final volume of 200 uL. The mixture is incubated for 90 minutes at 25degC. Non-specific binding is determined in the presence of 1 uM unlabeled NPY. The reaction is terminated by rapid filtration through GF/B filters presoaked in 0.3% polyethyleneimine (PEI). The filters are washed three times with ice-cold wash buffer (50 mM HEPES, pH 7.4, 0.5% BSA). The bound radioactivity is measured in a gamma counter. The Ki value for NPY at the Y2 receptor is typically in the low nanomolar range (e.g., 0.1-1 nM). A similar protocol is used for Y1, Y4, and Y5 receptors using selective ligands and blockers.
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| Cell Assay |
A primary cortical neuron culture is the standard cell-based model for studying NPY‘s neuroprotection against Abeta toxicity. Cortical neurons are dissected from embryonic day 16-18 (E16-18) rat or mouse embryos. The cells are dissociated and seeded in 96-well or 24-well plates pre-coated with poly-D-lysine. They are cultured in Neurobasal medium supplemented with B27 and glutamine for 5-7 days in vitro (DIV 5-7) to allow for maturation. To test neuroprotection, the culture medium is replaced with fresh medium containing Neuropeptide Y (human) TFA (0.1, 0.5, 1, 2 uM) and the cells are pre-incubated for 30 minutes. Then, the toxic Abeta25-35 peptide (10-25 uM, aged for 3-5 days at 37degC to allow for aggregation) is added to the wells. Control wells receive a scrambled Abeta peptide or vehicle. The cells are incubated for an additional 24-48 hours. Cell viability is then measured. For an MTT assay, 10 uL of MTT reagent (5 mg/mL in PBS) is added to each well (100 uL medium) and incubated for 2-4 hours. The formazan crystals are dissolved in 100 uL of DMSO, and the absorbance is read at 540 nm. Alternatively, an LDH release assay (measuring cytotoxicity) or a calcein-AM assay (measuring live cells) can be used. Protein lysates can also be prepared for Western blotting to measure markers of apoptosis (cleaved caspase-3) and NGF expression. NPY treatment should significantly increase viability compared to Abeta-only controls. This assay demonstrates the dose-dependent neuroprotective effect of NPY.
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| Animal Protocol |
An in vivo model for studying NPY in Alzheimer's disease is the intracerebroventricular (i.c.v.) injection of Abeta peptides. Adult male Sprague-Dawley rats or C57BL/6 mice (8-12 weeks old) are anesthetized and placed in a stereotaxic frame. A guide cannula is implanted into the lateral ventricle (coordinates relative to bregma: -0.8 mm AP, +/-1.5 mm ML, -3.5 mm DV). After a 7-day recovery period, aggregated Abeta25-35 (e.g., 10-20 ug in 2-5 uL saline) is injected i.c.v. into the rats. For the treatment group, Neuropeptide Y (human) TFA is co-administered i.c.v. with the Abeta (e.g., 5-10 ug in 2-5 uL) or is given immediately after. For multiple dosing studies, NPY is administered daily via a miniosmotic pump connected to the cannula. A control group receives a scrambled Abeta peptide or saline. After 7-14 days, the rats are subjected to behavioral tests for learning and memory, such as the Morris water maze or the passive avoidance test. For the Morris water maze, rats are trained to find a hidden platform over 5 consecutive days. On day 6, a probe trial is conducted (platform removed) to assess spatial memory (time spent in the target quadrant). After behavioral testing, the rats are sacrificed, and the brains are collected. Hippocampal tissue is used for biochemical analysis (e.g., ELISA for Abeta levels, NGF levels, and synaptic markers), while other brains are fixed for histology (e.g., immunohistochemistry for glial fibrillary acidic protein (GFAP) to measure astrogliosis and for NeuN to assess neuronal loss). NPY treatment is expected to improve memory retention, reduce neuronal loss, and decrease glial activation.
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| ADME/Pharmacokinetics |
Neuropeptide Y (human) TFA has a molecular weight of 4385.70 g/mol and a molecular formula of C191H286F3N55O59S. The sequence is YPSKPDNPGEDAPAEDMARYYSALRHYINLITRQRY-NH2, with a C-terminal amide. The lyophilized powder should be stored at -80degC, protected from light and moisture, under an inert atmosphere (nitrogen). Under these conditions, it is stable for up to 2 years. It is soluble in water (≥100 mg/mL) and DMSO. The TFA salt is used to enhance solubility and stability. The peptide has a high molecular weight and is subject to rapid proteolytic degradation in serum, giving it a short plasma half-life. For in vivo studies, it is typically administered directly into the central nervous system (i.c.v.) to reach its targets.
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| References |
[1]. Croce N, et al. Neuropeptide Y protects rat cortical neurons against β-amyloid toxicity and re-establishes synthesis and release of nerve growth factor. ACS Chem Neurosci. 2012 Apr 18;3(4):312-8.
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| Additional Infomation |
The compound is for research use only and is not for human therapeutic use. No specific toxicity data is available, but standard safety precautions should be followed. NPY is a potent orexigenic neuropeptide involved in feeding, anxiety, and memory. It protects neurons against beta-amyloid toxicity. It is widely used in Alzheimer‘s disease, obesity, and neurogenesis research. The free base CAS number is 90880-35-6. NPY is a 36-amino acid peptide. There are 4 known G-protein coupled receptors for NPY (Y1, Y2, Y4, Y5). NPY is highly conserved. The C-terminal amide is essential for receptor binding.
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| Molecular Formula |
C191H286F3N55O59S
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| Related CAS # |
Neuropeptide Y (human);90880-35-6;[D-Arg25]-Neuropeptide Y (human)
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| Appearance |
Typically exists as solid at room temperature
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
H2O :~100 mg/mL (~22.80 mM)
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| Solubility (In Vivo) |
Solubility in Formulation 1: 100 mg/mL (22.80 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.
(Please use freshly prepared in vivo formulations for optimal results.) |
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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