Unraveling the Unconventional Mechanism of Tau Secretion and its Implications in Neurodegenerative Diseases

Unraveling the Unconventional Mechanism of Tau Secretion and its Implications in Neurodegenerative Diseases

Introduction:
The secretion of Tau, a protein associated with neurodegenerative diseases like Alzheimer's, has been a subject of intense research. Recent studies have shed light on an unconventional non-vesicular mechanism through which Tau is secreted. This article aims to explore the findings of these studies, highlighting the role of membrane interactions and the potential implications for therapeutic interventions.

Membrane Interactions and Tau Secretion:
Previous studies have reported the localization of Tau to membranes, suggesting a potential role in its secretion. The interaction of Tau with membranes leads to structural compaction, as observed in various experiments (Elbaum-Garfinkle et al., 2010, Jones et al., 2012, Künze et al., 2012, Georgieva et al., 2014, Flach et al., 2012). Additionally, the formation of pore-like structures in membranes has been implicated in mediating the penetration of Tau (Lasagna-Reeves et al., 2014, Patel et al., 2015).

Inhibiting GAG Biosynthesis and Tau Secretion:
To investigate the factors involved in Tau secretion, researchers have explored the role of 3'-phosphoadenosine 5'-phosphosulphate (PAPS), a general sulfate donor in glycosaminoglycan (GAG) biosynthesis. NaClO3, a widely used inhibitor of PAPS synthesis, has been employed to reduce the amount of cell surface heparan sulfate proteoglycans (HSPGs). The reduction in HSPGs resulted in a decrease in both intracellular and secreted Tau (comment: 薬剤処理ばっかりで微妙なんだよな　あとは。TransientでPCAで分泌見ているから、薬剤処理の時間とか分泌を待つ時間が短すぎる).

Specificity in Reducing Tau Secretion:
To further investigate the specific Tau species involved in membrane penetration and subsequent secretion, researchers utilized four different Tau aggregation inhibitors (TAIs). These inhibitors, including emodin, BSc3094, phthalocyanine tetrasulfonate (PcTS), and epigallocatechin gallate (EGCG), target different stages of Tau aggregation (note: タウ凝集体の形成の別のタイミングで抑制できる薬剤がそれぞれ存在する). By employing these inhibitors, researchers were able to narrow down the Tau species responsible for membrane penetration and secretion.

Insights and Future Implications:
The findings of these studies provide valuable insights into the unconventional mechanism of Tau secretion and its potential implications in neurodegenerative diseases. Understanding the factors that regulate Tau secretion opens up new avenues for therapeutic interventions. By targeting membrane interactions and inhibiting specific Tau species, it may be possible to modulate Tau secretion and potentially slow down the progression of neurodegenerative diseases.

Actionable Advice:

1. Explore novel therapeutic strategies: The identification of membrane interactions and specific Tau species involved in secretion provides a foundation for developing targeted therapeutic interventions. Researchers and pharmaceutical companies should focus on exploring novel strategies to modulate Tau secretion for the treatment of neurodegenerative diseases.
2. Investigate the role of membrane-compromising agents: Given the significance of membrane interactions in Tau secretion, further research should be conducted to understand the effects of membrane-compromising agents. By identifying compounds or drugs that can disrupt the interaction between Tau and membranes, it may be possible to inhibit its secretion.
3. Optimize experimental protocols for Tau secretion studies: Researchers should consider extending the duration of drug treatments and secretion assays to improve the accuracy of their findings. Longer treatment times and sufficient waiting periods for Tau secretion will provide more reliable data for studying the unconventional mechanism of Tau secretion.

Conclusion:
The unconventional non-vesicular mechanism of Tau secretion has unveiled new insights into the pathogenesis of neurodegenerative diseases. The role of membrane interactions and specific Tau species in this process has highlighted potential targets for therapeutic interventions. By exploring novel strategies, investigating membrane-compromising agents, and optimizing experimental protocols, researchers can pave the way for the development of effective treatments that aim to modulate Tau secretion and mitigate the devastating effects of neurodegenerative diseases.