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Finn, S.

Publications and source records attributed to Finn, S..

4 recordsLinked to original sources

The Human Contraceptive Antibody Targets A Semenogelin Galectin-3 N-Linked Glycan Complex on the Sperm Surface

The human contraception antibody (HCA) is a non-hormonal topical contraceptive entering Phase II clinical trials that functions by agglutinating and immobilizing sperm. To date, the HCA epitope has been described as an N-linked polylactosamine glycan motif on CD52, but this assignment has been inferred only by colocalization with anti-CD52 and S19 antibodies in western blots. Here, we report that HCA may instead bind semenogelin-galectin-3 complexes associated with the sperm surface. Semenogelins are gel forming, highly glycosylated proteins, with molecular weights of 50-70 kDa that are cleaved into smaller segments that adhere to sperm during semen liquefaction. In this study, we isolated the HCA antigen from seminal plasma and sperm using an HCA affinity column and identified semenogelin by mass spectrometry. Western blot analysis of seminal plasma showed that HCA binds to a large smear of proteins with a higher apparent molecular mass than CD52, and that these may correspond to semenogelin sequences. Flow cytometric analysis of enzymatically deglycosylated sperm demonstrated that HCA binding requires sperm surface N-linked glycans. However, despite this apparent glycan dependence, HCA failed to bind any glycans represented on a comprehensive glycan microarray. In addition to semenogelin, Galectin-3 was identified in the HCA purified sperm lysates, supporting a model in which HCA recognizes semenogelin-derived glycopeptides that are tethered to the sperm surface via a galectin mediated interaction with an N-linked glycan. We found that O-linked glycan modifications on the semenogelin proteins contain LacNAc motifs that can bind to galectins. Finally, we found that depletion of galectins bound to the sperm surface by competitive inhibitors reduced HCA-mediated agglutination, and this could be rescued by addition of recombinant galectin-3/semenogelin-2 complexes to sperm cultures. Collectively, our findings suggest that HCA's binding site involves a semenogelin-galectin-3 complex anchored to the sperm surface via an N-linked glycan.

immunology↗

Contrasting life history strategies explain contrasting phenology of two co-occurring bumble bee species

Across species, changing environmental conditions are altering major phenological milestones. In seasonal environments, this can involve shifts in the timing of activity onset, growth, reproduction, and senescence; however, predicting these responses can be challenging and often requires species-specific information. In this study, we investigated phenological patterns of bumble bee colony development using observations from wild nests of two common species, Bombus griseocollis and B. impatiens. Using observations of nest traffic, we documented dates of nest-searching, peak worker activity, first gyne (new queen) production, and colony senescence over three years of field data collection. We also tested whether colony growth was density dependent, because longstanding life history models have shown that colony growth patterns determine the optimal timing of reproduction in constant environments. Here, we present a novel extension of these models, using them to infer that density-independent colony growth should be associated with extended phenology in warmer years, while density-dependent should have consistent phenology. In total, we found 79 wild nests, including 34 reproductive colonies (19 B. griseocolis and 15 B. impatiens). Bombus impatiens colonies were larger, had a longer activity period, and showed density-independent growth and later reproduction in warmer years, while B. griseocollis colonies were smaller, shorter-lived, and showed density-dependent growth and similar dates of reproduction across years. Both species had higher gyne production in warmer years. These results highlight the role of life history theory for predicting interspecific variation in phenological changes, as well as a research framework for exploring possible evolutionary mismatches of existing life histories in changing environments.

ecology↗

Brief report on the development of patient-derived lung cancer organoids with keratinizing squamous cell carcinoma morphology

IntroductionNovel therapeutic options are urgently required to improve outcomes and survival for patients with lung squamous cell carcinoma (LUSC). In particular, understanding the unique histological features that define LUSC is essential to improving lung cancer mortality. Many pre-clinical models fail to accurately represent intratumour heterogeneity and recapitulate the tumour microenvironment. This is partly responsible for the poor translation of clinical findings to approved therapies. Our objective was to investigate whether patient-derived organoids, replicate the histological morphological, and structural features of keratinizing LUSC, a poor prognostic subtype of lung cancer. MethodsOrganoid cultures were established and maintained from two patients presenting with keratinizing lung squamous cell carcinomas. Immunofluorescent staining of individual organoids and confocal microscopy was performed to confirm expression of tumour markers. Whole organoid domes were fixed, and immunofluorescent staining and imaging was performed to investigate the structural features of the organoid cultures. Findings were compared with histopathological features of the original tumour tissue. ResultsPatient-derived organoids expressed tumour markers specific to the squamous cell carcinoma subtype of non-small cell lung cancer, which were confirmed to be expressed in the parent tissue. Within organoid cultures, keratin pearl structures spontaneously developed, matching the keratinizing pattern demonstrated by hematoxylin and eosin staining of the original tumour. ConclusionsPatient-derived organoids have the capability to replicate key histological features of their parent tumour. This high degree of fidelity makes these 3D models an important and valuable tool for understanding complex tumour biology and as a platform for preclinical drug testing to advance novel therapies into the clinic.

cancer biology↗

Renalase is a novel tissue and serological biomarker in pancreatic ductal adenocarcinoma

Dysregulated expression of the secretory protein renalase (RNLS) can promote pancreatic ductal adenocarcinoma (PDAC) growth in animal models. We characterized RNLS expression in premalignant and malignant PDAC tissue and investigated whether plasma RNLS levels corresponded to clinical PDAC characteristics. RNLS immunohistochemistry was used to determine the presence and distribution of RNLS in normal pancreas, chronic pancreatitis, PDAC precursor lesions, and PDAC tissues. Associations between pretreatment plasma RNLS and PDAC clinical status were assessed in patients with varied clinical stages of PDAC and included tumor characteristics, surgical resection in locally advanced/borderline resectable PDAC, and overall survival. Data were retrospectively obtained and correlated using non-parametric analysis. Mild to no RNLS was detected by histochemistry in the normal pancreas in the absence of abdominal trauma. In chronic pancreatitis, RNLS immunoreactivity localized to peri-acinar spindle-shaped cells in some samples. It was also widely present in PDAC precursor lesions and PDAC tissue. Among 240 patients with PDAC, elevated plasma RNLS levels were associated with worse tumor characteristics, including greater angiolymphatic invasion (80.0% vs. 58.1%, p = 0.012) and greater node positive disease (76.5% vs. 56.5%, p = 0.024). Overall survival was worse in patients with high plasma RNLS levels with median follow-up of 27.70 months vs. 65.03 months (p < 0.001). RNLS levels also predicted whether patients with locally advanced/borderline resectable (LA/BR) PDAC underwent resection (AUC 0.674; 95%CI 0.42-0.82, p = 0.04). Overall tissue RNLS was increased in both premalignant and malignant PDAC tissues compared to normal pancreas. Elevated plasma RNLS levels were associated with advanced tumor characteristics, decreased overall survival, and reduced resectability in patients with LA/BR PDAC. These studies show that RNLS levels are increased in premalignant pancreatic tissues and that its levels in plasma correspond to the clinical behavior of PDAC.

cancer biology↗