Serum bone remodeling parameters and transcriptome profiling reveal abnormal bone metabolism associated with keel bone fractures in laying hens

Haidong Wei; Yanju Bi; Yulai Wang; Qian Zhao; Runxiang Zhang; Jianhong Li; Jun Bao

doi:10.1016/j.psj.2022.102438

Serum bone remodeling parameters and transcriptome profiling reveal abnormal bone metabolism associated with keel bone fractures in laying hens

Poult Sci. 2023 Apr;102(4):102438. doi: 10.1016/j.psj.2022.102438. Epub 2022 Dec 19.

Authors

Haidong Wei¹, Yanju Bi², Yulai Wang², Qian Zhao², Runxiang Zhang³, Jianhong Li¹, Jun Bao⁴

Affiliations

¹ College of Life Science, Northeast Agricultural University, 150030 Harbin, China.
² College of Animal Science and Technology, Northeast Agricultural University, 150030 Harbin, China.
³ College of Animal Science and Technology, Northeast Agricultural University, 150030 Harbin, China; Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, China.
⁴ College of Animal Science and Technology, Northeast Agricultural University, 150030 Harbin, China; Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, China. Electronic address: jbao@neau.edu.cn.

Abstract

Keel bone fractures affect welfare, health, and production performance in laying hens. A total of one hundred and twenty 35-wk-old Hy-line Brown laying hens with normal keel (NK) bone were housed in furnished cages and studied for ten weeks to investigate the underlying mechanism of keel bone fractures. At 45 wk of age, the keel bone state of birds was assessed by palpation and X-ray, and laying hens were recognized as NK and fractured keel (FK) birds according to the presence or absence of fractures in keel bone. The serum samples of 10 NK and 10 FK birds were collected to determine bone metabolism-related indexes and slaughtered to collect keel bones for RNA-sequencing (RNA-seq), Micro-CT, and histopathological staining analyses. The results showed that the concentrations of Ca, phosphorus, calcitonin, 25-hydroxyvitamin D₃, and osteocalcin and activities of alkaline phosphatase and tartrate-resistant acid phosphatase (TRAP) in serum samples of FK birds were lower than those of NK birds (P < 0.05), but the concentrations of parathyroid hormone, osteoprotegerin, and corticosterone in serum samples of FK birds were higher than those of NK birds (P < 0.05). TRAP staining displayed that FK bone increased the number of osteoclasts (P < 0.05). Micro-CT analysis indicated that FK bone decreased bone mineral density (P < 0.05). Transcriptome sequencing analysis of NK and FK bones identified 214 differentially expressed genes (DEGs) (|log2FoldChange| > 1, P < 0.05), among which 88 were upregulated and 126 downregulated. Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) analysis indicated that 14 DEGs related to skeletal muscle movement and bone Ca transport (COL6A1, COL6A2, COL6A3, PDGFA, MYLK2, EGF, CAV3, ADRA1D, BDKRB1, CACNA1S, TNN, TNNC1, TNNC2, and RYR3) were enriched in focal adhesion and Ca signaling pathway, regulating bone quality. This study suggests that abnormal bone metabolism related to keel bone fractures is possibly responded to fracture healing in laying hens.

Keywords: RNA-seq; bone health; bone metabolism; keel bone fracture; laying hen.

MeSH terms

Animals
Bone Density
Bone Remodeling
Bone and Bones / pathology
Chickens* / genetics
Female
Fractures, Bone* / genetics
Fractures, Bone* / pathology
Fractures, Bone* / veterinary
Housing, Animal