Telomere dynamics in human pluripotent stem cells

Pluripotent stem cells (PSCs) are a promising source of stem cells for regenerative therapies. Stem cell function depends on telomere maintenance mechanisms that provide them with the proliferative capacity and genome stability necessary to multiply and regenerate tissues. We show here that established human embryonic stem cells (hESCs) have stable telomere length that is dependent on telomerase but not on alternative mechanisms based on homologous recombination pathways. Here, we show that human-induced pluripotent stem cells (hiPSCs) reprogrammed from somatic cells show progressive telomere lengthening until reaching a length similar to ESCs. hiPSCs also acquire telomeric chromatin marks of ESCs including decreased abundance of tri-methylated histone H3K9 and H4K20 and HP1 heterochromatic marks, as well as of the shelterin component TRF2. These chromatin features are accompanied with increased abundance of telomere transcripts or TERRAs. We also found that telomeres of both hESCs and hiPSCs are well protected from DNA damage during telomere elongation and once full telomere length is achieved, and exhibit stable genomes. Collectively, this study highlights that hiPSCs acquire ESC features during reprogramming and reveals the telomere biology in human pluripotent stem cells (hPSCs).

Telomerase Upregulation Induces Progression of Mouse BrafV600E-Driven Thyroid Cancers and Triggers Nontelomeric Effects

Mutations in the promoter of the telomerase reverse transcriptase (TERT) gene are the paradigm of a cross-cancer alteration in a noncoding region. TERT promoter mutations (TPM) are biomarkers of poor prognosis in cancer, including thyroid tumors. TPMs enhance TERT transcription, which is otherwise silenced in adult tissues, thus reactivating a bona fide oncoprotein. To study TERT deregulation and its downstream consequences, we generated a Tert mutant promoter mouse model via CRISPR/Cas9 engineering of the murine equivalent locus (Tert-123C>T) and crossed it with thyroid-specific BrafV600E-mutant mice. We also employed an alternative model of Tert overexpression (K5-Tert). Whereas all BrafV600E animals developed well-differentiated papillary thyroid tumors, 29% and 36% of BrafV600E+Tert-123C>T and BrafV600E+K5-Tert mice progressed to poorly differentiated cancers at week 20, respectively. Tert-upregulated tumors showed increased mitosis and necrosis in areas of solid growth, and older animals displayed anaplastic-like features, that is, spindle cells and macrophage infiltration. Murine TPM increased Tert transcription in vitro and in vivo, but temporal and intratumoral heterogeneity was observed. RNA-sequencing of thyroid tumor cells showed that processes other than the canonical Tert-mediated telomere maintenance role operate in these specimens. Pathway analysis showed that MAPK and PI3K/AKT signaling, as well as processes not previously associated with this tumor etiology, involving cytokine, and chemokine signaling, were overactivated. These models constitute useful preclinical tools to understand the cell-autonomous and microenvironment-related consequences of Tert-mediated progression in advanced thyroid cancers and other aggressive tumors carrying TPMs.

IMPLICATIONS

Telomerase-driven cancer progression activates pathways that can be dissected and perhaps therapeutically exploited.

Short telomeres in alveolar type II cells associate with lung fibrosis in post COVID-19 patients with cancer

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) pandemic. The severity of COVID-19 increases with each decade of life, a phenomenon that suggest that organismal aging contributes to the fatality of the disease. In this regard, we and others have previously shown that COVID-19 severity correlates with shorter telomeres, a molecular determinant of aging, in patient's leukocytes. Lung injury is a predominant feature of acute SARS-CoV-2 infection that can further progress to lung fibrosis in post-COVID-19 patients. Short or dysfunctional telomeres in Alveolar type II (ATII) cells are sufficient to induce pulmonary fibrosis in mouse and humans. Here, we analyze telomere length and the histopathology of lung biopsies from a cohort of alive post-COVID-19 patients and a cohort of age-matched controls with lung cancer. We found loss of ATII cellularity and shorter telomeres in ATII cells concomitant with a marked increase in fibrotic lung parenchyma remodeling in post- COVID-19 patients compared to controls. These findings reveal a link between presence of short telomeres in ATII cells and long-term lung fibrosis sequel in Post-COVID-19 patients.

Telomerase deficiency and dysfunctional telomeres in the lung tumor microenvironment impair tumor progression in NSCLC mouse models and patient-derived xenografts

Non-small cell lung cancer (NSCLC) is a leading cause of cancer death. Tumor progression depends on interactions of cancer cells with the tumor microenvironment. Here, we find increased copy number and mRNA expression of the catalytic subunit of telomerase, TERT, in tumors from NSCLC patients, contributing to a lower survival. Moreover, TERT expression in NSCLC patients from the TCGA cohort is mainly associated to the reduced infiltration of CD8⁺ T lymphocytes, as well as to increased infiltration of myeloid-derived suppressor cells (MDSCs). We also show that TERT deficiency and dysfunctional telomeres induced by 6-thio-dG treatment in mice reduced lung tumor implantation and vascularization, increased DNA damage response, cell cycle arrest and apoptosis, as well as reduced proliferation, inflammation, lung tumor immunosupression and invasion upon induction of a Lewis lung carcinoma (LLC). Furthermore, 6-thio-dG-treated human NSCLC xenografts exhibited increased telomere damage, cell cycle arrest and apoptosis, as well as reduced proliferation, resulting in a reduced tumor growth. Our results show that targeting telomeres might be an effective therapeutic strategy in NSCLC.

Treatment of symptomatic macromastia in a breast unit. Outcomes analysis of breast reduction using BREAST-Q

INTRODUCTION

The BREAST-Q (breast reduction module) is a specific and validated questionnaire to evaluate breast reduction in the treatment of symptomatic macromastia, offering information on their quality of life and degree of satisfaction.

METHODS

Prospective study of a cohort of 34 patients treated by bilateral breast reduction in a breast unit in 2017-2020 surveyed with the Spanish version of BREAST-Q version 2. The statistical study to assess the effect of reduction, changes from the pre to postoperative scores of the domains were performed using the Wilcoxon signed rank test. Statistical significance was determined with p values ​​<0.05.

RESULTS

The mean time elapsed from surgery to the postoperative survey was 16 (SD 9) months. Post-surgical complications or sequelae occurred in 14 (42%) patients with 23 events. The preoperative scores, median and interquartile range, in satisfaction with the breasts (28, 26), psychological (33, 14), physical (42, 19) and sexual (34, 14) well-being improved in the postoperative survey to (82, 15), (81.29), (82, 30) and (90, 38), respectively. These changes were statistically significant, p < 0.001.

CONCLUSIONS

The first application of the BREAST-Q in its version in Spanish for Spanish women in patients with symptomatic macromastia treated surgically in a breast unit shows that breast reduction improves the quality of life of patients and that they are very satisfied with the outcome of the surgery and its surgeon, although the information received should clearly be improved.

Quality of life in cancer survivorship: Sociodemographic and disease-related moderators

RATIONALE

To identify high-risk survivors in order to provide appropriate care.

PURPOSE

To analyse the quality of life (QOL) of cancer survivors using an instrument designed specifically for this population and considering different sociodemographic and disease-related characteristics as possible modulating variables.

METHODS

The Quality of Life in Adult Cancer Survivors (QLACS) was filled out by a large and heterogeneous sample of disease-free post-treatment Spanish cancer survivors (N = 1862).

RESULTS

QLACS scores were comparable to those obtained in other studies and indicative of worse QOL as a function of shorter elapsed time since the end of primary treatment. The best QOL was shown by prostate, and the worst by hematologic cancer survivors. Both systemic treatments (chemotherapy and hormone therapy) and the combination of radiotherapy and chemotherapy were associated with worse QOL. Likewise, younger age, female sex, unemployment status and not having a stable partner were associated with worse QOL.

CONCLUSION

Greater understanding of the QOL experienced by the already large and continuously growing population of cancer survivors is relevant for guiding both clinical practice and health policy. In addition, knowing the risk factors associated with worse QOL facilitates the development of targeted prevention programmes for those survivors who need it the most.

Comprehensive molecular analysis of immortalization hallmarks in thyroid cancer reveals new prognostic markers

BACKGROUND

Comprehensive molecular studies on tumours are needed to delineate immortalization process steps and identify sensitive prognostic biomarkers in thyroid cancer.

METHODS AND RESULTS

In this study, we extensively characterize telomere-related alterations in a series of 106 thyroid tumours with heterogeneous clinical outcomes. Using a custom-designed RNA-seq panel, we identified five telomerase holoenzyme-complex genes upregulated in clinically aggressive tumours compared to tumours from long-term disease-free patients, being TERT and TERC denoted as independent prognostic markers by multivariate regression model analysis. Characterization of alterations related to TERT re-expression revealed that promoter mutations, methylation and/or copy gains exclusively co-occurred in clinically aggressive tumours. Quantitative-FISH (fluorescence in situ hybridization) analysis of telomere lengths showed a significant shortening in these carcinomas, which matched with a high proliferative rate measured by Ki-67 immunohistochemistry. RNA-seq data analysis indicated that short-telomere tumours exhibit an increased transcriptional activity in the 5-Mb-subtelomeric regions, site of several telomerase-complex genes. Gene upregulation enrichment was significant for specific chromosome-ends such as the 5p, where TERT is located. Co-FISH analysis of 5p-end and TERT loci showed a more relaxed chromatin configuration in short telomere-length tumours compared to normal telomere-length tumours.

CONCLUSIONS

Overall, our findings support that telomere shortening leads to a 5p subtelomeric region reorganization, facilitating the transcription and accumulation of alterations at TERT-locus.

Embodied transfer of knowledge using dynamic systems concepts in high school: A preliminary study

The transfer of knowledge among academic subjects and linking different phenomena are crucial education competencies in Bloom's taxonomy of learning goals. From another side, modern cognitive science defines cognition and learning as embodied. The Synthetic Understanding through Movement Analogies (SUMA) educational framework proposes embodied learning of general scientific principles and concepts and knowledge transfer among academic disciplines encompassing sciences, humanities and arts. Accordingly, this research aimed to evaluate the educational potential of teaching a set of Dynamic Systems Theory (DST) concepts through body movement experiences in first-grade high school students. Five classes of high school students (n = 71; 23 girls, 46 boys and 2 non-binaries, aged 12-13 y.) followed a four-week intervention addressed to teaching five DST concepts (order parameter, stability, control parameter, instability and phase transition) and transfer them to biological and social phenomena. Students followed four teaching phases: a) embodied experience, b) reflective observation of the experience, c) abstract conceptualization of the experience using the five general concepts, d) transfer of knowledge through the concepts to different phenomena from biological and social science academic subjects. Students' integration and transfer of knowledge abilities were evaluated pre- and post-intervention through a questionnaire and three open-ended questions. Results were compared using non-parametric Wilcoxon matched-pairs test and effect sizes were calculated through PS _dep measures. Students' abilities to integrate and transfer knowledge increased post-intervention (Z = 7.322, p < 0.0001, PS_dep = 1). The effect of the intervention points to the potential of teaching general DST concepts through body movement experiences in high school students for achieving the goals of an embodied and unificatory transdisciplinary education.

A mouse model for Li-Fraumeni-Like Syndrome with cardiac angiosarcomas associated to POT1 mutations

The shelterin protein POT1 has been found mutated in many different familial and sporadic cancers, however, no mouse models to understand the pathobiology of these mutations have been developed so far. To address the molecular mechanisms underlying the tumorigenic effects of POT1 mutant proteins in humans, we have generated a mouse model for the human POT1^R117C mutation found in Li-Fraumeni-Like families with cases of cardiac angiosarcoma by introducing this mutation in the Pot1a endogenous locus, knock-in for Pot1a^R117C. We find here that both mouse embryonic fibroblasts (MEFs) and tissues from Pot1a^+/ki mice show longer telomeres than wild-type controls. Longer telomeres in Pot1a^+/ki MEFs are dependent on telomerase activity as they are not found in double mutant Pot1a^+/kiTert^-/- telomerase-deficient MEFs. By using complementation assays we further show that POT1a pR117C exerts dominant-negative effects at telomeres. As in human Li-Fraumeni patients, heterozygous Pot1a^+/ki mice spontaneously develop a high incidence of angiosarcomas, including cardiac angiosarcomas, and this is associated to the presence of abnormally long telomeres in endothelial cells as well as in the tumors. The Pot1a^+/R117C mouse model constitutes a useful tool to understand human cancers initiated by POT1 mutations.

We have generated a mouse model for the human POT1^R117C mutation found in Li-Fraumeni-Like (LFL) families with cases of cardiac angiosarcoma by introducing this mutation in the Pot1a endogenous locus, knock-in for Pot1a^R117C. The Pot1a^+/ki mice show longer telomeres than wild-type controls. Longer telomeres in mutant mice are dependent on telomerase activity as they are not found in a telomerase deficient background. As in human Li-Fraumeni patients, heterozygous Pot1a^+/ki mice spontaneously develop a high incidence of angiosarcomas, including cardiac angiosarcomas, and this is associated to the presence of abnormally long telomeres in endothelial cells as well as in the tumors. The ki-Pot1a^R117C mouse constitutes a potential pre-clinical mouse model for LFL syndrome presenting with high angiosarcoma incidence that could provide in the future a very useful tool for the study of treatments for these tumors.

Unveiling the Multitarget Anti-Alzheimer Drug Discovery Landscape: A Bibliometric Analysis

Multitarget anti-Alzheimer agents are the focus of very intensive research. Through a comprehensive bibliometric analysis of the publications in the period 1990-2020, we have identified trends and potential gaps that might guide future directions. We found that: (i) the number of publications boomed by 2011 and continued ascending in 2020; (ii) the linked-pharmacophore strategy was preferred over design approaches based on fusing or merging pharmacophores or privileged structures; (iii) a significant number of in vivo studies, mainly using the scopolamine-induced amnesia mouse model, have been performed, especially since 2017; (iv) China, Italy and Spain are the countries with the largest total number of publications on this topic, whereas Portugal, Spain and Italy are the countries in whose scientific communities this topic has generated greatest interest; (v) acetylcholinesterase, β-amyloid aggregation, oxidative stress, butyrylcholinesterase, and biometal chelation and the binary combinations thereof have been the most commonly pursued, while combinations based on other key targets, such as tau aggregation, glycogen synthase kinase-3β, NMDA receptors, and more than 70 other targets have been only marginally considered. These results might allow us to spot new design opportunities based on innovative target combinations to expand and diversify the repertoire of multitarget drug candidates and increase the likelihood of finding effective therapies for this devastating disease.

Optimism as a protective factor against the psychological impact of COVID-19 pandemic through its effects on perceived stress and infection stress anticipation

The 2019 coronavirus disease (COVID-19) and the recommended social isolation presented a challenge to people's mental health status. Optimism is a psychological factor that plays a key role in the evaluation of stressful situations. The purpose of this study was to investigate the mediating role of perceived stress and Covid-19-related stress anticipation in the relationship between optimism and post-traumatic stress symptoms. Our sample included 1015 participants ranging in age from 18 to 79 years, 80% of whom were Spaniards. At the beginning of the worldwide pandemic, participants were confined to their homes for at least seven days and completed an online survey measuring various sociodemographic and psychological variables. We found an indirect effect of optimism on intrusion and hyperarousal through perceived stress and stress anticipation. In addition, we observed an indirect effect of optimism on avoidance through perceived stress. Finally, the results showed a significant indirect effect of optimism on the total post-traumatic stress symptoms score through perceived stress and stress anticipation. Our results indicate that positive beliefs inherent to optimism are related to less psychological impact of the COVID-19 outbreak.

Operation of a triage committee for advanced life support during the COVID-19 pandemic

BACKGROUND

During the first weeks of March 2020 in Spain, the cases of severe respiratory failure progressively increased, generating an imbalance between the clinical needs for advanced life support (ALS) measures and the effective availability of ALS resources. To address this problem, the creation of triage committees (TC) was proposed, whose main function is to select the best candidates to receive ALS. The main objective of our study is to describe the clinical characteristics of the patients evaluated by the TC of the Alcorcón Foundation University Hospital (AFUH) during the first wave of SARS CoV-2. Other objectives are to determine if there are differences between the patients considered candidates / not candidates for ALS and to analyze the functioning of the TC.

METHODS

Retrospective observational study of all patients assessed by the AFUH TC.

RESULTS

There were 19 meetings, in which 181 patients were evaluated, 65.4% male and with a mean age of 70.1 years. 31% had some degree of functional dependence, the Barthel median was 100 and Charlson 4. 58.5% were not considered a candidate for ALS at that time. The patients considered candidates to receive ALS were younger (72 vs 66; p < 0.001), had less comorbidity (Charlson 4 vs 3; p < 0.001) and had a better previous functional situation. A median of 5 physicians participated in each meeting and, after being assessed by the TC, 13.6% received ALS: 29.3% of those considered candidates for ALS and 2% of the non-candidates.

CONCLUSIONS

The patients evaluated by the TC had a mean age of 70 years, high comorbidity and almost a third had some degree of functional dependence. More than half were not considered candidates for ALS at that time, these patients being older, with more comorbidity and a worse previous functional situation. TC decisions, based on objective clinical criteria, were almost always respected. Public institutions must get involved in triage procedures, which should and in our opinion must include the creation of TC in health centers. The implementation of Anticipated Decision programs (ADP) would help enable patients affected by triage decisions to participate in them.

Simplified risk-prediction for benchmarking and quality improvement in emergency general surgery. Prospective, multicenter, observational cohort study

BACKGROUND AND AIMS

Emergency General Surgery (EGS) conditions account for millions of deaths worldwide, yet it is practiced without benchmarking-based quality improvement programs. The aim of this observational, prospective, multicenter, nationwide study was to determine the best benchmark cutoff points in EGS, as a reference to guide improvement measures.

METHODS

Over a 6-month period, 38 centers (5% of all public hospitals) attending EGS patients on a 24-h, 7-days a week basis, enrolled consecutive patients requiring an emergent/urgent surgical procedure. Patients were stratified into cohorts of low (i.e., expected morbidity risk <33%), middle and high risk using the novel m-LUCENTUM calculator.

RESULTS

A total of 7258 patients were included; age (mean ± SD) was 51.1 ± 21.5 years, 43.2% were female. Benchmark cutoffs in the low-risk cohort (5639 patients, 77.7% of total) were: use of laparoscopy ≥40.9%, length of hospital stays ≤3 days, any complication within 30 days ≤ 17.7%, and 30-day mortality ≤1.1%. The variables with the greatest impact were septicemia on length of hospital stay (21 days; adjusted beta coefficient 16.8; 95% CI: 15.3 to 18.3; P < .001), and respiratory failure on mortality (risk-adjusted population attributable fraction 44.6%, 95% CI 29.6 to 59.6, P < .001). Use of laparoscopy (odds ratio 0.764, 95% CI 0.678 to 0.861; P < .001), and intraoperative blood loss (101-500 mL: odds ratio 2.699, 95% CI 2.152 to 3.380; P < .001; and 500-1000 mL: odds ratio 2.875, 95% CI 1.403 to 5.858; P = .013) were associated with increased morbidity.

CONCLUSIONS

This study offers, for the first time, clinically-based benchmark values in EGS and identifies measures for improvement.

Improving the comparability of Brief-COPE results through examination of second-order structures: A study with Spanish adolescents

The Brief-Coping Orientation to Problems Experienced (Brief-COPE) is a widely used instrument, although with limitations regarding reliability and factorial structure. This study with 611 adolescents examines the Brief-COPE’s internal structure, reliability, and convergent validity. Structures tested through confirmatory factor analysis were the original 14 subscales, as well as three second-order structures derived from previous COPE research and from Connor-Smith and Flachsbart’s proposal. All the structures examined obtained a good fit. However, internal consistency and convergent validity findings only supported the use of a model in which religion and self-blame constitute independent subscales while the remaining subscales shaped three second-order factors: self-sufficient, socially supported, and disengagement coping. This hierarchical structure reflects a model emphasized by research with adolescents, makes the use of this instrument valuable, and does not prevent the exploration of original subscales with appropriate reliability levels. Consequently, our results constitute a significant step forward in the improvement of the usefulness and comparability of the coping results obtained with the Brief-COPE.

Prolonged intravenous immunoglobulin treatment in very low birth weight infants with late onset sepsis

BACKGROUND

Neonatal infections are a leading cause of morbi-mortality despite advances in antimicrobials and neonatal care. Preterm infants have greater susceptibility to sepsis due to an immature immune system and lower immunoglobulin levels. Intravenous immunoglobulins (IVIG) have been used in several studies as an adjuvant treatment to improve this physiological immune deficiency, with different outcomes.

METHODS

Very low birth weight (VLBW) infants who developed sepsis in the neonatal ICU were studied. They were randomly divided in 2 groups: one group was treated with antibiotics (Group I), and the other received antibiotics plus a 500 mg/kg/day of IVIG during 7 days (Group II). Serum IgG concentration was determined at initiation, during and after treatment Group I, and daily during the 7 days of therapy in Group II.

RESULTS

The baseline IgG concentration in group II was 486 g/dL, and increased to 852 mg/dL after the first dose of IVIG (p < 0.01). After the seventh day of infusion a mean IgG level of 1898 mg/dL was achieved. A direct correlation (r = 0.94) between IgG concentration and days of treatment was observed. Blood cultures were positive in 70% of the infants in group I and 75.5% in group II. Staphylococcus epidermidis was the most frequent isolated bacteria in blood cultures. The lethality rate was 25.0% in group I and 5.0% in Group II (p < 0.03). We did not observe collateral effects with the administration of IVIG.

CONCLUSIONS

Prolonged therapy with IVIG seems to be safe and effective as an adjuvant treatment in VLBW infants with sepsis.

Beaming in the Charcot foot: A case series with 12-month minimum follow-up

BACKGROUND

Charcot neuropathic arthropathy is a progressive degeneration of the weightbearing joints of the foot induced by denervation and disturbance of sensorial perception. This entity clinically behaves as a destructive fast-progressive arthropathy, resulting in loss of independent walking and often requiring amputation of the leg. This study analyzes our experience with midfoot realignment arthrodesis and stabilization by intramedullary beaming in patients with Charcot diabetic foot as a limb-sparing procedure.

METHODS

Patients with Charcot foot treated in our Foot and Ankle unit between January 2018 and December 2019 were analyzed. In all of the patients beaming technique was performed: open reduction and stabilization by a midfoot medial fusion beam and a lateral fusion bolt. Demographical, clinical and radiological pre and post-surgery data were assessed. The primary outcome measure was defined as an autonomous ambulation through an ulcer-free plantigrade foot. A minimum follow-up of 12 months was performed.

RESULTS

A total of 5 patients were treated. Median age 64 years, mean follow-up 25 months (12-31). An ulcer-free plantigrade foot was obtained in 80% of the patients. Complications were observed in 80% of patients: 1 deep infection, 2 hardware failure, 3 Charcot foot progression. Rate of reoperation 40%, including 1 amputation. Significant improvement in all radiographic angles was observed.

CONCLUSION

Beaming the medial and lateral columns of the foot in patients with Charcot foot enabled the restoration of a functional plantigrade foot and an ulcer-free autonomous ambulation, despite a relatively high complication rate.

LEVEL OF EVIDENCE

IV, prospective case series.

Analysis of the vomeronasal organ transcriptome reveals variable gene expression depending on age and function in rabbits

The vomeronasal organ (VNO) is a chemosensory organ specialized in pheromone detection that shows a broad morphofunctional and genomic diversity among mammals. However, its expression patterns have only been well-characterized in mice. Here, we provide the first comprehensive RNA sequencing study of the rabbit VNO across gender and sexual maturation stages. We characterized the VNO transcriptome, updating the number and expression of the two main vomeronasal receptor families, including 128 V1Rs and 67 V2Rs. Further, we defined the expression of formyl-peptide receptor and transient receptor potential channel families, both known to have specific roles in the VNO. Several sex hormone-related pathways were consistently enriched in the VNO, highlighting the relevance of this organ in reproduction. Moreover, whereas juvenile and adult VNOs showed significant transcriptome differences, male and female did not. Overall, these results contribute to understand the genomic basis of behavioural responses mediated by the VNO in a non-rodent model.

Short and dysfunctional telomeres protect from allergen-induced airway inflammation

Asthma is a chronic inflammatory disease affecting 300 million people worldwide. As telomere shortening is a well-established hallmark of aging and that asthma incidence decreases with age, here we aimed to study the role of short telomeres in asthma pathobiology. To this end, wild-type and telomerase-deficient mice with short telomeres (third-generation (G3 Tert^-/- mice)) were challenged with intranasal house dust mite (HDM) extract. We also challenged with HDM wild-type mice in which we induced a telomere dysfunction by the administration of 6-thio-2´-deoxyguanosine (6-thio-dG). Following HDM exposure, G3 Tert^-/- and 6-thio-dG treated mice exhibited attenuated eosinophil counts and presence of hematopoietic stem cells in the bone marrow, as well as lower levels of IgE and circulating eosinophils. Accordingly, both G3 Tert^-/- and 6-thio-dG treated wild-type mice displayed reduced airway hyperresponsiveness (AHR), as indicated by decreased airway remodeling and allergic airway inflammation markers in the lung. Furthermore, G3 Tert^-/- and 6-thio-dG treated mice showed lower differentiation of Club cells, attenuating goblet cell hyperplasia. Club cells of G3 Tert^-/- and 6-thio-dG treated mice displayed increased DNA damage and senescence and reduced proliferation. Thus, short/dysfunctional telomeres play a protective role in murine asthma by impeding both AHR and mucus secretion after HDM exposure. Therefore, our findings imply that telomeres play a relevant role in allergen-induced airway inflammation.

Telomerase treatment prevents lung profibrotic pathologies associated with physiological aging

Short/dysfunctional telomeres are at the origin of idiopathic pulmonary fibrosis (IPF) in patients mutant for telomere maintenance genes. However, it remains unknown whether physiological aging leads to short telomeres in the lung, thus leading to IPF with aging. Here, we find that physiological aging in wild-type mice leads to telomere shortening and a reduced proliferative potential of alveolar type II cells and club cells, increased cellular senescence and DNA damage, increased fibroblast activation and collagen deposits, and impaired lung biophysics, suggestive of a fibrosis-like pathology. Treatment of both wild-type and telomerase-deficient mice with telomerase gene therapy prevented the onset of lung profibrotic pathologies. These findings suggest that short telomeres associated with physiological aging are at the origin of IPF and that a potential treatment for IPF based on telomerase activation would be of interest not only for patients with telomerase mutations but also for sporadic cases of IPF associated with physiological aging.

Short and dysfunctional telomeres sensitize the kidneys to develop fibrosis

Accumulation of short telomeres is a hallmark of aging. Mutations in telomerase or telomere-binding proteins lead to telomere shortening or dysfunction and are at the origin of human pathologies known as 'telomere syndromes', which are characterized by loss of the regenerative capacity of tissues and fibrotic pathologies. Here, we generated two mouse models of kidney fibrosis, either by combining telomerase deficiency to induce telomere shortening and a low dose of folic acid, or by conditionally deleting Trf1, a component of the shelterin telomere protective complex, from the kidneys. We find that short telomeres sensitize the kidneys to develop fibrosis in response to folic acid and exacerbate the epithelial-to-mesenchymal transition (EMT) program. Trf1 deletion in kidneys led to fibrosis and EMT activation. Our findings suggest that telomere shortening or dysfunction may contribute to pathological, age-associated renal fibrosis by influencing the EMT program.

Shorter telomere lengths in patients with severe COVID-19 disease

The incidence of severe manifestations of COVID-19 increases with age with older patients showing the highest mortality, suggesting that molecular pathways underlying aging contribute to the severity of COVID-19. One mechanism of aging is the progressive shortening of telomeres, which are protective structures at chromosome ends. Critically short telomeres impair the regenerative capacity of tissues and trigger loss of tissue homeostasis and disease. The SARS-CoV-2 virus infects many different cell types, forcing cell turn-over and regeneration to maintain tissue homeostasis. We hypothesize that presence of short telomeres in older patients limits the tissue response to SARS-CoV-2 infection. We measure telomere length in peripheral blood lymphocytes COVID-19 patients with ages between 29 and 85 years-old. We find that shorter telomeres are associated to increased severity of the disease. Individuals within the lower percentiles of telomere length and higher percentiles of short telomeres have higher risk of developing severe COVID-19 pathologies.

Impact of Routine and Long-Term Follow-Up on Weight Loss after Bariatric Surgery

BACKGROUND

Weight loss after bariatric surgery varies among patients. Patients who do not complete long-term follow-up are considered to loose less weight than those with regular follow-up visits.

OBJECTIVE

To evaluate the influence of patients' follow-up compliance on long-term excess weight loss (%EWL) and total weight loss (%TWL) after bariatric surgery, comparing results between gastric bypass (GB) and sleeve gastrectomy (SG).

METHODS

Patients with up to 5 years of follow-up data after bariatric surgery were included in this retrospective analysis. Patients were divided in 2 groups: those in group 1 who had attended every scheduled postoperative appointment and those in group 2 who had been lost to follow-up before 1 year and were later contacted by telephone. %EWL and %TWL were compared to determine the possible relationship between type of surgery and regularity of the follow-up.

RESULTS

A total of 385 patients were included. A significant difference in EWL was observed at 5 years in the SG group (78% for group 1 versus 39% for group 2; p = 0.02) and GB group (75% for group 1 versus 62% for group 2; p = 0.01). No significant differences between surgeries were found when comparing long-term EWL in group 1 patients 77% for SG versus 75% for GB. For group 2 patients, GB achieved greater EWL than SG; p = 0.005. %TWL patients in group 2 showed significant differences in all periods of study (p < 0.05).

CONCLUSION

Bariatric surgery patients who attended all scheduled follow-up appointments experienced significantly greater long-term EWL and TWL than those who did not. GB has apparent increased benefits for weight loss in long-term follow-up when compared with SG for patients who did not attend long-term follow-up. Therefore, continued long-term follow-up of bariatric patients should be encouraged to increase postoperative weight loss results.

Diagnostic delay and outcome in immunocompetent patients with primary central nervous system lymphoma in Spain: a multicentric study

INTRODUCTION

To assess the management of immunocompetent patients with primary central nervous system lymphomas (PCNSL) in Spain.

METHODS

Retrospective analysis of 327 immunocompetent patients with histologically confirmed PCNSL diagnosed between 2005 and 2014 in 27 Spanish hospitals.

RESULTS

Median age was 64 years (range: 19-84; 33% ≥ 70 years), 54% were men, and 59% had a performance status (PS) ≥ 2 at diagnosis. Median delay to diagnosis was 47 days (IQR 24-81). Diagnostic delay > 47 days was associated with PS ≥ 2 (OR 1.99; 95% CI 1.13-3.50; p = 0.016) and treatment with corticosteroids (OR 2.47; 95% CI 1.14-5.40; p = 0.023), and it did not improve over the years. Patients treated with corticosteroids (62%) had a higher risk of additional biopsies (11.7% vs 4.0%, p = 0.04) but corticosteroids withdrawal before surgery did not reduce this risk and increased the diagnostic delay (64 vs 40 days, p = 0.04). Median overall survival (OS) was 8.9 months [95% CI 5.9-11.7] for the whole series, including 52 (16%) patients that were not treated, and 14.1 months (95%CI 7.7-20.5) for the 240 (73.4%) patients that received high-dose methotrexate (HD-MTX)-based chemotherapy. Median OS was shorter in patients ≥ 70 years (4.1 vs. 13.4 months; p < 0.0001). Multivariate analysis identified age ≥ 65 years, PS ≥ 2, no treatment, and cognitive/psychiatric symptoms at diagnosis as independent predictors of short survival.

CONCLUSIONS

Corticosteroids withdrawal before surgery does not decrease the risk of a negative biopsy but delays diagnosis. In this community-based study, only 73.4% of patients could receive HD-MTX-based chemotherapy and OS remains poor, particularly in elderly patients ≥ 70 years.

Heart-Breaking Telomeres

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual's lifetime. Accumulation of critically short telomeres is proposed to be a primary molecular cause of aging and age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as or telomeropathies. The rate of telomere shortening throughout life is determined by endogenous (genetic) and external (nongenetic) factors. Therapeutic strategies based on telomerase activation are being developed to treat and prevent telomere-associated diseases, namely aging-related diseases and telomeropathies. Here, we review the molecular mechanisms underlying telomere driven diseases with particular emphasis on cardiovascular diseases.

TERRA regulate the transcriptional landscape of pluripotent cells through TRF1-dependent recruitment of PRC2

The mechanisms that regulate pluripotency are still largely unknown. Here, we show that Telomere Repeat Binding Factor 1 (TRF1), a component of the shelterin complex, regulates the genome-wide binding of polycomb and polycomb H3K27me3 repressive marks to pluripotency genes, thereby exerting vast epigenetic changes that contribute to the maintenance of mouse ES cells in a naïve state. We further show that TRF1 mediates these effects by regulating TERRA, the lncRNAs transcribed from telomeres. We find that TERRAs are enriched at polycomb and stem cell genes in pluripotent cells and that TRF1 abrogation results in increased TERRA levels and in higher TERRA binding to those genes, coincidental with the induction of cell-fate programs and the loss of the naïve state. These results are consistent with a model in which TRF1-dependent changes in TERRA levels modulate polycomb recruitment to pluripotency and differentiation genes. These unprecedented findings explain why TRF1 is essential for the induction and maintenance of pluripotency.

Validation of the Geriatric Anxiety Inventory in Chilean older people

OBJECTIVE

Currently in Chile there is a lack of validated tools for measuring anxiety in the elderly population. Considering this, the purpose of this study was to validate the Geriatric Anxiety Inventory (GAI) in the country.

METHOD

An analysis of the psychometric properties of the GAI was carried out, using a non-clinical sample of 301 older adults in the Metropolitan and Valparaíso regions of Chile. Older people were asked about anxiety, rumination, depression, well-being and sociodemographic data.

RESULTS

An excellent internal reliability was obtained with a Cronbach score of 0.931. An adequate convergent validity was observed with the Depression scales (CES-D) (Rho = 0.549, p < .01), Rumination (RSS) (Rho = 0.618; p < 0.01) and Experiential avoiding (Rho = 0.485; p < 0.01). On the other hand, the discriminant validity of the psychological well-being scale presented a negative correlation of Rho = -0.699 (p < 0.01). Finally, and Exploratory Factor Analysis was made, revealing a one-dimensional model of the instrument.

CONCLUSION

The Geriatric Anxiety Inventory has very good psychometric properties measuring anxiety in elderly people, being an adequate instrument for the screening of anxiety on this population.

Mice lacking RAP1 show early onset and higher rates of DEN-induced hepatocellular carcinomas in female mice

RAP1, a component of the telomere-protective shelterin complex, has been shown to have both telomeric and non-telomeric roles. In the liver, RAP1 is involved in the regulation of metabolic transcriptional programs. RAP1-deficient mice develop obesity and hepatic steatosis, these phenotypes being more severe in females than in males. As hepatic steatosis and obesity have been related to increased liver cancer in mice and humans, we set out to address whether RAP1 deficiency resulted in increased liver cancer upon chemical liver carcinogenesis. We found that Rap1-/- females were more susceptible to DEN-induced liver damage and hepatocellular carcinoma (HCC). DEN-treated Rap1-/- female livers showed an earlier onset of both premalignant and malignant liver lesions, which were characterized by increased abundance of γH2AX-positive cells, increased proliferation and shorter telomeres. These findings highlight an important role for RAP1 in protection from liver damage and liver cancer.

AAV9-mediated telomerase activation does not accelerate tumorigenesis in the context of oncogenic K-Ras-induced lung cancer

Short and dysfunctional telomeres are sufficient to induce a persistent DNA damage response at chromosome ends, which leads to the induction of senescence and/or apoptosis and to various age-related conditions, including a group of diseases known as “telomere syndromes”, which are provoked by extremely short telomeres owing to germline mutations in telomere genes. This opens the possibility of using telomerase activation as a potential therapeutic strategy to rescue short telomeres both in telomere syndromes and in age-related diseases, in this manner maintaining tissue homeostasis and ameliorating these diseases. In the past, we generated adeno-associated viral vectors carrying the telomerase gene (AAV9-Tert) and shown their therapeutic efficacy in mouse models of cardiac infarct, aplastic anemia, and pulmonary fibrosis. Although we did not observe increased cancer incidence as a consequence of Tert overexpression in any of those models, here we set to test the safety of AAV9-mediated Tert overexpression in the context of a cancer prone mouse model, owing to expression of oncogenic K-ras. As control, we also treated mice with AAV9 vectors carrying a catalytically inactive form of Tert, known to inhibit endogenous telomerase activity. We found that overexpression of Tert does not accelerate the onset or progression of lung carcinomas, even when in the setting of a p53-null background. These findings indicate that telomerase activation by using AAV9-mediated Tert gene therapy has no detectable cancer-prone effects in the context of oncogene-induced mouse tumors.

The ends of our chromosomes, or telomeres, shorten with age. When telomeres become critically short cells stop dividing and die. Shortened telomeres are associated with onset of age-associated diseases. Telomerase is a retrotranscriptase enzyme that is able to elongate telomeres by coping an associated RNA template. Telomerase is silenced after birth in the majority of cells with the exception of adult stem cells. Cancer cells aberrantly reactivate telomerase facilitating indefinite cell division. Mutations in genes encoding for proteins involved in telomere maintenance lead the so-called “telomere syndromes” that include aplastic anemia and pulmonary fibrosis, among others. We have developed a telomerase gene therapy that has proven to be effective in delaying age-associated diseases and showed therapeutic effects in mouse models for the telomere syndromes. Given the potential cancer risk associated to telomerase expression in the organism, we set to analyze the effects of telomerase gene therapy in a lung cancer mouse model. Our work demonstrates that telomerase gene therapy does not aggravate the incidence, onset and progression of lung cancer in mice. These findings expand on the safety of AAV-mediated telomerase activation as a novel therapeutic strategy for the treatment of diseases associated to short telomeres.

Highly dense linkage maps from 31 full-sibling families of turbot (Scophthalmus maximus) provide insights into recombination patterns and chromosome rearrangements throughout a newly refined genome assembly

Highly dense linkage maps enable positioning thousands of landmarks useful for anchoring the whole genome and for analysing genome properties. Turbot is the most important cultured flatfish worldwide and breeding programs in the fifth generation of selection are targeted to improve growth rate, obtain disease resistant broodstock and understand sex determination to control sex ratio. Using a Restriction-site Associated DNA approach, we genotyped 18,214 single nucleotide polymorphism in 1,268 turbot individuals from 31 full-sibling families. Individual linkage maps were combined to obtain a male, female and species consensus maps. The turbot consensus map contained 11,845 markers distributed across 22 linkage groups representing a total normalised length of 3,753.9 cM. The turbot genome was anchored to this map, and scaffolds representing 96% of the assembly were ordered and oriented to obtain the expected 22 megascaffolds according to its karyotype. Recombination rate was lower in males, especially around centromeres, and pairwise comparison of 44 individual maps suggested chromosome polymorphism at specific genomic regions. Genome comparison across flatfish provided new evidence on karyotype reorganisations occurring across the evolution of this fish group.

The factor structure of the Medical Outcomes Study-Social Support Survey: A comparison of different models in a sample of recently diagnosed cancer patients

OBJECTIVE

To analyse the factor structure and psychometric properties of the original and abbreviated versions of the Medical Outcomes Study-Social Support Survey (MOS-SSS) in recently-diagnosed cancer patients.

METHOD

A sample of 128 newly-diagnosed cancer patients were assessed with the Spanish versions of the MOS-SSS and the Hospital Anxiety and Depression Scale (HADS). Confirmatory factor analyses were conducted to analyse six different factor structures. Internal consistency and convergent validity indexes were calculated. The models tested included all of the following: 1) the original five-factor model (comprised of the following dimensions: emotional, informational, and tangible support, positive social interaction, and affection); 2) a four-factor empirical solution; 3 & 4) two different three-factor structures obtained in studies conducted in cancer patients; and 5 & 6) a two-factor solution for the abbreviated 8-item form and a one-factor solution for the 6-item form.

RESULTS

The original five-factor structure showed a better fit index than the three and four factor models. Both the 6- and 8-item versions showed excellent goodness-of-fit, with adequate internal consistency and convergent validity indexes.

CONCLUSION

The MOS-SSS is a powerful, highly flexible instrument to assess social support in cancer patients. The full 19-item scale allows for a comprehensive assessment of the essential dimensions of social support, while the abbreviated versions permit a quick assessment that minimizes the burden on patients.

Characterization of the bHLH family of transcriptional regulators in the acoel S. roscoffensis and their putative role in neurogenesis

Background

The basic helix-loop-helix (bHLH) family of transcription factors is one of the largest superfamilies of regulatory transcription factors and is widely used in eukaryotic organisms. They play an essential role in a range of metabolic, physiological, and developmental processes, including the development of the nervous system (NS). These transcription factors have been studied in many metazoans, especially in vertebrates but also in early branching metazoan clades such as the cnidarians and sponges. However, currently very little is known about their expression in the most basally branching bilaterian group, the xenacoelomorphs. Recently, our laboratory has characterized the full complement of bHLH in the genome of two members of the Xenacoelomorpha, the xenoturbellid Xenoturbella bocki and the acoel Symsagittifera roscoffensis. Understanding the patterns of bHLH gene expression in members of this phylum (in space and time) provides critical new insights into the conserved roles of the bHLH and their putative specificities in this group. Our focus is on deciphering the specific roles that these genes have in the process of neurogenesis.

Results

Here, we analyze the developmental expression of the whole complement of bHLH genes identified in the acoel S. roscoffensis. Based on their expression patterns, several members of bHLH class A appear to have specific conserved roles in neurogenesis, while other class A genes (as well as members of other classes) have likely taken on more generalized functions. All gene expression patterns are described in embryos and early juveniles.

Conclusion

Our results suggest that the main roles of the bHLH genes of S. roscoffensis are evolutionarily conserved, with a specific subset dedicated to patterning the nervous system: SrAscA, SrAscB, SrHes/Hey, SrNscl, SrSrebp, SrE12/E47 and SrOlig.

Electronic supplementary material

The online version of this article (10.1186/s13227-018-0097-y) contains supplementary material, which is available to authorized users.

Genetic structure and evidence of anthropogenic effects on wild populations of two Neotropical catfishes: baselines for conservation

Genetic diversity and structure of Pseudoplatystoma corruscans and P. reticulatum, large migratory South America catfishes, where overfishing and the construction of numerous dams in their feeding and reproducing areas are affecting their migratory processes negatively, were studied using microsatellites in samples from Paraguay (that comprises the Pantanal biome), and the upper and lower Paraná Basins. Genetic diversity was in accordance to that observed for other large migratory fishes, but the most geographically isolated populations of P. reticulatum and those P. corruscans subject to anthropogenic effects (stocking and dams) showed lower genetic diversity and evidences of bottlenecks compatible with low effective population size. Pseudoplatystoma reticulatum presented subtle genetic differentiation within the Paraguay area, especially between the edges of its distribution. Pseudoplatystoma corruscans, in this same area, presented a quite homogeneous but significant genetic break between the Paraguay and upper Paraná populations, apparently resulting from natural and historical isolation between the basins until recently. These data demonstrates that, although these Pseudoplatystoma spp. are abundant in the Pantanal area, anthropogenic events are leading to negative effects on their populations, particularly in the upper Paraná Basin. Genetic differentiation observed along each species distribution demands conservation actions to preserve each population's biodiversity. These results represent important genetic information using new microsatellite markers and the first genetic study of P. reticulatum covering this area of its native distribution. Data may also contribute to a better understanding of species migration patterns and to be used as a baseline for proper management.

Study of graphene dispersions in sodium dodecylsulfate by steady-state fluorescence of pyrene

HYPOTHESIS

Aqueous solutions of ionic surfactants allow the exfoliation of graphene, that can be explained considering the adsorption model of ionic surfactants to hydrophobic surfaces. For many years, pyrene has been used as a fluorescent probe because its sensitivity to the micro-environment. The study of pyrene fluorescence in the presence of different graphene dispersions in an ionic surfactant, would improve the knowledge of the graphene-surfactant interactions.

EXPERIMENTS

Different dispersions of graphene in sodium dodecylsulfate were prepared at different weight ratios 0.5, 1 and 2%. The dispersions have been studied by Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The influence of the dispersions on the pyrene fluorescence has been investigated.

FINDINGS

The graphene sheets modified by the surfactant quench the fluorescence of pyrene, which depends on the amount of graphene, the concentration of surfactant and the weight ratio. For surfactant concentrations below the critical micelle concentration, the quenching effect is higher as the weight ratio increases. Once this concentration is reached, the fluorescence increases slightly and then levels off. This behavior has been explained by the adsorption model. For a constant surfactant concentration, two straight lines can be observed in the Stern-Volmer plots whose cut-off point is approximately 20 mg L^-1 of graphene.

Modulation of telomere protection by the PI3K/AKT pathway

Telomeres and the insulin/PI3K pathway are considered hallmarks of aging and cancer. Here, we describe a role for PI3K/AKT in the regulation of TRF1, an essential component of the shelterin complex. PI3K and AKT chemical inhibitors reduce TRF1 telomeric foci and lead to increased telomeric DNA damage and fragility. We identify the PI3Kα isoform as responsible for this TRF1 inhibition. TRF1 is phosphorylated at different residues by AKT and these modifications regulate TRF1 protein stability and TRF1 binding to telomeric DNA in vitro and are important for in vivo TRF1 telomere location and cell viability. Patient-derived breast cancer PDX mouse models that effectively respond to a PI3Kα specific inhibitor, BYL719, show decreased TRF1 levels and increased DNA damage. These findings functionally connect two of the major pathways for cancer and aging, telomeres and the PI3K pathway, and pinpoint PI3K and AKT as novel targets for chemical modulation of telomere protection.

Regulation of telomeres and the insulin/PI3K pathway both have roles in aging and cancer development but have not been functionally linked. Here the authors demonstrate that PI3K, via downstream targets, regulates TRF1 via phosphorylation.

EARLY-ESLI study: Long-term experience with eslicarbazepine acetate after first monotherapy failure

PURPOSE

Evaluate real-life experience with eslicarbazepine acetate (ESL) after first monotherapy failure in a large series of patients with focal epilepsy.

METHOD

Multicentre, retrospective, 1-year, observational study in patients older than 18 years, with focal epilepsy, who had failed first antiepileptic drug monotherapy and who received ESL. Data from clinical records were analysed at baseline, 3, 6 and 12 months to assess effectiveness and tolerability.

RESULTS

Eslicarbazepine acetate was initiated in 253 patients. The 1-year retention rate was 92.9%, and the final median dose of ESL was 800 mg. At 12 months, 62.3% of patients had been seizure free for 6 months; 37.3% had been seizure free for 1 year. During follow-up, 31.6% of the patients reported ESL-related adverse events (AEs), most commonly somnolence (8.7%) and dizziness (5.1%), and 3.6% discontinued due to AEs. Hyponatraemia was observed in seven patients (2.8%). After starting ESL, 137 patients (54.2%) withdrew the prior monotherapy and converted to ESL monotherapy; 75.9% were seizure free, 87.6% were responders, 4.4% worsened, and 23.4% reported ESL-related AEs.

CONCLUSION

Use of ESL after first monotherapy failure was associated with an optimal seizure control and tolerability profile. Over half of patients were converted to ESL monotherapy during follow-up.

Decreasing the Expression of GABAA α5 Subunit-Containing Receptors Partially Improves Cognitive, Electrophysiological, and Morphological Hippocampal Defects in the Ts65Dn Model of Down Syndrome

Trisomy 21 or Down syndrome (DS) is the most common cause of intellectual disability of a genetic origin. The Ts65Dn (TS) mouse, which is the most commonly used and best-characterized mouse model of DS, displays many of the cognitive, neuromorphological, and biochemical anomalies that are found in the human condition. One of the mechanisms that have been proposed to be responsible for the cognitive deficits in this mouse model is impaired GABA-mediated inhibition. Because of the well-known modulatory role of GABA_A α5 subunit-containing receptors in cognitive processes, these receptors are considered to be potential targets for improving the intellectual disability in DS. The chronic administration of GABA_A α5-negative allosteric modulators has been shown to be procognitive without anxiogenic or proconvulsant side effects. In the present study, we use a genetic approach to evaluate the contribution of GABA_A α5 subunit-containing receptors to the cognitive, electrophysiological, and neuromorphological deficits in TS mice. We show that reducing the expression of GABA_A α5 receptors by deleting one or two copies of the Gabra5 gene in TS mice partially ameliorated the cognitive impairments, improved long-term potentiation, enhanced neural differentiation and maturation, and normalized the density of the GABAergic synapse markers. Reducing the gene dosage of Gabra5 in TS mice did not induce motor alterations and anxiety or affect the viability of the mice. Our results provide further evidence of the role of GABA_A α5 receptor-mediated inhibition in cognitive impairment in the TS mouse model of DS.

Progesterone Receptor Isoform Ratio: A Breast Cancer Prognostic and Predictive Factor for Antiprogestin Responsiveness

Background

Compelling evidence shows that progestins regulate breast cancer growth. Using preclinical models, we demonstrated that antiprogestins are inhibitory when the level of progesterone receptor isoform A (PR-A) is higher than that of isoform B (PR-B) and that they might stimulate growth when PR-B is predominant. The aims of this study were to investigate ex vivo responses to mifepristone (MFP) in breast carcinomas with different PR isoform ratios and to examine their clinical and molecular characteristics.

Methods

We performed human breast cancer tissue culture assays (n = 36) to evaluate the effect of MFP on cell proliferation. PR isoform expression was determined by immunoblotting (n = 282). Tumors were categorized as PRA-H (PR-A/PR-B ≥ 1.2) or PRB-H (PR-A/PR-B ≤ 0.83). RNA was extracted for Ribo-Zero-Seq sequencing to evaluate differentially expressed genes. Subtypes and risk scores were predicted using the PAM50 gene set, the data analyzed using The Cancer Genome Atlas RNA-seq gene analysis and other publicly available gene expression data. Tissue microarrays were performed using paraffin-embedded tissues (PRA-H n = 53, PRB-H n = 24), and protein expression analyzed by immunohistochemistry. All statistical tests were two-sided.

Results

One hundred sixteen out of 222 (52.3%) PR+ tumors were PRA-H, and 64 (28.8%) PRB-H. Cell proliferation was inhibited by MFP in 19 of 19 tissue cultures from PRA-H tumors. A total of 139 transcripts related to proliferative pathways were differentially expressed in nine PRA-H and seven PRB-H tumors. PRB-H and PRA-H tumors were either luminal B or A phenotypes, respectively ( P = .03). PRB-H cases were associated with shorter relapse-free survival (hazard ratio [HR] = 2.70, 95% confidence interval [CI] = 1.71 to 6.20, P = .02) and distant metastasis-free survival (HR = 4.17, 95% CI = 2.18 to 7.97, P <  .001). PRB-H tumors showed increased tumor size ( P <  .001), Ki-67 levels ( P <  .001), human epidermal growth factor receptor 2 expression ( P =  .04), high grades ( P =  .03), and decreased total PR ( P =  .004) compared with PRA-H tumors. MUC-2 ( P <  .001) and KRT6A ( P =  .02) were also overexpressed in PRB-H tumors.

Conclusion

The PRA/PRB ratio is a prognostic and predictive factor for antiprogestin responsiveness in breast cancer.

Telomere-driven diseases and telomere-targeting therapies

Martínez and Blasco review the molecular mechanisms underlying diseases associated with telomere dysfunction, including telomeropathies, age-related disorders, and cancer. Current and future therapeutic strategies to treat and prevent these diseases, including preclinical development of telomere-targeted therapies using mouse models, are discussed.

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual’s lifetime. Telomere shortening is proposed to be a primary molecular cause of aging. Short telomeres block the proliferative capacity of stem cells, affecting their potential to regenerate tissues, and trigger the development of age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as telomere syndromes, including Hoyeraal-Hreidarsson syndrome, dyskeratosis congenita, pulmonary fibrosis, aplastic anemia, and liver fibrosis. Telomere shortening induces chromosomal instability that, in the absence of functional tumor suppressor genes, can contribute to tumorigenesis. In addition, mutations in telomere length maintenance genes and in shelterin components, the protein complex that protects telomeres, have been found to be associated with different types of cancer. These observations have encouraged the development of therapeutic strategies to treat and prevent telomere-associated diseases, namely aging-related diseases, including cancer. Here we review the molecular mechanisms underlying telomere-driven diseases and highlight recent advances in the preclinical development of telomere-targeted therapies using mouse models.

CMOS based image cytometry for detection of phytoplankton in ballast water

We introduce an image cytometer (I-CYT) for the analysis of phytoplankton in fresh and marine water environments. A linear quantification of cell numbers was observed covering several orders of magnitude using cultures of Tetraselmis and Nannochloropsis measured by autofluorescence in a laboratory environment. We assessed the functionality of the system outside the laboratory by phytoplankton quantification of samples taken from a marine water environment (Dutch Wadden Sea, The Netherlands) and a fresh water environment (Lake Ijssel, The Netherlands). The I-CYT was also employed to study the effects of two ballast water treatment systems (BWTS), based on chlorine electrolysis and UV sterilization, with the analysis including the vitality of the phytoplankton. For comparative study and benchmarking of the I-CYT, a standard flow cytometer was used. Our results prove a limit of detection (LOD) of 10 cells/ml with an accuracy between 0.7 and 0.5 log, and a correlation of 88.29% in quantification and 96.21% in vitality, with respect to the flow cytometry results.