Browsing by Subject "Claudins"

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    Distinct presence of the tight junction protein claudin-3 in olfactory bulb and fila olfactoria of the mouse
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Eppler, Elisabeth; Müller Gerbl, Magdalena; Maly, I. Piotr
    The tight junction protein claudin-3 is overexpressed in diverse epithelial tumours and is associated with increased survival, progression and motility of tumour cells. Claudin-3 expression profiles are being increasingly used for diagnostic and prognostic tumour classification. Claudin-3 has been identified as a receptor for Clostridium perfringens enterotoxin, which is under consideration for selective lysis of claudin-3- expressing tumours, particularly brain metastases, and other translational medicine uses. However, the localization of claudin-3 in the brain has not been completely elucidated. While claudin-3 in brain tissue adjacent to claudin-3-expressing metastases had been excluded and low or undetectable levels proposed in the CNS, under physiological conditions, in adult human, rat and mouse brains, claudin-3 was exclusively found in choroid plexus epithelium where it is considered an integral component of the blood-cerebrospinal-fluid barrier. We report here the pronounced presence of claudin-3 not only in the nasal region (as described for rat), but also in the mouse olfactory bulb and nerve using immunohistochemistry and Western blot. Claudin-3 was present in the fila olfactoria from the epithelium to the olfactory nerve and in the main and accessory olfactory bulb. We propose that the abundant presence of claudin3 in the olfactory system, particularly in nerve fibres and the olfactory bulb cone, which we present here, may play a role at the interface of the central and peripheral nervous system, both as barrier and for axonal growth and communication. Thus, claudin-3 should be considered and further explored with regards to treatment approaches addressing the olfactory bulb and nasal region.
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    Impaired spermatogenesis, tubular wall disruption, altered blood-testis barrier composition and intratubular lymphocytes in an infertile Beagle dog – a putative case of autoimmune orchitis
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Matschurat, Carolin; Rode, Kristina; Hollenbach, Julia; Wolf, Karola; Urhausen, Carola; Beineke, Andreas; Günzel Apel, Anne Rose; Brehm, Ralph
    Impairment of blood-testis barrier integrity can be observed during inflammation, infection, trauma and experimental autoimmune orchitis, which is inducible in rodents. In the present study, an initially fertile two-year-old Beagle dog was presented with a decline in total sperm number resulting in azoospermia within five months, verified by twice-monthly semen analyses. The dog was clinically healthy with bilateral small testes and showed normal thyroid function. Bacterial cultures of semen were negative and serum biochemical analyses showed no abnormal findings. To determine causes of azoospermia, the dog was castrated. Histological examinations of hematoxylin-eosin stained testicular sections revealed impaired spermatogenesis, seminiferous tubules with spermatogenic arrest or Sertoli-cell-only syndrome as well as focal interstitial and even intratubular lymphocytic infiltrations. Germ cell sloughing, apoptosis and giant cells were also observed in some tubules. Subsequent immunostainings of smooth-muscle-actin, claudin3, claudin11 and connexin43 demonstrated, for the first time, a mechanical and functional disruption of the tubular wall and alterations of blood-testis barrier proteins in these tubules. Presence of claudin3 and claudin11 in canine testis was confirmed using RT-PCR and sequencing and/ or Western-blot analyses. All findings suggested a possible spontaneous autoimmune orchitis to be the underlying cause for the observed azoospermia.