Name: Immunostaining of Mouse Stria Vascularis and Tissue Mounting
Uploaded: 2023-04-21T12:50:00
Description: Watch this Scientific Journal Video about Immunostaining of Mouse Stria Vascularis and Tissue Mounting at JoVE.com

immunostaining of mouse stria vascularis and tissue mounting

Stria Vascularis Microdissection for Single-Nucleus Sequencing or Immunostaining

The cochlea consists of three fluid filled chambers, the scala vestibuli, scala media, and scala tympani. The scala vestibuli and scala tympani each contain perilymph, which has a high concentration of sodium (138 mM) and a low concentration of potassium (6.8 mM)1. The scala media contains endolymph, which has a high concentration of potassium (154 mM) and a low concentration of sodium (0.91 mM)1,2,3. This difference in ion concentration can be referred to as the endocochlear potential (EP), and is primarily generated by the movement of potassium ions through various ion channels and gap junctions in the stria vascularis (SV) along the lateral wall of the cochlea4,5,6,7,8,9,10,11. The SV is a heterogenous, highly vascularized tissue that lines the medial aspect of the lateral wall of the cochlea and contains three main cell types: marginal, intermediate, and basal cells12 (Figure 1).
Marginal cells are connected by tight junctions to form the most medial surface of the SV. The apical membrane faces the endolymph of the scala media and contributes to potassium ion transport into the endolymph using various channels, including KCNE1/KCNQ1, SLC12A2, and Na+-K+-ATPase (NKA)5,10,13,14. Intermediate cells are pigmented cells that reside between marginal and basal cells and facilitate potassium transport through the SV using KCNJ10 (Kir 4.1)15,16. Basal cells lie in close proximity to the lateral wall of the cochlea and are closely associated with fibrocytes of the spiral ligament to promote potassium recycling from the perilymph12. Pathology of the SV has been implicated in numerous otologic disorders17,18. Mutations in genes expressed in the major SV cell types, such as Kcnq1, Kcne1, Kcnj10, and Cldn11, can cause deafness and SV dysfunction, including the loss of EP19,20,21,22,23. In addition to the three major cell types, there are other less-studied cell types in the SV, such as spindle cells22, root cells12,24, macrophages25, pericytes26, and endothelial cells27, that have incompletely defined roles involving ionic homeostasis and the generation of EP28.
In comparison to bulk RNA-sequencing, single-nuclei RNA-sequencing (sNuc-Seq) provides information about cell heterogeneity, rather than an average of mRNA across a group of cells29, and can be particularly useful when studying the heterogenous SV30. For example, sNuc-Seq has produced transcriptional analysis that suggests there may be a role for spindle and root cells in EP generation, hearing loss, and Meniere&#39;s disease18. Further transcriptional characterization of the various SV cell types can provide us with invaluable information on the pathophysiology underlying different mechanisms and subtypes of SV-related hearing fluctuation and hearing loss. The harvest of these delicate inner ear structures is of paramount importance to optimal tissue analysis.
In this study, the microdissection approach to access and isolate the stria vascularis from the adult mouse cochlea for sNuc-Seq or immunostaining is described. Dissection of the adult mouse SV is required to understand various SV cell types and further characterize their role in hearing.

Author Spotlight: Dissection of Adult Mouse Stria Vascularis for Single-Nucleus Sequencing or Immunostaining  

Dissektion af stria vascurose hos voksne mus til enkeltkernesekventering eller immunfarvning

The stria vascularis functions to generate the endocochlear potential and regulate ion homeostasis in the cochlea. The auditory development and restoration program seeks to understand the underlying mechanisms connecting dysfunctional ion homeostasis with hearing and stability disorders, which are diseases where either fluctuation in or sudden hearing loss occurs. Work in my lab has established the transcriptional landscape of the stria vascularis and has contributed to our understanding of its importance in hearing.We have used these data to draw parallels to poorly-understood hearing and stability disorders, including Meniere's disease. This protocol enables the dissection and isolation of whole-mount stria vascularis for further molecular studies including immunohistochemistry. Given that stria vascularis cell types are intricately intertwined with one another, the use of nuclear isolation and single-nucleus RNA sequencing has facilitated our understanding of the distinct transcriptional machinery involved.

Watch this Scientific Journal Video about Immunostaining of Mouse Stria Vascularis and Tissue Mounting at JoVE.com

Immunostaining of Mouse Stria Vascularis and Tissue Mounting  

Immunfarvning af musestria vascularis, og vævsmontering

Forbered immunfarvning ved at dissekere stria vascularis fra musen og tilsæt vævet til en 24-brønds plade indeholdende 200 mikroliter 4% paraformaldehyd i 1X PBS. Inkuber vævet i 20 minutter ved stuetemperatur. Udfør to korte vaske af 1X PBS på en orbitalryster ved lave omdrejningstal.Fjern PBS, udfør derefter permeabilisering og blokering i mindst en time ved stuetemperatur i 300 mikroliter PBST-opløsning. Derefter pletter vævet med det primære antistof natten over ved fire grader Celsius. Derefter tilsættes et sekundært antistof og inkuberes i to timer ved stuetemperatur på en orbitalryster ved lavt omdrejningstal.Dæk pladen for at beskytte det fluorescerende mærkede sekundære antistof mod lys. Forbered derefter et større mikrodias ved at placere to små striber lim langs 25 mm-aksen, lige mindre end 18 x 18 millimeter glasdæksel. Anbring en dråbe monteringsreagens mellem limstriberne.Brug nummer 55 tang, gab så lidt væv som muligt på den ene ende af SV, og overfør det fra PBS til monteringsreagenset. Placer den ene ende af dækselen på diaset, hvor en limstribe blev placeret. Slip derefter forsigtigt dækslet for at undgå at skabe luftbobler.Forsegl holderen ved at duppe en dråbe gennemsigtig neglelak på hvert hjørne af holderen. Mærk prøven på glasdækslet væk fra visualiseringsfeltet. Visualiser SV-vævet under et dissektionsmikroskop for at sikre, at det ligger fladt og ikke i nærheden af luftbobler.Hvis SV-vævet ikke vender korrekt, skal du prøve at skubbe luftbobler ud eller forsigtigt fjerne det mindre glasdæksel og flytte SV. En hel montering af SV fra P30-musen blev forberedt, og konfokal billeddannelse blev udført. ZsGreen-ekspression blev observeret i mellemcellerne, GSIB4-mærkede endotelceller, og DAPI mærkede kernerne.