Name: an in vivo estrogen deficiency mouse model for screening exogenous estrogen treatments of cardiovascular dysfunction after menopause
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Description: Watch this Scientific Journal Video about An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause at JoVE.com

This work was supported by the National Natural Science Foundation of China (81202526 to J.X.), the National Natural Science Foundation of China (81302769 to B.S.), the Beijing Municipal Natural Science Foundation (47144226 to B.S.), the Chinese Postdoctoral Science Foundation (20110490325 to J.X.), and the Ph.D. Programs Foundation of Ministry of Education of China (20121106120031 to B.S.).

All animal care and experimental protocols were approved by the Institutional Animal Care and Use Committee of the Chinese Academy of Medical Sciences and Peking Union Medical College (Permission No.: SYXK (Beijing) 2013-0023). The origin of apoE-/- mice is C57BL/6J9,10.
1. Bilateral Ovariectomy via a Double Dorsal-lateral Incision in apoE-/- Mice
<ol>
	<li>At weaning (age 28 days), anesthetize female apoE-...

<ol>
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K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estrogen+inhibits+vascular+calcification+via+vascular+RANKL+system:+common+mechanism+of+osteoporosis+and+vascular+calcification.">Estrogen inhibits vascular calcification via vascular RANKL system: common mechanism of osteoporosis and vascular calcification.</a> Circulation Research. 107 (4), 466-475 (2010).</li><li>Ivanova, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Screening+of+some+saponins+and+phenolic+components+of+Tribulus+terrestris+and+Smilax+excelsa+as+MDR+modulators.">Screening of some saponins and phenolic components of Tribulus terrestris and Smilax excelsa as MDR modulators.</a> In vivo. 23 (4), 545-550 (2009).</li><li>Xiao, J., Zhu, T., Yin, Y. 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Lack of an effect of added progesterone.</a> Arteriosclerosis. 10 (6), 1051-1057 (1990).</li><li>Keaney, J. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=17+beta-estradiol+preserves+endothelial+vasodilator+function+and+limits+low-density+lipoprotein+oxidation+in+hypercholesterolemic+swine.">17 beta-estradiol preserves endothelial vasodilator function and limits low-density lipoprotein oxidation in hypercholesterolemic swine.</a> Circulation. 89 (5), 2251-2259 (1994).</li><li>Nakashima, Y., Plump, A. S., Raines, E. W., Breslow, J. 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The methodology described here is a mouse model resembling lipid disruption and atherosclerosis seen in menopausal women. It is well-documented that estrogen deficiency in postmenopausal women can aggravate the incidence of pre-existing or ongoing hypercholesterolemia with progressively complex and widespread atherosclerostic lesions1. To mimic the atherosclerosis-prone status in clinic, apoE-deficient mice, a reproducible and convenient source of animals with which to study atherogenesis<sup clas...

Epidemiological and clinical studies have shown that postmenopausal women are at considerably greater risk of cardiovascular disease than premenopausal women1,2. Hormone replacement therapy (HRT) may reduce the relative risk of cardiovascular disease to 0.37-0.793. Among other complications, atherosclerosis caused by cardiovascular diseases is the leading cause of death worldwide4. However, laboratory models involving estrogen-deficient mice presenting atherosclerosis prone status are lacking. This protocol provides an in vivo estrogen deficiency mouse model for screening exogenous estrogen treatments of cardiovascular dysfunction after menopause.
Previous studies show that the application of OVX in atherosclerotic rodents fed a high-cholesterol diet can mimic postmenopausal women suffering from atherosclerosis5,6,7,8. A reproducible and convenient animal model resembling the atherosclerotic state in menopausal women is the basis of exogenous estrogen research. Here, a double dorsal-lateral incision of bilateral ovariectomy was applied in atherosclerosis-prone apolipoprotein E knockout (apoE-/-) mice9,10. Compared with middle abdominal or dorsal incision, double dorsal-lateral incision is an easier, less time-consuming method that can avoid severe abdominal cavity adhesion and inflammation. Peroral administration via hazelnut spread (see Table of Materials) is noninvasive and convenient, rendering it widely applicable as a long-term administration mode11. Slow-release pellet implantation is also popular6. However, implants mayaggravate the incidence of infection especially in mice subjected to OVX. Other noninvasive administration modes, such as oral gavage and water administration, also have many drawbacks. Oral gavage typically stress mice and may cause esophageal injury. Administering the hormone via drinking water is highly beneficial; however, the adding of DMSO as an emulsifier is inevitable as exogenous estrogens are insoluble in water. Here, we chose peroral 17&#946;-estradiol or phytoestrogen hormone replacement via hazelnut spread for long-term administration.
Recently, the beneficial effect of HRT on the cardiovascular system of postmenopausal women has been contested in women&#39;s health initiative (WHI) trials12. On the one hand, exogenous estrogen alone exerts a beneficial effect on the cardiovascular system; on the other hand, it can combine with metohydroxyprogesterone acetate to increase the risk of cardiovascular events. More seriously, HRT may lead to breast and uterine tumor progression, and this effect has markedly limited its use13,14. More interest has been focused on the cardiovascular-protective effects of exogenous estrogens lacking mitotic activity in tumor cells15,16,17. Multiple studies in humans and animals suggest that phytoestrogens with structures similar to that of estrogens can play a beneficial role in cardiovascular protection15,18.
Thus, the aims of the present work are (i) to build an in vivo estrogen deficiency mouse model by bilateral ovariectomy via a double dorsal-lateral incision in apoE-/- mice and (ii) to compare the cardiovascular protective effects of perorally administered 17&#946;-estradiol and pseudoprotodioscin (PPD), via hazelnut spread. 17&#946;-estradiol is one kind of exogenous estrogen that belongs to female sexual hormones6,11,19. PPD, a steroid saponin and phytoestrogen from Dioscorea plants, has been previously reported to exert anti-tumor properties20.

<table>
	<tbody>
		<tr>
			<td>17&#946;-estradiol, &#62;98%</td>
			<td>Sigma-Aldrich</td>
			<td>E8875-250MG</td>
			<td>Estrogen</td>
		</tr>
		<tr>
			<td>Disposable syringes (with 25G needles)</td>
			<td>Hunan Luzhou Huikang Development Co., Ltd</td>
			<td>0.5*19TWLB</td>
			<td>Cardiac bleeding</td>
		</tr>
		<tr>
			<td>High-cholesterol mouse diet</td>
			<td>Huafukang Bio-Technology</td>
			<td>N/A</td>
			<td>1.25% cholesterol, 0% cholate</td>
		</tr>
		<tr>
			<td>High-Resolution In Vivo Micro-Imaging System</td>
			<td>VisualSonics</td>
			<td>Vevo&#174;770</td>
			<td>Measurements of intima-media thickness and cardiac dysfunction</td>
		</tr>
		<tr>
			<td>2-Methyl-2-butanol</td>
			<td>Sigma-Aldrich</td>
			<td>152463-250ML</td>
			<td>Preparation of avertin</td>
		</tr>
		<tr>
			<td>Micro Dissecting forceps, Curved 8mm</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Micro Dissecting forceps, Straight 8mm</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Micro Dissecting Scissors, Curved/Sharp 8mm</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Micro Dissecting Scissors, Straight/Sharp 8mm</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Monofilament suture 4-0 1/2 5*12 19mm</td>
			<td>Shanghai Pudong Jinhuan Medical Supplies Co., Ltd</td>
			<td>R413</td>
			<td>Suture and ligation of the tissues</td>
		</tr>
		<tr>
			<td>Nut cream (Nutella)</td>
			<td>Ferrero</td>
			<td>N/A</td>
			<td>Medium for peroral 17&#946;-estradiol or PPD</td>
		</tr>
		<tr>
			<td>OptiVisor optical glass binocular magnifier</td>
			<td>Dohegan Optical Company Inc.</td>
			<td>N/A</td>
			<td>Assistant of identifying the tissues during ovariectomy</td>
		</tr>
		<tr>
			<td>Phosphate-buffered saline at pH 7.4</td>
			<td>SIGMA</td>
			<td>P3813</td>
			<td>Preparing 1 L saline</td>
		</tr>
		<tr>
			<td>Pro MultiLabel Microplate Reader</td>
			<td>Tecan</td>
			<td>Infinite M1000</td>
			<td>Plasma TC and TG determination</td>
		</tr>
		<tr>
			<td>Pseudoprotodioscin</td>
			<td>Shanghai Winherb Medical S &#38; T Development</td>
			<td>W-0427</td>
			<td>CAS registry no. 102115-79-7</td>
		</tr>
		<tr>
			<td>Rimadyl, 50 mg/mL</td>
			<td>Pfizer Pharma GmbH</td>
			<td>462986</td>
			<td>Postoperative analgesia after ovariectomy</td>
		</tr>
		<tr>
			<td>Sesame oil</td>
			<td>Sigma-Aldrich</td>
			<td>S3547-1L</td>
			<td>Dissolving the 17&#946;-estradiol or PPD</td>
		</tr>
		<tr>
			<td>Solcoseryl Eye-Gel</td>
			<td>Menarini, Solco Basle Ltd.</td>
			<td></td>
			<td>Eye protection during anesthesia</td>
		</tr>
		<tr>
			<td>Stereo microscope</td>
			<td>MCALON</td>
			<td>MCL-6STV</td>
			<td>Image of the intimal region of aorta</td>
		</tr>
		<tr>
			<td>Table model high speed centrifuge</td>
			<td>SIGMA</td>
			<td>1-14K</td>
			<td>Preparation of plasma</td>
		</tr>
		<tr>
			<td>Scissors, slight Curve (14cm)</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Scissors, straight Flat (14cm)</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Tissue forceps, serrated, slight Curve (14cm)</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Tissue forceps, serrated, straight Flat (14cm)</td>
			<td>Kanghua Medical Equipment Co., Ltd</td>
			<td></td>
			<td>Surgical tools</td>
		</tr>
		<tr>
			<td>Tribromoethanol</td>
			<td>Sigma-Aldrich</td>
			<td>T48402-5G</td>
			<td>Preparation of avertin</td>
		</tr>
		<tr>
			<td>Triglycerides (TG) assay kit</td>
			<td>Institute of Nanjing Jiancheng Biology Engineering</td>
			<td>A110-1</td>
			<td>Plasma TG determination</td>
		</tr>
		<tr>
			<td>Total cholesterols (TC) assay kit</td>
			<td>Institute of Nanjing Jiancheng Biology Engineering</td>
			<td>A111-1</td>
			<td>Plasma TC determination</td>
		</tr>
	</tbody>
</table>

an in vivo estrogen deficiency mouse model for screening exogenous estrogen treatments of cardiovascular dysfunction after menopause

Postmenopausal women are at greater risk of developing cardiovascular diseases than premenopausal women. Female mice ovariectomized (OVX) at weaning display increased atherosclerotic lesions in the aorta compared with female mice with intact ovarian function. However, laboratory models involving estrogen-deficient mice with atherosclerosis-prone status are lacking. This deficit is crucial because clinical estrogen deficiency in menopausal women may aggravate the incidence of pre-existing or ongoing lipid disruption and atherosclerosis. In this study, we establish an in vivo estrogen-deficient mouse model by bilateral ovariectomy via a double dorsal-lateral incision in apolipoprotein E (apoE)-/- mice. We then compare the effects of 17&#946;-estradiol and pseudoprotodioscin (PPD) (a phytoestrogen) perorally administered via hazelnut spread. We find that although PPD exerts some effect on reducing final body weight and plasma TG in OVX apoE-/- mice, it has anti-atherosclerotic and cardiac-protective capacities comparable with its 17&#946;-estradiol counterpart. PPD is a phytoestrogen that has been reported to exert anti-tumor properties. Thus, the proposed method is applicable for screening phytoestrogens via peroral administration to substitute for traditional hormone replacement therapy in postmenopausal women, which has been reported to have potentially deleterious tumorigenetic capacity. Peroral administration via hazelnut spread is noninvasive, rendering it widely applicable to many patients. This article contains step-by-step demonstrations of bilateral ovariectomy via the double dorsal-lateral incision in apoE-/- mice and peroral 17&#946;-estradiol or phytoestrogen hormone replacement via hazelnut spread. Plasma lipid and cardiovascular function analyses using echocardiography follow.

A typical experimental treatment scheme, as used in this study, is illustrated in Figure 1. At weaning (age 28 days), female apoE-/- C57BL/6J mice were anesthetized withavertin (tribromoethanol; 200 mg/kg; intraperitoneally). Mice were bilaterally OVX or sham operated through a 1 cm dorsal incision. One week after bilateral OVX, the mice were fed a high-cholesterol diet (1.25% cholesterol, 0% cholate) for 12 weeks. 17&#946;-Estradiol (0.1 mg&#183;k...

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An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause

Clinically, estrogen deficiency in menopausal women may aggravate the incidence of lipid disruption and atherosclerosis. We established an in vivo estrogen deficiency model by bilateral ovariectomy via a double dorsal-lateral incision in apoE-/- mice. The mouse model is applicable for screening exogenous estrogen treatments of cardiovascular dysfunction after menopause.

Postmenopausal women are at greater risk of developing cardiovascular diseases than premenopausal women. Female mice ovariectomized (OVX) at weaning ...

Laboratory models involving estrogen deficient mice presenting an arteriosclerosis pons datas are lacking. This procedure is especially helpful for screening exogenous estrogen treatments of cardiovascular dysfunction after menopause. The main advantage of this technique is that ovariectomy without double dorsolateral incision is a easier, less time-consuming method that avoids severe abdominal cavity adhesion and inflammation.Demonstrating the procedure will be Yue-Zhang Yin, a graduate student from my laboratory. To perform a bilateral ovariectomy in APOE knockout mice, first confirm a lack of response to the pedal reflex and place the animal in the prone position on a heating pad. Apply ointment to the animal's eyes and cover the animal with a surgical drape.Make a one-centimeter incision lateral to the midline, and one centimeter lateral to the costal ribs, and use forceps to bluntly dissect the subcutaneous tissue. Using dissecting goggles, identify the white adipose tissue in the abdominal cavity. Using micro scissors and micro forceps, make a 0.5-to one centimeter incision through the fascia, until the abdominal cavity is reached, and use the micro forceps to gently retract the white adipose tissue.A pink, mulberry-shaped ovary, wrapped in adipose tissue, should be observed within the abdominal cavity. Use a monofilament suture to ligate the 0.5-to one-centimeter proximal vessel and uterine horn, and use the micro scissors to harvest the ovary. Return the remaining tissue to the abdominal cavity, and use individual monofilament sutures to separately close the muscle and skin layers.Then harvest the ovary on the contralateral side of the animal, as just demonstrated, and allow the mouse to recover on a heating pad with monitoring, until full recumbency. Once a week, from the week before to 12 weeks after the surgery, measure the body weight of each sham and experimental animal on a balance. For plasma total cholesterol and triglyceride measurement, at week 12, prepare the ventral chest area with 70%ethanol, and insert a 25-gauge needle into the right ventricle.Aspirate slowly, until one milliliter of blood flows into the syringe, and dispense the sample into a 1.5 milliliter collection tube containing ten microliters of 0.5 molar EDTA. Invert the tube several times thoroughly to mix the EDTA into the blood, and immediately place the tube on ice. Within 30 minutes of collection, centrifuge the sample for 20 minutes at 400 times G and four degrees Celsius.Carefully collect the plasma supernatant for storage at minus 80 degrees Celsius. To isolate the aorta, at week 12, attach a 25-gauge needle to a 50 milliliter syringe filled with PBS, and insert the needle into the left ventricle of the experimental animal. Cut the right atrium to avoid high pressure from the perfusion, and perfuse the cardiac tissue at a 05 to 08 milliliters of PBS per minute rate of flow.Absorb the perfusion fluid with lab tissues and use scissors and forceps to remove the ribs and lungs. Open the abdominal cavity to remove the internal organs, for a better view of the aorta. Grasp the heart with micro forceps to allow separation of the aorta dorsally, from the spine, until the iliac bifurcation.Then fix the heart and aorta for 48 hours in 4%paraformaldehyde, before storing the tissue sample in saline at room temperature or at two to eight degrees Celsius for a few hours. After twelve weeks of a high-cholesterol diet, ovariectomized mice demonstrate a remarkable increase in plasma total cholesterol and triglyceride concentrations. Ovariectomized mice, per orally administered with 17-beta oestradiol, or PPD via hazelnut spread, exhibit significantly lower plasma total cholesterol concentrations than sham-operated mice.Plasma triglyceride levels decrease in ovariectomized mice, per orally administered with 17-beta oestradiol, but not with PPD. While a tendency toward an increased body weight is observed in ovariectomized mice, compared to sham-operated mice, no significant changes in body weight are observed overall, between the four groups of animals. The maximal plaque of the ascending aorta is increased in ovariectomized mice, compared to all other groups, in conjunction with an overall decrease in cardiac function, observed in these animals.Further, the average percentage of aortic lesion area, relative to the entire aortic area, is significantly increased in ovariectomized mice. As expected, the presence of these lesions is decreased with 17-beta oestradiol, or PPD treatment. The main risk for the ovariectomy operation is ureteral ligation, which results in a high mortality.Also remember to cut deeply near the renal artery branches, to avoid aortic damage.

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Research

JoVE Journal

Biochemistry

Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase

Activity-based protein profiling (ABPP) is a method for the identification of an enzyme of interest in a complex proteome through the use of a chemical probe that targets the enzyme&#39;s active sites. A reporter tag introduced into the probe allows for the detection of the labeled enzyme by in-gel fluorescence scanning, protein blot, fluorescence microscopy, or liquid chromatography-mass spectrometry. Here, we describe the preparation and use of the compound ARN14686, a click chemistry activity-based probe (CC-ABP) that selectively recognizes the enzyme N-acylethanolamine acid amidase (NAAA). NAAA is a cysteine hydrolase that promotes inflammation by deactivating endogenous peroxisome proliferator-activated receptor (PPAR)-alpha agonists such as palmitoylethanolamide (PEA) and oleoylethanolamide (OEA). NAAA is synthesized as an inactive full-length proenzyme, which is activated by autoproteolysis in the acidic pH of the lysosome. Localization studies have shown that NAAA is predominantly expressed in macrophages and other monocyte-derived cells, as well as in B-lymphocytes. We provide examples of how ARN14686 can be used to detect and quantify active NAAA ex vivo in rodent tissues by protein blot and fluorescence microscopy.

Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase

Here, we describe the preparation and use of an activity-based probe (ARN14686, undec-10-ynyl-N-[(3S)-2-oxoazetidin-3-yl]carbamate) that allows for the detection and quantification of the active form of the proinflammatory enzyme N-acylethanolamine acid amidase (NAAA), both in vitro and ex vivo.

Activity-based protein profiling (ABPP) is a method for the identification of an enzyme of interest in a complex proteome through the use of a chemical ...

Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization

Assessing the synaptic protein composition and function constitutes an important challenge in neuroscience. However, it is not easy to evaluate neurotransmission that occurs within synapses because it is highly regulated by dynamic protein-protein interactions and phosphorylation events. Accordingly, when any method is used to study synaptic transmission, a major goal is to preserve these transient physiological modifications. Here, we present a brain membrane fractionation protocol that represents a robust procedure to isolate proteins belonging to different synaptic compartments. In other words, the protocol describes a biochemical methodology to carry out protein enrichment from presynaptic, postsynaptic, and extrasynaptic compartments. First, synaptosomes, or synaptic terminals, are obtained from neurons that contain all synaptic compartments by means of a discontinuous sucrose gradient. Of note, the quality of this initial synaptic membrane preparation is critical. Subsequently, the isolation of the different subsynaptic compartments is achieved with light solubilization using mild detergents at differential pH conditions. This allows for separation by gradient and isopycnic centrifugations. Finally, protein enrichment at the different subsynaptic compartments (i.e., pre-, post- and extrasynaptic membrane fractions) is validated by means of immunoblot analysis using well-characterized synaptic protein markers (i.e., SNAP-25, PSD-95, and synaptophysin, respectively), thus enabling a direct assessment of the synaptic distribution of any particular neuronal protein.

Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization

Here, we present a brain membrane fractionation protocol that represents a robust procedure to isolate proteins belonging to different synaptic compartments.

Assessing the synaptic protein composition and function constitutes an important challenge in neuroscience. However, it is not easy to evaluate ...

Measuring and Interpreting Oxygen Consumption Rates in Whole Fly Head Segments

Regulated metabolic activity is essential for the normal functioning of living cells. Indeed, altered metabolic activity is causally linked with the progression of cancer, diabetes, neurodegeneration, and aging to name a few. For instance, changes in mitochondrial activity, the cell&#39;s metabolic powerhouse, have been characterized in many such diseases. Generally, the oxygen consumption rates of mitochondria were considered a reliable readout of mitochondrial activity and measurements in some of these studies were based on isolated mitochondria or cells. However, such conditions may not represent the complexity of a whole tissue. Recently, we have developed a novel method that enables the dynamic measurement of oxygen consumption rates from whole isolated fly heads. By utilizing this method, we have recorded lower oxygen consumption rates of the whole head segment in young versus aged flies. Secondly, we have discovered that lysine deacetylase inhibitors rapidly alter the oxygen consumption in the whole head. Our novel technique may therefore aid in uncovering new properties of various drugs, which may impact metabolic rates. Furthermore, our method may give a better understanding of metabolic behavior in an experimental setup that more closely resembles physiological states.

Measuring alterations in metabolic rates is central to understanding the progression of various diseases and aging. Here, we present a novel technique to measure whole head oxygen consumption that more closely resembles the physiological state and may aid in revealing novel drugs that modify mitochondrial activity.

Regulated metabolic activity is essential for the normal functioning of living cells. Indeed, altered metabolic activity is causally linked with the ...

Kinase Inhibitor Screening In Self-assembled Human Protein Microarrays

The screening of kinase inhibitors is crucial for better understanding properties of a drug and for the identification of potentially new targets with clinical implications. Several methodologies have been reported to accomplish such screening. However, each has its own limitations (e.g., the screening of only ATP analogues, restriction to using purified kinase domains, significant costs associated with testing more than a few kinases at a time, and lack of flexibility in screening protein kinases with novel mutations). Here, a new protocol that overcomes some of these limitations and can be used for the unbiased screening of kinase inhibitors is presented. A strength of this method is its ability to compare the activity of kinase inhibitors across multiple proteins, either between different kinases or different variants of the same kinase. Self-assembled protein microarrays generated through the expression of protein kinases by a human-based in vitro transcription and translation system (IVTT) are employed. The proteins displayed on the microarray are active, allowing for measurement of the effects of kinase inhibitors. The following procedure describes the protocol steps in detail, from the microarray generation and screening to the data analysis.

A detailed protocol for the generation of self-assembled human protein microarrays for the screening of kinase inhibitors is presented.

The screening of kinase inhibitors is crucial for better understanding properties of a drug and for the identification of potentially new targets with ...

Screening for Thermotoga maritima Membrane-Bound Pyrophosphatase Inhibitors

Membrane-bound pyrophosphatases (mPPases) are dimeric enzymes that occur in bacteria, archaea, plants, and protist parasites. These proteins cleave pyrophosphate into two orthophosphate molecules, which is coupled with proton and/or sodium ion pumping across the membrane. Since no homologous proteins occur in animals and humans, mPPases are good candidates in the design of potential drug targets. Here we present a detailed protocol to screen for mPPase inhibitors utilizing the molybdenum blue reaction in a 96 well plate system. We use mPPase from the thermophilic bacterium Thermotoga maritima (TmPPase) as a model enzyme. This protocol is simple and inexpensive, producing a consistent and robust result. It takes only about one hour to complete the activity assay protocol from the start of the assay until the absorbance measurement. Since the blue color produced in this assay is stable for a long period of time, subsequent assay(s) can be performed immediately after the previous batch, and the absorbance can be measured later for all batches at once. The drawback of this protocol is that it is done manually and thus can be exhausting as well as require good skills of pipetting and time keeping. Furthermore, the arsenite-citrate solution used in this assay contains sodium arsenite, which is toxic and should be handled with necessary precautions.

Screening for Thermotoga maritima Membrane-Bound Pyrophosphatase Inhibitors

Here we present a screening method for membrane-bound pyrophosphatase (from Thermotoga maritima) inhibitors based on the molybdenum blue reaction in a 96 well plate format.

Membrane-bound pyrophosphatases (mPPases) are dimeric enzymes that occur in bacteria, archaea, plants, and protist parasites. These proteins cleave ...

Visualization of Estrogen Receptors in Colons of Mice with TNBS-Induced Crohn's Disease using Immunofluorescence

Crohn&#39;s disease is the most diagnosed type of inflammatory bowel disease. Chronic inflammation developing in the intestine leads to peristalsis disorder and damage of intestinal mucosa and seems to be associated with an increased risk of colon neoplastic transformation. Accumulating evidence indicates that estrogens and estrogen receptors affect not only hormone-sensitive tissues, but also other tissues not directly related to estrogens, such as the lungs or colon. Here, we describe the protocol for the successful immunofluorescence staining of estrogen receptors in colon obtained from a murine model of TNBS-induced Crohn&#39;s disease. A detailed protocol for the induction of Crohn&#39;s disease in mice and intestine preparation is provided as well as a step-by-step immunohistochemical procedure using formalin-fixed paraffin-embedded intestine sections. The described methods are not only useful for estrogen receptor detection and estrogen signaling investigation in vivo but can also be applied to for other proteins which may be involved in the development of colitis.

Visualization of Estrogen Receptors in Colons of Mice with TNBS-Induced Crohn&#039;s Disease using Immunofluorescence

The protocol presents a complete validated TNBS-induced murine model of Crohn&#39;s disease and methods for visualization of estrogen receptors by immunohistochemistry using immunofluorescence of formalin-fixed colon sections embedded in paraffin.

Crohn&#39;s disease is the most diagnosed type of inflammatory bowel disease. Chronic inflammation developing in the intestine leads to peristalsis ...

Screening for Phytoestrogens using a Cell-based Estrogen Receptor  &#946; Reporter Assay

Plants are a source of food for many animals, and&#160;they can produce thousands of chemicals. Some of these compounds affect physiological processes in the vertebrates that consume them, such as endocrine function. Phytoestrogens, the most well studied endocrine-active phytochemicals, directly interact with the hypothalamo-pituitary gonadal axis of the vertebrate endocrine system. Here we present the novel use of a cell-based assay to screen plant extracts for the presence of compounds that have estrogenic biological activity. This assay uses mammalian cells engineered to highly express estrogen receptor beta (ER&#946;) and that have been transfected with a luciferase gene. Exposure to compounds with estrogenic activity results in the cells producing light. This assay is a reliable and simple way to test for biological estrogenic activity. It has several improvements over transient transfection assays, most notably, ease of use, the stability of the cells, and the sensitivity of the assay.

Screening for Phytoestrogens using a Cell-based Estrogen Receptor  &amp;#946; Reporter Assay

We have optimized a commercially available estrogen receptor &#946; reporter assay for screening human and nonhuman primate foods for estrogenic activity. We validated this assay by showing that the known estrogenic human food soy registers high, while other foods show no activity.

Plants are a source of food for many animals, and&#160;they can produce thousands of chemicals. Some of these compounds affect physiological processes in ...

Transplantation of Neonatal Mouse Cardiac Macrophages into Adult Mice

In an injured neonatal myocardium, macrophages facilitate cardiomyocyte proliferation and angiogenesis and promote heart regeneration. The present study reveals that transplantation of neonatal cardiac macrophages recruited by injury promotes adult heart regeneration after myocardial infarction with improvement of cardiac function and cardiomyocyte proliferation. The results indicate that neonatal cardiac macrophage transplantation could be a promising strategy for cardiac injury treatment. Here, we provide the technical details, including the isolation of neonatal cardiac macrophages from apical resection-injured neonatal mouse hearts, the transplantation of macrophages into myocardial-infarcted adult mice, and the estimation of heart regeneration after a macrophage graft.

We provide a protocol for neonatal cardiac macrophage separation and transplantation into an adult mouse heart, which could be a promising way to promote cardiac repair.

In an injured neonatal myocardium, macrophages facilitate cardiomyocyte proliferation and angiogenesis and promote heart regeneration. The present study ...

Nano-Differential Scanning Fluorimetry for Screening in Fragment-based Lead Discovery

Thermal shift assays (TSAs) examine how the melting temperature (Tm) of a target protein changes in response to changes in its environment (e.g., buffer composition). The utility of TSA, and specifically of nano-Differential Scanning Fluorimetry (nano-DSF), has been established over the years, both for finding conditions that help stabilize a specific protein and for looking at ligand binding by monitoring changes in the apparent Tm. This paper presents an efficient screening of the Diamond-SGC-iNEXT Poised (DSi-Poised) fragment library (768 compounds) by the use of nano-DSF, monitoring Tm to identify potential fragment binding. The prerequisites regarding protein quality and concentration for performing nano-DSF experiments are briefly outlined followed by a step-by-step protocol that uses a nano-liter robotic dispenser commonly used in structural biology laboratories for preparing the required samples in 96-well plates. The protocol describes how the reagent mixtures are transferred to the capillaries needed for nano-DSF measurements. In addition, this paper provides protocols to measure thermal denaturation (monitoring intrinsic tryptophan fluorescence) and aggregation (monitoring light back-scattering) and the subsequent steps for data transfer and analysis. Finally, screening experiments with three different protein targets are discussed to illustrate the use of this procedure in the context of lead discovery campaigns. The overall principle of the method described can be easily transferred to other fragment libraries or adapted to other instruments.

Monitoring changes in the melting temperature of a target protein (i.e., thermal shift assay, TSA) is an efficient method for screening fragment libraries of a few hundred compounds. We present a TSA protocol implementing robotics-assisted nano-Differential Scanning Fluorimetry (nano-DSF) for monitoring intrinsic tryptophan fluorescence and light back-scattering for fragment screening.

Thermal shift assays (TSAs) examine how the melting temperature (Tm) of a target protein changes in response to changes in its environment (e.g., buffer ...

Ex Vivo Hepatic Perfusion Through the Portal Vein in Mouse

Metabolic diseases such as diabetes, pre-diabetes, non-alcoholic fatty liver disease (NAFLD), and nonalcoholic steatohepatitis (NASH) are becoming increasingly common. Ex vivo liver perfusions allow for a comprehensive analysis of liver metabolism using nuclear magnetic resonance (NMR), in nutritional conditions that can be rigorously controlled. As in silico simulations remain a primarily theoretical means of assessing hormone actions and the effects of pharmaceutical intervention, the perfused liver remains one of the most valuable test beds for understanding hepatic metabolism. As these studies guide basic insights into hepatic physiology, results must be accurate and reproducible. The greatest factor in the reproducibility of ex vivo hepatic perfusion is the quality of surgery. Therefore, we have introduced an organized and streamlined method to perform ex vivo mouse liver perfusions in the context of in situ NMR experiments. We also describe a unique application and discuss common issues encountered in these studies. The overall purpose is to provide an uncomplicated guide to a technique we have refined over several years that we deem the golden standard for obtaining reproducible results in hepatic resections and perfusions in the context of in situ NMR experiments. The distance to the center of the field for the magnet as well as the inaccessibility of the tissue to intervention during the NMR experiment makes our methods novel.

Ex Vivo Hepatic Perfusion Through the Portal Vein in Mouse

The protocol describes a straightforward method of resectioning an intact mouse liver for metabolic studies through portal vein perfusion.