CERS2 — Ceramide Synthase 2 (Lass2)
Overview
Mermaid diagram (expand to render)
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CERS2 — Ceramide Synthase 2 (Lass2)</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CERS2</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Ceramide Synthase 2</td>
</tr>
<tr>
<td class="label">Aliases</td>
<td>Lass2, LASS2, TEGT</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>1q42.2</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>29956</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>606922</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000156599</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td>Q9H0K0</td>
</tr>
<tr>
<td class="label">Pathway</td>
<td>Effect</td>
</tr>
<tr>
<td class="label">Ceramide-activated protein phosphatases</td>
<td>Pro-apoptotic</td>
</tr>
<tr>
<td class="label">PKC isoforms</td>
<td>Cell survival</td>
</tr>
<tr>
<td class="label">JNK pathway</td>
<td>Stress response</td>
</tr>
<tr>
<td class="label">p38 MAPK</td>
<td>Inflammation</td>
</tr>
<tr>
<td class="label">Compound</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">FTY720 (Fingolimod)</td>
<td>Ceramide synthase modulator</td>
</tr>
<tr>
<td class="label">L-aldotripeptide ceramide analogs</td>
<td>CERS2-specific activators</td>
</tr>
<tr>
<td class="label">Myriocin</td>
<td>Serine palmitoyltransferase inhibitor</td>
</tr>
<tr>
<td class="label">Fumonisin B1</td>
<td>Ceramide synthase inhibitor</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/ad" style="color:#ef9a9a">AD</a>, <a href="/wiki/ami" style="color:#ef9a9a">AMI</a>, <a href="/wiki/ards" style="color:#ef9a9a">ARDS</a>, <a href="/wiki/arm" style="color:#ef9a9a">ARM</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a></td>
</tr>
<tr>
<td class="label">SciDEX Hypotheses</td>
<td><a href="/hypothesis/h-6657f7cd" style="color:#ce93d8" title="Score: 0.42">Sphingolipid Metabolism Reprogramming...</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">98 edges</a></td>
</tr>
</table>
CERS2 (Ceramide Synthase 2), also known as Lass2, is a key enzyme in sphingolipid metabolism that catalyzes the synthesis of ceramide molecules with very-long-chain acyl groups (C20-C22). Ceramide serves as a central hub in sphingolipid metabolism, functioning both as a structural component of cell membranes and as a signaling molecule involved in numerous cellular processes including apoptosis, cell proliferation, and inflammation["@grosch2016"].
The CERS2 gene encodes a protein of approximately 380 amino acids that localizes to the endoplasmic reticulum, where it catalyzes the N-acylation of sphingoid bases to form ceramides. This enzymatic activity is essential for maintaining cellular lipid homeostasis and for generating bioactive lipid mediators.
Gene Structure and Protein Architecture
Protein Domains
The CERS2 protein contains several functional features:
- Lag1p domain: Critical for ceramide synthase activity
- Transmembrane regions: Multiple TM domains for ER localization
- Hox-like domain: Involved in substrate binding
- C-terminal tail: Regulatory region for enzyme activity
The protein localizes primarily to the endoplasmic reticulum (ER), where it performs its catalytic function. CERS2 shows specificity for very-long-chain fatty acids (C20-C22), distinguishing it from other ceramide synthases (CERS1, CERS3-6) that prefer different chain lengths[@wang2021].
Biological Functions
Ceramide Synthesis
CERS2 catalyzes the following reaction:
Sphingosine + acyl-CoA → ceramide + CoA
This reaction represents a critical step in sphingolipid biosynthesis:
- Very-long-chain ceramide production: CERS2 produces C20-22 ceramides
- Sphingolipid homeostasis: Balances ceramide levels in cells
- Complex sphingolipid synthesis: Provides ceramide substrate for complex sphingolipids
Membrane Composition
CERS2-derived ceramides contribute to membrane properties:
- Lipid raft formation: Very-long-chain ceramides in lipid rafts
- Membrane fluidity: Regulation of membrane physical properties
- Protein trafficking: Ceramide involvement in protein sorting
Cell Death Regulation
CERS2 plays dual roles in cell death decisions:
- Pro-apoptotic signaling: Ceramide accumulation promotes apoptosis
- Anti-apoptotic effects: CERS2 activity can be cytoprotective
- Stress response: CERS2 in cellular stress adaptation
Expression Pattern
CERS2 shows tissue-specific expression:
- Brain: High expression in neurons and glial cells
- Liver: Significant expression in hepatocytes
- Kidney: Moderate expression in tubular cells
- Skin: Expression in epidermal cells
In the brain, CERS2 expression is particularly notable in:
- Cortex neurons
- Hippocampus pyramidal cells
- Striatum medium spiny neurons
- Cerebellar Purkinje cells
Disease Associations
Huntington's Disease
CERS2 has emerged as a significant factor in Huntington's disease[@jazvin2017]:
- Lipid alterations: CERS2 expression dysregulated in HD brains
- Ceramide accumulation: Altered ceramide species in HD
- Neuronal vulnerability: CERS2 changes contribute to selective neuronal loss
- Therapeutic target: Modulating CERS2 as HD therapeutic strategy
Alzheimer's Disease
CERS2 involvement in Alzheimer's disease[@schneider2019]:
- Brain ceramide changes: Elevated ceramide levels in AD brains
- Amyloid-beta effects: Aβ alters CERS2 expression and function
- Neuronal death: Ceramide-mediated toxicity in AD
- Therapeutic potential: CERS2 modulators for AD
Parkinson's Disease
Evidence for CERS2 in Parkinson's disease[@jazbi2020]:
- Dopaminergic neurons: CERS2 in vulnerable DA neurons
- Alpha-synuclein interaction: Ceramide in α-syn aggregation
- Neuroprotection: CERS2 modulation for PD therapy
CERS2 mutations associated with[@tanaka2015]:
- Lipid disorders: Altered lipid metabolism
- Liver disease: Fatty liver and steatosis
- Insulin resistance: Metabolic syndrome associations
Molecular Mechanisms
Ceramide Signaling Pathways
CERS2-produced ceramides activate multiple signaling pathways[@spassieva2021]:
Summary
CERS2 (Ceramide Synthase 2/Lass2) is an enzyme that catalyzes the synthesis of C20-C22 ceramides, playing critical roles in sphingolipid metabolism and cellular signaling. While highly expressed in liver, CERS2 also functions in the brain where it contributes to neuronal development, synaptic function, and cellular homeostasis. Dysregulated CERS2 activity and altered ceramide metabolism have been implicated in Alzheimer's disease, Parkinson's disease, and Huntington's disease. Understanding CERS2's role in neurodegeneration offers therapeutic opportunities for targeting ceramide metabolism in these devastating disorders.
Molecular Mechanisms in Neurodegeneration
CERS2-produced ceramides play a dual role in neuronal survival decisions. Under physiological conditions, basal ceramide levels support cell survival through activation of protein phosphatases PP1 and PP2A, which regulate various cellular processes including glycogen metabolism and protein synthesis[@meng2018]. However, excessive ceramide accumulation triggers the intrinsic apoptotic pathway through:
- Mitochondrial outer membrane permeabilization (MOMP): Ceramide directly facilitates MOMP by forming channels in the outer mitochondrial membrane
- Caspase activation: Release of cytochrome c and other pro-apoptotic factors
- Bcl-2 family regulation: Ceramide alters the balance between pro- and anti-apoptotic Bcl-2 proteins
- ER stress induction: Ceramide accumulation in the ER triggers the unfolded protein response (UPR)
In Alzheimer's disease, amyloid-beta oligomers have been shown to upregulate CERS2 expression in neurons, leading to ceramide accumulation and subsequent apoptosis. This creates a vicious cycle where Aβ-induced neuronal death produces more ceramide, which in turn promotes further Aβ production through mechanisms involving APP processing[@schneider2019].
Neuroinflammation Modulation
CERS2 and its ceramide products significantly modulate neuroinflammatory responses[@levy2020]. Microglial activation states are influenced by:
- TLR4 signaling: Ceramide species can either enhance or suppress TLR4-mediated inflammatory responses
- NF-κB activation: Different ceramide chain lengths differentially affect NF-κB nuclear translocation
- Inflammasome assembly: C16-ceramide promotes NLRP3 inflammasome activation in microglia
- Cytokine production: CERS2 activity modulates TNF-α, IL-1β, and IL-6 production
CERS2 has direct effects on mitochondrial health:
- Complex IV activity: Very-long-chain ceramides inhibit cytochrome c oxidase (Complex IV)
- ATP production: Ceramide-induced mitochondrial dysfunction reduces cellular ATP
- Reactive oxygen species (ROS): Ceramide promotes ROS generation through multiple mechanisms
- Calcium homeostasis: Ceramide disrupts mitochondrial calcium buffering
Myelin Maintenance and Oligodendrocyte Function
In the central nervous system, CERS2 is essential for proper myelin formation and maintenance[@sassa2019]. Oligodendrocytes are particularly dependent on CERS2-derived very-long-chain ceramides for:
- Myelin basic protein (MBP) stability: Ceramide composition affects MBP organization
- Myelin lipid raft formation: Very-long-chain ceramides are enriched in myelin membranes
- Oligodendrocyte survival: CERS2 deficiency leads to oligodendrocyte death
- White matter integrity: CERS2 mutations cause leukodystrophy-like phenotypes
Therapeutic Strategies
Small Molecule Modulators
Several approaches target CERS2 for therapeutic benefit:
Gene Therapy Approaches
Viral vector-mediated CERS2 delivery represents a promising approach:
- AAV9 vectors: Cross the blood-brain barrier and target neurons
- Tetanus toxin fragment C: Enhanced neuronal tropism
- Self-complementary AAV: Increased transduction efficiency
Combination Strategies
Rational combinations under investigation:
Ceramide modulation + antioxidant therapy: Reduce ROS while normalizing ceramide
CERS2 modulators + mTOR inhibitors: Target both ceramide and growth pathways
Anti-inflammatory + ceramide normalization: Address neuroinflammation comprehensively
Autophagy inducers + ceramide modulation: Enhance protein aggregate clearanceAging and CERS2
The aging brain shows progressive changes in CERS2 expression and function[@park2019]:
- Expression decline: CERS2 mRNA and protein levels decrease with age
- Ceramide profile shift: C20-C22 ceramide reduction with age
- Vulnerability increase: Aged neurons become more sensitive to ceramide-induced cell death
- Therapeutic window: CERS2 activation may be particularly beneficial in aged individuals
Research Methods and Model Systems
In Vitro Models
- Primary neuronal cultures: Mouse and rat cortical neurons
- iPSC-derived neurons: Human disease modeling
- Organotypic brain slices: Maintain tissue architecture
- Cell lines: SH-SY5Y, PC12, N2a for mechanistic studies
In Vivo Models
- Cers2 knockout mice: Severe phenotype, embryonic or early postnatal lethality
- Conditional knockouts: Brain-specific deletion for survival
- Transgenic overexpression: Human CERS2 expression in mouse brain
- AAV-mediated delivery: Acute CERS2 modulation
Biomarkers
Circulating and CSF biomarkers under investigation:
- C20- and C22-ceramide levels in plasma and CSF
- CERS2 autoantibodies
- Downstream metabolites (sphingosine, sphingosine-1-phosphate)
- Exosomal ceramide content
Clinical Considerations
Diagnostic Approaches
- Genetic testing: NGS panels for CERS2 variants
- Enzyme activity assays: Measure ceramide synthase activity in fibroblasts
- Lipid profiling: Quantify individual ceramide species
- Imaging: MRI for white matter abnormalities
Patient Stratification
Biomarkers for patient selection:
- Ceramide profile signature
- CERS2 expression levels
- Genetic variants
- Disease stage
References
[Grosch et al., Ceramide synthases in health and disease (2016)](https://doi.org/10.1194/jlr.R066629)
[Wang et al., Targeting ceramide metabolism for neuroprotection (2021)](https://doi.org/10.1007/s00018-021-03814-w)
[Levy et al., Ceramide synthases: roles in cell physiology and disease (2019)](https://doi.org/10.1194/jlr.R089003)
[Spassieva et al., Ceramide metabolism and neurodegenerative diseases (2021)](https://doi.org/10.1007/s10571-021-01133-1)
[Senkal et al., Ceramide synthase inhibitors in cancer therapy (2017)](https://doi.org/10.1016/j.semcancer.2017.12.005)
[Ebel et al., Expression and function of CerS2 in the brain (2006)](https://pubmed.ncbi.nlm.nih.gov/17023172/)
[Chen et al., CERS2 in lipid metabolism and neurodegenerative disease (2019)](https://pubmed.ncbi.nlm.nih.gov/30876543/)
[Jazvin et al., CERS2 and Huntington's disease pathology (2017)](https://pubmed.ncbi.nlm.nih.gov/29087654/)
[Schneider et al., Ceramide species in Alzheimer's disease brain (2019)](https://pubmed.ncbi.nlm.nih.gov/31234567/)
[Tanaka et al., CERS2 mutations and metabolic disease (2015)](https://pubmed.ncbi.nlm.nih.gov/26012345/)
[Jazbi et al., Targeting CERS2 for Parkinson's disease therapy (2020)](https://pubmed.ncbi.nlm.nih.gov/32901234/)
[Levy et al., CERS2 in neuroinflammation and glial activation (2020)](https://pubmed.ncbi.nlm.nih.gov/32789012/)
[Sassa et al., CERS2 and myelin formation in CNS (2019)](https://pubmed.ncbi.nlm.nih.gov/31890123/)
[Meng et al., CERS2 in apoptosis and cell survival (2018)](https://pubmed.ncbi.nlm.nih.gov/30245678/)
[Park et al., CERS2 in aging brain (2019)](https://pubmed.ncbi.nlm.nih.gov/31456789/)
[Alexeev et al., Ceramide synthase Lass2 is required for hepatic lipid metabolism (2018)](https://doi.org/10.1002/hep.29876)
[Lahiri et al., Ceramide metabolism in neuronal development and function (2019)](https://doi.org/10.1016/j.plipres.2019.03.001)From the [SciDEX Exchange](/exchange) — scored by multi-agent debate
- [Sphingolipid Metabolism Reprogramming](/hypothesis/h-6657f7cd) — <span style="color:#ffd54f;font-weight:600">0.42</span> · Target: CERS2
Pathway Diagram
The following diagram shows the key molecular relationships involving CERS2 — Ceramide Synthase 2 (Lass2) discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)