Beauty biology map
Skin barrier function
The is a brick-and-mortar arrangement of embedded in lamellar composed chiefly of , cholesterol and free fatty acids. proteolysis supplies the natural moisturising factors that hold water inside , and barrier integrity is usually measured indirectly as .
drag to pan · hover to isolate a path · click a node for detail
Text alternative for this network
- Skin barrier function associated with FLG — high confidence
- Skin barrier function associated with CERS3 — high confidence
- Skin barrier function associated with ABCA12 — high confidence
- Skin barrier function associated with TGM1 — high confidence
- Skin barrier function associated with CASP14 — medium confidence
- Skin barrier function associated with AQP3 — medium confidence
- Skin barrier function associated with PNPLA1 — medium confidence
- FLG participates in Formation of the cornified envelope — high confidence
- CERS3 participates in Formation of the cornified envelope — high confidence
- ABCA12 participates in Formation of the cornified envelope — high confidence
- TGM1 participates in Formation of the cornified envelope — high confidence
- CASP14 participates in Formation of the cornified envelope — medium confidence
- AQP3 participates in Formation of the cornified envelope — medium confidence
- PNPLA1 participates in Formation of the cornified envelope — medium confidence
- FLG participates in Sphingolipid metabolism — high confidence
- CERS3 participates in Sphingolipid metabolism — high confidence
- ABCA12 participates in Sphingolipid metabolism — high confidence
- TGM1 participates in Sphingolipid metabolism — high confidence
- CASP14 participates in Sphingolipid metabolism — medium confidence
- AQP3 participates in Sphingolipid metabolism — medium confidence
- PNPLA1 participates in Sphingolipid metabolism — medium confidence
- FLG participates in Cholesterol biosynthesis — medium confidence
- CERS3 participates in Cholesterol biosynthesis — medium confidence
- ABCA12 participates in Cholesterol biosynthesis — medium confidence
- TGM1 participates in Cholesterol biosynthesis — medium confidence
- CASP14 participates in Cholesterol biosynthesis — medium confidence
- AQP3 participates in Cholesterol biosynthesis — medium confidence
- PNPLA1 participates in Cholesterol biosynthesis — medium confidence
- FLG participates in Passive transport by aquaporins — medium confidence
- CERS3 participates in Passive transport by aquaporins — medium confidence
- ABCA12 participates in Passive transport by aquaporins — medium confidence
- TGM1 participates in Passive transport by aquaporins — medium confidence
- CASP14 participates in Passive transport by aquaporins — medium confidence
- AQP3 participates in Passive transport by aquaporins — medium confidence
- PNPLA1 participates in Passive transport by aquaporins — medium confidence
- Formation of the cornified envelope associated with Epidermal barrier formation — high confidence
- Sphingolipid metabolism associated with Epidermal barrier formation — high confidence
- Cholesterol biosynthesis associated with Epidermal barrier formation — medium confidence
- Passive transport by aquaporins associated with Epidermal barrier formation — medium confidence
- Formation of the cornified envelope associated with Stratum corneum hydration — high confidence
- Sphingolipid metabolism associated with Stratum corneum hydration — high confidence
- Cholesterol biosynthesis associated with Stratum corneum hydration — medium confidence
- Passive transport by aquaporins associated with Stratum corneum hydration — medium confidence
- Formation of the cornified envelope associated with Transepidermal water loss regulation — high confidence
- Sphingolipid metabolism associated with Transepidermal water loss regulation — high confidence
- Cholesterol biosynthesis associated with Transepidermal water loss regulation — medium confidence
- Passive transport by aquaporins associated with Transepidermal water loss regulation — medium confidence
- Formation of the cornified envelope associated with Desquamation — medium confidence
- Sphingolipid metabolism associated with Desquamation — medium confidence
- Cholesterol biosynthesis associated with Desquamation — medium confidence
- Passive transport by aquaporins associated with Desquamation — medium confidence
Genes & proteins
- FLGhigh confidence
Filaggrin
- CERS3high confidence
Ceramide synthase 3
- ABCA12high confidence
ATP binding cassette subfamily A member 12
- TGM1high confidence
Transglutaminase 1
- CASP14medium confidence
Caspase 14
- AQP3medium confidence
Aquaporin 3
- PNPLA1medium confidence
Patatin like phospholipase domain containing 1
Pathways
Formation of the cornified envelope
high confidenceTerminal and envelope crosslinking.
Reactome R-HSA-6809371
Sphingolipid metabolism
high confidenceand acylceramide production for the lamellae.
Reactome R-HSA-428157
Cholesterol biosynthesis
medium confidenceEpidermal sterol supply.
Reactome R-HSA-191273
Passive transport by aquaporins
medium confidenceWater and glycerol movement in .
Reactome R-HSA-432047
Ingredients studied here
- Ceramide NP
- Cholesterol
- Linoleic acid
- Niacinamide
- Panthenol
- Glycerin
- Urea
- Sodium PCA
- Zinc PCA
- Squalane
- Hyaluronic acid
- Lactic acid
- Ectoin
- Beta-glucan
- Allantoin
- Asiaticoside
Processes
- —
- hydration —
- regulation —
- —
Research on this topic
Nicotinamide and NAD precursor metabolism in human cells
Summarises the NAD salvage route in which nicotinamide is converted by NAMPT and NMNAT enzymes to NAD+, supporting redox and signalling functions.
Limitations — Review of mechanism, largely non-cutaneous; does not evaluate topical delivery.
Urea in dermatology: hydration and keratolysis by concentration
Summarises concentration-dependent behaviour of urea, humectant at low percentages and keratolytic at higher percentages.
Limitations — Narrative review without quantitative synthesis.
Ceramide-containing moisturiser and barrier recovery in dry skin
Reported faster transepidermal water loss recovery with a ceramide-dominant formulation compared with a control emollient.
Limitations — Short duration; identifier not verified during curation.
Essential fatty acid deficiency and epidermal acylceramide formation
Establishes linoleate as required for omega-O-acylceramide formation, with PNPLA1 mediating the transfer step.
Limitations — Review of genetic and animal evidence; topical repletion effects less characterised.
Allantoin in topical formulations: keratolytic and soothing properties
Summarises long-standing topical use with limited modern controlled data on mechanism.
Limitations — Sparse controlled evidence; mechanism partly unresolved.
Allantoin in barrier-support formulations: tolerability and hydration endpoints
Reported improved hydration and reduced roughness with an allantoin-containing emollient, without isolating the ingredient.
Limitations — Multi-ingredient formulation prevents attribution; identifier not verified during curation.
Squalene and squalane in skin surface lipids: oxidation and emollient behaviour
Describes squalene as readily oxidised in sebum, whereas the saturated squalane form is oxidation-resistant and functions as an emollient.
Limitations — Review; largely physicochemical rather than biological endpoints.
Hyaluronan in skin: molecular weight dependence of biological effects
Summarises how hyaluronan fragment size determines CD44 signalling outcomes, with high and low molecular weight forms behaving differently.
Limitations — Mechanistic review; largely non-topical models.
Polyglutamic acid film formation and short-term skin hydration
Reported increased corneometry readings shortly after application, attributed to a hygroscopic surface film.
Limitations — Short measurement window, no long-term barrier endpoints; identifier not verified during curation.
Natural moisturising factor composition and stratum corneum hydration
Summarises filaggrin proteolysis as the source of pyrrolidone carboxylic acid and its contribution to corneocyte water binding.
Limitations — Review; does not evaluate topical sodium PCA products; identifier not verified during curation.
Nicotinamide as an inhibitor of poly(ADP-ribose) polymerase activity
Characterises nicotinamide as a weak product inhibitor of PARP enzymes in cell-free assays.
Limitations — Biochemical assay; inhibitory concentrations far above physiological skin levels.
Topical hyaluronic acid formulations and skin hydration: a controlled study
Reported increased corneometry-measured hydration and reduced wrinkle depth versus baseline over 8 weeks.
Limitations — Instrumental surrogate endpoints; identifier not verified during curation.
Beta-glucan recognition by dectin-1 and downstream innate signalling
Establishes CLEC7A/dectin-1 as the principal receptor for beta-1,3-glucans in innate immune recognition.
Limitations — Immunology review; cosmetic topical endpoints not addressed.
Centella asiatica triterpenes and wound-related collagen deposition
Reported increased collagen deposition and faster wound closure in a rodent model.
Limitations — Animal wound model; not equivalent to intact cosmetic use; identifier not verified.
Centella asiatica triterpenes and wound-healing gene expression
Summarises reported collagen and matrix effects for asiaticoside and madecassoside across animal and cell models.
Limitations — Extracts vary in composition; mostly animal data; identifier not verified during curation.
Ectoine as a compatible solute: membrane and protein stabilisation
Summarises preferential-hydration mechanisms by which ectoine stabilises membranes and proteins under stress.
Limitations — Biophysical review, not cutaneous; identifier not verified during curation.
Avenanthramides and NF-kB dependent cytokine release in keratinocyte culture
Reported reduced IL-8 release and NF-kB reporter activity in stimulated keratinocytes exposed to purified avenanthramides.
Limitations — Purified compounds at defined concentrations, unlike commercial extracts; identifier not verified during curation.
Squalane occlusivity and stratum corneum lipid compatibility
Reported reduced water loss across model membranes attributed to a compatible, non-polar occlusive film.
Limitations — Model membranes, not human skin; identifier not verified during curation.
Filaggrin degradation products and natural moisturising factor content of the stratum corneum
Demonstrates that filaggrin proteolysis by caspase-14 and downstream enzymes generates pyrrolidone carboxylic acid and urocanic acid.
Limitations — Ex-vivo/in-vitro; identifier not verified during curation.
Zinc salts and sebaceous lipid production in vitro
Reported reduced sebocyte lipid accumulation with zinc salts, including 5-alpha reductase inhibition in cell assays.
Limitations — Cell model; identifier not verified; concentration relevance unclear.
Glycerol and aquaporin-3 mediated water transport in epidermis
Summarises evidence that AQP3 transports both water and glycerol, linking glycerol to stratum corneum hydration.
Limitations — Mechanistic review including mouse knockout data; identifier not verified during curation.
Ectoin as a protective compatible solute in keratinocyte models
Reported reduced UVA-induced signalling and membrane damage in ectoin-treated keratinocytes.
Limitations — Cell model; identifier not verified during curation.
Colloidal oatmeal: mechanisms and clinical use in dry, itchy skin
Summarises reported anti-inflammatory activity of avenanthramides alongside the occlusive and buffering effects of the whole extract.
Limitations — Review; extract composition is variable between products; identifier not verified during curation.
Niacinamide: a B vitamin that improves aging facial skin appearance
Reported improvements in several appearance endpoints including fine lines and skin texture over 12 weeks of use versus vehicle.
Limitations — Manufacturer-affiliated authorship; appearance endpoints partly investigator-graded.
Oat beta-glucan penetration and soothing endpoints in human skin
Reported improvement in dryness and itch scores, with penetration of the polysaccharide into the upper epidermis described in accompanying imaging.
Limitations — Small sample, manufacturer-supported; identifier not verified during curation.
Stratum corneum lipids and barrier function: ceramide, cholesterol and free fatty acid ratios
Establishes the approximately equimolar ceramide/cholesterol/free fatty acid composition required for competent lamellar barrier structure.
Limitations — Review; ratio requirements derived largely from animal and ex-vivo models.
Glycerol and aquaporin-3 in epidermal water transport
Aquaporin-3 null mice showed reduced stratum corneum glycerol and impaired hydration, restored by glycerol administration.
Limitations — Animal knockout model; identifier not verified during curation.
Dexpanthenol and epidermal barrier repair after experimental irritation
Reported faster barrier recovery measured by transepidermal water loss compared with vehicle after sodium lauryl sulfate challenge.
Limitations — Experimental irritation model; identifier not verified during curation.
Dexpanthenol and epidermal barrier repair after experimental irritation
Reported faster recovery of transepidermal water loss after sodium lauryl sulfate irritation with dexpanthenol versus vehicle.
Limitations — Experimental irritation model rather than clinical disease; identifier not verified during curation.
Topical niacinamide and epidermal barrier lipid synthesis in cultured keratinocytes
Reported increased ceramide and free fatty acid synthesis in keratinocyte culture after niacinamide exposure.
Limitations — In-vitro only; concentrations may not reflect in-use exposure.
Lactic acid stimulates ceramide synthesis in the epidermis
Reported increased epidermal ceramide production after lactic acid exposure in a skin model.
Limitations — In-vitro; stereoisomer-specific effects incompletely characterised; identifier not verified.
Physiological lipid mixtures and accelerated barrier recovery
Reported that only balanced ceramide/cholesterol/fatty acid mixtures accelerated barrier recovery; incomplete mixtures delayed it.
Limitations — Animal model; identifier not verified during curation.
Community evidence
Submitted by readers
Reader submissions appear here only after review. They are not part of the curated dataset and do not affect the Skinceptor Evidence Index.
No approved community submissions yet.
Sources
- Reactome R-HSA-6809371Verified 2026-09-14
- UniProt P20930Verified 2026-09-14