Veillonella ⇒ Cutibacterium acnes {10000230}

Shared Reference Notes

• [1.1] [#Staphylococcus epidermidis] 
  - #Acne > increased #Actinobacteria followed by #Firmicutes and #Proteobacteria, #Cutibacterium,#Staphylococcus and #Corynebacterium. - C. acnes > major species in terms of mean abundance, followed by #Staphylococcus epidermidis (S. epidermidis) and #Staphylococcus hominis (S. hominis);
• [1.2] [#Acne] 
  - An acneic Cutibacterium acnes strain as well as its porphyrins activate NRLP3 inflammasome assembly, while this was not observed with a non-acneic strain.
• [1.3] [#Atopic Dermatitis] 
  - AD subjects is characterized by reduced microbial richness, depletion of Cutibacterium acnes, #Dermacoccus and #Methylobacterium species.
• [1.4] [#Skin anatomy] 
  - C. acnes lineages coexist across an individual’s skin but not within the same pore
• [1.5] 
  - Cutibacterium acnes (formerly, #Propionibacterium acnes) is a skin-associated commensal that has been detected in the prostate of men with #Prostate cancer in several studies. - C. acnes can induce cell proliferation and the secretion of cytokines and chemokines such as IL-6 and IL-8
• [1.6] [#Propionic acid] [#Ultraviolet Exposure] 
• [1.7] 
  - #Lauric acid was shown to exert antimicrobial activity against Cutibacterium acnes
• [1.8] [#Antibiotic Therapy] 
  - a strain of #Staphylococcus capitis (S. capitis E12) that selectively inhibited growth of C. acnes with potency greater than antibiotics commonly used in the treatment of #Acne.
• [1.9] 
  - #Cutibacterium acnes secretes a thiopeptide RiPP called #Cutimycin that inhibits members of #Staphylococcus but does not affect the members of the genera #Corynebacterium and #Cutibacterium.
• [#Escherichia coli, #Staphylococcus aureus] - #RNAse7 showed higher inhibitory activity against E. Coli and Cutibacterium acnes compared to S. aureus
• [#Staphylococcus aureus] - Cutibacterium acnes secretes a lipase that converts triacylglycerols contained in sebum to #Propionic acid, which contributes to the acidification of the skin surface; a factor that limits the growth of S. aureus
• [#Natural Skin Microbiome] - Cutibacterium acnes associated with healthy skin were shown to activate the release of extracellular traps from specialized Th17 subsets
• - More than 4% of people whose blood came back positive for a bacterial DNA, it was for a dominant skin microbiota, i.e. Cutibacterium acnes.
• [1.11] 
  - patients with #Atopic Dermatitis have a decrease of C. acnes and a decrease of TAG46:2, TAG48:2, TAG50:2, and TAG50:3 that correlates with higher TEWL. - TAGs (TAG46, TAG48, and TAG50) were increased with increased exposure to C. acnes.
• - TAGs were most abundantly induced by C. acnes, TAGs are a minor component of lamellar bodies in the stratum corneum, and their role in epidermal homeostasis is poorly defined
• - sebum, which is a major nutrient source for C. acnes on the skin, is used by C. acnes for growth in the anaerobic environment of the hair follicle.
• [#Staphylococcus epidermidis] [#Short Chain Fatty Acid] - some SCFAs produced by C. acnes are antimicrobial and can inhibit biofilm formation by other organisms such as S. epidermidis
• - Cutibacterium acnes induced a large increase in essential lipids including triglycerides, #Ceramides, #Cholesterol, and free fatty acids. - C. acnes can mediate this effect through its production of #Propionic acid and subsequent activation of keratinocyte PPARα. - This increase in lipids was mediated by short-chain fatty acids produced by Cutibacterium acnes and was dependent on increased expression of several lipid synthesis genes including glycerol-3-phosphate-acyltransferase-3. - Inhibition or RNA silencing of peroxisome proliferator–activated receptor–α (PPARα), but not PPARβ and PPARγ, blocked this response.
• - two key barrier proteins, #Filaggrin and #Loricrin, were found to be increased in human reconstructed epidermis after treatment with C. acnes CM.
• - lipid extracted from neonatal human epidermal keratinocytes (NHEKs) after exposure to C. acnes CM or #Propionic acid has increased antimicrobial potency against C. acnes. - Many lipids potentially made by NHEK have antimicrobial activity including #Lauric acid, #Palmitoleic acid isomer (C16:1Δ6), sphingosine, and dihydrosphingosine
• - lipidomic analyses showed an increase of triglycerides containing linolenic acid (TAG18:2) and an increase of total ceramide in NHEKs after C. acnes exposure. - #Linoleic acid may be hydrolyzed from TAG and then contribute to acylceramide synthesis to maintain skin barrier function.
• - #Linoleic acid in NHEK lipid extract could partially explain the increased potency for C. acnes inhibition and has previously been shown to directly inhibit the growth of C. acnes
• [#Short Chain Fatty Acid] - C. acnes produces high amounts of #Propionic acid and other SCFAs, which creates a lipid-rich environment that is favorable for the growth and proliferation of the bacteria.
• [#Short Chain Fatty Acid] - Production of SCFA including #Propionic acid promotes an acidic environment that influences the survival of skin microbiota, formation of biofilms, as well as the function of pH-dependent enzymes required for lipid synthesis
• [1.12] [#Alzheimer’s disease] 
  - Cutibacterium acnes and #Methylobacterium spp > co-occurrence in the brains of the AD cohort, primarily in the frontal lobe, suggests possible pathogenicity.
• [1.13] [#Short peptide bacteriocins] 
  - C. acnes is responsible for the production of the SPB #Cutimycin, a peptide which is capable of inhibiting #Staphylococcus species growth.
• [1.14] 
  - C. acnes clade C is functionally related to #Skin aging.
• [#Skin aging] - C. acnes was likely responsible for the #Aging-related depletion of #Cutibacterium

References Notes