<meta charset="utf8"></head><body>使用异凝集素 B4 染色评估小鼠的肺微血管系统

<ol>
	<li>Jia, T., 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=Fgf-2+promotes+angiogenesis+through+a+srsf1/srsf3/srpk1-dependent+axis+that+controls+vegfr1+splicing+in+endothelial+cells.">Fgf-2 promotes angiogenesis through a srsf1/srsf3/srpk1-dependent axis that controls vegfr1 splicing in endothelial cells.</a> BMC Biol. 19 (1), 173 (2021).</li><li>Schneider, J. L., 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=The+aging+lung:+Physiology,+disease,+and+immunity.">The aging lung: Physiology, disease, and immunity.</a> Cell. 184 (8), 1990-2019 (2021).</li><li>Rafii, S., Butler, J. M., Ding, B. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Angiocrine+functions+of+organ-specific+endothelial+cells.">Angiocrine functions of organ-specific endothelial cells.</a> Nature. 529 (7586), 316-325 (2016).</li><li>Lipskaia, L., 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=Induction+of+telomerase+in+p21-positive+cells+counteracts+capillaries+rarefaction+in+aging+mice+lung.">Induction of telomerase in p21-positive cells counteracts capillaries rarefaction in aging mice lung.</a> bioRxiv. , (2022).</li><li>Hoshino, M., Takahashi, M., Aoike, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+vascular+endothelial+growth+factor,+basic+fibroblast+growth+factor,+and+angiogenin+immunoreactivity+in+asthmatic+airways+and+its+relationship+to+angiogenesis.">Expression of vascular endothelial growth factor, basic fibroblast growth factor, and angiogenin immunoreactivity in asthmatic airways and its relationship to angiogenesis.</a> J Allergy Clin Immunol. 107 (2), 295-301 (2001).</li><li>Ackermann, M., 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=Pulmonary+vascular+endothelialitis,+thrombosis,+and+angiogenesis+in+covid-19.">Pulmonary vascular endothelialitis, thrombosis, and angiogenesis in covid-19.</a> New Engl J Med. 383 (2), 120-128 (2020).</li><li>Wertheim, B. M., 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=Isolating+pulmonary+microvascular+endothelial+cells+ex+vivo:+Implications+for+pulmonary+arterial+hypertension,+and+a+caution+on+the+use+of+commercial+biomaterials.">Isolating pulmonary microvascular endothelial cells ex vivo: Implications for pulmonary arterial hypertension, and a caution on the use of commercial biomaterials.</a> PLoS One. 14 (2), e0211909 (2019).</li><li>Thomas, S. M., Bednarek, J., Janssen, W. J., Hume, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Air-inflation+of+murine+lungs+with+vascular+perfusion-fixation.">Air-inflation of murine lungs with vascular perfusion-fixation.</a> J Vis Exp. (168), e62215 (2021).</li><li>Ramasamy, S. K., Kusumbe, A. P., Adams, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+tissue+morphogenesis+by+endothelial+cell-derived+signals.">Regulation of tissue morphogenesis by endothelial cell-derived signals.</a> Trends Cell Biol. 25 (3), 148-157 (2015).</li><li>Amersfoort, J., Eelen, G., Carmeliet, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunomodulation+by+endothelial+cells+-+partnering+up+with+the+immune+system.">Immunomodulation by endothelial cells - partnering up with the immune system.</a> Nat Rev Immunol. 22 (9), 576-588 (2022).</li><li>Niethamer, T. 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=Defining+the+role+of+pulmonary+endothelial+cell+heterogeneity+in+the+response+to+acute+lung+injury.">Defining the role of pulmonary endothelial cell heterogeneity in the response to acute lung injury.</a> eLife. 9, e53072 (2020).</li><li>Corliss, B. A., Mathews, C., Doty, R., Rohde, G., Peirce, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+to+label,+image,+and+analyze+the+complex+structural+architectures+of+microvascular+networks.">Methods to label, image, and analyze the complex structural architectures of microvascular networks.</a> Microcirculation. 26 (5), e12520 (2019).</li><li>Phillips, M. R., 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=A+method+for+evaluating+the+murine+pulmonary+vasculature+using+micro-computed+tomography.">A method for evaluating the murine pulmonary vasculature using micro-computed tomography.</a> J Surg Res. 207, 115-122 (2017).</li><li>Chadwick, E. 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=Vessel+network+extraction+and+analysis+of+mouse+pulmonary+vasculature+via+x-ray+micro-computed+tomographic+imaging.">Vessel network extraction and analysis of mouse pulmonary vasculature via x-ray micro-computed tomographic imaging.</a> PLoS Comput Biol. 17 (4), e1008930 (2021).</li></ol>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>4% Paraformaldehyde</td>
			<td>Biosharp</td>
			<td>BL539A</td>
			<td>Tissue Fixative</td>
		</tr>
		<tr>
			<td>4&#39;,6-diamidino-2-phenylindole</td>
			<td>MCE</td>
			<td>HY-D0814</td>
			<td>Nucleic Dyes</td>
		</tr>
		<tr>
			<td>Alexa-647 Fluor Conjugated Isolectin B4</td>
			<td>Thermo</td>
			<td>I32450</td>
			<td>Binding Microvessels</td>
		</tr>
		<tr>
			<td>Anti-fluorescent Tablet Sealer</td>
			<td>Abcam</td>
			<td>AB104135</td>
			<td>Sample Fixation</td>
		</tr>
		<tr>
			<td>Antigen Repair Fluid</td>
			<td>Biosharp</td>
			<td>BL151A</td>
			<td>Repair of Antigenic Sites</td>
		</tr>
		<tr>
			<td>Biopsy Cassette</td>
			<td>ActivFlo</td>
			<td>39LC-500-1</td>
			<td>Fixing and Positioning Tissue Samples</td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin</td>
			<td>Sigma</td>
			<td>B2064-50G</td>
			<td>Sealing Solution</td>
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			<td>Cold Plate</td>
			<td>Leica</td>
			<td>HistoCore Arcadia H&#160;</td>
			<td>Freezing Samples</td>
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		<tr>
			<td>Constant Temperature Electric Drying Oven</td>
			<td>Taisite</td>
			<td>101-0AB</td>
			<td>High Temperature Repair</td>
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		<tr>
			<td>Disposable Microtome Blade</td>
			<td>Leica</td>
			<td>14035838383</td>
			<td>Cutting Tissue Samples to Prepare Sections</td>
		</tr>
		<tr>
			<td>Embedding Molds</td>
			<td>Shitai</td>
			<td>26155166627</td>
			<td>Fixing Tissue Samples</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Kelong</td>
			<td>CAS 64-17-5</td>
			<td>Tissue Dehydration Solution</td>
		</tr>
		<tr>
			<td>Heated Paraffin Embedding Station</td>
			<td>Leica</td>
			<td>EG1150</td>
			<td>Embedding Tssue Samples in Paraffin</td>
		</tr>
		<tr>
			<td>HistoCore Water Bath</td>
			<td>Leica</td>
			<td>HI1220</td>
			<td>Flatten and Fix Tissue Samples</td>
		</tr>
		<tr>
			<td>ImageJ (Fiji)&#160;</td>
			<td>NIH</td>
			<td>1.54f</td>
			<td>Quantitative Tool</td>
		</tr>
		<tr>
			<td>Immunohistochemistry Pens</td>
			<td>Biosharp</td>
			<td>BC004</td>
			<td>Water-blocking Agent</td>
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		<tr>
			<td>Medical Forceps</td>
			<td>Shanghai Medical Equipment</td>
			<td>N/A</td>
			<td>Grasping, Manipulating, or Moving tissue samples</td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Nikon</td>
			<td>Ts2</td>
			<td>Imaging Device</td>
		</tr>
		<tr>
			<td>Mounting Media</td>
			<td>Jiangyuan</td>
			<td>Tasteless</td>
			<td>Fixing and Preserving Tissue Sections</td>
		</tr>
		<tr>
			<td>Paraffin Wax</td>
			<td>SCHLEDEN</td>
			<td>80200-0014</td>
			<td>Fixing Tissue Structure</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Beyotime</td>
			<td>C0221A</td>
			<td>Wash Buffer</td>
		</tr>
		<tr>
			<td>Pentobarbital Sodium</td>
			<td>Beijing Chemical Reagent Company</td>
			<td>Q/H82-F158-2002</td>
			<td>Anesthetic</td>
		</tr>
		<tr>
			<td>Rotary Microtome</td>
			<td>Biobase</td>
			<td>Bk-2258</td>
			<td>Preparing Slices</td>
		</tr>
		<tr>
			<td>Sterile Scissors</td>
			<td>Shanghai Medical Equipment</td>
			<td>N/A</td>
			<td>segmenting Tissue Samples</td>
		</tr>
		<tr>
			<td>Surgical Scalpel</td>
			<td>Shanghai Medical Equipment</td>
			<td>N/A</td>
			<td>Cutting Tissue Samples</td>
		</tr>
		<tr>
			<td>Triton&#160;</td>
			<td>Solarbio</td>
			<td>T8200</td>
			<td>Permeabilization Solution</td>
		</tr>
		<tr>
			<td>Wash-Free Slide</td>
			<td>PLATINUM PRO</td>
			<td>PRO-04</td>
			<td>Fixing Samples for Staining</td>
		</tr>
		<tr>
			<td>Xylene</td>
			<td>SUM</td>
			<td>XK13-011-00031</td>
			<td>Tissue De-waxing Solution</td>
		</tr>
	</tbody>
</table>

quantifying pulmonary microvascular density in mice across lobules

<meta charset="utf8"></head><body>作者聚焦：量化衰老小鼠肺微血管密度的进展

量化小鼠跨小叶的肺微血管密度

The abnormal alternation of pulmonary angiogenesis is related to lung microvascular dysfunction and is deeply linked to vascular wall integrity, blood ...

quantifying-pulmonary-microvascular-density-in-mice-across-lobules

Research

JoVE Journal

Biology

Quantifying Pulmonary Microvascular Density in Mice Across Lobules

2.1K 次观看.  Sichuan University. 我们的研究旨在使用等凝集素 B4 染色和 ImageJ 分析量化各种小鼠肺小叶中的肺微血管密度，考虑解剖差异和与年龄相关的变化。我们试图解决的关键问题是如何准确量化不同肺小叶的微血管密度，以及随着年龄的增长，小叶的微血管密度会发生什么变化。肺微血管研究的最新进展，包括改进的组织透明化和固定技术、先进的成像和用于准确定量的软?...

视频: 作者聚焦：量化衰老小鼠肺微血管密度的进展

Isolation and Culture of Pulmonary Endothelial Cells from Neonatal Mice

Endothelial cells provide a useful research model in many areas of vascular biology. Since its first isolation 1, human umbilical vein endothelial cells (HUVECs) have shown to be convenient, easy to obtain and culture, and thus are the most widely studied endothelial cells. However, for research focused on processes like angiogenesis, permeability or many others, microvascular endothelial cells (ECs) are a much more physiologically relevant model to study 2. Furthermore, ECs isolated from knockout mice provide a useful tool for analysis of protein function ex vivo. Several approaches to isolate and culture microvascular ECs of different origin have been reported to date 3-7, but consistent isolation and culture of pure ECs is still a major technical problem in many laboratories. Here, we provide a step-by-step protocol on a reliable and relatively simple method of isolating and culturing mouse lung endothelial cells (MLECs). In this approach, lung tissue obtained from 6- to 8-day old pups is first cut into pieces, digested with collagenase/dispase (C/D) solution and dispersed mechanically into single-cell suspension. MLECS are purified from cell suspension using positive selection with anti-PECAM-1 antibody conjugated to Dynabeads using a Magnetic Particle Concentrator (MPC). Such purified cells are cultured on gelatin-coated tissue culture (TC) dishes until they become confluent. At that point, cells are further purified using Dynabeads coupled to anti-ICAM-2 antibody. MLECs obtained with this protocol exhibit a cobblestone phenotype, as visualized by phase-contrast light microscopy, and their endothelial phenotype has been confirmed using FACS analysis with anti-VE-cadherin 8 and anti-VEGFR2 9 antibodies and immunofluorescent staining of VE-cadherin. In our hands, this two-step isolation procedure consistently and reliably yields a pure population of MLECs, which can be further cultured. This method will enable researchers to take advantage of the growing number of knockout and transgenic mice to directly correlate in vivo studies with results of in vitro experiments performed on isolated MLECs and thus help to reveal molecular mechanisms of vascular phenotypes observed in vivo.

Here, we describe a protocol for isolation and culture of murine pulmonary endothelial cells. This method comprises mechanic and enzymatic lung tissue dissociation as well as a 2-step purification process using anti-PECAM-1 and anti-ICAM-2 antibodies conjugated to magnetic beads, which produces a pure endothelial cell population of mostly microvascular origin.

从新生小鼠的肺血管内皮细胞的分离和培养

Endothelial cells provide a useful research model in many areas of vascular biology. Since its first isolation 1, human umbilical vein endothelial cells ...

科研

生物学

Bioengineering Human Microvascular Networks in Immunodeficient Mice

The future of tissue engineering and cell-based therapies for tissue regeneration will likely rely on our ability to generate functional vascular networks in vivo. In this regard, the search for experimental models to build blood vessel networks in vivo is of utmost importance 1. The feasibility of bioengineering microvascular networks in vivo was first shown using human tissue-derived mature endothelial cells (ECs) 2-4; however, such autologous endothelial cells present problems for wide clinical use, because they are difficult to obtain in sufficient quantities and require harvesting from existing vasculature. These limitations have instigated the search for other sources of ECs. The identification of endothelial colony-forming cells (ECFCs) in blood presented an opportunity to non-invasively obtain ECs 5-7. We and other authors have shown that adult and cord blood-derived ECFCs have the capacity to form functional vascular networks in vivo 7-11. Importantly, these studies have also shown that to obtain stable and durable vascular networks, ECFCs require co-implantation with perivascular cells. The assay we describe here illustrates this concept: we show how human cord blood-derived ECFCs can be combined with bone marrow-derived mesenchymal stem cells (MSCs) as a single cell suspension in a collagen/fibronectin/fibrinogen gel to form a functional human vascular network within 7 days after implantation into an immunodeficient mouse. The presence of human ECFC-lined lumens containing host erythrocytes can be seen throughout the implants indicating not only the formation (de novo) of a vascular network, but also the development of functional anastomoses with the host circulatory system. This murine model of bioengineered human vascular network is ideally suited for studies on the cellular and molecular mechanisms of human vascular network formation and for the development of strategies to vascularize engineered tissues.

Here, we describe a methodology to deliver human cord blood-derived endothelial colony-forming cells (ECFCs) and bone marrow-derived mesenchymal stem cells (MSCs), embedded in a collagen/fibronectin gel, subcutaneously into immunodeficient mice. This cell/gel combination generates a human vascular network that connects with the mouse vasculature.

生物人类免疫缺陷小鼠的微血管网络

The future of tissue engineering and cell-based therapies for tissue regeneration will likely rely on our ability to generate functional vascular networks ...

RNA-seq Analysis of Transcriptomes in Thrombin-treated and Control Human Pulmonary Microvascular Endothelial Cells

The characterization of gene expression in cells via measurement of mRNA levels is a useful tool in determining how the transcriptional machinery of the cell is affected by external signals (e.g. drug treatment), or how cells differ between a healthy state and a diseased state. With the advent and continuous refinement of next-generation DNA sequencing technology, RNA-sequencing (RNA-seq) has become an increasingly popular method of transcriptome analysis to catalog all species of transcripts, to determine the transcriptional structure of all expressed genes and to quantify the changing expression levels of the total set of transcripts in a given cell, tissue or organism1,2 . RNA-seq is gradually replacing DNA microarrays as a preferred method for transcriptome analysis because it has the advantages of profiling a complete transcriptome, providing a digital type datum (copy number of any transcript) and not relying on any known genomic sequence3.
Here, we present a complete and detailed protocol to apply RNA-seq to profile transcriptomes in human pulmonary microvascular endothelial cells with or without thrombin treatment. This protocol is based on our recent published study entitled "RNA-seq Reveals Novel Transcriptome of Genes and Their Isoforms in Human Pulmonary Microvascular Endothelial Cells Treated with Thrombin,"4 in which we successfully performed the first complete transcriptome analysis of human pulmonary microvascular endothelial cells treated with thrombin using RNA-seq. It yielded unprecedented resources for further experimentation to gain insights into molecular mechanisms underlying thrombin-mediated endothelial dysfunction in the pathogenesis of inflammatory conditions, cancer, diabetes, and coronary heart disease, and provides potential new leads for therapeutic targets to those diseases.
The descriptive text of this protocol is divided into four parts. The first part describes the treatment of human pulmonary microvascular endothelial cells with thrombin and RNA isolation, quality analysis and quantification. The second part describes library construction and sequencing. The third part describes the data analysis. The fourth part describes an RT-PCR validation assay. Representative results of several key steps are displayed. Useful tips or precautions to boost success in key steps are provided in the Discussion section. Although this protocol uses human pulmonary microvascular endothelial cells treated with thrombin, it can be generalized to profile transcriptomes in both mammalian and non-mammalian cells and in tissues treated with different stimuli or inhibitors, or to compare transcriptomes in cells or tissues between a healthy state and a disease state.

This protocol presents a complete and detailed procedure to apply RNA-seq, a powerful next-generation DNA sequencing technology, to profile transcriptomes in human pulmonary microvascular endothelial cells with or without thrombin treatment. This protocol is generalizable to various cells or tissues affected by different reagents or disease states.

RNA-seq的凝血酶处理和控制人肺微血管内皮细胞的转录组分析

The characterization of gene expression in cells via measurement of mRNA levels is a useful tool in determining how the transcriptional machinery of the ...

Isolation of Pulmonary Artery Smooth Muscle Cells from Neonatal Mice

Pulmonary hypertension is a significant cause of morbidity and mortality in infants. Historically, there has been significant study of the signaling pathways involved in vascular smooth muscle contraction in PASMC from fetal sheep. While sheep make an excellent model of term pulmonary hypertension, they are very expensive and lack the advantage of genetic manipulation found in mice. Conversely, the inability to isolate PASMC from mice was a significant limitation of that system. Here we described the isolation of primary cultures of mouse PASMC from P7, P14, and P21 mice using a variation of the previously described technique of Marshall et al.26 that was previously used to isolate rat PASMC. These murine PASMC represent a novel tool for the study of signaling pathways in the neonatal period. Briefly, a slurry of 0.5% (w/v) agarose + 0.5% iron particles in M199 media is infused into the pulmonary vascular bed via the right ventricle (RV). The iron particles are 0.2 &#956;M in diameter and cannot pass through the pulmonary capillary bed. Thus, the iron lodges in the small pulmonary arteries (PA). The lungs are inflated with agarose, removed and dissociated. The iron-containing vessels are pulled down with a magnet. After collagenase (80 U/ml) treatment and further dissociation, the vessels are put into a tissue culture dish in M199 media containing 20% fetal bovine serum (FBS), and antibiotics (M199 complete media) to allow cell migration onto the culture dish. This initial plate of cells is a 50-50 mixture of fibroblasts and PASMC. Thus, the pull down procedure is repeated multiple times to achieve a more pure PASMC population and remove any residual iron. Smooth muscle cell identity is confirmed by immunostaining for smooth muscle myosin and desmin.

We have developed a novel and reproducible technique to isolate primary cultures of pulmonary artery smooth muscle cells (PASMC) from mice as young as P7, thereby allowing better study of the signaling pathways involved in neonatal smooth muscle cell contraction and relaxation.

肺动脉平滑肌细胞从新生小鼠隔离

Pulmonary hypertension is a significant cause of morbidity and mortality in infants. Historically, there has been significant study of the signaling ...

Induction of Right Ventricular Failure by Pulmonary Artery Constriction and Evaluation of Right Ventricular Function in Mice

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of RVF. Previous rat models imitating RVF progression have been described. Compared with rats, mice are more accessible, economical, and widely used in animal experiments. We developed a pulmonary artery constriction (PAC) approach which is comprised of banding the pulmonary trunk in mice to induce right ventricular (RV) hypertrophy. A special surgical latch needle was designed that allows for easier separation of the aorta and the pulmonary trunk. In our experiments, the use of this fabricated latch needle reduced the risk of arteriorrhexis and improved the surgical success rate to 90%. We used different padding needle diameters to precisely create quantitative constriction, which can induce different degrees of RV hypertrophy. We quantified the degree of constriction by evaluating the blood flow velocity of the PA, which was measured by noninvasive transthoracic echocardiography. RV function was precisely evaluated by right heart catheterization at 8 weeks after surgery. The surgical instruments made inhouse were composed of common materials using a simple process that is easy to master. Therefore, the PAC approach described here is easy to imitate using instruments made in the lab and can be widely used in other labs. This study presents a modified PAC approach that has a higher success rate than other models and an 8-week postsurgery survival rate of 97.8%. This PAC approach provides a useful technique for studying the mechanism of RVF and will enable an increased understanding of RVF.

Here, we provide a useful approach for studying the mechanism of right ventricular failure. A more convenient and efficient approach to pulmonary artery constriction is established using surgical instruments made inhouse. In addition, methods to evaluate the quality of this approach by echocardiography and catheterization are provided.

小鼠肺动脉收缩引起的右心室衰竭及右心室功能评价

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of ...

Quantifying Spatiotemporal Parameters of Cellular Exocytosis in Micropatterned Cells

Live imaging of the pHluorin tagged Soluble N-ethylmaleimide-sensitive-factor Attachment protein REceptor (v-SNARE) Vesicle-associated membrane protein 7 (VAMP7) by total internal reflection fluorescence microscopy (TIRFM) is a straightforward way to explore secretion from the lysosomal compartment. Taking advantage of cell culture on micropatterned surfaces to normalize cell shape, a variety of statistical tools were employed to perform a spatial analysis of secretory patterns. Using Ripley&#8217;s K function and a statistical test based on the nearest neighbor distance (NND), we confirmed that secretion from lysosomes is not a random process but shows significant clustering. Of note, our analysis revealed that exocytosis events are also clustered in nonadhesion areas, indicating that adhesion molecules are not the only structures that can induce secretory hot spots at the plasma membrane. Still, we found that cell adhesion enhances clustering. In addition to precisely defined adhesive and nonadhesive areas, the circular geometry of these micropatterns allows the use of polar coordinates, simplifying analyses. We used Kernel Density Estimation (KDE) and the cumulative distribution function on polar coordinates of exocytosis events to identify enriched areas of exocytosis. In ring-shaped micropattern cells, clustering occurred at the border between the adhesive and nonadhesive areas. Our analysis illustrates how statistical tools can be employed to investigate spatial distributions of diverse biological processes.

Live imaging of lysosomal exocytosis on micropatterned cells allows a spatial quantification of this process. Morphology normalization using micropatterns is an outstanding tool to uncover general rules about the spatial distribution of cellular processes.

定量微模式细胞细胞外细胞异细胞的时态参数

Live imaging of the pHluorin tagged Soluble N-ethylmaleimide-sensitive-factor Attachment protein REceptor (v-SNARE) Vesicle-associated membrane protein 7 ...

Quantifying Tissue-Specific Proteostatic Decline in Caenorhabditis elegans

The ability to maintain proper function and folding of the proteome (protein homeostasis) declines during normal aging, facilitating the onset of a growing number of age-associated diseases. For instance, proteins with polyglutamine expansions are prone to aggregation, as exemplified with the huntingtin protein and concomitant onset of Huntington&#8217;s disease. The age-associated deterioration of the proteome has been widely studied through the use of transgenic Caenorhabditis elegans expressing polyQ repeats fused to a yellow fluorescent protein (YFP). This polyQ::YFP transgenic animal model facilitates the direct quantification of the age-associated decline of the proteome through imaging the progressive formation of fluorescent foci (i.e., protein aggregates) and subsequent onset of locomotion defects that develop as a result of the collapse of the proteome. Further, the expression of the polyQ::YFP transgene can be driven by tissue-specific promoters, allowing the assessment of proteostasis across tissues in the context of an intact multicellular organism. This model is highly amenable to genetic analysis, thus providing an approach to quantify aging that is complementary to lifespan assays. We describe how to accurately measure polyQ::YFP foci formation within either neurons or body wall muscle during aging, and the subsequent onset of behavioral defects. Next, we highlight how these approaches can be adapted for higher throughput, and potential future applications using other emerging strategies for C. elegans genetic analysis.

Quantifying Tissue-Specific Proteostatic Decline in Caenorhabditis elegans

Proteostatic decline is a hallmark of aging, facilitating the onset of neurodegenerative diseases. We outline a protocol to quantifiably measure proteostasis in two different Caenorhabditis elegans tissues through heterologous expression of polyglutamine repeats fused to a fluorescent reporter. This model allows rapid in vivo genetic analysis of proteostasis.

量化秀丽隐杆线虫中组织特异性蛋白静剂下降

The ability to maintain proper function and folding of the proteome (protein homeostasis) declines during normal aging, facilitating the onset of a ...

Microvascular and Macrovascular Endothelial Cell Isolation and Purification from Lung-Derived Samples

The availability of cells isolated from healthy and diseased tissues and organs represents a key element for personalized medicine approaches. Although biobanks can provide a wide collection of primary and immortalized cells for biomedical research, these do not cover all experimental needs, particularly those related to specific diseases or genotypes. Vascular endothelial cells (ECs) are key components of the immune inflammatory reaction and, thus, play a central role in the pathogenesis of a variety of disorders. Notably, ECs from different sites display different biochemical and functional properties, making the availability of specific EC types (i.e., macrovascular, microvascular, arterial, and venous) essential for designing reliable experiments. Here, simple procedures to obtain high-yield, virtually pure human macrovascular and microvascular endothelial cells from the pulmonary artery and lung parenchyma are illustrated in detail. This methodology can be easily reproduced at a relatively low cost by any laboratory to achieve independence from commercial sources and obtain EC phenotypes/genotypes that are not yet available.

Although challenging, the isolation of pulmonary endothelial cells is essential for studies on lung inflammation. The present protocol describes a procedure for the high-yield, high-purity isolation of macrovascular and microvascular endothelial cells.

从肺源性样品中分离和纯化微血管和大血管内皮细胞

The availability of cells isolated from healthy and diseased tissues and organs represents a key element for personalized medicine approaches. Although ...

细胞骨架对小鼠卵母细胞核形状和凝聚物动力学的影响

Capturing Cytoskeleton-Based Agitation of the Mouse Oocyte Nucleus Across Spatial Scales

A major challenge in understanding the causes of female infertility is to elucidate mechanisms governing the development of female germ cells, named oocytes. Their development is marked by cell growth and subsequent divisions, two critical phases that prepare the oocyte for fusion with sperm to initiate embryogenesis. During growth, oocytes reorganize their cytoplasm to position the nucleus at the cell center, an event predictive of successful oocyte development in mice and humans and, thus, their embryogenic potential. In mouse oocytes, this cytoplasmic reorganization was shown to be driven by the cytoskeleton, the activity of which generates mechanical forces that agitate, reposition, and penetrate the nucleus. Consequently, this cytoplasmic-to-nucleoplasmic force transmission tunes the dynamics of nuclear RNA-processing organelles known as biomolecular condensates. This protocol provides an experimental framework to document, with high temporal resolution, the impact of the cytoskeleton on the nucleus across spatial scales in mouse oocytes. It details the imaging and image analysis steps and tools necessary to evaluate i) cytoskeletal activity in the oocyte cytoplasm, ii) cytoskeleton-based agitation of the oocyte nucleus, and iii) its effects on biomolecular condensate dynamics in the oocyte nucleoplasm. Beyond oocyte biology, the methods elaborated here can be adapted for use in somatic cells to similarly address cytoskeleton-based tuning of nuclear dynamics across scales.

作者聚焦：阐明小鼠卵母细胞中机械转导和核搅动的动力学

This protocol provides an experimental framework to document the physical impact of the cytoskeleton on nuclear shape and the internal membrane-less organelles in the mouse oocyte system. The framework can be adapted for use in other cell types and contexts.

跨空间尺度捕获基于细胞骨架的小鼠卵母细胞核搅动

A major challenge in understanding the causes of female infertility is to elucidate mechanisms governing the development of female germ cells, named ...