2. • They are located in plasma membrane
• Have structural function
• Serve as sites of adherence of
extracellular proteins
3. • Important function in cellular physiology
• Current as second messengers
• They are part of lipids rafts
• Sphingosine is the most simple sphingolipid
• Ceramide is precursor of many molecules
4. STRUCTURE
• Long – chain base
(Sphingosine)
• Fatty acid of variable
length bind to C2 of
long – chain base
• Various pollar´s head
bind to C1 of long –
chain base
5. METABOLISM
Generation of Ceramide (principal precursor
of metabolites) follow this pathway
• De novo synthesis
• Membrane Sphingomyelin degradation
6. DE NOVO SYNTHESIS
• Occur in Endoplasmic
Reticulum and Golgi
apparatus
• Sphingomyelinase
catalizes
Sphingomyelin
synthesis transferring
Phosphorilcholine to
Ceramide forming
7. SPHINGOMYELINE
DEGRADATION
• Catalyzed by
Sphingomyelinase
enzyme (SMasa)
• It is the principal
pathway for
Ceramide`s
production
8. LIPIDS RAFTS
• Sphingolipids with
cholesterol outside of
lipid bilayer
• Lipid and protein
composition is
different for each raft
• Signaling activity is
due to interaction of
lipids and proteins
9. • The caveolaes are rafts specialized of invaginated shape
than regulates receptor activity (tyrosin kinase, growth factor
receptor etc)
• Allow entry of various biological entities to cell (virus,
hormones, bacteria etc)
10. • Rafts promotes signaling in response to a
stimule
• Regulates signaling because they kidnaps
signaling molecules in inactive status
• Activated receptor changes the composition of
Sphingolipids raft altering the structure of the
membrane and thereby initiates the signaling
cascade
• Sphingolipids of caveolaes allows interaction of
pathogen entities with the cell iniciating
11. SIGNALING
APOPTOSIS MITOSIS
• Esfingosina 1 fosfato
• Ceramida
• Ceramida 1 fosfato
Balance between Ceramide and his metabolites is important for cellular
survival regulation
12. CERAMIDE`S ACTION
Ceramide acts as second messenger, is
formated by:
• Activation of cell dead receptors
• Gamma and UV radiation
• Hypoxia
• Deprivation of growth factors
• Thermic shock
• Pharmacs
15. • CAPK: Ras suppressor kinase
• PKCζ: Active the NF-кB survival pathway
• JNK: His activation produces apoptosis
• PP1: Bad phosphorilation, producing apoptosis
• PP2A: Bcl-2 dephosphorilation, becoming in apoptotic
molecule doing permeable mitochondrial membrane
• Ceramide can produce oxidative stress by ON
synthetase and antioxidantes enzymes desregulation
16. CERAMIDAE 1 PHOSPHATE
ACTION
C1P is produced by a Ceramide kinase ATP-ligand. This
C1P is implicated in inflammatory responses, apoptosis
inhibition and cell survival.
• Current in the araquidónic acid release
• Acid sphingomyelinase inhibition, this decrese
ceramide`s levels inhibiting apoptosis
• PI3K/PKB pathway activation, increasing cell survival
20. S1P can act as second messenger or act in extracellular
surface by transporters who carry from intracellular to
extracellular space
• 5 S1P receptors are linked to various kind of G protein
(S1P1-5)
• Receptors linked to G12/13 protein activate the Rho
GTPasa than regulates cytoskeleton and cell motility
• Receptors linked to Gq protein coupling to
Phospholipase C increasing intracellular calcium
• Receptors linked to Gi protein regulate the PI3K/Akt and
Ras/ERK pathways
21. GANGLIOSIDES
• Glycosphingolipids
than contain sialic
acid residues (NANA)
• Are the 25% of lipids
in outside of neural
membrane
• There are 188
differents kinds of
gangliosides
23. • Glycosphingolipids precursors of gangliosides into the
Golgi apparatus and wrapped in reactions of
glycotransferases and sialotransferases
• Extraneural primary gangliosides in vertebrates is GM3
• A sialidase different from the Golgi apparatus is located
in the plasma membrane where it changes the
composition of gangliosides in surface
• Myelinic maintenance and neural regeneration functions
• Cerebral primary gangliosides are GM1, GD1a, GD1b y
GT1
24. GANGLIOSIDES AND
DISEASE
• Certain types of gangliosides found in
cancer cells and not in healthy tissue
• GM3 has therapeutic applications to
promote apoptosis of tumor cells by
suppressing the phosphorylation of
receptors for growth hormone in her
surface
• GD1a promote proliferation and tumoral
cells metastasis
25. • Gullain – Barré syndrome there are
gangliosides antibodies
• GM1 disorder in the Alzheimer disease
cause β amyloid protein accumulation in
brain
• Damages in metabólicas pathways for
gangliosides are involved in Huntington`s
disease
• In childhood epylepsia there is mutation in
Sialotransferase gen
26. CEREBROSIDE S
• Monohexoses
Ceramides
• They are primary in
brain, but too in
spleen and
erythrocytes
27. Cerebrosides are synthesized from the Ceramide
and activated sugar nucleotides UDP-galactose and
UDP-glucose
Biosynthesis is in endoplasmic reticulum and the
involved enzymes in this process are glycosil and
galactosil transferases
28. • Promote the increase of body temperature
to form networks compact hydrogen
bridges with other cerebrosides
• Increased cerebrosides in liver, spleen,
bone marrow and lungs causing Gaucher
disease due to defects in the enzyme
glycocerebrosidase