Insights into the influence of canine breed on proteomics of the spermatozoa and seminal plasma

Pharmacologically assisted semen collection and sperm morphology assessment methods in wild six-banded armadillos (Euphractus sexcinctus)

Six-banded armadillos (Euphractus sexcinctus), a non-endangered species, serve as a valuable experimental model for developing assisted reproductive technologies aimed at conserving endangered species within the order Cingulata. However, limited knowledge of their reproductive biology presents a critical challenge. This study aimed to evaluate the effectiveness of a pharmacological semen collection protocol and compare Karras-modified staining using brightfield microscopy (KA), phase contrast microscopy (PC), and differential interference contrast microscopy (DIC) for assessing sperm morphology. Twenty free-ranging male six-banded armadillos were captured and subjected to the following pharmacological sedation protocol: butorphanol tartrate, detomidine hydrochloride and midazolam hydrochloride (i.m., 0.1 mg/kg each). Ten minutes after administration, semen was extracted by applying gentle pressure along the penis, from its base to the tip. The expelled semen, which accumulated into the urethral fossa, was collected using a variable-volume micropipette and assessed for macro and microscopic characteristics. Ninety-five percent of the males exhibited a partial ejaculation, with no aversive behavior or signs of discomfort observed. Most semen samples (83 %) contained more than 30 % of morphologically abnormal sperm with considerable individual variability in sperm defect profiles. While all microscopy techniques allowed effective assessment of sperm morphology, KA was the most efficient in identifying acrosome integrity and head abnormalities. This method offers a practical and cost-effective solution, particularly suited for field conditions. This study reports the first successful pharmacological protocol for semen collection in six-banded armadillos, highlighting its potential use for reproductive assessments and contributing to developing conservation strategies for related species.

Molecular Biomarkers of Canine Reproductive Functions

The aim of the current study is to review potential molecular biomarker substances selected so far as useful for assessing the quality of dog semen. Proteins, lipids, carbohydrates, and ions can serve as molecular biomarkers of reproductive functions (BRFs) for evaluating male reproductive health and identifying potential risk factors for infertility or reproductive disorders. Evaluation of BRF levels in semen samples or reproductive tissues may provide insights into the underlying causes of infertility, such as impaired sperm function, abnormal sperm-egg interaction, or dysfunction of the male reproductive tract. Molecular biomarker proteins may be divided into two groups: proteins that are well-studied, such as A-kinase anchoring proteins (AKAPs), albumins (ALBs), alkaline phosphatase (ALPL), clusterin (CLU), canine prostate-specific esterase (CPSE), cysteine-rich secretory protein 2 (CRISP2), lactotransferrin (LTF), metalloproteinases (MMPs), and osteopontin (OPN) and proteins that are not well-studied. Non-protein markers include lipid-based substances (fatty acids, phosphatidylcholine), carbohydrates (glycosaminoglycans), and ions (zinc, calcium). Assessing the levels of BRFs in semen samples may provide valuable information for breeding management and reproductive assessments in dogs. This review systematizes current knowledge that could serve as a starting point for developing practical tests with the use of biomarkers of canine reproductive functions and their predictive value for assisted reproductive technique outcomes and semen preservation.

Hippocampal proteins discovery of Panax quinquefolius and Acorus gramineus ameliorating cognitive impairment in diabetic rats

RATIONALE

Early diagnosis of diabetic cognitive impairment (DCI) and investigation of effective medicines are significant to prevent or delay the occurrence of irreversible dementia.

OBJECTIVES

In this study, proteomics was applied to investigate the changes of hippocampal proteins after administration of Panax quinquefolius-Acorus gramineus (PQ-AG) to DCI rats, with a view to discover the differentially expressed proteins of PQ-AG action and elucidated the potential biological relationships.

METHODS

The model and PQ-AG group rats were injected intraperitoneally with streptozotocin, and the PQ-AG group rats were continuously administered with PQ-AG. Social interaction and Morris water maze were performed to evaluate the behavior of rats on the 17th week after the model was established, and DCI rats were screened out from the model group by a screening approach. The hippocampal protein differences were investigated with proteomics in DCI and PQ-AG-treated rats.

RESULTS

The learning and memory abilities and contact duration of DCI rats were improved after 16 weeks of PQ-AG administration. Altogether, 9 and 17 differentially expressed proteins were observed in control versus DCI rats and in DCI versus PQ-AG-treated rats, respectively. Three proteins were confirmed with western blotting analyses. These proteins were mainly involved in the pathways of JAK-STAT, apoptosis, PI3K/AKT, fork-head box protein O3, fructose, and mannose metabolism.

CONCLUSIONS

This suggested that PQ-AG ameliorated cognitive impairment of diabetic rats by influencing the above pathways and providing an experimental basis for the mechanism of DCI and PQ-AG.

Canine Semen Evaluation and Processing

Advances in canine semen evaluation have progressed over time in fits and spurts, interspersed with long periods of relative inactivity. Despite exciting advances in the semen analysis, clinical canine theriogenology has been in a period of relative inactivity for a number of decades since initial advances in canine semen freezing in the mid 20th century. This review describes ways that the clinical practice of canine semen evaluation should improve, given the state of current knowledge.

Proteomics Evaluation of Semen of Clinically Healthy Beagle-Breed Dogs

The objectives of the present work were to evaluate the semen of dogs by means of proteomics methods and to compare with proteomics results of the blood of the animals, in order to increase available knowledge on the topic and present relevant reference values for semen samples. Semen samples were collected from five Beagle-breed dogs. Reproductive assessment of the animals by means of clinical, ultrasonographic and seminological examinations confirmed their reproductive health. The sperm-rich fraction and the prostatic fraction of semen were processed for proteomics evaluation. LC-MS/MS analysis was performed by means of a LTQ Orbitrap Elite system. The technology combines high separation capacity and strong qualitative ability of proteins in biological samples that require deep proteome coverage. Protein classification was performed based on their functional annotations using Gene Ontology (GO). In blood plasma, semen sperm-rich fraction, and semen prostatic fraction, 59, 42 and 43 proteins, respectively, were detected. Two proteins were identified simultaneously in plasma and the semen sperm-rich fraction, 11 proteins in plasma and the semen prostatic fraction, and three proteins in the semen sperm-rich and prostatic fractions. In semen samples, most proteins were related to cell organization and biogenesis, metabolic processes or transport of ions and molecules. Most proteins were located in the cell membrane, the cytosol or the nucleus. Finally, most proteins performed functions related to binding or enzyme regulation. There were no differences between the semen sperm-rich fraction and prostatic fractions in terms of the clustering of proteins. In conclusion, a baseline reference for proteins in the semen of Beagle-breed dogs is provided. These proteins are involved mostly in supporting spermatozoan maturation, survival and motility, enhancing the reproductive performance of male animals. There appears potential for the proteomics examination of semen to become a tool in semen evaluation. This analysis may potentially identify biomarkers for reproductive disorders. This can be particularly useful in stud animals, also given its advantage as a non-invasive method.

Age-Dependent Variations in Functional Quality and Proteomic Characteristics of Canine (Canis lupus familiaris) Epididymal Spermatozoa

Increased male age is associated with a significant reduction in semen quality. Little is known about the sperm proteome changes resulting from the aging process. This study aimed to investigate the relationship between the functional quality and proteome of epididymal spermatozoa of dogs that were differing in age. The study was conducted on 30 male dogs that were divided into three age groups. G1—12 to 41 months old, G2—42 to 77 months old, and G3—78 to 132 months old. The sperm samples were assessed using a computer-assisted semen analysis (CASA). The epididymal sperm proteins were analyzed using gel electrophoresis (SDS-PAGE), nano-liquid chromatography coupled to quadrupole time of flight mass spectrometry (NanoUPLC-Q-TOF/MS) and bioinformatic tools. The sperm quality parameters were significantly lower in older dogs. NanoUPLC-Q-TOF/MS identification resulted in 865 proteins that were found in the G1, 472 in G2, and 435 in G3. There were seven proteins that were present in all three age groups, and four of them (ACTB, CE10, NPC2, CRISP2) showed significant changes among the studied groups. Age-dependent variations were detected in the sperm proteome composition and were related to important metabolite pathways, which might suggest that several proteins are implicated in sperm maturation and could be potential aging biomarkers.

Proteomic Analysis of Intracellular and Membrane-Associated Fractions of Canine (Canis lupus familiaris) Epididymal Spermatozoa and Sperm Structure Separation

Simple Summary

Epididymal spermatozoa have great potential in current dog reproductive technologies. In the case of azoospermia or when the male dies, the recovery of epididymal spermatozoa opens new possibilities for reproduction. It is of great importance to analyze the quality of the sperm in such cases. Proteomic studies contribute to explaining the role of proteins at various stages of epididymal sperm maturation and offer potential opportunities to use them as markers of sperm quality. The present study showed, for the first time, mass spectrometry and bioinformatic analysis of intracellular and membrane-associated proteins of canine epididymal spermatozoa. Additionally, sonication was used for the separation of dog epididymal sperm morphological elements (heads, tails and acrosomes). The results revealed the presence of differentially abundant proteins in both sperm protein fractions significant for sperm function and fertilizing ability. It was also shown that these proteins participate in important sperm metabolic pathways, which may suggest their potential as sperm quality biomarkers.

Abstract

This study was provided for proteomic analysis of intracellular and membrane-associated fractions of canine (Canis lupus familiaris) epididymal spermatozoa and additionally to find optimal sonication parameters for the epididymal sperm morphological structure separation and sperm protein isolation. Sperm samples were collected from 15 dogs. Sperm protein fractions: intracellular (SIPs) and membrane-associated (SMAPs) were isolated. After sonication, sperm morphology was evaluated using Spermac Stain™. The sperm protein fractions were analyzed using gel electrophoresis (SDS-PAGE) and nanoliquid chromatography coupled to quadrupole time-of-flight mass spectrometry (NanoLC-Q-TOF/MS). UniProt database-supported identification resulted in 42 proteins identified in the SIPs and 153 proteins in the SMAPs. Differentially abundant proteins (DAPs) were found in SIPs and SMAPs. Based on a gene ontology analysis, the dominant molecular functions of SIPs were catalytic activity (50%) and binding (28%). Hydrolase activity (33%) and transferase activity (21%) functions were dominant for SMAPs. Bioinformatic analysis of SIPs and SMAPs showed their participation in important metabolic pathways in epididymal sperm, which may suggest their potential as sperm quality biomarkers. The use of sonication 150 W, 10 min, may be recommended for the separation of dog epididymal sperm heads, tails, acrosomes and the protein isolation.