Oncology
Probing organelle dysfunction at the heart of neurodegenerative disease.
When Organelles Fail: The Subcellular Origins of Neurodegeneration
Neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and ALS share a common subcellular denominator: the progressive dysfunction of lysosomes, mitochondria, and the endoplasmic reticulum. When these organelles fail to degrade misfolded proteins, sustain energy supply, or maintain calcium homeostasis, neurons degenerate irreversibly. This article reviews the organelle biology underpinning neurodegeneration, examines TMEM175 as a paradigmatic lysosomal drug target, and explains how ORIA Bioscience’s purified organelle platform opens a direct route to organelle-level drug discovery at scale.
u003ch2u003eA Global Crisis With a Subcellular Rootu003c/h2u003ernNeurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and amyotrophic lateral sclerosis (ALS), collectively affect over 50 million people worldwide and are projected to triple in prevalence by 2050 as populations age. Despite decades of research and billions invested in clinical trials, disease-modifying treatments remain limited. The vast majority of candidates have failed in late-stage trials, not for lack of scientific ambition, but because they targeted the wrong layer of biology.rnrnA growing body of evidence now points to a convergent, subcellular explanation: regardless of the disease or the specific genetic risk factor involved, neurodegeneration consistently involves the breakdown of organelle function, primarily in lysosomes, mitochondria, and the endoplasmic reticulum (ER). These are not peripheral bystanders. They are the operational core of neuronal survival, and their dysfunction is increasingly recognised as both a cause and an amplifier of disease progression.rnrnu003cimg class=u0022aligncenter wp-image-853u0022 src=u0022https://oriabs.com/wp-content/uploads/2026/05/Capture-decran-2026-06-18-161028-300×49.pngu0022 alt=u0022u0022 width=u00221200u0022 height=u0022198u0022 /u003ernu003ch2u003eu003c/h2u003ernu003ch2u003eu003c/h2u003ernu003ch2 id=u0022s2u0022u003eState of the Art: Three Organelles at the Heart of Neuronal Survivalu003c/h2u003ernOrganelles do not operate in isolation. They form a physically interconnected network that exchanges calcium ions, lipids, and metabolic signals through membrane contact sites (MCSs). Disruption at any node propagates dysfunction across the network. In neurons, which are post-mitotic cells that cannot dilute damage through division, such dysfunction accumulates over decades into irreversible pathology.rnrnu003cstrongu003eLysosomes: the cell’s degradation hubu003c/strongu003ernrnLysosomes maintain an acidic lumen (pH 4.5–5.5) essential for over 60 hydrolytic enzymes that degrade misfolded proteins, damaged organelles, and metabolic by-products via the autophagy-lysosome pathway (ALP). In neurodegenerative diseases, lysosomal acidification failure, impaired enzyme activity, and defective vesicular trafficking converge to prevent the clearance of toxic aggregates, including alpha-synuclein (PD), amyloid-beta and tau (AD), and mutant huntingtin (HD). This proteostatic failure is now recognised as a unifying mechanism across the major neurodegenerative diseases.rnrnu003cstrongu003eMitochondria: the neuron’s power plantu003c/strongu003ernrnMitochondria sustain neuronal survival through oxidative phosphorylation, calcium homeostasis, and regulation of apoptosis. Mitochondrial dysfunction in neurodegeneration manifests as decreased ATP production, elevated reactive oxygen species (ROS), loss of mitochondrial membrane potential, and impaired mitophagy, which is the selective autophagy of damaged mitochondria. Dysfunctional mitochondria that escape clearance become destructive, activating the intrinsic cell death pathway. Given that neurons cannot compensate through glycolysis, mitochondrial bioenergetic failure represents a direct route to neuronal death.rnrnu003cstrongu003eEndoplasmic reticulum: proteostasis checkpointu003c/strongu003ernrnThe ER is the entry point of the secretory pathway and a major calcium reservoir. In neurodegenerative conditions, accumulation of misfolded proteins triggers the unfolded protein response (UPR), which, when chronic, drives neuroinflammation and apoptosis. ER-lysosome and ER-mitochondria contact sites are particularly sensitive to disruptions in protein trafficking and calcium homeostasis, meaning ER stress frequently amplifies downstream organelle dysfunction.rnrnu003cimg class=u0022aligncenter wp-image-854u0022 src=u0022https://oriabs.com/wp-content/uploads/2026/05/Capture-decran-2026-06-18-161408-300×171.pngu0022 alt=u0022u0022 width=u00221400u0022 height=u0022797u0022 /u003e
View Resourcesu003csection id=u0022section-3-case-studyu0022 aria-labelledby=u0022s3u0022u003ernu003ch2u003eCase Study – TMEM175, a Lysosomal Ion Channel at the Centre of Parkinson’s Diseaseu003c/h2u003ernu003cp id=u0022s3u0022u003eAmong the most compelling recent developments in Parkinson’s disease genetics is the identification of TMEM175 (transmembrane protein 175) as a lysosomal ion channel whose dysfunction directly links organelle biophysics to neurodegeneration. TMEM175 resides in the lysosomal membrane, where it mediates K⁺ and H⁺ conductance to stabilise luminal pH, a function essential for the au003c/pu003ernrnu003cimg class=u0022wp-image-681 alignrightu0022 src=u0022https://oriabs.com/wp-content/uploads/2026/05/CRC-Current-V2u002du002d1024x655.pngu0022 alt=u0022u0022 width=u0022522u0022 height=u0022334u0022 /u003ernu003cp id=u0022s3u0022u003ectivity of hydrolytic enzymes including glucocerebrosidase (GCase). Loss of this buffering function destabilises lysosomal pH, impairs enzyme activity, and ultimately prevents the clearance of alpha-synuclein aggregates, a hallmark of Parkinson’s disease pathology.u003c/pu003ernrnu003cdiv class=u0022case-partu0022u003ernrnTMEM175 is encoded at one of the most significant loci in Parkinson’s disease GWAS (rs34311866, p = 1.47 × 10⁻⁵⁰, OR = 1.23). The causal variant, p.M393T, reduces lysosomal K⁺ current by approximately 40% and has been directly linked to accelerated disease progression and earlier age of onset. Its structural novelty relative to canonical K⁺ channels, combined with the identification of first-in-class selective inhibitors in 2024, makes TMEM175 one of the most tractable emerging targets in neurodegeneration.rnrnCharacterising TMEM175 pharmacology requires direct access to native lysosomal membranes, which whole-cell assays and crude lysates fundamentally cannot provide. Whole-cell patch-clamp cannot resolve lysosomal currents without artefactual vacuolin-based enlargement; cell-based pH assays conflate lysosomal, cytoplasmic, and ER signals. This is precisely where ORIA’s platform becomes enabling.rnrnu003c/divu003ernu003cdiv class=u0022case-partu0022u003ernu003cp style=u0022text-align: center;u0022u003eFigure 2 – TMEM175 channel activity in LYSO-Prep™ preparations: dose-response profiling of selective inhibitorsu003c/pu003ernrnu003c/divu003ernu003c/sectionu003ernu003ch2 id=u0022s4u0022u003eKey Organelle-Linked Targets in Neurodegenerationu003c/h2u003ernThe table below lists validated and emerging therapeutic targets in neurodegeneration that are directly linked to organelle dysfunction, with the associated diseases and organelle compartment for each.rnrnu003cimg class=u0022aligncenter wp-image-855u0022 src=u0022https://oriabs.com/wp-content/uploads/2026/05/Capture-decran-2026-06-18-161903-251×300.pngu0022 alt=u0022u0022 width=u00221400u0022 height=u00221671u0022 /u003e
Frequently Asked Questions
u003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u00220u0022u003eNeurons u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u00228u0022u003eare post-mitotic, u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u002226u0022u003elong-lived cells that u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u002248u0022u003ecannot dilute accumulated damage u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u002281u0022u003ethrough cell division. u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022104u0022u003eThey rely almost u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022121u0022u003eexclusively on mitochondrial oxidative u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022160u0022u003ephosphorylation for energy production, u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022199u0022u003eunlike most other cell types which can u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022238u0022u003ecompensate through glycolysis. They u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022274u0022u003ealso accumulate misfolded proteins over u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022314u0022u003edecades, making lysosomal degradation u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022352u0022u003ecapacity a rate-limiting survival u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022386u0022u003efactor. Any disruption to these u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022418u0022u003esystems therefore has u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022440u0022u003edisproportionate consequences in u003c/spanu003eu003cspan class=u0022_animating_6ta1u_10u0022 data-newtext-seq=u0022473u0022u003eneurons compared to dividing tissues.u003c/spanu003e
TMEM175 is a lysosomal K⁺/H⁺ channel that stabilises luminal pH by balancing V-ATPase proton pumping. It is encoded at the top Parkinson’s disease GWAS locus (rs34311866, p = 1.47 × 10⁻⁹, OR = 1.23). The causal p.M393T variant reduces K⁺ current by approximately 40%, destabilises lysosomal pH, impairs GCase activity, and increases alpha-synuclein accumulation. Its structural uniqueness relative to canonical K⁺ channels and the 2024 identification of first-in-class selective inhibitors make it one of the most tractable emerging drug targets in neurodegeneration.
LYSO-Prep™ provides greater than 90% pure, functionally intact lysosomes compatible with HTS platforms. For TMEM175 specifically, it enables native-membrane patch-clamp electrophysiology (avoiding artefactual vacuolin-based protocols), direct lysosomal pH profiling, downstream GCase activity measurement, and inhibitor dose-response screening, all at organelle-level resolution not achievable in whole-cell or crude lysate systems.
The landscape of organelle-linked NDD targets is rich. For Parkinson’s disease: TMEM175, GBA1/GCase, LRRK2, PINK1/Parkin, ATP13A2. For Alzheimer’s disease: V-ATPase, PSEN1/2, TPC2, VPS35, TFEB. For ALS and Huntington’s disease: Drp1/Mfn1-2, mTORC1/AMPK, TRPML1. Many targets, including TFEB, V-ATPase, and mTORC1, are relevant across multiple diseases, reflecting the shared organelle dysfunction that underpins the entire NDD spectrum.
Whole-cell assays conflate signals from multiple compartments, including lysosomal, cytoplasmic, mitochondrial, and nuclear, making it impossible to attribute a pharmacological response to a specific organelle. Crude lysates rapidly lose membrane integrity and enzyme activity, eliminating functional channel and enzyme measurements. Purified organelle preparations allow direct biochemical interrogation of a single compartment with intact membranes, native enzyme activity, and physiological ion gradients, producing cleaner SAR data earlier in the drug discovery pipeline.