The study was supported by grants from the National Natural Science Foundation of China (81960226, 81760223), the Natural Science Foundation of Yunnan Province (202001AS070045, 202301AY070001-011), and the Scientific Research Foundation of Yunnan Province Department of Education (2023Y0784).

This research received approval from the Animal Experiment Ethics Committee of Kunming Medical University (kmmu20220945). All experiments adhered to established animal care guidelines. Leptomeningeal lymphatic endothelial cells (LLECs) were harvested from male C57Bl/6J mice aged 6-8 weeks and weighing between 20-25 g. These mice were procured from Kunming Medical University in Kunming, China. The entire experimental procedure was conducted under strict sterile conditions. All the centrifugation steps are performed at roo...

Establishing In Vitro LLEC Cultures Using Magnetic Cell Selection

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Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organ-specific+lymphatic+vasculature:+From+development+to+pathophysiology.">Organ-specific lymphatic vasculature: From development to pathophysiology.</a> The Journal of Experimental Medicine. 215 (1), 35-49 (2018).</li><li>Wilting, J., 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+transcription+factor+Prox1+is+a+marker+for+lymphatic+endothelial+cells+in+normal+and+diseased+human+tissues.">The transcription factor Prox1 is a marker for lymphatic endothelial cells in normal and diseased human tissues.</a> The FASEB Journal. 16 (10), 1271-1273 (2002).</li><li>Yin, X., 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=Lymphatic+endothelial+heparan+sulfate+deficiency+results+in+altered+growth+responses+to+vascular+endothelial+growth+factor-C+(VEGF-C).">Lymphatic endothelial heparan sulfate deficiency results in altered growth responses to vascular endothelial growth factor-C (VEGF-C).</a> The Journal of Biological Chemistry. 286 (17), 14952-14962 (2011).</li><li>DeSisto, J., 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=Single-cell+transcriptomic+analyses+of+the+developing+meninges+reveal+meningeal+fibroblast+diversity+and+function.">Single-cell transcriptomic analyses of the developing meninges reveal meningeal fibroblast diversity and function.</a> Developmental Cell. 54 (1), 43-59 (2020).</li><li>Chen, Z., 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+eliminating+fibroblast+contamination+in+mouse+and+human+primary+corneal+epithelial+cell+cultures.">A method for eliminating fibroblast contamination in mouse and human primary corneal epithelial cell cultures.</a> Current Eye Research. , 1-11 (2023).</li><li>Starzonek, C., 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=Enrichment+of+human+dermal+stem+cells+from+primary+cell+cultures+through+the+elimination+of+fibroblasts.">Enrichment of human dermal stem cells from primary cell cultures through the elimination of fibroblasts.</a> Cells. 12 (6), 949 (2023).</li><li>Lam, C. 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The existing protocol for harvesting and culturing LLECs in vitro has not been previously reported. This study introduces a reproducible, multi-procedural protocol for harvesting and culturing LLECs from mouse leptomeninges.
While this multi-procedural protocol is reproducible, there are several key considerations. For example, fibronectin-coated T25 flasks promote the adhesion of LLECs and function by eliminating non-adherent cells, thereby ensuring a more homogenous cellular populat...

The newly discovered leptomeningeal lymphatic endothelial cells (LLECs) form a meshwork of individual cells within the leptomeninges, exhibiting a distinct distribution pattern when compared to peripheral lymphatic endothelial cells1,2. The cellular functions and clinical implications associated with LLECs remain largely uncharted territory. In order to pave the way for functional research on LLECs, it is imperative to establish an in vitro model for their study. Therefore, this study has devised a comprehensive protocol for the isolation and primary culture of LLECs.
Mice are the preferred animal model due to their suitability for genetic manipulation in disease research. Previous studies have successfully isolated lymphatic endothelial cells from various mouse tissues, including lymph nodes3, mesenteric tissue4, dermal tissue5, collecting lymphatics6, and lung tissue7. These isolation procedures have primarily relied on techniques such as magnetic-activated cell sorting (MACS) and flow cytometry sorting8,9,10. Additionally, research efforts have led to the establishment of rat arachnoid cell lines and rat lymphatic capillary cell lines11,12. Despite the existence of explant culture techniques for leptomeninges13, there exists an urgent need for a standardized protocol for the isolation and culture of LLECs. Consequently, this study has successfully harvested and cultured LLECs by meticulously dissociating leptomeninges under the guidance of a microscope and promoting LLECs expansion through the use of vascular endothelial growth factor-C (VEGF-C). The distinctive marker for lymphatic endothelial cells is lymphatic vessel hyaluronic receptor-1 (LYVE-1)14. This multi-step protocol selectively isolates LYVE-1-positive LLECs using MACS and subsequently verifies their purity through flow cytometric analysis and immunofluorescent staining.
The primary steps of this multi-step protocol can be summarized as follows: flask coating, dissociation of leptomeninges, enzymatic digestion of leptomeninges, cell expansion, magnetic cell selection, and subsequent culture of LLECs. Finally, the purity of the isolated LLECs is confirmed through flow cytometric analysis and immunofluorescent staining. The overarching aim of this study is to present a reproducible, multi-step protocol for the isolation of LLECs from mouse leptomeninges and their subsequent in vitro culture. This protocol is poised to greatly facilitate investigations into the cellular functions and clinical implications of LLECs.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Block buffer</td>
			<td>Beyotime</td>
			<td>P0102</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>Collagenase I</td>
			<td>Solarbio</td>
			<td>C8140</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Beyotime</td>
			<td>P0131</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Solarbio</td>
			<td>11995</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>D-PBS</td>
			<td>Solarbio</td>
			<td>D1041</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>EGM-2 MV Bullet Kit</td>
			<td>Lonza</td>
			<td>C-3202</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Solarbio</td>
			<td>S9010</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>Fibronectin</td>
			<td>Solarbio</td>
			<td>F8180&#160;</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>FlowJo Software</td>
			<td>BD Biosciences</td>
			<td>V10.8.1</td>
			<td></td>
		</tr>
		<tr>
			<td>LYVE-1 antibody</td>
			<td>eBioscience</td>
			<td>12-0443-82</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>Magnetic separator</td>
			<td>Miltenyi</td>
			<td>130-042-302</td>
			<td>Sterile before use</td>
		</tr>
		<tr>
			<td>Magnetic separator stand</td>
			<td>Miltenyi</td>
			<td>130-042-303</td>
			<td>Sterile before use</td>
		</tr>
		<tr>
			<td>Microbeads</td>
			<td>Miltenyi</td>
			<td>130-048-801</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>P/S</td>
			<td>Solarbio</td>
			<td>P1400</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>Papain</td>
			<td>Solarbio</td>
			<td>G8430-25g</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Solarbio</td>
			<td>D1040</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>PDPN antibody</td>
			<td>Santa</td>
			<td>sc-53533</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>PFA</td>
			<td>Solarbio</td>
			<td>P1110</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>PROX1 antibody</td>
			<td>Santa</td>
			<td>sc-81983</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
		<tr>
			<td>Selection column&#160;</td>
			<td>Miltenyi</td>
			<td>130-042-401</td>
			<td>Sterile before use</td>
		</tr>
		<tr>
			<td>Trypsin</td>
			<td>Gibco</td>
			<td>25200072</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>VEGF-C&#160;</td>
			<td>Abcam</td>
			<td>ab51947</td>
			<td>Store aliquots at &#8211;20 &#176;C</td>
		</tr>
		<tr>
			<td>VEGFR-3 antibody</td>
			<td>Santa</td>
			<td>sc-514825</td>
			<td>Store aliquots at &#8211;4 &#176;C</td>
		</tr>
	</tbody>
</table>

harvest and primary culture of leptomeningeal lymphatic endothelial cells

Leptomeningeal lymphatic endothelial cells (LLECs) are a recently discovered intracranial cellular population with a unique distribution clearly distinct from peripheral lymphatic endothelial cells. Their cellular function and clinical implications remain largely unknown. Consequently, the availability of a supply of LLECs is essential for conducting functional research in vitro. However, there is currently no existing protocol for harvesting and culturing LLECs in vitro.
This study successfully harvested LLECs using a multi-step protocol, which included coating the flask with fibronectin, dissecting the leptomeninges with the assistance of a microscope, enzymatically digesting the leptomeninges to prepare a single-cell suspension, inducing the expansion of LLECs with vascular endothelial growth factor-C (VEGF-C), and selecting lymphatic vessel hyaluronic receptor-1 (LYVE-1) positive cells through magnetic-activated cell sorting (MACS). This process ultimately led to the establishment of a primary culture. The purity of the LLECs was confirmed through immunofluorescence staining and flow cytometric analysis, with a purity level exceeding 95%. This multi-step protocol has demonstrated reproducibility and feasibility, which will greatly facilitate the exploration of the cellular function and clinical implications of LLECs.

Author Spotlight: Unveiling Cellular Functions and Potential Clinical Implications of Leptomeningeal Lymphatic Endothelial Cells 

Harvest and Primary Culture of Leptomeningeal Lymphatic Endothelial Cells

This protocol is designed for areas of by other researchers only interested where established the multi procedure to and cultural primary areas Our protocol ultimately led to the establishment of our primary culture of area CS with a purity level exceeding 95%There is currently no existing protocol for harvesting and culturing Our results paved the way for further investigating the similar function of LLECS in virtual. At RUC, our recent discovery intracranial cellular population, the biological significance of RUC We will conduct further research on the cellular function and review its clinical implication.

This study presents a reproducible, multi-step protocol for harvesting lymphatic endothelial cells (LLECs) from mice and subsequently establishing their primary culture in vitro. The key steps involve flask preparation and fibronectin coating, dissociation of leptomeninges, obtaining a single-cell suspension through enzymatic digestion, and inducing LLECs expansion with VEGF-C. LYVE-1-positive LLECs are then selectively isolated using magnetic-activated cell sorting (MACS). Finally, immunofluorescence staining a...

Watch this Scientific Journal Video about Unveiling Cellular Functions and Potential Clinical Implications of Leptomeningeal Lymphatic Endothelial Cells at JoVE.com

Leptomeningeal lymphatic endothelial cells (LLECs), a recently identified intracranial cell type, have poorly understood functions. This study presents a reproducible protocol for harvesting LLECs from mice and establishing in vitro primary cultures. This protocol is designed to enable researchers to delve into the cellular functions and potential clinical implications of LLECs.

Leptomeningeal lymphatic endothelial cells (LLECs) are a recently discovered intracranial cellular population with a unique distribution clearly distinct ...

harvest-primary-culture-leptomeningeal-lymphatic-endothelial