Expression of sfrp2 is increased in catagen of hair follicles and inhibits keratinocyte proliferation

Hair follicle-resident progenitor cells are a major cellular contributor to heterotopic subcutaneous ossifications in a mouse model of Albright hereditary osteodystrophy

Heterotopic ossifications (HOs) are the pathologic process by which bone inappropriately forms outside of the skeletal system. Despite HOs being a persistent clinical problem in the general population, there are no definitive strategies for their prevention and treatment due to a limited understanding of the cellular and molecular mechanisms contributing to lesion development. One disease in which the development of heterotopic subcutaneous ossifications (SCOs) leads to morbidity is Albright hereditary osteodystrophy (AHO). AHO is caused by heterozygous inactivation of GNAS, the gene that encodes the α-stimulatory subunit (Gαs) of G proteins. Previously, we had shown using our laboratory's AHO mouse model that SCOs develop around hair follicles (HFs). Here we show that SCO formation occurs due to inappropriate expansion and differentiation of HF-resident stem cells into osteoblasts. We also show in AHO patients and mice that Secreted Frizzled Related Protein 2 (SFRP2) expression is upregulated in regions of SCO formation and that elimination of Sfrp2 in male AHO mice exacerbates SCO development. These studies provide key insights into the cellular and molecular mechanisms contributing to SCO development and have implications for potential therapeutic modalities not only for AHO patients but also for patients suffering from HOs with other etiologies.

Comprehensive transcriptome profiling between balding and non-balding scalp of female pattern hair loss in Asian

While many gene expression studies have focused on male pattern baldness (MPB), few studies have investigated the genetic differences between bald and non-bald hair follicles in female pattern hair loss (FPHL). This study aimed to identify molecular biomarkers associated with FPHL through genetic analysis of paired bald and non-bald hair follicles from 18 FPHL patients, using next-generation sequencing (NGS) techniques. RNA transcriptome analysis was performed to identify differentially expressed genes (DEGs) between bald and non-bald hair follicles in FPHL. The DEGs were validated using real-time PCR, and protein expression was confirmed through immunohistochemistry and western blot analysis. Our findings suggest that HOXB13, SFRP2, PTGDS, CXCR3, SFRP4, SOD3, and DCN are significantly upregulated in bald hair follicles compared to non-bald hair follicles in FPHL. SFRP2 and PTGDS were found to be consistently highly expressed in bald hair follicles in all 18 samples. Additionally, elevated protein levels of SFRP2 and PTGDS were confirmed through western blot and immunohistochemical analysis. Our study identified SFRP2 and PTGDS as potential biomarkers for FPHL and suggests that they may play a role in inducing hair loss in this condition. These findings provide a foundation for further research on the pathogenesis of FPHL and potential therapeutic targets.

Melatonin promotes hair regeneration by modulating the Wnt/β-catenin signalling pathway

Melatonin (MLT) is a circadian hormone that reportedly influences the development and cyclic growth of secondary hair follicles; however, the mechanism of regulation remains unknown. Here, we systematically investigated the role of MLT in hair regeneration using a hair depilation mouse model. We found that MLT supplementation significantly promoted hair regeneration in the hair depilation mouse model, whereas supplementation of MLT receptor antagonist luzindole significantly suppressed hair regeneration. By analysing gene expression dynamics between the MLT group and luzindole-treated groups, we revealed that MLT supplementation significantly up-regulated Wnt/β-catenin signalling pathway-related genes. In-depth analysis of the expression of key molecules in the Wnt/β-catenin signalling pathway revealed that MLT up-regulated the Wnt/β-catenin signalling pathway in dermal papillae (DP), whereas these effects were facilitated through mediating Wnt ligand expression levels in the hair follicle stem cells (HFSCs). Using a DP-HFSCs co-culture system, we verified that MLT activated Wnt/β-catenin signalling in DPs when co-cultured with HFSCs, whereas supplementation of DP cells with MLT alone failed to activate Wnt/β-catenin signalling. In summary, our work identified a critical role for MLT in promoting hair regeneration and will have potential implications for future hair loss treatment in humans.

Single nucleotide polymorphisms in the KRT82 promoter region modulate irregular thickening and patchiness in the dorsal skin of New Zealand rabbits

BACKGROUND

While rabbits are used as models in skin irritation tests, the presence of irregular patches and thickening on the dorsal skin can affect precise evaluation. In this study, genes associated with patchiness or non-patchiness on the dorsal skin of New Zealand rabbits were investigated to identify potential regulators of the patchiness phenotype.

RESULTS

The results showed that parameters associated with hair follicles (HFs), such as HF density, skin thickness, and HF depth, were augmented in rabbits with the patchiness phenotype relative to the non-patchiness phenotype. A total of 592 differentially expressed genes (DEGs) were identified between the two groups using RNA-sequencing. These included KRT72, KRT82, KRT85, FUT8, SOX9, and WNT5B. The functions of the DEGs were investigated by GO and KEGG enrichment analyses. A candidate gene, KRT82, was selected for further molecular function verification. There was a significant positive correlation between KRT82 expression and HF-related parameters, and KRT82 overexpression and knockdown experiments with rabbit dermal papilla cells (DPCs) showed that it regulated genes related to skin and HF growth and development. Investigation of single nucleotide polymorphisms (SNPs) in the exons and promoter region of KRT82 identified four SNPs in the promoter region but none in the exons. The G.-631G > T, T.-696T > C, G.-770G > T and A.-873 A > C alleles conformed to the Hardy - Weinberg equilibrium, and three identified haplotypes showed linkage disequilibrium. Luciferase reporter assays showed that the core promoter region of KRT82 was located in the - 600 to - 1200 segment, in which the four SNPs were located.

CONCLUSIONS

The morphological characteristics of the patchiness phenotype were analyzed in New Zealand rabbits and DEGs associated with this phenotype were identified by RNA-sequencing. The biological functions of the gene KRT82 associated with this phenotype were analyzed, and four SNPs were identified in the promoter region of the gene. These findings suggest that KRT82 may be a potential biomarker for the breeding of experimental New Zealand rabbits.

Modulation of tooth regeneration through opposing responses to Wnt and BMP signals in teleosts

Most vertebrate species undergo tooth replacement throughout adult life. This process is marked by the shedding of existing teeth and the regeneration of tooth organs. However, little is known about the genetic circuitry regulating tooth replacement. Here, we tested whether fish orthologs of genes known to regulate mammalian hair regeneration have effects on tooth replacement. Using two fish species that demonstrate distinct modes of tooth regeneration, threespine stickleback (Gasterosteus aculeatus) and zebrafish (Danio rerio), we found that transgenic overexpression of four different genes changed tooth replacement rates in the direction predicted by a hair regeneration model: Wnt10a and Grem2a increased tooth replacement rate, whereas Bmp6 and Dkk2 strongly inhibited tooth formation. Thus, similar to known roles in hair regeneration, Wnt and BMP signals promote and inhibit regeneration, respectively. Regulation of total tooth number was separable from regulation of replacement rates. RNA sequencing of stickleback dental tissue showed that Bmp6 overexpression resulted in an upregulation of Wnt inhibitors. Together, these data support a model in which different epithelial organs, such as teeth and hair, share genetic circuitry driving organ regeneration.

Identification of Critical Genes for Ovine Horn Development Based on Transcriptome during the Embryonic Period

Horns, also known as headgear, are a unique structure of ruminants. As ruminants are globally distributed, the study of horn formation is critical not only for increasing our understanding of natural and sexual selection but also for the breeding of polled sheep breeds to facilitate modern sheep farming. Despite this, a significant number of the underlying genetic pathways in sheep horn remain unclear. In this study, to clarify the gene expression profile of horn buds and investigate the key genes in horn bud formation, RNA-sequencing (RNA-seq) technology was utilized to investigate differential gene expression in the horn buds and adjacent forehead skin of Altay sheep fetuses. There were only 68 differentially expressed genes (DEGs) identified, consisting of 58 up-regulated genes and 10 down-regulated genes. RXFP2 was differentially up-regulated in the horn buds and had the highest significance (p-value = 7.42 × 10^-14). In addition, 32 DEGs were horn-related genes identified in previous studies, such as RXFP2, FOXL2, SFRP4, SFRP2, KRT1, KRT10, WNT7B, and WNT3. Further, Gene Ontology (GO) analysis showed that the DEGs were mainly enriched with regard to growth, development, and cell differentiation. Pathway analysis revealed that the Wnt signaling pathway may be responsible for horn development. Further, through combining the protein-protein interaction networks of the DEGs, it was found that the top five hub genes, namely, ACAN, SFRP2, SFRP4, WNT3, and WNT7B, were also associated with horn development. Our results suggest that only a few key genes, including RXFP2, are involved in bud formation. This study not only validates the expression of candidate genes identified at the transcriptome level in previous studies but also provides new possible marker genes for horn development, which may promote our understanding of the genetic mechanisms of horn formation.

Insights into male androgenetic alopecia using comparative transcriptome profiling: hypoxia-inducible factor-1 and Wnt/β-catenin signalling pathways

BACKGROUND

The key pathophysiological changes in androgenetic alopecia (AGA) are limited to hair follicles (HFs) in frontal and vertex regions, sparing the occipital region.

OBJECTIVES

To identify biological differences among HF subpopulations.

METHODS

Paired vertex and occipital HFs from 10 male donors with AGA were collected for RNA sequencing assay. Furthermore, HF and cell experiments were conducted on the identified key genes to reveal their roles in AGA.

RESULTS

Transcriptome profiles revealed that 506 mRNAs, 55 microRNAs and 127 long noncoding RNAs were differentially expressed in the AGA vertex HFs. Pathway analysis of mRNAs and microRNAs revealed involvement of the hypoxia-inducible factor (HIF)-1, Wnt/β-catenin, and focal adhesion pathways. Differential expression of HIF-1 prolyl hydroxylase enzymes (EGLN1, EGLN3) and Wnt/β-catenin pathway inhibitors (SERPINF1, SFRP2) was experimentally validated. In vitro studies revealed that reduction of EGLN1, EGLN3, SERPINF1 and SFRP2 stimulated proliferation of dermal papilla cells. Ex vivo HF studies showed that downregulation of EGLN1, EGLN3 and SERPINF1 promoted HF growth, postponed HF catagen transition, and prolonged the anagen stage, suggesting that these genes may be potentially utilized as therapeutic targets for AGA.

CONCLUSIONS

We characterized key transcriptome changes in male AGA HFs, and found that HIF-1 pathway-related genes (EGLN1, EGLN3) and Wnt pathway inhibitors (SERPINF1, SFRP2) may play important roles in AGA. What is already known about this topic? Multiple differentially expressed genes and signalling pathways have been found between hair follicles (HFs) in the balding area (frontal and vertex regions) and nonbalding area (occipital region) of individuals with androgenetic alopecia (AGA). A whole-transcriptome atlas of the vertex and occipital region is lacking. What does this study add? We identified a number of differentially expressed genes and pathways between balding vertex and nonbalding occipital AGA HFs by using whole-transcriptome analyses. We identified pathways not previously reported in AGA, such as the hypoxia-inducible factor (HIF)-1 signalling pathway. We verified that HIF-1 pathway-related genes (EGLN1, EGLN3) and Wnt pathway inhibitors (PEDF, SFRP2) played important roles in dermal papilla cell activity, hair growth and the hair cycle. What is the translational message? The EGLN1, EGLN3, SERPINF1 and SFRP2 genes may be potentially utilized as therapeutic targets for AGA.

Characterisation and functional analysis of the WIF1 gene and its role in hair follicle growth and development of the Angora rabbit

Growth and development of hair follicles (HF) is a complex and dynamic process in most mammals. As HF growth and development regulate rabbit wool yield, exploring the role of genes involved in HF growth and development may be relevant. In this study, the coding sequence of the Angora rabbit (Oryctolagus cuniculus) WIF1 gene was cloned. The length of the coding region sequence was found to be 1140 bp, which encodes 379 amino acids. Bioinformatics analysis indicated that the WIF1 protein was unstable, hydrophilic and located in the extracellular region, contained a putative signal peptide and exhibited a high homology in different mammals. Moreover, WIF1 was significantly downregulated in the high wool production in the Angora rabbit group. Overexpression and knockdown studies revealed that WIF1 regulates HF growth and development-related genes and proteins, such as LEF1 and CCND1. WIF1 activated β-catenin/TCF transcriptional activity, promoted cell apoptosis and inhibited cellular proliferation. These results indicate that WIF1 might be important for HF development. This study, therefore, provides a theoretical foundation for investigating WIF1 in HF growth and development.

miR-129-5p Participates in Hair Follicle Growth by Targeting HOXC13 in Rabbit

Mammalian hair formation is critically determined by the growth of hair follicles (HF). MiRNAs are crucial in the periodic development of hair follicles; they maintain epidermal homeostasis by targeting genes and influencing the activity of signaling pathways and related regulators. Our study discovered miR-129-5p to be overexpressed in the skin of Angora rabbits during catagen, and was negatively correlated with HOXC13 expression (Pearson’s R = −0.313, p < 0.05). The dual-Luciferase reporter gene detection system and Western blotting confirmed that miR-129-5p targeted HOXC13. In addition, miR-129-5p overexpression was found to significantly inhibit the expression of hair follicle development-related genes (HFDRGs), such as BCL2, WNT2, CCND1, and LEF1 (p < 0.01), and promoted the expression of SFRP2, TGF-β1, and FGF2 (p < 0.01), which was the same as the knockdown of HOXC13. In contrast, the knockout of miR-129-5p was the opposite, and it demonstrated similar results to the overexpression of HOXC13. CCK8 and flow cytometry demonstrated that miR-129-5p mimics significantly promoted the apoptosis of dermal papilla cells (DPCs) and inhibited proliferation (p < 0.01), while the inhibitor was found to reduce the apoptosis of DPCs and promote proliferation (p < 0.01). These results showed that miR-129-5p can participate in the periodic development of HF by targeting HOXC13, and it can induce apoptosis and inhibit proliferation of DPCs. These results will help to understand the role and mechanism of miR-129-5p in the periodic development of HF, and will provide support for subsequent studies, not only providing a theoretical basis for genetically improving the quality of hair in animals in the future, but also a new theory and method for diagnosing and treating hair loss in humans.

Exosomal miRNA-181a-5p from the cells of the hair follicle dermal papilla promotes the hair follicle growth and development via the Wnt/β-catenin signaling pathway

Exosomal miRNAs are verified critical biomarkers, which participate in several biological processes. The growth and development of the hair follicle (HF) are typically controlled by the exosomal miRNAs via cell-to-cell communication. This study identified a high expression of miR-181a-5p in the low-passage DPC-Exos (exosomes derived from dermal papilla cell), revealing the transportation patterns of the DPC-Exos-derived miR-181a-5p entering the HFSC (hair follicle stem cell). The exosomal miR-181a-5p activates the Wnt/β-catenin signaling pathway by targeting the Wnt inhibitor WIF1 and thereby regulates the proteins and genes related to HF growth and development. Moreover, the exosomal miR-181a-5p was found to suppress the HFSC apoptosis but promoted the HFSC proliferation. The in vitro culture of the HF organ revealed that the exosomal miR-181a-5p possesses a positive role in hair growth. Collectively, the exosomal miR-181a-5p affects the HF growth and development through the Wnt/β-catenin signaling pathway. The exosomal miR-181a-5p might, therefore, act as the novel biomarker and therapeutic target for treating hair-related diseases and wool production in mammals.

Langerhans cells and SFRP2/Wnt/beta-catenin signalling control adaptation of skin epidermis to mechanical stretching

Skin can be mechanically stimulated to grow through a clinical procedure called tissue expansion (TE). Using a porcine TE model, we determined that expansion promptly activates transcription of SFRP2 in skin and we revealed that in the epidermis, this protein is secreted by Langerhans cells (LCs). Similar to well‐known mechanosensitive genes, the increase in SFRP2 expression was proportional to the magnitude of tension, showing a spike at the apex of the expanded skin. This implies that SFRP2 might be a newly discovered effector of mechanotransduction pathways. In addition, we found that acute stretching induces accumulation of b‐catenin in the nuclei of basal keratinocytes (KCs) and LCs, indicating Wnt signalling activation, followed by cell proliferation. Moreover, TE‐activated LCs proliferate and migrate into the suprabasal layer of skin, suggesting that LCs rebuild their steady network within the growing epidermis. We demonstrated that in vitro hrSFRP2 treatment on KCs inhibits Wnt/b‐catenin signalling and stimulates KC differentiation. In parallel, we observed an accumulation of KRT10 in vivo in the expanded skin, pointing to TE‐induced, SFRP2‐augmented KC maturation. Overall, our results reveal that a network of LCs delivers SFRP2 across the epidermis to fine‐tune Wnt/b‐catenin signalling to restore epidermal homeostasis disrupted by TE.

Rabbits - their domestication and molecular genetics of hair coat development and quality

The European rabbit (Oryctolagus cuniculus) is the only representative of its genus living in present-day Europe and North Africa, and all domestic rabbits are descendants of this one species, which is native to the Iberian Peninsula. There are over 300 breeds of rabbits that differ in size, coat color, length of ears and type of fur. Rabbits are bred for various reasons, such as for laboratory animals and a source of meat, wool and fur, as well as for pets and exhibition animals. The hair coat is a important economic trait of rabbits. Its development and quality are influenced by various factors, both environmental and genetic. The genetic mechanisms underlying its development have not been thoroughly researched. The aim of this review is to discuss the domestication of rabbits and the different aspects of rabbit genetics. A brief review of the properties of rabbit hair coat, hair coat development and hair cycle will be provided, followed by discussion of the factors regulating hair coat development, molecular control of hair coat development and the role of non-coding RNAs in the regulation of gene expression in the hair follicles of rabbits. Information about genetic regulation of pathways could provide useful tools for improving hair coat quality and be of practical use in rabbit breeding.

Characterization and functional analysis of SIAH1 during skin and hair follicle development in the angora rabbit (Oryctolagus cuniculus)

BACKGROUND

Seven in absentia homolog 1 (SIAH1) is an E3 ubiquitin ligase containing a RING-finger domain and a key regulator of normal development. Skin and hair follicle development is a complex and special process of morphogenesis involving multiple signaling pathways. SIAH1 is enriched in the Wnt signaling pathway and potentially related to hair follicle cycle and skin development. This study aims to provide evidence for the role of SIAH1 in skin and hair development.

RESULTS

Full-length cloning and analysis of SIAH1 was conducted to better understand its function. Phylogenetically, the sequence of SIAH1 in the rabbit shares the greatest homology with Home sapiens, Pongo abelii and Mus mulatta. Based on the rabbit hair follicle synchronization model, we found that the expression level of SIAH1 in the regressive period of the rabbit hair cycle is significantly lower than in the active growth and rest periods. In addition, the mRNA expression levels of skin and hair follicle development-related genes changed significantly when SIAH1 was overexpressed and silenced. After SIAH1 overexpression, the expression levels of WNT2, LEF1 and FGF2 decreased, and those of SFRP2 and DKK1 increased (P < 0.05). After interference of SIAH1, the expression levels of WNT2, LEF1 and FGF2 increased (P < 0.05), and SFRP2 and DKK1 decreased.

CONCLUSIONS

SIAH1 can affect skin and hair follicle development and exert an inhibitory effect. These results could provide foundamental insights into the role of SIAH1 as a target gene in rabbit skin and hair follicle development.

Genome-wide identification and characterization of long non-coding RNAs expressed during sheep fetal and postnatal hair follicle development

Long non-coding RNAs (lncRNAs), >200 nt in length, are transcribed from mammalian genomes. They play important regulatory roles in various biological processes; However, the function and expression profile of lncRNAs involved in the development of hair follicles in the fetus, have been relatively under-explored area. To investigate the specific role of lncRNAs and mRNAs that regulate hair follicle development, we herein performed a comprehensive study on the lncRNA and mRNA expression profiles of sheep at multiple embryonic days (E65, E85, E105, and E135) and six lambs aged one week (D7) and one month (D30) using RNA-seq technology. The number of genes (471 lncRNAs and 12,812 mRNAs) differentially expressed and potential targets of differentially expressed lncRNAs were predicted. Differentially expressed lncRNAs were grouped into 10 clusters based on their expression pattern by K-means clustering. Moreover, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that some differentially expressed mRNAs, such as DKK1, DSG4, FOXE1, Hoxc13, SFRP1, SFRP2, and Wnt10A overlapped with lncRNAs targets, and enriched in important hair follicle developmental pathways, including Wnt, TNF, and MAPK signaling pathways. In addition, 9 differentially expressed lncRNAs and 4 differentially expressed mRNAs were validated using quantitative real-time PCR (qRT-PCR). This study helps enrich the Ovis lncRNA databases and provides a comprehensive lncRNA transcriptome profile of fetal and postnatal skin of sheep. Additionally, it provides a foundation for further experiments on the role of lncRNAs in the regulation of hair growth in sheep.

De Novo Transcriptome Sequencing Analysis of Goose (Anser anser) Embryonic Skin and the Identification of Genes Related to Feather Follicle Morphogenesis at Three Stages of Development

The objective of this study was to evaluate the changes in the goose embryo transcriptome during feather development. RNA-Sequencing (RNA-Seq) was used to find the transcriptome profiles of feather follicles from three stages of embryonic dorsal skin at embryonic day 13, 18, and 28 (E13, E18, E28). The results showed that 3001, 6634, and 13,780 genes were differently expressed in three stages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that differentially expressed genes (DEGs) in E13 vs. E18 were significantly mapped into the GO term of extracellular structure organization and the pathway of extracellular matrix (ECM)-receptor interaction. In E18 vs. E28, the top significantly mapped into GO term was the single-organism developmental process; the pathway was also the ECM-receptor interaction. DEGs in E13 vs. E28 were significantly mapped into the GO term of the multicellular organismal process and the pathway of cell adhesion molecules. Subsequently, the union of DEGs was categorized by succession cluster into eight profiles, which were then grouped into four ideal profiles. Lastly, the seven genes spatio-temporal expression pattern was confirmed by real-time PCR. Our findings advocate that interleukin 20 receptor subunit alpha (IL20RA), interleukin 6 receptor (IL6R), interleukin 1 receptor type 1 (IL-1R1), Wnt family member 3A (WNT3A), insulin-like growth factor binding protein 3 (IGFBP3), bone morphogenetic protein 7 (BMP7), and secreted-frizzled related protein 2 (SFRP2) might possibly play vital roles in skin and feather follicle development and growth processes.

Study of gene expression alteration in male androgenetic alopecia: evidence of predominant molecular signalling pathways

BACKGROUND

Male androgenetic alopecia (AGA) is the most common form of hair loss in men. It is characterized by a distinct pattern of progressive hair loss starting from the frontal area and the vertex of the scalp. Although several genetic risk loci have been identified, relevant genes for AGA remain to be defined.

OBJECTIVES

To identify biomarkers associated with AGA.

METHODS

Molecular biomarkers associated with premature AGA were identified through gene expression analysis using cDNA generated from scalp vertex biopsies of hairless or bald men with premature AGA, and healthy volunteers.

RESULTS

This monocentric study reveals that genes encoding mast cell granule enzymes, inflammatory mediators and immunoglobulin-associated immune mediators were significantly overexpressed in AGA. In contrast, underexpressed genes appear to be associated with the Wnt/β-catenin and bone morphogenic protein/transforming growth factor-β signalling pathways. Although involvement of these pathways in hair follicle regeneration is well described, functional interpretation of the transcriptomic data highlights different events that account for their inhibition. In particular, one of these events depends on the dysregulated expression of proopiomelanocortin, as confirmed by polymerase chain reaction and immunohistochemistry. In addition, lower expression of CYP27B1 in patients with AGA supports the notion that changes in vitamin D metabolism contributes to hair loss.

CONCLUSIONS

This study provides compelling evidence for distinct molecular events contributing to alopecia that may pave the way for new therapeutic approaches.

Gene expression profiling analysis reveals fur development in rex rabbits (Oryctolagus cuniculus)

Fur is an important economic trait in rabbits. The identification of genes that influence fur development and knowledge regarding the actions of these genes provides useful tools for improving fur quality. However, the mechanism of fur development is unclear. To obtain candidate genes related to fur development, the transcriptomes of tissues from backs and bellies of Chinchilla rex rabbits were compared. Of the genes analyzed, 336 showed altered expression in the two groups (285 upregulated and 51 downregulated, P ≤ 0.05, fold-change ≥2 or ≤0.5). Using GO and KEGG to obtain gene classes that were differentially enriched, we found several genes to be involved in many important biological processes. In addition, we identified several signaling pathways involved in fur development, including the Wnt and MAPK signaling pathways, revealing mechanisms of skin and hair follicle development, and epidermal cell and keratinocytes differentiation. The obtained rabbit transcriptome and differentially expressed gene profiling data provided comprehensive gene expression information for SFRP2, FRZB, CACNG1, SLC25A4, and SLC16A3. To validate the RNA-seq data, the expression levels of eight differentially expressed genes involved in fur development were confirmed by qRT-PCR. The results of rabbit transcriptomic profiling provide a basis for understanding the molecular mechanisms of fur development.

Secreted Frizzled-Related Protein 2 (sFRP2) Functions as a Melanogenic Stimulator; the Role of sFRP2 in UV-Induced Hyperpigmentary Disorders

In this study, we found that secreted frizzled-related protein 2 (sFRP2) is overexpressed in the hyperpigmentary skin of melasma and solar lentigo and in acutely UV-irradiated skin. To investigate the effect of sFRP2 on melanogenesis, normal human melanocytes were infected with sFRP2-lentivirus or sh-sFRP2. It was found that sFRP2 stimulates melanogenesis through microphthalmia-associated transcription factor and/or tyrosinase upregulation via β-catenin signaling. The stimulatory action of sFRP2 in pigmentation was further confirmed in melanocytes cocultured with fibroblasts and in ex vivo cultured skin. The findings suggest that sFRP2 functions as a melanogenic stimulator and that it plays a role in the development of UV-induced hyperpigmentary disorders.

Transfection with recombinant adenovirus vector expressing secreted frizzled related protein inhibits liver fibrosis in mice

AIM: To construct a recombinant adenovirus vector expressing secreted frizzled related protein (SFRP), and to assess the inhibitory effect of SFRP overexpression on experimental hepatic fibrosis (HF) in mice.

METHODS: Liposome-mediated transfection was used to introduce recombinant adenovirus pAd-Track-PPARγ2-CMV carrying the SFRP5 gene into liver cells from mice with CCl₄ induced HF to obtain recombinant adenovirus infected HF cells. Western blot, immunofluorescence microscopy and confocal laser microscopy were used to analyze the inhibitory effect of SFRP overexpression on experimental HF.

RESULTS: Cells infected with the recombinant adenovirus vector had higher expression of SFRP5 protein. Double immunofluorescence showed SFRP5 over expression inhibited the expression of α-smooth muscle actin (α-SMA) and fibroblast-specific protein-1 (FSP-1) in liver cells. Pathological examination revealed that SFRP5 over expression significantly reduced the occurrence of epithelial-mesenchymal transition (EMT) in liver cells (SFRP group vs control group, P < 0.05).

CONCLUSION: We have successfully constructed a recombinant adenovirus containing the SFRP5 gene, and it can effectively increase the expression of SFRP5 gene in mouse HF cells, thereby inhibiting the occurrence of EMT and HF.