Biomaterials for tissue regeneration must mimic the biophysical properties of the native physiological environment. A protein engineering approach allows the generation of protein hydrogels with specific and customised biophysical properties designed to suit a particular physiological environment. Herein, repetitive engineered proteins were successfully designed to form covalent molecular networks with defined physical characteristics able to sustain cell phenotype. Our hydrogel design was made possible by the incorporation of the SpyTag (ST) peptide and multiple repetitive units of the SpyCatcher (SC) protein that spontaneously formed covalent crosslinks upon mixing. Changing the ratios of the protein building blocks (ST:SC), allowed the viscoelastic properties and gelation speeds of the hydrogels to be altered and controlled. The physical properties of the hydrogels could readily be altered further to suit different environments by tuning the key features in the repetitive protein sequence. The resulting hydrogels were designed with a view to allow cell attachment and encapsulation of liver derived cells. Biocompatibility of the hydrogels was assayed using a HepG2 cell line constitutively expressing GFP. The cells remained viable and continued to express GFP whilst attached or encapsulated within the hydrogel. Our results demonstrate how this genetically encoded approach using repetitive proteins could be applied to bridge engineering biology with nanotechnology creating a level of biomaterial customisation previously inaccessible.

As concerns related to the COVID-19 pandemic continue, it is critical to understand the impact of vaccination type on neutralizing antibody response durability as well as to identify individual difference factors related to decline in neutralization. This was a head-to-head comparison study following 498 healthy, community volunteers who received the BNT162b2 (n = 287), mRNA-1273 (n = 149), and Ad26.COV2.S (n = 62). Participants completed questionnaires and underwent blood draws prior to vaccination, 1 month, and 6 months after the vaccination series, and neutralizing antibody (nAB) titers at 1- and 6-months post vaccination were quantified using a high-throughput pseudovirus assay. Over 6 months of follow-up, nABs declined in recipients of BNT162b2 and mRNA-1273, while nABs in recipients of Ad26.COV2.S showed a significant increase. At the 6-month time point, nABs to Ad26.COV2.S were significantly higher than nABs to BNT162b2 and equivalent to mRNA-1273. Irrespective of follow-up timing, being older was associated with lower nAB for participants who received BNT162b2 and Ad26.COV2.S but not for those who received mRNA-1273. A higher baseline BMI was associated with a lower nAB for Ad26.COV2.S recipients but not for recipients of other vaccines. Women and non-smokers showed higher nAB compared to men and current smokers, respectively. The durability of neutralizing antibody responses differed by vaccine type and several sociodemographic factors that predicted response. These findings may inform booster recommendations in the future.

Telomere length (TL) is a marker of biological aging, and shorter telomeres have been associated with several medical and psychiatric disorders, including cardiometabolic dysregulation and Major Depressive Disorder (MDD). In addition, studies have shown shorter TL to be associated with poorer response to certain psychotropic medications, and our previous work suggested shorter TL and higher telomerase activity (TA) predicts poorer response to Selective Serotonin Reuptake Inhibitor (SSRI) treatment. Using a new group of unmedicated medically healthy individuals with MDD (n = 48), we sought to replicate our prior findings demonstrating that peripheral blood mononuclear cell (PBMC) TL and TA predict response to SSRI treatment and to identify associations between TL and TA with biological stress mediators and cardiometabolic risk indices. Our results demonstrate that longer pre-treatment TL was associated with better response to SSRI treatment ( β = .407 p = .007). Additionally, we observed that TL had a negative relationship with allostatic load ( β = − .320 p = .017) and a cardiometabolic risk score (β = − .300 p = .025). Our results suggest that PBMC TL reflects, in part, the cumulative effects of physiological stress and cardiovascular risk in MDD and may be a biomarker for predicting SSRI response.

Did you know that your daily choices, including how much you exercise, what you eat, and even how you think, can change the basic units that are present in your cells? In this article, I will tell you about telomeres, which are the protective tips of DNA molecules—the molecules where the organism’s genes are stored. I will also introduce you to an enzyme that we discovered, called telomerase, which is responsible for the addition and maintenance of telomeres. After diving into the molecular details of telomeres and telomerase, I will reveal to you some very interesting connections between telomeres and human health. I hope, by the end of this article, you will be amazed by the way in which psychological, environmental, and societal factors can influence the fundamentals of our biology.

Discussion, Figures and legends

Related Article from Walking the Walk from Genes through Telomere Maintenance to Cancer Risk

Supplementary Figures 1-5 from Assembly of Mutant-Template Telomerase RNA into Catalytically Active Telomerase Ribonucleoprotein That Can Act on Telomeres Is Required for Apoptosis and Cell Cycle Arrest in Human Cancer Cells

Centromere association of the chromosomal passenger complex (CPC; Borealin-Survivin-INCENP-Aurora B) and Sgo1 is crucial for chromosome biorientation, a process essential for error-free chromosome segregation. Phosphorylated histone H3 Thr3 (H3T3ph; directly recognized by Survivin) and histone H2A Thr120 (H2AT120ph; indirectly recognized via Sgo1), together with CPC's intrinsic nucleosome-binding ability, facilitate CPC centromere recruitment. However, the molecular basis for CPC-Sgo1 binding and how their physical interaction influences CPC centromere localization are lacking. Here, using an integrative structure-function approach, we show that the "histone H3-like" Sgo1 N-terminal tail-Survivin BIR domain interaction acts as a hotspot essential for CPC-Sgo1 assembly, while downstream Sgo1 residues and Borealin contribute for high-affinity binding. Disrupting Sgo1-Survivin interaction abolished CPC-Sgo1 assembly and perturbed CPC centromere localization and function. Our findings reveal that Sgo1 and H3T3ph use the same surface on Survivin to bind CPC. Hence, it is likely that these interactions take place in a spatiotemporally restricted manner, providing a rationale for the Sgo1-mediated "kinetochore-proximal" CPC centromere pool.

The Chromosomal Passenger Complex (CPC; consisting of Borealin, Survivin, INCENP and Aurora B kinase) and Shugoshin 1 (Sgo1) are key regulators of chromosome bi-orientation, a process essential for error-free chromosome segregation. Their functions rely on their ability to associate with centromeres. Two histone phosphorylations, histone H3 Thr3 (H3T3ph; directly recognised by Survivin) and histone H2A Thr120 (H2AT120ph; indirectly recognised via Sgo1), together with CPC’s intrinsic ability to bind nucleosome, facilitate CPC centromere recruitment. The molecular basis for CPC-Sgo1 binding and how their direct interaction influences CPC centromere localisation and function are lacking. Here, using an integrative structure-function approach, we show that the histone H3-like Sgo1 N-terminal tail interacts with Survivin acting as a hot-spot for CPC-Sgo1 assembly, while downstream Sgo1 residues, mainly with Borealin contributes for high affinity interaction. Disruption of the Sgo1 N-terminal tail-Survivin interaction abolished CPC-Sgo1 assembly in vitro and perturbed centromere localisation and function of CPC. Our findings provide evidence that CPC binding to Sgo1 and histone H3 N-terminal tail are mutually exclusive, suggesting that these interactions will likely take place in a spatially/temporally restricted manner and provide a rationale for the Sgo1-mediated ‘kinetochore proximal centromere’ pool of CPC.

Peptides with pan-antimicrobial affinity were synthesized and decorated with environmentally sensitive fluorophores nitrobenzoxadiazole (green) and merocyanine (red). The labeling efficacies against a range of clinically relevant fungal and Gram-negative and positive bacterial species (Candida albicans, Escherichia coli, and Staphylococcus aureus) were explored. The fluorogenic probes containing exclusively l or d-amino acids showed rapid and efficient labeling of all microbial species, whereas probes with a mixture of l or d-amino acids failed to label fungi or bacteria, highlighting the importance of the alpha-helical peptide structure for interaction with the microbial cell membrane. Importantly, the nature of the dye allowed fluorescence detection/labeling without the need for a wash step, paving the way for direct application of the probes.

The parasitic protist Trypanosoma brucei is the causative agent of Human African Trypanosomiasis, also known as sleeping sickness. The parasite enters the blood via the bite of the tsetse fly where it is wholly reliant on glycolysis for the production of ATP. Glycolytic enzymes have been regarded as challenging drug targets because of their highly conserved active sites and phosphorylated substrates. We describe the development of novel small molecule allosteric inhibitors of trypanosome phosphofructokinase (PFK) that block the glycolytic pathway resulting in very fast parasite kill times with no inhibition of human PFKs. The compounds cross the blood brain barrier and single day oral dosing cures parasitaemia in a stage 1 animal model of human African trypanosomiasis. This study demonstrates that it is possible to target glycolysis and additionally shows how differences in allosteric mechanisms may allow the development of species-specific inhibitors to tackle a range of proliferative or infectious diseases.

Lymphostatin (LifA) is a 366 kDa protein expressed by attaching & effacing Escherichia coli. It plays an important role in intestinal colonisation and inhibits the mitogen- and antigen-stimulated proliferation of lymphocytes and the synthesis of proinflammatory cytokines. LifA exhibits N-terminal homology with the glycosyltransferase domain of large clostridial toxins (LCTs). A DTD motif within this region is required for lymphostatin activity and binding of the sugar donor uridine diphosphate N-acetylglucosamine. As with LCTs, LifA also contains a cysteine protease motif (C1480, H1581, D1596) that is widely conserved within the YopT-like superfamily of cysteine proteases. By analogy with LCTs, we hypothesised that the CHD motif may be required for intracellular processing of the protein to release the catalytic N-terminal domain after uptake and low pH-stimulated membrane insertion of LifA within endosomes. Here, we created and validated a C1480A substitution mutant in LifA from enteropathogenic E. coli strain E2348/69. The purified protein was structurally near-identical to the wild-type protein. In bovine T lymphocytes treated with wild-type LifA, a putative cleavage product of approximately 140 kDa was detected. Appearance of the putative cleavage product was inhibited in a concentration-dependent manner by bafilomycin A1 and chloroquine, which inhibit endosome acidification. The cleavage product was not observed in cells treated with the C1480A mutant of LifA. Lymphocyte inhibitory activity of the purified C1480A protein was significantly impaired. The data indicate that an intact cysteine protease motif is required for cleavage of lymphostatin and its activity against T cells.

Background: Psychological stress is a risk factor for major adverse cardiovascular events in individuals with coronary artery disease (CAD). Accelerated biological aging, as indicated by telomere shortening, is a recognized pathway by which stress may lead to cardiovascular disease incidence and mortality. We sought to investigate brain correlates of acute psychological stress and short telomeres in men and women with CAD. Methods: Individuals with CAD (N = 170) underwent a validated mental stress protocol including public speaking and mental arithmetic. Imaging of the brain with [O-15] water positron emission tomography (PET) was performed during mental stress and control conditions. Telomere length in peripheral leucocytes was measured by quantitative PCR and expressed as T/S-units. Voxel-wise regression models were constructed to assess the association between brain areas and activity during rest and mental stress after adjustments for demographic factors and clinical characteristics. Methods: The mean (SD) age was 62 (8) years, and 69% were men. The median telomere length was 0.84 T/S-units. Increased activation with mental stress in the lingual gyrus, cerebellum and superior and inferior gyrus in the frontal lobe were associated with reduced telomere length; 1.6 higher voxel activation of the inferior frontal gyrus was associated with 0.1 T/S-units reduction in telomere length (P < 0.005). Additionally, higher resting activities of the precentral, middle and superior frontal gyri and middle temporal gyri were associated with short telomeres. Results remained consistent after adjustment for demographic and clinical risk factors. Conclusion: Increased resting brain activity and reactivity to mental stress within the frontal lobe is associated with short telomeres. These frontal areas may regulate biological aging at rest and in connection with stress, which may contribute to cardiovascular vulnerability.

During cell division, misaligned chromosomes are captured and aligned by motors before their segregation. The CENP-E motor is recruited to polar unattached kinetochores, to facilitate chromosome alignment. The spindle checkpoint protein BubR1 has been reported as a CENP-E interacting partner, but to what extent, if at all, BubR1 contributes to CENP-E localization at kinetochores, has remained controversial. Here we define the molecular determinants that specify the interaction between BubR1 and CENP-E. The basic C-terminal helix of BubR1 is necessary but not sufficient for CENP-E interaction, while a minimal key acidic patch on the kinetochore-targeting domain of CENP-E, is also essential. We then demonstrate that BubR1 is required for the recruitment of CENP-E to kinetochores to facilitate chromosome alignment. This BubR1-CENP-E axis is critical to align chromosomes that have failed to congress through other pathways and recapitulates the major known function of CENP-E. Overall, our studies define the molecular basis and the function for CENP-E recruitment to BubR1 at kinetochores during mammalian mitosis.

OBJECTIVE:In the context of the importance of elucidating the determinants of the initial, newborn setting of telomere length (TL), it is increasingly evident that maternal stress and stress-related processes during pregnancy play a major role. Although psychological resilience may function as a buffer, research in this area has not yet examined its potential role vis-à-vis that of stress. The authors examined the relationship between maternal psychological resilience during pregnancy and newborn TL.METHODS:In a sample of 656 mother-child dyads from the Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction cohort, multiple serial assessments were conducted over the course of pregnancy to quantify maternal stress, negative and positive emotional responses to pregnancy events, positive affect, and perceived social support. Principal component analysis identified two latent factors: stress and positivity. A measure of resilience was computed by regressing the positivity factor on the stress factor, in order to quantify positivity after accounting for stress. TL was measured using quantitative polymerase chain reaction in leukocytes extracted from cord blood shortly after birth. Linear regression was used to predict newborn TL from maternal resilience during pregnancy, adjusting for other potential determinants.RESULTS:Maternal stress significantly predicted shorter newborn TL (β=-0.079), and positivity significantly predicted longer TL (β=0.135). Maternal resilience (positivity accounting for stress) was significantly and positively associated with newborn TL (β=0.114, 95% CI=0.035, 0.189), with each standard deviation increase in resilience predicting 12% longer newborn TL.CONCLUSIONS:The results indicate that maternal psychological resilience may exert a salubrious effect on offspring telomere biology and highlight the importance of enhancing maternal mental health and well-being during pregnancy.

Introduction: Telomere biology plays a fundamental role in maintaining the integrity of the genome and cell, and shortened telomeres have been linked to several age-related diseases. The initial (newborn) telomere length (TL) represents a critically important feature of the telomere biology system. Exposure to a variety of adverse prenatal conditions such as maternal stress, suboptimal diet, obesity, and obstetric complications, is associated with shorter offspring TL at birth and in adult life. Many, if not all, of these exposures are believed to have an inflammatory component. In this context, stress-related immunological processes during pregnancy may constitute a potential additional biological pathway because they can affect telomere length and telomerase activity via transcriptions factors such as cyclic adenosine monophosphate-dependent transcription factor (ATF7) and nuclear factor-kappa B (NF-kappa B). Thus, in the present study we examined the hypothesis that maternal pro-inflammatory state across pregnancy, operationalized as the balance between tumor necrosis factor (TNF)-alpha, a major pro-inflammatory cytokine, and interleukin-10 (IL-10), the major anti-inflammatory cytokine, is associated with newborn leukocyte telomere length (LTL) at birth. Methods and Materials: Participants were healthy women (N = 112) recruited in early pregnancy. Concentrations of TNF-alpha and IL-10 were quantified in early, mid and late pregnancy from maternal blood samples. Telomere length was assessed in newborn blood samples soon after birth. Results: After adjusting for maternal age, maternal pre-pregnancy BMI, birth weight percentile, and infant sex, a higher mean TNF-alpha/IL-10 ratio across pregnancy was significantly associated with shorter newborn TL (beta = -.205, p = .030). Newborn TL was, on average, 10% shorter in offspring of women in the upper compared to lower quartile of the TNF-alpha/IL-10 ratio during pregnancy. Discussion: These findings provide new evidence in humans for a potential "programming" mechanism linking maternal systemic pro-inflammatory processes during pregnancy with the initial (newborn) setting of her offspring's telomere system.