Read the Paper (>) GBA Pathway Biomarkers for Genetic and Idiopathic PD
The number of papers from PPMI data analysis continues to climb. PPMI researchers, led by a team at Brigham & Women’s Hospital, recently reported on potential of (i) the glucosylceramide lipid as a GBA pathway biomarker in GBA-PD and (ii) the ratio of glucosylceramide to sphingomyelin as a predictor of cognitive decline in idiopathic Parkinson’s.
Stratification by GBA pathway
| marker | Feasibility in CSF, Serum | Normal values | pros | Cons |
|---|---|---|---|---|
| GBA protein | ? Otake said he would do this assay! (to be checked!) | Not yet |
- ↓ in GBA+PD (Ambroxol P2, ucl) - In GBA+PD, this may have caused PD |
- AAV-GBA improved PD in rodent with normal GBA (Rocha's correction) - Our GBA activator activates WT gba too. |
| GBA activity | The best rationale, ?, probably not possible d/t internal standard? need to check with Otake | Not yet |
In GBA+PD, this may have caused PD. In CSF, correlated with H&Y in sPD(Parnetti 2014), (중요) GBA activity reduction is not established in every/some GBA variants! |
- In peripheral cells, Not correlated with clinical variables (Atashrazm 2018, Alcaclay 2015), - AAV-GBA improved PD in rodent with normal GBA (Rocha's correction) - Our GBA activator activates WT gba too. |
| GlcCer | Assay feasible, | ? | ||
| GlcSph | Not feasible, because not detectible in CSF, Serum in GBA+PD | Present in serum, and maybe in CSF |
총정리중 GBA+PD에서 Lysosomal 반
| paper | note | N | Tissue / cell | Findings in GBA-PD Patients |
|---|---|---|---|---|
| (Ambrosi et al. 2015, PMID) | Disease duration:13 y, UPDRS III:13.2, Ave age=55y so mid to late | 5 | Skin Fibroblast |
No difference in Cathepsin D activity (fig2), but is increased by ambroxol No difference in LIMP2 (fig3), but is increased by ambroxol |
| (McNeill et al. 2014, PMID) | Ave age=56y, js ; should be similar stage as ambrosi | 5 | Skin Fibroblast | ↑ cathepsin D (js, young and relatively not small sample size, so why ↑), no difference in LC3II, p62, and LAMP1 |
| (Collins et al. 2017, PMID 29527290) | ? | 3 | Skin fibroblast | Altered LC3II |
| (Papagiannakis et al. 2015, PMID 26769460) | Ave age=56y, most trustable since large sample number (14) and relatively young. | 14, | PBMC | ↓ HSC70 protein, no difference in HSC70 mRNA, no difference in LAMP2 Protein & mRNA |
| (Kurzawa-Akanbi et al. 2012, PMID) | Postmortem, so late | 7 | Postmortem brain | ↓ Cathepsin D activity (fig S1) |
| (Gegg et al. 2012, PMID 23034917) | Postmortem, so late | 14 | Postmortem brain | No difference in LC3II level |
| (Yang et al. 2020, PMID 31634558) | Not stated | 3 (fig2c) | human neural crest stem cell-derived dopaminergic neurons from GBA+PD patients | ↓ Cathepsin D protein & activity (which is restored by cerezyme and Ambroxol) |
| (Fernandes et al. 2016, PMID) | Ave age=66y, ave disease duration was 4y (what?) | 3 | iPSC-derived dopaminergic neurons GBA+PD patients | ↑ cathepsin D, ↑ LAMP1, ↑ LAMP2a, ↑ and LIMP2, ↑ p62, ↑ lysosomal number with undegraded cargo |
| (Blauwendraat et al. 2019, PMID) | Not stated | ? (n=2 lines) | iPSC-derived neurons derived from GBA+PD patients | lower level of processed (ie mature) Cathepsin B protein |
| (Schondorf et al. 2014, PMID 24905578) | Ave age=62y, ave disease duration was 12y | 4 | iPSC-derived dopaminergic neurons from GBA+PD patients | ↑ LAMP1, ↑ LC3II (basal), ↓ LC3 influx, these were corrected by gene correction |
Js, age rather than disease duration should be more trustable considering underDx
S: Lysosome Lysosomal autophagy POSTMORTEM
| source | material | assay / row | Synopaty + GBA Hetero | Synopaty | Gba hetero | normal / notes |
|---|---|---|---|---|---|---|
| Kurzawa, 2012 | Postmortem | LAMP1 as a marker of lysosome mass (Eskelinen 2006) | ↑ than Synopath only | 어떻게 normal보다 낮나? | ↑ than normal | |
| Kurzawa, 2012 | Postmortem | LAMP2 | ↑ than Synopath only | 어떻게 normal보다 낮나? | Very small ↑ than normal (자료자체15%) | |
| Murphy 2014 | Post-mortem | Not done |
1. SDS-soluble LAMP1: No change 2. SDS-soluble LAMP2: ↓ 3. SDS-soluble LC3II: no change | Not done | GBA hetero없으니 별 가치 없구만, PD는 원래 자료 있으니 | |
| Gegg 2012 | Post-mortem | LC, Cathepsin | a trend for higher LC3-II in GBA+PD and sporadic PD putamen, although this was not significant (이것이 Schapira 2015에선 other lysosomal enzymes were unaffected) | Not done | ||
| Chiasserini 2015 | Post-mortem | Activities of Other lysosomal enz (β-hexosaminidase, α-fucosidase, β-mannosidase, α-annosidase, β-galactosidase and cathepsin E | Not done | No change | Not done |
Lysosomal autophagy model rows
| source | cell / model | condition | readout |
|---|---|---|---|
| (Bae et al. 2015, PMID 25813221) | SH-SY5Y | GBA deficienc | LysoTracker ↑ |
| (Sanyal, 2020 #2621) | astrocyte | GBA heterozygous KI | LysoTracker ↓ |
| (Sanyal, 2020 #2622) | Human iPSC-Derived Neurons | GBA heterozygous | LysoTracker ↓ |
CBE / Model Comparison Table
| row | Prence (1996) | Korkotian (1999) | Pelled (2000) | Cleeter (2013) | AB (2009) | Manning-Bog | Osellame (2013) | Dermentzaki G et al. 2013 | Cullen | Noelker (2015) | Mazzulli (2011) | Eun-Jin Bae (2014) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| cells / model | SH-SY5Y | hippocampal | Rat hippocampal cells | SH-SY5Y (undifferentiated): mito & ROS | SH-SY5Y (differentiated & undifferentiated) | Mixed midbrain culture (Mixed cultures of cortical neurons and astrocytes) | SH-SY5Y(differentiate d), rat embryonic cortical cultures | Mouse embryonic neuronal cultre | CBE NOT USED via RNAi, (보통 KD라고 하네?) and human iPS neurons derived from a GBA mutation carrier) |
GBA gene deletion =GBA KO In SV cell line, | ||
| incubation | 8 days | 4 days | 5 days | 30 days | 2 days | 7 days | 찾아야겠다. | 48 h | ||||
| concentration | 50 uM | 200uM | 200uM | 50uM | 50-200 | 50,100,200uM | 50,100,200,400 | |||||
| GBA activity assay | Done | Not done | Not done | Done | 필요없음 | Done in both SH-SY5Y & rat embryonic cortical cultures | GBA activity assay NOT DONE | 필요없음 | Complete Inhibition (>90%) | |||
| cell death / viability | Other kit | LDH assay | ||||||||||
| concentration vs cell death | Glutamate 10 Mm for 1hr | Glutamate 10 mM (max after 3hr) | ↑ accumulation of glucosylceramide | |||||||||
| visible outcomes |
No change in LC3II, LAMP1, UPS, but ↑ a-syn BUT, GBA knockdown SH-SY5Y 에서는 a-syn 이 통계적으로 유의하지 않은 정도로 증가. | SH-SY5Y: differentiated에서만 ↑ a-sy. cell line, midbrain from mice treated with CBE 모두 에서 ↑ a-syn | ↓ LC3, ↓ Atg5/12, ↑ p62, ↑ snca | (Both model에서) - No change in snca, - no change in LC3, LAMP2A, Hsc70, p62 | Cell line에선 No change in SNCA | A-syn overexpression model was used to induce toxicity, but the effect of GBA inhibition on a-syn was not looked at. | ↓ lysosomes, (KD: ↓ lysosome-mediated proteolysis, ↑ LAMP1) |
↑ accumulation of p62 and polyubiquitinated proteins (suggesting lysosomal dysfunction) asyn은 transmission을 봤네? | ||||
| bottom visible row | Calcium | Calcium | ↓ mito, ↑ ROS | ↓ lysosome, ↓ mito, |
Dermentzaki vs AB Manning-Bog: the same cell line (differentiated SH-SY5Y), the same cbe concentration (50-200uM), but different results on SNCA.
Uncertain Spans
| location | transcription | uncertainty |
|---|---|---|
| page heading | Read the Paper (>) GBA Pathway Biomarkers for Genetic and Idiopathic PD | The (>) marker reads as written; in the source it appears to be a small icon/arrow whose exact character is OCR-sensitive. |
| 총정리중 lysosomal heading | 총정리중 GBA+PD에서 Lysosomal 반 | The Korean heading appears clipped/truncated at the right edge; the trailing word may be 반응 or similar. |
| Fernandes row Findings | ↑ and LIMP2 | The cell appears to omit a marker symbol or include an extra and; preserved as visible source. |
| Lysosomal model row | GBA deficienc | reads as written; the trailing y is clipped/missing. |
| CBE / Model Comparison Table | column headers Prence (1996), Korkotian (1999), Pelled (2000), Cleeter (2013), etc. | The CBE table is clipped at top and bottom edges; the topmost column-label row and the bottom continuation rows extend outside this capture. |
| CBE table / Manning-Bog and Cullen columns | mostly empty cells | The Manning-Bog and Cullen columns appear sparse in this capture; some content may appear in adjacent captures. |
| CBE outcomes row | ↑ a-sy. vs ↑ a-syn; snca/SNCA | small line-wrapped text; preserved with the visible spelling/case from each cell. |