ref

content/target_tspo.html

 ---
 title: TSPO
 author: Vesa Oikonen
-updated_at: 2021-04-28
+updated_at: 2021-06-07
 created_at: 2012-09-14
 tags:
   - TSPO
@@ -34,7 +34,9 @@ In the brain parenchyma TSPO is located in glial cells (microglia and astrocytes
 used as a biomarker of activated glial cells 
 (<a href="https://doi.org/10.1016/j.pharmthera.2007.12.004">Chen &amp; Guilarte, 2008</a>; 
 <a href="https://doi.org/10.1007/s13139-017-0475-8">Alam et al., 2017</a>;
-<a href="https://doi.org/10.1007/s12149-020-01530-2">Nomura et al., 2021</a>).
+<a href="https://doi.org/10.1007/s12149-020-01530-2">Nomura et al., 2021</a>), but it is present
+also in the neurovascular unit, including endothelial cells, smooth muscle cells, and red blood 
+cells (<a href="https://doi.org/10.1007/s00259-021-05248-9">Wimberley et al., 2021</a>).
 Mitochondrial dysfunction or abnormal microglia autophagy may be seen as reduced TSPO expression
 (<a href="https://doi.org/10.1038/s41380-020-0682-z">Zürcher et al., 2020</a>). 
 Outside of the brain, TSPO is expressed in macrophages, and could be targeted in 
@@ -129,9 +131,9 @@ model of MS</a>, the healthy hemisphere can be used as reference region
 model</a> (SRTM) can be applied, although an ideal <a href="./model_reference_tissue.html">reference 
 tissue</a> (containing no TSPO) is not available. A clustering method has been introduced to produce 
 a reference curve for brain [<sup>11</sup>C]-(<em>R</em>)-PK11195 studies 
-(<a href="https://www.ncbi.nlm.nih.gov/pubmed/17204713">Turkheimer et al., 2007</a>), 
-and the experiences of using this method in Turku have been promising 
-(Tuisku J, personal communication).</p>
+(<a href="https://www.ncbi.nlm.nih.gov/pubmed/17204713">Turkheimer et al., 2007</a>).
+<a href="https://doi.org/10.1007/s00259-021-05248-9">Wimberley et al (2021)</a> have reviewed the
+brain TSPO quantification methods and their limitations.</p>
 
 <p>TSPO level in the normal brain is very low, and thus the blood vessel uptake of TSPO ligands 
 becomes predominant. In <a href="./dis_ad.html">AD</a> brain, vascular fibrosis decreases the size
@@ -279,4 +281,9 @@ The methodology of TSPO imaging with positron emission tomography.
 <em>Biochem Soc Trans.</em> 2015; 43: 586-592.
 doi: <a href="https://doi.org/10.1042/BST20150058">10.1042/BST20150058</a>.</p>
 
+<p>Wimberley C, Lavisse S, Hillmer A, Hinz R, Turkheimer F, Zanotti-Fregonara P. 
+Kinetic modeling and parameter estimation of TSPO PET imaging in the human brain. 
+<em>Eur J Nucl Med Mol Imaging</em> 2021 (in press). 
+doi: <a href="https://doi.org/10.1007/s00259-021-05248-9">10.1007/s00259-021-05248-9</a>.</p>
+
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