Inhibition of PKCε induces primordial germ cell reprogramming into pluripotency by HIF1&2 upregulation and histone acetylation

Historically, primordial germ cells (PGCs) have been a good model to study pluripotency. Despite their low numbers and limited accessibility in the mouse embryo, they can be easily and rapidly reprogrammed at high efficiency with external physicochemical factors and do not require transcription factor transfection. Employing this model to deepen our understanding of cell reprogramming, we specifically aimed to determine the relevance of Ca2+ signal transduction pathway components in the reprogramming process. Our results showed that PGC reprogramming requires a normal extracellular [Ca2+] range, in contrast to neoplastic or transformed cells, which can continue to proliferate in Ca2+-deficient media, differentiating normal reprogramming from neoplastic transformation. Our results also showed that a spike in extracellular [Ca2+] of 1-3 mM can directly reprogram PGC. Intracellular manipulation of Ca2+ signal transduction pathway components revealed that inhibition of classical Ca2+ and diacylglycerol (DAG)-dependent PKCs, or intriguingly, of only the novel DAG-dependent PKC, PKCε, were able to induce reprogramming. PKCε inhibition changed the metabolism of PGCs toward glycolysis, increasing the proportion of inactive mitochondria. This metabolic switch from oxidative phosphorylation to glycolysis is mediated by hypoxia-inducible factors (HIFs), given we found upregulation of both HIF1α and HIF2α in the first 48 hours of culturing. PKCε inhibition did not change the classical pluripotency gene expression of PGCs, Oct4, or Nanog. PKCε inhibition changed the histone acetylation of PGCs, with histones H2B, H3, and H4 becoming acetylated in PKCε-inhibited cultures (markers were H2BacK20, H3acK9, and H4acK5K8, K12, K16), suggesting that reprogramming by PKCε inhibition is mediated by histone acetylation

Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke

Background and Objectives Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke. Methods We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18-59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS. Results We observed genome-wide significant associations of EOS with 2 variants in ABO, a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85-0.91) in EOS vs 0.96 (95% CI: 0.92-1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11-1.21) for EOS vs 1.05 (0.99-1.11) in LOS; p-values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS (p = 0.008). Discussion The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.Peer reviewe

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Stroke genetics informs drug discovery and risk prediction across ancestries

Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries

Derivation of Limbal Stem Cells from Human Adult Mesenchymal Stem Cells for the Treatment of Limbal Stem Cell Deficiency

Approximately 10 million individuals have blindness due to limbal stem cell (LSCs) deficiency, one of the most challenging problems in ophthalmology. To replenish the LSC pool, an autologous extraocular cell source is appropriate, thereby avoiding the risk of immune rejection, the need for immunosuppression and the risk of damaging the contralateral eye. In recent years, adipose-derived mesenchymal stem cells (ADSCs) have been a key element in ocular regenerative medicine. In this study, we developed a protocol for deriving human LSCs from ADSCs compatible with the standard carrier human amniotic membrane, helping provide a stem cell pool capable of maintaining proper corneal epithelial homeostasis. The best protocol included an ectodermal induction step by culturing ADSCs with media containing fetal bovine serum, transforming growth factor-β inhibitor SB-505124, Wnt inhibitor IWP-2 and FGF2 for 7 days, followed by an LSC induction step of culture in modified supplemental hormonal epithelial medium supplemented with pigment epithelium-derived factor and keratinocyte growth factor for 10 additional days. The optimal differentiation efficiency was achieved when cells were cultured in this manner over vitronectin coating, resulting in up to 50% double-positive αp63/BMI-1 cells. The results of this project will benefit patients with LSC deficiency, aiding the restoration of vision

Improvement of an Effective Protocol for Directed Differentiation of Human Adipose Tissue-Derived Adult Mesenchymal Stem Cells to Corneal Endothelial Cells

Corneal disease affects 12.5 million individuals worldwide, with 2 million new cases each year. The standard treatment consists of a corneal transplantation from a human donor; however, the worldwide demand significantly exceeds the available supply. Lamellar endothelial keratoplasty, the replacement of only the endothelial layer of the cornea, can partially solve the problem. Progressive efforts have succeeded in expanding hCECs; however, the ability to expand hCECs is still limited, and new sources of CECs are being sought. Crucial advances have been achieved by the directed differentiation of embryonic or induced pluripotent stem cells, but these cells have disadvantages, such as the use of oncogenes, and are still difficult to establish. We aimed to transfer such knowledge to obtain hCECs from adipose tissue-derived adult mesenchymal stem cells (ADSC) by modifying four previously published procedures. We present several protocols capable of the directed differentiation of human ADSCs to hCECs. In our hands, the protocol by Ali et al. was the best adapted to such differentiation in terms of efficiency, time, and financial cost; however, the protocol by Wagoner et al. was the best for CEC marker expression. Our results broaden the type of cells of autologous extraocular origin that could be employed in the clinical setting for corneal endothelial deficiency

Predictors of cardiovascular events and all-cause of death in patients with transfusion-dependent myelodysplastic syndrome

Cardiovascular disease (CVD) involves the second cause of death in low-risk myelodysplastic syndrome (MDS) population. Prospective study to characterise the CVD and to identify predictors for the combined event (CE) cardiovascular event and/or all-cause mortality in transfusion dependent low-risk MDS patients. Thirty-one patients underwent a cardiac assessment including biomarkers and cardiac magnetic resonance (cMR) with parametric sequences (T1, T2 and T2* mapping) and myocardial deformation by feature tracking (FT) and were analysed for clonal hematopoiesis of indeterminate potential mutations. Cardiac assessment revealed high prevalence of unknown structural heart disease (51% cMR pathological findings). After 2·2 [0·44] years follow-up, 35·5% of patients suffered the CE: 16% death, 29% cardiovascular event. At multivariate analysis elevated NT-proBNP ≥ 486pg/ml (HR 96·7; 95%-CI 1·135–8243; P = 0·044), reduced native T1 time < 983ms (HR 44·8; 95%-CI 1·235–1623; P = 0·038) and higher left ventricular global longitudinal strain (LV-GLS) (HR 0·4; 95%-CI 0·196–0·973; P = 0·043) showed an independent prognostic value. These variables, together with the myocardial T2* time < 20ms, showed an additive prognostic value (Log Rank: 12·4; P = 0·001). In conclusion, low-risk MDS patients frequently suffer CVD. NT-proBNP value, native T1 relaxation time and longitudinal strain by FT are independent predictors of poor cardiovascular prognosis, thus, their determination would identify high-risk patients who could benefit from a cardiac treatment and follow-up.This work was funded by aGerencia Regional de Salud de Castilla y León grant(GRS1203/A/15) and a Rıo Hortega contract (CM19/00055),supported by the Instituto de Salud Carlos III in Spain (co-funded by the European Social Fund ‘Investing in yourfuture’)

„Iron Heart”: Reversible Cause of Dilated Cardiomyopathy Secondary to Cardiac Toxicity in Elderly Patient with Myelodysplastic Syndrome

Triptorelin as the luteinizing hormone releasing hormone (LHRH) analogue has its own place among other available forms of androgen-depravation therapy (ADT) of locally advanced and metastatic prostate cancer (PCa). Nowadays, in times of development of new therapies in castration-resistant PCa, ADT remains the back bone therapy, which may be supplemented with one of novel drugs. The results of basic research indicate, that apart from the main mechanism of action based on lowering a testosterone concentration to the castration level, triptorelin may have a direct inhibitory effect on tumor cells. Formulations of tryptorelin are available to administer as 1-month, 3-months and 6-months sustained-release forms that may be given intramuscularly or subcutaneously. Constant concentration of triptoreline is maintained by using special microspheres in drug production. Pharmacokinetic and pharmacodynamic properties of particular forms were extensively tested, which allows for safe usage and retain of predictable and high efficacy. Indicators of effective ADT are fast reduction and maintenance of the state of castration. This phenomenon translates into a decrease of the prostate-specific antigen and longer survival. Triptorelin successfully meets these objectives based on a number of phase I–III studies. There is a noticeable lack of comparative studies on effectiveness of particular ADT forms. This may stem from an assumption, that all LHRH analogues demonstrate similar effectiveness because of the class effect. However, some evidence highlight significant differences in efficacy among these drugs. Triptorelin compares especially favourably, particularly as a drug reducing the testosterone level to the lower recommended values (< 20 ng/dl). Side effect profile during the therapy with triptorelin is largely the result of inhibition of the hypothalamic- pituitary-testicular axis. Hormonal disturbances linked to hipoandrogenism cause changes in lipid metabolism and glucose tolerance, which may influence the cardiovascular risk. This article is a review of key reports regarding triptorelin and a summary of the role that triptorelin plays in contemporary ADT in advanced PCa

Treatment of corneal endothelial damage in a rabbit model with a bioengineered graft using human decellularized corneal lamina and cultured human corneal endothelium.

ObjectiveWe aimed to investigate the functionality of human decellularized stromal laminas seeded with cultured human corneal endothelial cells as a tissue engineered endothelial graft (TEEK) construct to perform endothelial keratoplasty in an animal model of corneal endothelial damage.MethodsEngineered corneal endothelial grafts were constructed by seeding cultured human corneal endothelial cell (hCEC) suspensions onto decellularized human corneal stromal laminas with various coatings. The functionality and survival of these grafts with cultured hCECs was examined in a rabbit model of corneal endothelial damage after central descemetorhexis. Rabbits received laminas with and without hCECs (TEEK and control group, respectively).ResultshCEC seeding over fibronectin-coated laminas provided an optimal and consistent endothelial cell count density and polygonal shape on the decellularized laminas, showing active pump fuction. Surgery was performed uneventfully as standard Descemet stripping automated endothelial keratoplasty (DSAEK). Corneal transparency gradually recovered in the TEEK group, whereas haze and edema persisted for up to 4 weeks in the controls. Histologic examination showed endothelial cells of human origin covering the posterior surface of the graft in the TEEK group.ConclusionsGrafting of decellularized stroma carriers re-surfaced with human corneal endothelial cells ex vivo can be a readily translatable method to improve visual quality in corneal endothelial diseases