A new matrikine-derived peptide up-regulates longevity genes for improving extracellular matrix architecture and connections of dermal cell with its matrix

OBJECTIVE

Skin extracellular matrix (ECM) is a dense and well-organized structure produced by fibroblasts. This ECM transduces environmental mechano-signals to cell nucleus through the integrin-actin complex, thus triggering ECM protein syntheses. The aim of this study was to discover a novel peptide, structurally related to dermal matrikines, that promotes syntheses of ECM components.

METHODS AND RESULTS

Screening tests with 120 peptides were carried out by using normal dermal human fibroblasts (HF). As a result, one candidate of interest was isolated, the N-Prolyl Palmitoyl Tripeptide-56 Acetate (PP56), which increases collagen and fibronectin productions at gene and/or protein levels. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a recent and innovative analytical technology, in addition to more traditional techniques, it was showed that two metabolic pathways were significantly modulated: one for collagen production and one for actin. Moreover, this peptide up-regulated the transcription of Forkhead Box O (FOXO) and sestrin messenger RNAs (mRNA), leading to production of proteins involved into longevity and more recently in collagen production.

RESULTS

Results indicated that this peptide is a potential candidate to improve ECM density and organization in a new way.

Reinforcement of barrier function and scalp homeostasis by Senkyunolide A to fight against dandruff

OBJECTIVE

Senkyunolide-A (SENKY) can be isolated from Apium graveolens seed oil obtained using supercritical CO₂ extraction. SENKY and its parent compounds, the N-butyl phthalides, have been demonstrated to protect cells from CO poisoning, to prevent diabetes mellitus and to decrease cancer cell proliferation. This study was undertaken to evaluate in vitro and in vivo the effect of SENKY on epidermal function improvement, Malassezia effect control, scalp soothing and dandruff reduction via skin protection-related pathways.

METHODS

DNA-array and proteomic studies were performed on human keratinocytes, sebocytes and skin explants to demonstrate SENKY activities. Two clinical evaluations were performed under dermatologist control on 106 volunteers, with greasy or dry scalp, experiencing dandruff, itching and redness. Volunteers tested a shampoo followed, or not, by a leave-on, containing SENKY, or their placebos. Dandruff severity and redness were scored on the scalp. Moisturization and sebum release were recorded using relevant measuring apparatus. Itching and scratching evaluations came from volunteers' self-declarations.

RESULTS

DNA-array studies on keratinocytes showed a clear regulation of skin barrier functions and epidermis defence pathways. Upregulation of epidermal differentiation complex genes was observed. These preliminary observations were reinforced by immunocytochemistry and immunohistochemistry studies showing a significant increase of involucrin, filaggrin, loricrin, SPRR, LC3B and ceramide 2 productions. Tight-junctions and corneodesmosomes were significantly reinforced both in keratinocyte cultures (corneodesmosin, claudin, ZO-1) and in skin explants (desmoglein). DNA-array studies also demonstrated upregulation of genes involved in detoxification and anti-inflammation pathways. Proteomic studies revealed that hBD2 production was increased in keratinocytes in contact with SENKY, whereas IL-8, PGE-2 and TLR-9 releases were repressed as well as sebocyte lipid production. Clinical evaluations confirmed that after 3 weeks, SENKY significantly reduced dandruff intensity, redness, itching and scalp histamine content compared to placebo and beginning of treatment.

CONCLUSION

For the first time, SENKY has been shown to promote scalp homoeostasis by reinforcing barrier and defence functions at both gene and protein levels. It reduces irritation and redness in promoting detoxification and anti-inflammation pathways while controlling the niche of Malassezia. Applied on scalp, SENKY significantly reduces the formation of dandruff and soothes the scalp.

A novel episomal shuttle vector for transformation of Cryptococcus neoformans with the ccdB gene as a positive selection marker in bacteria

We report the engineering of a new shuttle vector featuring its episomal maintenance in Cryptococcus neoformans and the lethal Escherichia coli ccdB gene for positive selection in bacteria. Telomere-like sequences from C. neoformans and the STAB fragment confer episomal maintenance to the vector (pPM8) upon transformation in C. neoformans. The vector generated high transformation frequencies and each transformant was estimated to harbor thirty copies of the plasmid. The plasmids recovered in E. coli from the C. neoformans transformants showed no evidence of rearrangement. This construct will be very useful for cloning and studying the regulation of genes in C. neoformans.

Temperature-sensitive strain of Cryptococcus neoformans producing hyphal elements in a feline nasal granuloma

We report the isolation of a temperature-sensitive, serotype A, mating type alpha strain of Cryptococcus neoformans from a case of nasal cryptococcosis in a cat. The strain grew extremely slowly at 35 degrees C and failed to grow at 37 degrees C in vitro. Histopathological sections of the infected tissue revealed yeast cells producing hyphae up to several hundred micrometers in length, in addition to numerous encapsulated yeast cells typical of C. neoformans. The cultures grown on yeast extract-peptone-glucose agar at 35 degrees C also produced some yeast cells with germ tube-like hyphal elements up to 100 microm in length.

Heteroresistance to fluconazole and voriconazole in Cryptococcus neoformans

Cryptococcus neoformans isolates that exhibited unusual patterns of resistance to fluconazole and voriconazole were isolated from seven isolates from two different geographical regions: one isolate from an Israeli non-AIDS patient and six serial isolates from an Italian AIDS patient who had suffered six recurrent episodes of cryptococcal meningitis. Each isolate produced cultures with heterogeneous compositions in which most of the cells were susceptible, but cells highly resistant to fluconazole (MICs, >/=64 microg/ml) were recovered at a variable frequency (7 x 10(-3) to 4.6 x 10(-2)). Evidence showed that this type of resistance is innate and is unrelated to drug exposure since the Israeli patient had never been treated with azoles or any other antimycotic agents. Analysis of clonal subpopulations of these two strains showed that they exhibited heterogeneous patterns of resistance. The number of subpopulations which grew on fluconazole or voriconazole agar declined progressively with increasing azole concentration without a sharp cutoff point. For the Italian serial isolates, the number of clonal populations resistant to fluconazole (64 microg/ml) and voriconazole (1 microg/ml) increased steadily, yielding the highest number for the isolate from the last episode. Attempts to purify a sensitive subpopulation failed, but clones highly resistant to fluconazole (100 microg/ml) and moderately resistant to voriconazole (1 microg/ml) always produced a homogeneous population of resistant cells. Upon maintenance on drug-free medium, however, the majority of the homogeneously resistant cells of these subclones lost their resistance and returned to the stable initial heteroresistant phenotype. The pattern of heteroresistance was not affected by the pH or osmolarity of the medium but was influenced by temperature. The resistance appeared to be suppressed at 35 degrees C and was completely abolished at 40 degrees C. Although heterogeneity in azole resistance among subpopulations of single isolates has been reported for Candida species, the transient changes in expression of resistance under different growth conditions reported here have not been observed in fungal pathogens.

Combination of three typing methods for the molecular epidemiology of Aspergillus fumigatus infections. European Research Group on Biotype and Genotype of Aspergillus

This study investigated the source of infection and strain relatedness of Aspergillus fumigatus isolates from bronchial colonisation and invasive aspergillosis (IA) in four transplant patients. Environmental isolates from the patient's home and from the hospital and infecting isolates were obtained for patient A who developed IA. Clinic environmental and colonising isolates were obtained for patient B. Sequential isolates were obtained from various organs from patient C who developed IA and also from patient D who had a bronchitic aspergillosis that developed into IA. Ninety-one A. fumigatus isolates were analysed by three typing methods: multi-locus enzyme electrophoresis (MLEE), random amplified polymorphic DNA (RAPD) and sequence-specific DNA primers (SSDP). The three combined typing methods demonstrated a greater differentiation of isolates than the typing methods used separately or in pairs. This demonstrated the genotypic variability of A. fumigatus and facilitated better epidemiological analysis. Large polymorphisms were demonstrated for each patient isolate between and colonies within various samples. The relatedness of the isolates suggested nosocomially acquired aspergillosis for patient B, but the source of infection for patient A remained unclear. The results suggested at least three multiple infections among the four patients. This study enabled the identification of the source of infection and strain relatedness, which in turn facilitates the development of preventive measures for patient management in the future.

Aspergillus and lung transplant recipients: a mycologic and molecular epidemiologic study

BACKGROUND

After lung transplantation, filamentous fungi and more particularly Aspergillus fumigatus are commonly isolated, although the origin of contamination is unclear.

METHODS

To investigate the fungal flora in bronchoscopic fluids, we retrospectively reviewed 20 cases of lung transplant recipients. Using sequence-specific DNA primers analysis, we typed the clinical strains of A. fumigatus isolated from 6 lung transplant recipients. For 4 of them, the strains of this species were isolated from their environment.

RESULTS

At least once 90% of patients had filamentous fungi, and A. fumigatus was the most frequently isolated. Bronchial colonization was detected in 14 patients, invasive bronchial mycosis was diagnosed in 4 others, and no case of invasive pulmonary fungal infection was detected. Genome typing of the 47 clinical strains revealed that a given patient could be affected by several different strains. A very extensive polymorphism existed among the 38 environmental strains. Origin of contamination at home was possible in 1 case and in the hospital in 3 cases.

CONCLUSIONS

Bronchial colonization is frequent after lung transplantation. Although the clinical strains show a polymorphism, it is less widespread than the polymorphism of environmental strains. The origin of acquisition may be in the patient's community.

Molecular typing of Aspergillus fumigatus strains by sequence-specific DNA primer (SSDP) analysis

A PCR typing method has been developed and tested to investigate the polymorphism of clinical strains of Aspergillus fumigatus. Firstly, the DNA fragments from random amplified polymorphic DNA (RAPD) patterns of nine epidemiologically and geographically non-related monosporal strains of A. fumigatus were cloned and sequenced. The pairs of five sequence-specific DNA primers (SSDP), characteristic of the 5' and 3' extremities of the RAPD products, were then used in high stringency PCR to type 43 clinical strains of A. fumigatus from 13 patients, according to the presence or absence of a single amplified band. This original approach, which uses the advantages of PCR, has made it possible to overcome the difficulties resulting from the low stringency amplification. The SSDP analysis of 51 A. fumigatus strains (9 unrelated monosporal strains and 43 clinical strains from 13 patients) can be classed into 22 different types with a high reproducibility and a high level of discrimination (D = 0.96). The results suggest that seven lung transplant patients with necrotizing aspergillosis, bronchitis aspergillosis and bronchial colonization were infected by multiple strain genotypes, whereas three patients with invasive aspergillosis seem to have been infected by a single strain.

Multicentric epidemiological study of Aspergillus fumigatus isolates by multilocus enzyme electrophoresis

The genotypes of 63 isolates of Aspergillus fumigatus obtained from three hospitals in different geographical areas and of eight culture collection strains were determined by multilocus enzyme electrophoresis. Twelve of the 17 enzymatic loci studied were polymorphic, giving rise to 48 different electrophoretic types. The existence of fixed multilocus genotypes, significant heterozygote deficits and excesses at the different loci, and linkage disequilibria within subpopulations strongly suggests a clonal reproduction mode for A. fumigatus. Numerical analysis of the comparison and disposition of the different electrophoretic types demonstrates a significant genetic differentiation between the three sampling sites. However, no correlation could be found between geographical distances and genetic differentiation. On account of the multiple discriminatory markers, multilocus enzyme electrophoresis typing seems to be a very powerful tool for epidemiological and reproductive mode studies of A. fumigatus.

Variation in virulence of Aspergillus fumigatus strains in a murine model of invasive pulmonary aspergillosis

The diversity in virulence of different Aspergillus fumigatus strains was studied in an experimental murine model of invasive pulmonary aspergillosis (IPA) and the results were correlated with possession of a putative molecular marker of virulence. Seven strains from different patients with non-invasive or invasive aspergillosis and four environmental strains were typed by PCR with specific primers and scored as positive or negative, according to whether or not a 0.95-kb DNA fragment was amplified. Immunosuppressed mice were inoculated intranasally with A. fumigatus conidia from these different strains. The mortality curves revealed differences in virulence between the strains. The environmental strains produced a weaker infection than the strains from patients and the 0.95-kb-positive patient strains caused significantly higher mortality rates in mice than the 0.95-kb-negative patient strains. These findings support the hypothesis that certain isolates of A. fumigatus are more virulent than others and that their virulence appears to be associated with the 0.95-kb molecular marker.

Virulence of Aspergillus fumigatus strains investigated by random amplified polymorphic DNA analysis

A possible relationship between the ability of Aspergillus fumigatus strains to invade tissues and genetic polymorphism was studied by random amplified polymorphic DNA (RAPD) analysis. One hundred randomly designed oligonucleotide decamers were examined with DNA of three reference strains, eight environmental isolates and 21 isolates from two distinct clinical situations: non-invasive aspergillosis (predominantly aspergilloma) and invasive aspergillosis. One primer (OPQ 6) was found to generate a reproducible amplification product that enabled distinction between the two groups according to the presence or absence of a 0.95-kb fragment that correlated with the nature of the infection (non-invasive or invasive) and immune status of the patient. The results indicated that the pathogenicity of A. fumigatus was related not only to the host's immune status but also to the virulence of the strain of A. fumigatus.

Protective effect of two sunscreens against lethal and genotoxic effects of UVB in V79 Chinese hamster cells and Saccharomyces cerevisiae strains XV185-14C and D5

Effects of p-aminobenzoic acid (PABA) and of 4-[(2-oxo-3-bornylidene)methyl]-phenyl trimethylammonium methylsulfate (OMM), two components used in sunscreen formulations, on the mutagenicity of UVB irradiation are compared in three genetic assay systems. A haploid strain of Saccharomyces cerevisiae XV185-14C was used to measure reverse mutations at three loci. The diploid strain D5 of Saccharomyces cerevisiae was used to screen for reciprocal mitotic recombination. The induction of forward mutations was measured in Chinese hamster V79 cells. Our results indicate that UVB irradiation induced HGPRT- mutants in V79 cells, reverse mutations in Saccharomyces cerevisiae strain XV185-14C, and mitotic crossing over and other genetic alterations in Saccharomyces cerevisiae strain D5. V79 Chinese hamster lung cells were the most sensitive to UVB irradiation, followed by Saccharomyces cerevisiae haploid strain XV185-14C and the diploid strain D5. PABA and OMM were both capable of protecting all three types of cells from UVB irradiation regarding both lethality and induction of various types of genetic alterations. At higher concentrations (above 10(-5) M), OMM was more effective in its photoprotective effect toward UVB irradiation than PABA.

Comparative studies on the lethal, mutagenic, and recombinogenic effects of ultraviolet -A, -B, -C, and visible light with and without 8-methoxypsoralen in Saccharomyces cerevisiae

Genetic effects of UV-A, UV-B, UV-C, and the combination of 8-methoxypsoralen (8-MOP) with UV-A or visible light were studied in the haploid strain XV185-14C and diploid strain D5 of Saccharomyces cerevisiae. The induction of his+, lys+, and hom+ reverse mutations was measured in strain XV185-14C. In strain D5 we measured the induction of genetically altered colonies, particularly twin spot colonies arising from a mitotic crossing-over. UV-C and UV-B induced point mutations at the three loci in the haploid strain and mitotic crossing-over and other genetic alterations in the diploid strain. UV-C was more mutagenic and recombinogenic than UV-B. UV-A or visible light alone did not induce genotoxic effects at the doses tested. However, UV-A plus 8-MOP produced lethal and mutagenic effects in the haploid strain XV185-14C, although mutagenic activity was less than that of UV-B. Visible light plus 8-MOP also induced genotoxic effects in strain XV185-14C. In the diploid strain D5, UV-A plus 8-MOP induced a higher frequency of genetic alterations than UV-B at comparative doses. Visible light plus 8-MOP was also genetically active in strain D5. The haploid strain was more sensitive to the lethal effects of UV-C, UV-B, UV-A, and impure visible light plus 8-MOP than the diploid strain.