Steroid Receptor Expression and HER-2/neu (c-erbB-2) Oncoprotein in the Uterus of Cats with Cystic Endometrial Hyperplasia-Pyometra Complex

Pyometra alters the redox status and expression of estrogen and progesterone receptors in the uterus of domestic cats

OBJECTIVES

The aim of this study was to evaluate the expression profile of sex steroid receptors and redox mediators in the uterus of domestic cats with pyometra.

METHODS

Twelve cats were used and divided into groups: (1) non-gestational healthy diestrus (n = 7) and (2) pyometra (n = 5). The plasma profiles of estradiol and progesterone (P4) as well as uterine expression levels of estradiol alpha (ERα), progesterone (PR) and androgen (AR) receptors, of the antioxidant enzymes superoxide dismutase 1 (SOD1), catalase and glutathione peroxidase 1 (GPX1), and of the oxidative damage marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) were evaluated.

RESULTS

Cats with pyometra showed higher plasma P4 levels and increased uterine messenger RNA (mRNA) and protein expression of ERα and PR, mainly in the glandular epithelium for ERα and in stromal and myometrial cells for PR. In addition, there was an increase in 8-OHdG immunostaining and GPX1 mRNA and protein expression in cats with pyometra compared with those in non-gestational diestrus, while catalase showed a reduction in endometrial immunostaining in cats with pyometra. There were no differences in uterine AR and SOD1 expression between the groups.

CONCLUSION AND RELEVANCE

The findings of this study showed that pyometra is associated with oxidative stress in the uterus of domestic cats and alterations of the profile of sex steroid receptors, especially ERα and PR, and of antioxidant enzymes, suggesting that changes in these mediators may play a role with the etiopathogenesis of this disease.

A Scoping Review on Tyrosine Kinase Inhibitors in Cats: Current Evidence and Future Directions

Tyrosine kinase inhibitors (TKIs) have become invaluable in the treatment of human and canine malignancies, but their role in feline oncology is less defined. While toceranib phosphate and masitinib mesylate are licensed for use in dogs, no TKI is yet approved for cats. This review systematically maps the research conducted on the expression of tyrosine kinases in neoplastic and non-neoplastic domestic feline tissues, as well as the in vitro/in vivo use of TKIs in domestic cats. We identify and discuss knowledge gaps and speculate on the further research and potential indications for TKI use in cats. A comprehensive search of three electronic databases and relevant paper reference lists identified 139 studies meeting the inclusion criteria. The most commonly identified tumors were mast cell tumors (MCTs), mammary and squamous cell carcinomas and injection-site sarcomas. Based on the current literature, toceranib phosphate appears to be the most efficacious TKI in cats, especially against MCTs. Exploring the clinical use of TKIs in mammary carcinomas holds promise. Despite the progress, currently, the evidence falls short, underscoring the need for further research to discover new indications in feline oncology and to bridge the knowledge gaps between human and feline medicine.

Acute phase proteins and antioxidant responses in queens with pyometra

Acute phase proteins (APP) and biomarkers of oxidative status have proved to be clinically useful biomarkers of pyometra in different species. Despite pyometra is considered one of the most important feline reproductive diseases, information about the APP response and the oxidative status in queens with pyometra is lacking. This study aimed to evaluate the APP and the antioxidant responses at diagnosis and in the post-operative period in feline pyometra. Serum concentrations of serum amyloid A (SAA), haptoglobin (Hp), albumin, total serum thiols (Thiol) and total antioxidant capacity determined by different assays, including trolox equivalent antioxidant capacity (TEAC) assessed by two different methodologies (TEAC1 and TEAC2), ferric reducing ability of plasma (FRAP), and cupric reducing antioxidant capacity (CUPRAC), were determined in 23 queens with pyometra at diagnosis and in 13 healthy control queens submitted to elective ovariohysterectomy. The APP and antioxidants were also evaluated in 11 queens of the pyometra group at days two and 10 after surgery. At diagnosis, queens with pyometra had serum concentrations of SAA, Hp, and FRAP significantly higher (P < 0.001, P < 0.001 and P < 0.05, respectively), and of albumin, Thiol, CUPRAC and TEAC2 significantly lower (P < 0.001, P < 0.001, P < 0.001 and P < 0.01, respectively) than controls. Moreover, concentrations of APP and antioxidants were significantly different (with a tendency to return to physiologic levels) at day 10 after surgery than before surgery. Significant associations were found between APP and antioxidants. According to these results, an APP response and the development of oxidative stress were detected in queens with pyometra. In addition, APP and antioxidants tended to return to physiologic values after surgery in the queens that recovered from the disease. Therefore, our results suggest that APP and selected antioxidants, such as Thiol and CUPRAC, could be potentially useful biomarkers in diagnosis and assessment of the post-operative period in feline pyometra.

Matrix metalloproteinase, vitamin A and methylprednisolone effects on experimentally induced amyloid arthropathy

We evaluated the role of some matrix metalloproteinases (MMPs) in enhancing the effect of vitamin A and the inhibiting effect of methylprednisolone on amyloid arthropathy in brown layer chicks. We used 100 one-day-old Isa brown layer chicks. The chicks were allocated to one of four groups as follows: negative control group (I), vitamin A group (II), positive control group (III) and methylprednisolone group (IV). Amyloid arthropathy was induced by injections of complete Freund's adjuvant into the left intertarsal joints of the chicks. Serum vitamin A and tissue MMP (MMP-1, MMP-2, MMP-9) levels were measured and differences among the groups were investigated. Serum vitamin A rates (μg/dl) were: 63.57 ± 4.10, 47.13 ± 10.62, 53.26 ± 10.79, 98.48 ± 8.20 in groups I, II, III and IV, respectively (p < 0.001). MMP-1, MMP-2 and MMP-9 levels were evaluated in tissues from the chickens with amyloid arthropathy. Methylprednisolone significantly suppressed the release of MMP-1 and MMP-2, and increased the release of MMP-9 in birds with amyloid arthropathy. In addition, vitamin A significantly increased the release of MMP-1, MMP-2 and MMP-9.

Expression of the erbB/HER receptor family in the bovine uterus during the sexual cycle and the relation of this family to serum sex steroids

Our study was designed to investigate immunohistochemically the expression of the receptors of the erbB/HER family (erbB1/HER1, erbB2/HER2, erbB3/HER3, erbB4/HER4) in the bovine uterus during the follicular and luteal phases of the sexual cycle, and the relation to ovarian sex steroids. The stage of the estrous cycle in 30 Holstein bovine was assessed based on the gross and histological appearance of the ovaries and uterus, and on blood steroid hormone levels. Tissue samples taken from the uterus were fixed in 10% formaldehyde for routine histological processing. Positive membrane and cytoplasmic staining of varying intensity were determined in the uterus during the follicular and luteal phases of the sexual cycle for erbB/HER receptors in luminal and glandular epithelial cells, connective tissue, smooth muscle and vascular endothelial and smooth muscle cells. We demonstrated that the apical and basal membranes of luminal epithelial cells and the apical membrane of glandular epithelial cells reacted with erbB1/HER1 and erbB2/HER2 during both the follicular and luteal phases. The reaction for erbB3/HER3 and erbB4/HER4 was stronger in the cytoplasm of luminal and glandular epithelial cells, but was heterogeneous. During both the follicular and luteal phases, the percentage and staining intensity of luminal and superficial glandular epithelial cells reacting positively with the receptors erbB1/HER1, erbB2/HER2, erbB3/HER3 and erbB4/HER4 were greater than those of deep glandular epithelial and connective tissue cells (p < 0.05). We demonstrated that the expression of the erbB/HER receptor family varied with different cell types in the bovine uterus during the follicular and luteal phases.

HER-2/neu (c-erbB-2) oncoprotein in hyperplastic endometrial polyps detected in two cats

The presence of HER-2/neu (c-erbB-2) oncoprotein, oestrogen-α receptor (ER), and progesterone receptor (PR) in hyperplastic endometrial polyps (EPs) of two cats with cystic endometrial hyperplasia-pyometra (CEH-P) complex was investigated. Immunohistochemistry assay for ER, PR and c-erbB-2 oncoprotein in the glandular and stromal tissue of the EPs was performed. ER and c-erbB-2 immunoreactivity was observed in the glandular epithelium of the EPs whereas PR immunoreactivity was detected only in the stromal fibroblasts. The c-erbB-2 oncoprotein may play a role with the ER in the pathogenesis of the hyperplastic EPs, although the role of this oncoprotein in the pathogenesis of EPs has yet to be determined.