iTRAQ-based proteomic analysis reveals key proteins affecting cardiac function in broilers that died of sudden death syndrome

Drp1-Dependent Mitochondrial Fission Contributes to Lactic Acid-Induced Chicken Cardiomyocyte Damage

Enhanced glycolysis and elevated lactic acid (LA) production are observed during sudden death syndrome (SDS) in broilers. However, the mechanism underlying LA-induced cardiomyocyte damage and heart failure in fast-growing broilers remains unclear. In this study, chicken embryo cardiomyocytes (CECs) were cultured and treated with LA to investigate LA-induced CEC injury and its mechanism, aiming to develop strategies to prevent LA-induced SDS in broilers. Results showed that LA inhibited CEC proliferation and contraction whereas inducing apoptosis. Furthermore, LA disrupted mitochondrial ultrastructure, reduced mitochondrial membrane potential, activated mitophagy, and disturbed mitochondrial dynamics. Treatment with Mdivi-1, a selective Drp1 inhibitor, improved CEC viability, restored mitochondrial network integrity, reduced reactive oxygen species production, and inhibited LA-induced apoptosis. These findings suggest that LA-induced cardiomyocyte injury during SDS in broilers is associated with mitochondrial damage and increased mitochondrial fission. The inhibition of mitochondrial hyperfission by Mdivi-1 effectively preserves CEC morphology, structure, and function, playing a critical role in preventing LA-induced damage. This study provides a foundation for strategies to prevent and control SDS in broilers.

Shotgun proteomics reveals changes in the pectoralis major muscle of broilers supplemented with passion fruit seed oil under cyclic heat stress conditions

The aim of this study was to characterize the proteins differentially expressed in the pectoralis major muscle of broilers supplemented with passion fruit seed oil (PFSO) under cyclic heat stress conditions. Ninety one-day-old male chicks were housed in cages arranged in a climatic chamber, where they were kept under cyclic heat stress for eight hours a day from the beginning to the end of the experiment. The birds were divided into two experimental groups, one group supplemented with 0.9% PFSO and a control group (CON) without PFSO supplementation. At 36 days of age, 18 birds were slaughtered to collect muscle samples. From pools of breast fillet samples from each group, proteolytic cleavage of the protein extracts was performed, and later, the peptides were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The 0.9% PFSO supplementation revealed the modulation of 57 proteins in the pectoralis major muscle of broilers exposed to cyclic heat stress. Among them, four proteins were upregulated, and 46 proteins were downregulated. In addition, seven proteins were expressed only in the CON group. These results suggest that PFSO may increase heat tolerance, with a possible reduction in oxidative stress, activation of neuroprotective mechanisms, protection against apoptosis, decrease in inflammatory responses, and regulation of energy metabolism.

Sudden death syndrome in broiler chickens: a review on the etiology and prevention of the syndrome

Sudden death syndrome (SDS) is a condition in which apparently healthy broiler chickens die suddenly. There are short convulsions and frantic wing-beating prior to death, and the weight of internal organs is the same as in healthy chickens. The exact etiology of SDS is unknown. Heart problems have been implicated as a potential cause of the disease in broiler chickens. Despite considerable research, effective methods of prevention are still being sought. Furthermore, the prophylactic measures often make production less profitable (reduced body weight gain resulting from restricted feeding) and prolong the growth period. It is necessary to continue research on SDS, in particular on stimulation of the cardiovascular system to reduce the susceptibility of broilers to sudden death syndrome under intensive production systems.

Proteomics study on the effect of silybin on cardiomyopathy in obese mice

Due to the increase in the number of obese individuals, the incidence of obesity-related complications such as cardiovascular disease and type 2 diabetes is higher. The aim of the present study was to explore the effects of silybin on protein expression in obese mice. Firstly, serum was collected, and it was used to detect serum lipids and other serological indicators. Secondly, total protein from epididymal adipose tissue was extracted for differential expression analysis by quantitative tandem mass tag (TMT) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), followed by bioinformatics and protein-protein interaction (PPI) network analyses of these proteins. Lastly, real-time polymerase chain reaction (RT-PCR) and parallel reaction monitoring (PRM) were used to further validate the expression of identified differentially expressed proteins (DEPs) at the mRNA and protein level, respectively. The results revealed that silybin could improve abnormal lipid metabolism caused by the high fat diet in obese mice. A total of 341, 538 and 243 DEPs were found in the high fat/control (WF/WC), silybin/high fat (WS/WF) and WS/WC groups, respectively. These DEPs mainly participated in lipid metabolism and energy metabolism. Notably, tropomyosin 1 (TPM1), myosin light chain 2 (MYL2), myosin heavy chain 11 (MYH11) and other DEPs were involved in hypertrophic cardiomyopathy, dilated cardiomyopathy and other pathways. Silybin could protect cardiac function by inducing the protein expression of TPM1, MYL2 and MYH11 in the adipose tissue of obese mice.

Quantitative proteomic analysis of chicken serum reveals key proteins affecting follicle development during reproductive phase transitions

Avian reproductive behavior is regulated through the neuroendocrine system. The transition from laying to brooding is strictly controlled by the hypothalamus-pituitary-gonadal (HPG) axis. Cross talk on the HPG axis relies on the circulatory system, where the dynamics of serum proteins can be observed during different reproductive phases. Some canonical hormones, such as prolactin and luteinizing hormone, play important roles in the transition through reproductive phases. However, little is known at the whole-proteome level. To discover novel serum proteins, we employed isobaric tags for relative and absolute quantification to assay the serum proteome during different reproductive phases in chicken. We identified a total of 1,235 proteins from chicken serum; 239 of these proteins showed differential expression between the laying and brooding stages, including a low concentration of steroid metabolism-related proteins and a high concentration of calcium signaling-related proteins (fold change ≥1.5 or ≤0.66; P < 0.05). Pathway analysis and protein–protein interaction networks predicated the difference in follicle development between the brooding stage and laying stages and were related to the 14-3-3 protein family, which is associated with oocyte meiosis and maturation. Together, these results provided a proteomics foundation for investigating the dynamic changes taking place in the circulatory system during reproductive phase transition, and also uncovered new insights regarding follicle development that underlie the avian reproductive cycle.