Serum proteomics analysis of feline mammary carcinoma based on label-free and PRM techniques

Salivary peptidomic profiling of chronic gingivostomatitis in cats by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and nanoscale liquid chromatography-tandem mass spectrometry

BACKGROUND

Chronic gingivostomatitis in cats (FCGS) is a moderately to severely painful condition, potentially caused by inadequate immune response to oral antigenic stimulation. Salivary peptidome analysis can identify inflammatory protein mediators and pathways involved in oral mucosal immune activation and may indicate potential therapeutic options for FCGS.

OBJECTIVE

Evaluate the diversity and abundance of salivary peptides in cats with FCGS using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and nanoscale liquid chromatography-tandem mass spectrometry (nano LC-MS/MS).

ANIMALS

Thirty-two cats with FCGS and 18 healthy controls.

METHODS

Case-control cross-sectional study. We compared the salivary peptide profiles of diseased and healthy cats. The diagnosis of FCGS was confirmed by histopathology. Saliva samples were analyzed for viral infections using polymerase chain reaction (PCR), peptide mass fingerprint (PMF) using MALDI-TOF MS, and peptide identification using nano LC-MS/MS.

RESULTS

Distinct clusters of peptide profiles were observed between groups. In FCGS, 26 salivary peptides were altered, including apolipoprotein A1, nuclear receptor subfamily 1 group I member 3, fibrinogen alpha chain, interleukin 2 receptor gamma, interleukin 23 receptor, hemoglobin subunit alpha, and serpin peptidase inhibitor clade A (alpha-1 antiproteinase, antitrypsin) member 12, protein-tyrosine-phosphatase, and cholinergic receptor nicotinic alpha 10 subunit. Protein-anti-inflammatory drug interaction networks were observed.

CONCLUSIONS AND CLINICAL IMPORTANCE

Peptide mass fingerprint and peptide profiles identified distinct clusters between FCGS and healthy cats. The 9 novel salivary peptide markers were associated with the JAK/STAT and PI3K/Akt pathways and immune responses. These potentially noninvasive biomarkers may facilitate understanding of FCGS pathophysiology and guide future therapeutic research.

Analysis of serum peptidome profiles of non-metastatic and metastatic feline mammary carcinoma using liquid chromatography-tandem mass spectrometry

BACKGROUND

Feline mammary carcinoma (FMC) is a common aggressive and highly metastatic cancer affecting female cats. Early detection is essential for preventing local and distant metastasis, thereby improving overall survival rates. While acquiring molecular data before surgery offers significant potential benefits, the current protein biomarkers for monitoring disease progression in non-metastatic FMC (NmFMC) and metastatic FMC (mFMC) are limited. The objective of this study was to investigate the serum peptidome profiles of NmFMC and mFMC using liquid chromatography-tandem mass spectrometry. A cross-sectional study was conducted to compare serum peptidome profiles in 13 NmFMC, 23 mFMC and 18 healthy cats. The liquid chromatography-tandem mass spectrometry analysis was performed on non-trypsinized samples.

RESULTS

Out of a total of 8284 expressed proteins observed, several proteins were found to be associated with human breast cancer. In NmFMC, distinctive protein expressions encompassed double-stranded RNA-binding protein Staufen homolog 2 (STAU2), associated with cell proliferation, along with bromodomain adjacent to zinc finger domain 2A (BAZ2A) and gamma-aminobutyric acid type A receptor subunit epsilon (GABRE), identified as potential treatment targets. Paradoxically, positive prognostic markers emerged, such as complement C1q like 3 (C1QL3) and erythrocyte membrane protein band 4.1 (EPB41 or 4.1R). Within the mFMC group, overexpressed proteins associated with poor prognosis were exhibited, including B-cell lymphoma 6 transcription repressor (BCL6), thioredoxin reductase 3 (TXNRD3) and ceruloplasmin (CP). Meanwhile, the presence of POU class 5 homeobox (POU5F1 or OCT4) and laminin subunit alpha 1 (LAMA1), reported as metastatic biomarkers, was noted.

CONCLUSION

The presence of both pro- and anti-proliferative proteins was observed, potentially indicating a distinctive characteristic of NmFMC. Conversely, proteins associated with poor prognosis and metastasis were noted in the mFMC group.

Serum proteome profiles in cats with chronic enteropathies

BACKGROUND

Serum protein biomarkers are used to diagnose, monitor treatment response, and to differentiate various forms of chronic enteropathies (CE) in humans. The utility of liquid biopsy proteomic approaches has not been examined in cats.

HYPOTHESIS/OBJECTIVES

To explore the serum proteome in cats to identify markers differentiating healthy cats from cats with CE.

ANIMALS

Ten cats with CE with signs of gastrointestinal disease of at least 3 weeks duration, and biopsy-confirmed diagnoses, with or without treatment and 19 healthy cats were included.

METHODS

Cross-sectional, multicenter, exploratory study with cases recruited from 3 veterinary hospitals between May 2019 and November 2020. Serum samples were analyzed and evaluated using mass spectrometry-based proteomic techniques.

RESULTS

Twenty-six proteins were significantly (P < .02, ≥5-fold change in abundance) differentially expressed between cats with CE and controls. Thrombospondin-1 (THBS1) was identified with >50-fold increase in abundance in cats with CE (P < 0.001) compared to healthy cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Damage to the gut lining released marker proteins of chronic inflammation that were detectable in serum samples of cats. This early-stage exploratory study strongly supports THBS1 as a candidate biomarker for chronic inflammatory enteropathy in cats.

Presence of immune factors in freshwater mussel (Hyriopsis cumingii) entails autologous serum an essential component in the culture of mantle cells

Mussel cell culture is a challenging problem and serum serves a crucial biological role in cell culture as an autologous supply and an immunizing agent. In this study, the biology (calcium ions, total protein, pH, and osmotic pressure) of fetal bovine serum (FBS) and Hyriopsis cumingii serum (HCS) was investigated, and the development of Hyriopsis cumingii (H. cumingii) mantle cells in HCS and FBS systems was examined. The results showed that total protein, calcium ions, and osmotic pressure varied significantly (p<0.05). The activity of mantle cells was superior in the HCS culture system to that in the FBS culture system. The label-free technique was used to distinguish the two serum proteins to investigate the supportive effect of autologous serum on cell culture. These were examined for 109 unique proteins and 35 particular HCS proteins. Most differentially expressed proteins (DEPs) were involved in immune response, cell differentiation, and calcium ion binding. Furthermore, immune factors such as HSP, CALR, APOB, C3 were identified with significant differences. HSP was significantly more present in HCS than in FBS as an endogenous protective protein that regulates immune system function, cell differentiation, transport, and activity regulation. Parallel reaction monitoring (PRM) analysis was carried out to validate the expression levels of 19 DEPs, indicating high reliability of the proteomic results. This study reveals the important role of immune factors in mussel cell culture, providing a theoretical basis for explaining the applicability of autologous serum in cell culture. It is also helpful in improving the cell culture conditions of mussels.

Acute phase proteins in cats: Diagnostic and prognostic role, future directions, and analytical challenges

While clinical studies on acute phase proteins (APPs) have significantly increased in the last decade, and most commercial labs are now offering major APPs in their biochemical profiles, APP testing has not been widely adopted by veterinary clinical pathologists and veterinarians. Measurement of APP concentration is a useful marker for detecting the presence or absence of inflammation in cats with various diseases. APPs can also be reliably measured in different biological fluids (eg, effusions and urine) to improve their diagnostic utility. Measurement of APPs can be extremely beneficial in cats with feline infectious peritonitis (FIP) to discriminate between FIP and non-FIP cats with similar clinical presentations. Additional benefits come from multiple and sequential measurements of APPs, particularly in the assessment of therapeutic efficacy. APPs are more sensitive than WBC counts for early detection of inflammation and to demonstrate an early remission or recurrence of the diseases. Given the potential utility of APPs, more studies are warranted, with a particular focus on the applications of APPs to guide the length of antimicrobial therapies, as suggested by the antimicrobial stewardship policy. New inflammatory markers have been discovered in human medicine, with a higher specificity for distinguishing between septic versus nonseptic inflammatory diseases. It is desirable that these new markers be investigated in veterinary medicine, to further test the power of APPs in diagnostic setting.

Label-free quantitative proteomics analysis of jujube (Ziziphus jujuba Mill.) during different growth stages

Chinese jujube (Zizyphus jujuba Mill.), a member of the Rhamnaceae family with favorable nutritional and flavor quality, exhibited characteristic climacteric changes during its fruit growth stage. Therefore, fruit samples were harvested at four developmental stages on days 55 (young fruits), 76 (white-mature fruits), 96 (half-red fruits), and 116 (full-red fruits) after flowering (DAF). This study then investigated those four growth stage changes of the jujube proteome using label-free quantification proteomics. The results identified 4762 proteins in the samples, of which 3757 proteins were quantified. Compared with former stages, the stages examined were designated as "76 vs. 55 DAF" group, "96 vs. 76 DAF" group, and "116 vs. 96 DAF" group. Gene Ontology (GO) and KEGG annotation and enrichment analysis of the differentially expressed proteins (DEPs) showed that 76 vs. 55 DAF group pathways represented amino sugar, nucleotide sugar, ascorbate, and aldarate metabolic pathways. These pathways were associated with cell division and resistance. In the study, the jujube fruit puffing slowed down and attained a stable growth stage in the 76 vs. 55 DAF group. However, fatty acid biosynthesis and phenylalanine metabolism was mainly enriched in the 96 vs. 76 DAF group. Fatty acids are precursors of aromatic substances and fat-soluble pigments in fruit. The upregulation of differential proteins at this stage indicates that aromatic compounds were synthesized in large quantities at this stage and that fruit would enter the ripening stage. During the ripening stage, 55 DEPs were identified to be involved in photosynthesis and flavonoid biosynthesis in the 116 vs. 96 DAF group. Also, the fruit entered the mature stage, which showed that flavonoids were produced in large quantities. Furthermore, the color of jujube turned red, and photosynthesis was significantly reduced. Hence, a link was established between protein profiles and growth phenotypes, which will help improve our understanding of jujube fruit growth at the proteomic level.