Metabolism of dietary cetoleic acid (22:1n-11) in mink (Mustela vison) and gray seals (Halichoerus grypus) studied using radiolabeled fatty acids

Cetoleic acid (22:1n-11) is a good indicator of diet in marine predators and has proven to be an important fatty acid (FA) when using adipose tissue FA composition to study diet in marine mammals and seabirds. Feeding studies have shown that 22:1 isomers are predictably underrepresented in adipose tissue relative to diet, implying that metabolism within the predator strongly influences the relationship between the level of these FAs in diet and adipose tissue. Fully understanding such metabolic processes for individual FAs is important for the quantitative estimation of predator diets. We employed a dual-label radioisotope tracer technique to investigate the potential modification of 22:1n-11 and its recovery in the blubber of gray seals (Halichoerus grypus) and in the adipose tissue and liver of mink (Mustela vison), a smaller model carnivore also accustomed to fish-based diets. In both seals and mink, (3)H radioactivity was found in the chain-shortened products of 22:1n-11, with 18:1 being the dominant product. We also found (3)H radioactivity in saturated FAs. The distribution patterns of (3)H radioactivity across the FAs isolated from seal blubber and mink subcutaneous adipose tissue were comparable, indicating that mink are a good model for the investigation of lipid metabolism in marine carnivores.     

Identification of collagen-induced arthritis loci in aged multiparous female mice

Collagen-induced arthritis in mice is one of the most commonly used autoimmune experimental models, with many similarities to rheumatoid arthritis. Since collagen-induced arthritis is a complex polygenic disease there is a need for identification of several major disease-controlling genes. Because rheumatoid arthritis particularly affects aged women, we have in the present study identified new genetic regions critical for collagen-induced arthritis by studying aged female mice of a cross between NFR/N and B10.Q (H-2^q haplotype). The mice in the present study had different reproductive histories, which did not significantly affect the onset, incidence or severity of the disease. A total of 200 female mice were used in a total genome-wide screening with 125 microsatellite markers. We found one new significant quantitative trait locus affecting the arthritis incidence, severity and day of onset on chromosome 11 (denoted Cia40), which colocalizes with a locus controlling pregnancy failure. Furthermore, a quantitative trait locus of suggestive significance associated with the incidence, severity and day of onset was identified on chromosome 1. Finally, a suggestively significant quantitative trait locus associated with collagen type II antibody titers was identified on chromosome 13. This study indicates that several gene loci control arthritis in aged multiparous females, and that at least one of these loci coincides with pregnancy failure.     

Expansion and Accelerated Evolution of 9-Exon Odorant Receptors in Polistes Paper Wasps

Independent origins of sociality in bees and ants are associated with independent expansions of particular odorant receptor (OR) gene subfamilies. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently derived social behavior. Here, we describe OR gene family evolution in the northern paper wasp, Polistes fuscatus, and compare it to four additional paper wasp species spanning ∼40 million years of evolutionary divergence. We find 200 putatively functional OR genes in P. fuscatus, matching predictions from neuroanatomy, and more than half of these are in the 9-exon subfamily. Most OR gene expansions are tandemly arrayed at orthologous loci in Polistes genomes, and microsynteny analysis shows species-specific gain and loss of 9-exon ORs within tandem arrays. There is evidence of episodic positive diversifying selection shaping ORs in expanded subfamilies. Values of omega (d_N/d_S) are higher among 9-exon ORs compared to other OR subfamilies. Within the Polistes OR gene tree, branches in the 9-exon OR clade experience relaxed negative (relaxed purifying) selection relative to other branches in the tree. Patterns of OR evolution within Polistes are consistent with 9-exon OR function in CHC perception by combinatorial coding, with both natural selection and neutral drift contributing to interspecies differences in gene copy number and sequence.     

Prognostic factors for early relapse in non-metastatic triple negative breast cancer — real world data

BackgroundTriple negative breast cancer (TNBC) has the worst prognosis amongst all subtypes. Studies have shown that the achievement of pathologic complete response in the breast and axilla correlates with improved survival. The aim of this study was to identify clinical or pathological features of real-life TNBC patients with a higher risk of early relapse.Materials and methodsSingle-centre retrospective analysis of 127 women with TNBC, stage II–III, submitted to neoadjuvant treatment and surgery between January 2016 and 2020. Multivariate Cox regression analysis for disease free survival (DFS) at 2 years was performed and statistically significant variables were computed into a prognostic model for early relapse.ResultsAfter 29 months of median follow-up, 105 patients (82.7%) were alive and, in total, 38 patients (29.9%) experienced recurrence. The 2-year DFS was 73% (95% CI: 21.3–22.7). In multivariate analysis, being submitted to neoadjuvant radiotherapy [HR 2.8 (95% CI: 1.2–6.4), p = 0.017] and not achieving pathologic complete response [HR 0.3 (95% CI: 0.1–1.7), p = 0.011] were associated with higher risk of recurrence. In our prognostic model, the presence of at least one of these variables defined a subgroup of patients with a worse 2-year DFS than those without these features (59% vs. 90%, p < 0.001, respectively).ConclusionsIn this real-life non-metastatic TNBC cohort, neoadjuvant radiotherapy (performed due to insufficient clinical response to neoadjuvant chemotherapy or significant toxicity) impacted as an independent prognostic factor for relapse along with the absence of pathologic complete response identifying a subgroup of higher risk patients for early relapse that might merit a closer follow-up.     

Presence and distribution of serotonin in the stomach of the Antarctic silverfish <Emphasis Type="Italic">Pleuragramma antarcticum</Emphasis>

Serotonin is a signal molecule with a wide range of functions in vertebrates. In Antarctic fishes, the serotonergic system has been studied in the brain, revealing differences from temperate fishes related to the long-term cold adaptation. To date, little is known regarding the peripheral nervous system, and no information is available for the stomach. In the present work, we contribute to fill the gaps by investigating the presence and the immunohistochemical distribution of serotonin in the stomach of the Antarctic silverfish Pleuragramma antarcticum, a cold-adapted key species of the Southern Ocean shelf food web. The main aim was to investigate the serotonergic system at the gastric level, in order to reveal possible peculiarities related to long-term cold adaptation, similar to the ones seen in the central nervous system of Antarctic fishes. Serotonin immunoreactivity was detected in the pyloric and cardiac mucosa of P. antarcticum stomach with immunopositive cells in the pyloric and cardiac surface epithelia and in the tubular glands. No immunopositive fibers and neuronal cell bodies were found. Our results highlight that the serotonin distribution pattern at the gastric level is similar to that described in temperate teleosts. This finding suggests that in P. antarcticum, long-term adaptations to the Antarctic condition do not affect the serotonergic system at the gastric level. In addition, our data constitute the baseline information for further investigations aimed at clarifying the effects of short-term temperature variations on the gastric serotonergic system of Antarctic species in the frame of the global climate change.     

Phosphofructokinase type 1 kinetics, isoform expression, and gene polymorphisms in cancer cells

Kinetic analysis of PFK-1 from rodent AS-30D, and human HeLa and MCF-7 carcinomas revealed sigmoidal [fructose 6-phosphate, Fru6P]-rate curves with different V(m) values when varying the allosteric activator fructose 2,6 bisphosphate (Fru2,6BP), AMP, Pi, NH(4)(+), or K(+). The rate equation that accurately predicted this behavior was the exclusive ligand binding concerted transition model together with non-essential hyperbolic activation. PFK-1 from rat liver and heart also exhibited the mixed cooperative-hyperbolic kinetic behavior regarding activators. Lowering pH induced decreased affinity for Fru6P, Fru2,6BP, citrate, and ATP (as inhibitor); as well as decreased V(m) and increased content of inactive (T) enzyme forms. High K(+) prompted increased (Fru6P) or decreased (activators) affinities; increased V(m); and increased content of active (R) enzyme forms. mRNA expression analysis and nucleotide sequencing showed that the three PFK-1 isoforms L, M, and C are transcribed in the three carcinomas. However, proteomic analysis indicated the predominant expression of L in liver, of M in heart and MCF-7 cells, of L>M in AS-30D cells, and of C in HeLa cells. PFK-1M showed the highest affinities for F6P and citrate and the lowest for ATP (substrate) and F2,6BP; PFK-1L showed the lowest affinity for F6P and the highest for F2,6BP; and PFK-1C exhibited the highest affinity for ATP (substrate) and the lowest for citrate. Thus, the present work documents the kinetic signature of each PFK-1 isoform, and facilitates the understanding of why this enzyme exerts significant or negligible glycolysis flux-control in normal or cancer cells, respectively, and how it regulates the onset of the Pasteur effect.     

Functional consequence of positive selection revealed through rational mutagenesis of human myeloperoxidase

Myeloperoxidase (MPO) is a member of the mammalian heme peroxidase (MHP) multigene family. Whereas all MHPs oxidize specific halides to generate the corresponding hypohalous acid, MPO is unique in its capacity to oxidize chloride at physiologic pH to produce hypochlorous acid (HOCl), a potent microbicide that contributes to neutrophil-mediated host defense against infection. We have previously resolved the evolutionary relationships in this functionally diverse multigene family and predicted in silico that positive Darwinian selection played a major role in the observed functional diversities (Loughran NB, O'Connor B, O'Fagain C, O'Connell MJ. 2008. The phylogeny of the mammalian heme peroxidases and the evolution of their diverse functions. BMC Evol Biol. 8:101). In this work, we have replaced positively selected residues asparagine 496 (N496), tyrosine 500 (Y500), and leucine 504 (L504) with the amino acids present in the ancestral MHP and have examined the effects on the structure, biosynthesis, and activity of MPO. Analysis in silico predicted that N496F, Y500F, or L504T would perturb hydrogen bonding in the heme pocket of MPO and thus disrupt the structural integrity of the enzyme. Biosynthesis of the mutants stably expressed in human embryonic kidney 293 cells yielded apoproMPO, the heme-free, enzymatically inactive precursor of MPO, that failed to undergo normal maturation or proteolytic processing. As a consequence of the maturational arrest at the apoproMPO stage of development, cells expressing MPO with mutations N496F, Y500F, L504T, individually or in combination, lacked normal peroxidase or chlorinating activity. Taken together, our data provide further support for the in silico predictions of positive selection and highlight the correlation between positive selection and functional divergence. Our data demonstrate that directly probing the functional importance of positive selection can provide important insights into understanding protein evolution.     

Social, psychological and existential well-being in patients with glioma and their caregivers: a qualitative study

Background:

Cerebral glioma has a devastating impact on cognitive, physical, social, psychological and spiritual well-being. We sought to understand the multidimensional experience of patients with this form of cancer as they progressed from receiving a diagnosis to the terminal phase of the disease.

Methods:

We recruited patients with a suspected brain tumour from a tertiary referral centre in the United Kingdom. We interviewed patients and their caregivers at key stages of the illness: before receiving a formal diagnosis, at the start of initial treatment, after initial treatment was completed and at six months’ follow-up; caregivers were also interviewed postbereavement. We interviewed the patients’ general practitioners once, after treatment had been completed. We transcribed the interviews and analyzed them thematically using the constant comparative method of a grounded theory approach.

Results:

We conducted in-depth interviews with 26 patients, 23 of their relatives and 19 general practitioners. We saw evidence of physical, social, psychological and existential distress even before a diagnosis was confirmed. Social decline followed a similar trajectory to that of physical decline, whereas psychological and existential distress were typically acute around diagnosis and again after initial treatment. Each patient’s individual course varied according to other factors including the availability of support and individual and family resources (e.g., personal resilience and emotional support).

Interpretation:

There are practical ways that clinicians can care for patients with glioma and their caregivers, starting from before a diagnosis is confirmed. Understanding the trajectories of physical, social, psychological and existential well-being for these patients allows health care professionals to predict their patients’ likely needs so they can provide appropriate support and sensitive and effective communication.Cerebral glioma (hereafter glioma) is a rare but devastating cancer.¹ Despite increased treatment options, average survival for the most aggressive form, glioblastoma multiforme, is less than one year.² In addition to physical decline and increasing social isolation,³ patients may undergo a shattering of preconscious assumptions about their life and its meaning,⁴ causing existential anxiety.^5–7 Fear around death and dying are not always verbalized, but may be expressed in other ways, such as concern for relatives or a desire to get one’s affairs in order.⁸ Anxiety related to shock, anger, fear and uncertainty may, with time, be replaced by acceptance.⁸ However, little is known about how these issues interact and vary dynamically as the tumour progresses.We sought to explore qualitatively whether patients with glioma follow archetypal trajectories of physical, social, psychological and existential well-being as their illness progresses. We investigated how people experience and deal with a diagnosis of glioma and the associated transition toward death in an effort to understand the issues patients and caregivers face and the support they need.     

Annexin A1 regulates neutrophil clearance by macrophages in the mouse bone marrow

Under homeostatic conditions, a proportion of senescent CXCR4(hi) neutrophils home from the circulation back to the bone marrow, where they are phagocytosed by bone marrow macrophages. In this study, we have identified an unexpected role for the anti-inflammatory molecule annexin A1 (AnxA1) as a critical regulator of this process. We first observed that AnxA1(-/-) mice have significantly increased neutrophil numbers in their bone marrow while having normal levels of GM and G colony-forming units, monocytes, and macrophages. Although AnxA1(-/-) mice have more neutrophils in the bone marrow, a greater proportion of these cells are senescent, as determined by their higher levels of CXCR4 expression and annexin V binding. Consequently, bone marrow neutrophils from AnxA1(-/-) mice exhibit a reduced migratory capacity in vitro. Studies conducted in vitro also show that expression of AnxA1 is required for bone marrow macrophages, but not peritoneal macrophages, to phagocytose apoptotic neutrophils. Moreover, in vivo experiments indicate a defect in clearance of wild-type neutrophils in the bone marrow of AnxA1(-/-) mice. Thus, we conclude that expression of AnxA1 by resident macrophages is a critical determinant for neutrophil clearance in the bone marrow.