Probes for INS

The epithelial lining of the Fallopian tube is vital for fertility, providing nutrition to gametes, and facilitating their transport. It is composed of two major cell types: secretory cells and ciliated cells. Interestingly, human ovarian cancer precursor lesions are primarily consisting of secretory cells. It is unclear why secretory cells are the dominant cell type in these lesions. Additionally, the underlying mechanisms governing Fallopian tube epithelial homoeostasis are currently unknown. In the present study, we showed that across the different developmental stages of mouse oviduct, secretory cells are the most frequently dividing cells of the oviductal epithelium. In vivo genetic cell lineage tracing showed that secretory cells not only self-renew, but also give rise to ciliated cells. Analysis of a Wnt reporter mouse model and different Wnt target genes showed that the Wnt signaling pathway is involved in oviductal epithelial homoeostasis. By developing two triple transgenic mouse models, we showed that Wnt/β-catenin signaling is essential for self-renewal as well as differentiation of secretory cells. In summary, our results provide mechanistic insight into oviductal epithelial homoeostasis.

Regardless of host, pathogenic mycobacteria of the Mycobacterium tuberculosiscomplex such as Mycobacterium bovis, induce a characteristic lesion known as agranuloma, tubercle or tuberculoid granuloma. Granulomas represent a distinct host response to chronic antigenic stimuli, such as foreign bodies, certain bacterial components, or persistent pathogens such as M. bovis. Granulomas are composed of specific cell types including epithelioid macrophages, lymphocytes and a morphologically distinctive cell type, the multinucleated giant cell. Multinucleated giant cells are formed by the fusion of multiple macrophages; however, their function remains unclear. In humans, giant cells in tuberculous granulomas have been shown to express various cytokines, chemokines and enzymes important to the formation and maintenance of the granuloma. The objective of this study was to quantitatively assess multinucleated giant cell cytokine expression in bovine tuberculoid granulomas; focusing on cytokines of suspected relevance to bovine tuberculosis. Using calves experimentally infected with M. bovis, in situ cytokine expression was quantitatively assessed using RNAScope^® for the following cytokines TNF-α, IFN-γ, TGF-β, IL-17A and IL-10. Multinucleated giant cells in bovine tuberculoid granulomas expressed all examined cytokines to varying degrees, with differential expression of TGF-β, IL-17A and IL-10 in giant cells from early versus late stage granulomas. There was a modest, positive correlation between the level of cytokine expression and cell size or number of nuclei. These results suggest that multinucleated giant cells are active participants within bovine tuberculoid granulomas, contributing to the cytokine milieu necessary to form and maintain granulomas.

The hallmark lesion of tuberculosis in humans and animals is the granuloma. The granuloma represents a distinct host cellular immune response composed of epithelioid macrophages, lymphocytes, and multinucleated giant cells, often surrounding a caseous necrotic core. Within the granuloma, host-pathogen interactions determine disease outcome. Factors within the granulomas such as cytokines and chemokines drive cell recruitment, activity, function and ultimately the success or failure of the host's ability to control infection. Hence, an understanding of the granuloma-level cytokine response is necessary to understand tuberculosis pathogenesis. In-situ cytokine expression patterns were measured using a novel in situ hybridization assay, known as RNAScope^® in granulomas of the lungs, tracheobronchial lymph nodes and caudal mediastinal lymph nodes of cattle experimentally infected with Mycobacterium bovis via aerosol exposure. In spite of microscopic morphological similarities, significant differences were seen between late stage granulomas of the lung compared to those of the tracheobronchial lymph nodes for IL-17A, IFN-γ, TGF-β, IL10 and IL-22 but not for TNF-α. Additionally, significant differences were noted between granulomas from two different thoracic lymph nodes that both receive afferent lymphatics from the lungs (i.e., tracheobronchial and caudal mediastinal lymph nodes) for TNF-α, IL-17A, IFN-γ, TGF-β and IL-10 but not for IL-22. These findings show that granuloma morphology alone is not a reliable indicator of granuloma function as granulomas of similar morphologies can have disparate cytokine expression patterns. Moreover, anatomically distinct lymph nodes (tracheobronchial vs caudal mediastinal) differ in cytokine expression patterns even when both receive afferent lymphatics from a lung containing tuberculoid granulomas. These findings show that selection of tissue and anatomic location are critical factors in assessing host immune response to M. bovis and should be considered carefully.

Bovine γδ T cells are amongst the first cells to accumulate at the site of Mycobacterium bovis infection; however, their role in the developing lesion remains unclear. We utilized transcriptomics analysis, in situ hybridization, and a macrophage/γδ T cell co-culture system to elucidate the role of γδ T cells in local immunity to M. bovis infection. Transcriptomics analysis revealed that γδ T cells upregulated expression of several novel, immune-associated genes in response to stimulation with M. bovis antigen. BCG-infected macrophage/γδ T cell co-cultures confirmed the results of our RNAseq analysis, and revealed that γδ T cells from M. bovis-infected animals had a significant impact on bacterial viability. Analysis of γδ T cells within late-stage M. bovis granulomas revealed significant expression of IFN-γ and CCL2, but not IL-10, IL-22, or IL-17. Our results suggest γδ T cells influence local immunity to M. bovis through cytokine secretion and direct effects on bacterial burden.

Hair growth disorders often carry a major psychological burden. Therefore, more effective human hair growth-modulatory agents urgently need to be developed. Here, we used the hypertrichosis-inducing immunosuppressant, Cyclosporine A (CsA), as a lead compound to identify new hair growth-promoting molecular targets. Through microarray analysis we identified the Wnt inhibitor, secreted frizzled related protein 1 (SFRP1), as being down-regulated in the dermal papilla (DP) of CsA-treated human scalp hair follicles (HFs) ex vivo. Therefore, we further investigated the function of SFRP1 using a pharmacological approach and found that SFRP1 regulates intrafollicular canonical Wnt/β-catenin activity through inhibition of Wnt ligands in the human hair bulb. Conversely, inhibiting SFRP1 activity through the SFRP1 antagonist, WAY-316606, enhanced hair shaft production, hair shaft keratin expression, and inhibited spontaneous HF regression (catagen) ex vivo. Collectively, these data (a) identify Wnt signalling as a novel, non-immune-inhibitory CsA target; (b) introduce SFRP1 as a physiologically important regulator of canonical β-catenin activity in a human (mini-)organ; and (c) demonstrate WAY-316606 to be a promising new promoter of human hair growth. Since inhibiting SFRP1 only facilitates Wnt signalling through ligands that are already present, this 'ligand-limited' therapeutic strategy for promoting human hair growth may circumvent potential oncological risks associated with chronic Wnt over-activation.

Spatiotemporal control of Wnt signaling is essential for the development and homeostasis of many tissues. The transmembrane E3 ubiquitin ligases ZNRF3 (zinc and ring finger 3) and RNF43 (ring finger protein 43) antagonize Wnt signaling by promoting degradation of frizzled receptors. ZNRF3 and RNF43 are frequently inactivated in human cancer, but the molecular and therapeutic implications remain unclear. Here, we demonstrate that adrenocortical-specific loss of ZNRF3, but not RNF43, results in adrenal hyperplasia that depends on Porcupine-mediated Wnt ligand secretion. Furthermore, we discovered a Wnt/β-catenin signaling gradient in the adrenal cortex that is disrupted upon loss of ZNRF3. Unlike β-catenin gain-of-function models, which induce high Wnt/β-catenin activation and expansion of the peripheral cortex, ZNRF3 loss triggers activation of moderate-level Wnt/β-catenin signaling that drives proliferative expansion of only the histologically and functionally distinct inner cortex. Genetically reducing β-catenin dosage significantly reverses the ZNRF3-deficient phenotype. Thus, homeostatic maintenance of the adrenal cortex is dependent on varying levels of Wnt/β-catenin activation, which is regulated by ZNRF3.