Heat stress decreased hair follicle population in rex rabbits

The Influence of a Nanoemulsion of Cardamom Essential Oil on the Growth Performance, Feed Utilization, Carcass Characteristics, and Health Status of Growing Rabbits under a High Ambient Temperature

Recently, nanotechnology approaches have been employed to enhance the solubility, availability, and efficacy of phytochemicals, overcoming some industrial obstacles and natural biological barriers. In this regard, 120 clinically healthy growing V-line rabbits (5 weeks old) reared during the summer season were divided randomly into four equal experimental groups (30 rabbits each). The first group received a basal diet without the supplementation of the nanoemulsion of cardamom essential oil (NCEO) (0 g/kg diet) and served as a control (NCEO 0). The other groups were given diets containing NCEO at levels of 150 (NCEO 150), 300 (NCEO 300), and 600 (NCEO 600) mg/kg diet, respectively. The growth performance (higher LBW and ADG), feed utilization (lower FCR), dressing percentage, and relative weight of the liver were improved significantly in the NCEO-treated groups compared to the control group. Moreover, the dietary treatment significantly decreased the rectum temperature and respiration rate, minimizing the 350 and 325 mg NECO/kg diets. The erythrocyte count, hematocrit, and hemoglobin concentration were significantly increased (p < 0.05), while white blood cells were significantly diminished (p = 0.0200) in the NCEO300 and NCEO600 groups compared to the control group. Treatment with 300 or 600 mg NCEO/kg significantly increased the blood serum total protein and albumin compared to the control group. Meanwhile, the liver enzymes (AST and ALT), uric acid, and creatinine concentrations decreased significantly in the NCEO300 group compared to the control group. The concentrations of triglycerides and total cholesterol were reduced significantly by the dietary treatment. The total antioxidant capacity, dismutase activity, and glutathione concentration were significantly higher, while the malondialdehyde and protein carbonyl levels were significantly lower in the NCEO300 group than in the control. The inflammatory responses and immunity statuses were improved in the blood serum of the NCEO-treated rabbits compared to the control. Heat-stress-induced pathological perturbations in renal/hepatic tissues and NCEO co-treatment successfully re-established and recovered near-control renal-hepatic morphology. In conclusion, a dietary supplementation of NCEO (300 mg/kg) could effectively enhance growing rabbits' growth indices, feed efficiency, redox balance, immunity, and inflammatory responses during the summer.

mTOR signaling in hair follicle and hair diseases: recent progress

Mammalian target of rapamycin (mTOR) signaling pathway is a major regulator of cell proliferation and metabolism, playing significant roles in proliferation, apoptosis, inflammation, and illness. More and more evidences showed that the mTOR signaling pathway affects hair follicle circulation and maintains the stability of hair follicle stem cells. mTOR signaling may be a critical cog in Vitamin D receptor (VDR) deficiency-mediated hair follicle damage and degeneration and related alopecia disorders. This review examines the function of mTOR signaling in hair follicles and hair diseases, and talks about the underlying molecular mechanisms that mTOR signaling regulates.

Vitamin A regulates dermal papilla cell proliferation and apoptosis under heat stress via IGF1 and Wnt10b signaling

Heat stress (HS) negatively affects the development of hair follicles. The present study investigated the effect of vitamin A (VA) on the development of rabbit dermal papilla cells (DPCs) under HS and the underlying regulatory mechanisms. Addition of 0.4 mg/L VA to the culture medium significantly enhanced cell proliferation (P < 0.001) and inhibited the apoptosis of DPCs (P < 0.01). VA decreased the proportion of DPCs in G0/G1 stage of the cell cycle under HS along with the expression of caspase 3, heat shock protein 70 (HSP70), and microRNA 195 (miR-195) (P < 0.05). VA also activated the insulin-like growth factor 1 (IGF1) and Wnt10b/β-catenin signaling pathways. The results of the dual luciferase reporter assay showed that IGF1 expression was modulated by miR-195-5p. Over-expression of miR-195-5p in DPCs with HS+VA treatment significantly reduced cell viability and IGF1 signaling (P < 0.01) and increased apoptosis (P < 0.01) compared with the HS+VA group. The positive effects of VA on proliferation and apoptosis of DPCs under HS were significantly attenu-ated by blocking Wnt10b and β-catenin signaling with IWP-2 and XAV-939, respectively. These results demonstrate that VA can promote hair follicle development following HS via modulation of miR-195/IGF1 and Wnt10b/β-catenin signaling pathways.

Methionine can subside hair follicle development prejudice of heat-stressed rex rabbits

In the present experiment, we study the function of methionine on hair follicle development in heat-stressed Rex Rabbits and its potential molecular mechanism. Rex rabbits were randomly divided into 5 groups (30 replicates per group): control group (20-25°C, fed basic diet), heat stress group (30-34°C, fed basic diet), heat stress + methionine group (30-34°C, fed 0.15% methionine in addition to the basic diet). fed basic diet (control), heat stress + methionine group (30-34°C, fed 0.3% methionine in addition to the basic diet), heat stress + methionine group (30-34°C, fed 0.45% methionine in addition to the basic diet). The results show that heat stress decreases the hair follicle density of Rex rabbits, and the diet methionine addition significantly increases the hair follicle density of heat-stressed Rabbits (p < .05). Heat stress increased serum HSP70 concentration and skin HSP70 gene expression, 0.15%-0.3% methionine but not 0.45% addition alleviated the effect of heat stress. Dietary 0.15% methionine addition significantly increases the gene expression of Wnt10b, β-catenin, LEF, FZD4, LRP6, Shh, HGF, EGF, and Noggin in heat-stressed Rex rabbits and observably decreases the gene expression of BMP2/4 and TGFb. There was no significant effect of methionine on the expression of IGF1 and FGF5/7 gene expression. In conclusion, methionine maybe promotes hair follicle development via TGFβ-BMP/Shh-Noggin, Wnt10b/β-catenin, EGF, and HGF signaling pathways in heat-stressed rabbits.

Vitamin A alleviates heat stress-induced damage to hair follicle development in Rex rabbits

BACKGROUND

Rex rabbits are important fur rabbits. Heat stress severely reduces the fur quality of Rex rabbits. The aim of this study was to experimentally investigate the effect of dietary vitamin A (VA) addition on hair follicle development and related signal pathways in Rex rabbits under heat stress.

RESULTS

In the experiment, 90 Rex rabbits were randomly divided into three groups: control group (20-25 °C, fed basic diet), heat stress group (30-34 °C, fed basic diet), and heat stress + VA group (20-25 °C, fed 12 000 IU/kg VA in addition to the basic diet). VA could significantly increase the hair follicle density (P < 0.01), hair length (P < 0.05), and the ratio of secondary to primary hair follicles (P < 0.05). In addition, VA could significantly inhibit the expression of BMP2, BMP4, FGF5, TGF-β1, and miR-214 in heat-stressed Rex rabbits and significantly increase the expression of noggin, IGF1, IGF1R, Wnt10b, CTNNB1, SHH, and miR-203 and the levels of Wnt10b and p-β-catenin; however, there was no significant effect of VA on the expression of EGF and miR-205.

CONCLUSION

The dietary addition of VA can increase the hair follicle density and fur quality of heat-stressed Rex rabbits. Wnt10/β-catenin, insulin-like growth factor 1 (IGF1), fibroblast growth factor 5 (FGF5), noggin-BMP, and sonic hedgehog (SHH) signaling were associated with VA regulation under heat stress. It is possible that miR-205 and miR-194 contribute to the regulation of Wnt10/β-catenin and bone morphogenetic protein (BMP) signaling. © 2021 Society of Chemical Industry.

BMP7 Functions to Regulate Proliferation of Dermal Papilla Cells in Hu Sheep

Bone morphogenetic proteins (BMPs) are the structurally similar and highly conserved type of functional proteins that play an important role in hair follicle growth and development. BMP7 was a differentially expressed gene in different patterns of Hu sheep lambskin identified using Agilent microarray. Since hair follicle is the basis of pattern formation of lambskin, and its growth and development is governed by dermal papilla cells (DPCs), to clarify the role of BMP7 and hair follicle, our study was designed to investigate the regulation between BMP7 and DPCs. Firstly, the CDS region of BMP7 was cloned by 3'Race and PCR in Hu sheep and performed serious of bioinformatic analysis. Then, the effects of BMP7 on DPCs were analyzed after overexpression and interference of BMP7 in dermal papilla cells by CCK8, EdU, and PI assay. Additionally, qPCR was also conducted to clarify the relationship between BMP7 and the TGF-β/Smad signaling pathway. A total of 1,296 bp of the BMP7 CDS region sequence was sucessfully cloned in Hu sheep, encoding a signal peptide of 431 amino acids, molecular weight was 49,316.9Da and the isoelectric point (Pi) was 7.75. Nucleotide sequencing analysis of BMP7 revealed that Hu sheep had high homology with Bos taurus, Homo sapiens, and Canis lupus familiaris. Structure domain prediction showed that TGF-β superfamily domain exist between 330th-431th amino acid, BMP7 protein is a secreted protein. In BMP7 up-regulated DPCs, DPCs proliferation rate and cell cycle were significantly higher than that of NC group (P < 0.05). Meanwhile, the expression level of Smad3, Smad4, Samd6, and TGF-β1 in TGF-β/Smad signaling pathway were significantly lower than that in NC group (P < 0.05). In BMP7 down-regulated DPCs, it presented the opposite result. In conclusion, our study showed that BMP7 had a positive effect on DPCs by accelerating the proliferation and cell cycle of DPCs, and hypothesized that regulate hair follicles growth and development via TGF-β/Smad signaling pathway. These findings may provide a synergistic target for the subsequent research of hair follicle growth and development.

Analysis of histology and long noncoding RNAs involved in the rabbit hair follicle density using RNA sequencing

BACKGROUND

Hair follicle density influences wool fibre production, which is one of the most important traits of the Wan Strain Angora rabbit. However, molecular mechanisms regulating hair follicle density have remained elusive.

RESULTS

In this study, hair follicle density at different body sites of Wan Strain Angora rabbits with high and low wool production (HWP and LWP) was investigated by histological analysis. Haematoxylin-eosin staining showed a higher hair follicle density in the skin of the HWP rabbits. The long noncoding RNA (lncRNA) profile was investigated by RNA sequencing, and 50 and 38 differentially expressed (DE) lncRNAs and genes, respectively, were screened between the HWP and LWP groups. A gene ontology analysis revealed that phospholipid, lipid metabolic, apoptotic, lipid biosynthetic, and lipid and fatty acid transport processes were significantly enriched. Potential functional lncRNAs that regulate lipid metabolism, amino acid synthesis, as well as the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) and hedgehog signalling pathways, were identified. Consequently, five lncRNAs (LNC_002171, LNC_000797, LNC_005567, LNC_013595, and LNC_020367) were considered to be potential regulators of hair follicle density and development. Three DE lncRNAs and genes were validated by quantitative real-time polymerase chain reaction (q-PCR).

CONCLUSIONS

LncRNA profiles provide information on lncRNA expression to improve the understanding of molecular mechanisms involved in the regulation of hair follicle density.

Transcriptomic Analysis Reveals the Involvement of lncRNA-miRNA-mRNA Networks in Hair Follicle Induction in Aohan Fine Wool Sheep Skin

Long non-coding RNAs (lncRNA) and microRNAs (miRNA) are new found classes of non-coding RNAs (ncRNAs) that are not translated into proteins but regulate various cellular and biological processes. In this study, we conducted a transcriptomic analysis of ncRNA and mRNA expression in Aohan fine wool sheep (AFWS) at different growth stages (embryonic day 90, embryonic day 120, and the day of birth), and explored their relationship with wool follicle growth. In total, 461 lncRNAs, 106 miRNAs, and 1,009 mRNAs were found to be differentially expressed during the three stages of wool follicle development. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to clarify the roles of the differentially expressed lncRNA, miRNA, and mRNA in the different stages of wool follicle development. Quantitative real-time PCR (qRT-PCR) was used to validate the results of RNA-seq analysis. lncRNA (MSTRG.223165) was found to act as a competing endogenous RNA (ceRNA) and may participate in wool follicle development by acting as an miR-21 sponge. Network prediction implicated the MSTRG.223165-miR-21-SOX6 axis in the wool follicle development. The targeting relationships of miR-21 with SOX6 and MSTRG.223165 were validated in dual-luciferase assays. This is the first report indicating the association of the lncRNA-miRNA-mRNA network with wool follicle development in AFWS. This study provides new insights into the regulation of the wool follicle growth and represents a solid foundation for wool sheep breeding programs.