Protocol for the three-dimensional analysis of rodent skeletal muscle.

Confocal imaging is a powerful tool capable of analyzing cellular spatial data within a given tissue. Here, we present a protocol for preparing optically cleared extensor digitorum longus (EDL) skeletal muscle samples suitable for confocal imaging/computational analysis. We describe steps for sample preparation (including perfusion fixation and tissue clearing of muscle samples), image acquisition, and computational analysis, with sample segmentation/3D rendering outlined.

S6K2 in Focus: Signaling Pathways, Post-Translational Modifications, and Computational Analysis.

S6 Kinase 2 (S6K2) is a key regulator of cellular signaling and is crucial for cell growth, proliferation, and survival. This review is divided into two parts: the first focuses on the complex network of upstream effectors, downstream modulators, and post-translational modifications (PTMs) that regulate S6K2 activity. We emphasize the dynamic nature of S6K2 regulation, highlighting its critical role in cellular homeostasis and its potential as a therapeutic target in diseases like cancer.

From responsibility to responsibilization in stem cell research: An ethical framework.

Adopting a responsibilization approach can further improve the ethical conduct of stem cell (SC) research and applications. This approach helps align new and existing solutions for ethical implications by focusing on equipping SC researchers with the knowledge, skills, and organizational arrangements to take (co-)responsibility for the socio-ethical implications of their research.

p63: A Master Regulator at the Crossroads Between Development, Senescence, Aging, and Cancer.

The p63 protein is a master regulatory transcription factor that plays crucial roles in cell differentiation, adult tissue homeostasis, and chromatin remodeling, and its dysregulation is associated with genetic disorders, physiological and premature aging, and cancer. The effects of p63 are carried out by two main isoforms that regulate cell proliferation and senescence. p63 also controls the epigenome by regulating interactions with histone modulators, such as the histone acetyltransferase p300, deacetylase HDAC1/2, and DNA methyltransferases.

Divergent roles of mA in orchestrating brown and white adipocyte transcriptomes and systemic metabolism.

N-methyladenosine (mA) is among the most abundant mRNA modifications, yet its cell-type-specific regulatory roles remain unclear. Here we show that mA methyltransferase-like 14 (METTL14) differentially regulates transcriptome in brown versus white adipose tissue (BAT and WAT), leading to divergent metabolic outcomes. In humans and mice with insulin resistance, METTL14 expression differs significantly from BAT and WAT in the context of its correlation with insulin sensitivity.

Ena-bile-ing liver cancer growth.

Bile acids differentially affect immune cell responses to liver cancer.

Next-generation sequencing protocol of hematopoietic stem cells (HSCs). Step-by-step overview and troubleshooting guide.

Populations of very small embryonic-like stem cells (VSELs) (CD34+lin-CD45- and CD133+lin-CD45-), circulating in the peripheral blood of adults in small numbers, have been identified in several human tissues and together with the populations of hematopoietic stem cells (HSCs) (CD34+lin-CD45+) and CD133+lin-CD45+constitute a pool of cells with self-renewal and pluripotent stem cell characteristics. Using advanced cell staining and sorting strategies, we isolated populations of VSELs and HSCs for bulk RNA-Seq analysis to compare the transcriptomic profiles of both cell populations. Libraries were prepared from an extremely small number of cells; however, their good quality was preserved, and they met the criteria for sequencing.

Predicting cell morphological responses to perturbations using generative modeling.

Advancements in high-throughput screenings enable the exploration of rich phenotypic readouts through high-content microscopy, expediting the development of phenotype-based drug discovery. However, analyzing large and complex high-content imaging screenings remains challenging due to incomplete sampling of perturbations and the presence of technical variations between experiments. To tackle these shortcomings, we present IMage Perturbation Autoencoder (IMPA), a generative style-transfer model predicting morphological changes of perturbations across genetic and chemical interventions.

Divergent destinies: insights into the molecular mechanisms underlying EPI and PE fate determination.

Mammalian pre-implantation development is entirely devoted to the specification of extra-embryonic lineages, which are fundamental for embryo morphogenesis and support. The second fate decision is taken just before implantation, as defined by the epiblast (EPI) and the primitive endoderm (PE) specification. Later, EPI forms the embryo proper and PE contributes to the formation of the yolk sac.

Crypt density and recruited enhancers underlie intestinal tumour initiation.

Oncogenic mutations that drive colorectal cancer can be present in healthy intestines for long periods without overt consequence. Mutation of Adenomatous polyposis coli (Apc), the most common initiating event in conventional adenomas, activates Wnt signalling, hence conferring fitness on mutant intestinal stem cells (ISCs). Apc mutations may occur in ISCs that arose by routine self-renewal or by dedifferentiation of their progeny.

Comparison of cellular-based therapies following a long-segmental peripheral nerve defect in a rat model.

Peripheral nerve injury (PNI) is characterized by a loss of cellular and axonal integrity, often leading to limited functional recovery and pain. Many PNIs are not amenable to repair with traditional techniques; however, cell therapies, particularly Schwann cells (SCs), offer the promise of neural tissue replacement and functional improvement. Exosomes, which carry cellular signaling molecules, can be secreted by SCs and have shown promise in PNI.

Enhancing Clinical Applications by Evaluation of Sensitivity and Specificity in Whole Exome Sequencing.

The cost-effectiveness of whole exome sequencing (WES) remains controversial due to variant call variability, necessitating sensitivity and specificity evaluation. WES was performed by three companies (AA, BB, and CC) using reference standards composed of DNA from hydatidiform mole and individual blood at various ratios. Sensitivity was assessed by the detection rate of null-homozygote (N-H) alleles at expected variant allelic fractions, while false positive (FP) errors were counted for unexpected alleles.

The transcription factor GABPA is a master regulator of naive pluripotency.

The establishment of naive pluripotency is a continuous process starting with the generation of inner cell mass (ICM) that then differentiates into epiblast (EPI). Recent studies have revealed key transcription factors (TFs) for ICM formation, but which TFs initiate EPI specification remains unknown. Here, using a targeted rapid protein degradation system, we show that GABPA is not only a regulator of major ZGA, but also a master EPI specifier required for naive pluripotency establishment by regulating 47% of EPI genes during E3.

Reducing functionally defective old HSCs alleviates aging-related phenotypes in old recipient mice.

Aging is a process accompanied by functional decline in tissues and organs with great social and medical consequences. Developing effective anti-aging strategies is of great significance. In this study, we demonstrated that transplantation of young hematopoietic stem cells (HSCs) into old mice can mitigate aging phenotypes, underscoring the crucial role of HSCs in the aging process.

Gliomagenesis mimics an injury response orchestrated by neural crest-like cells.

Glioblastoma is an incurable brain malignancy. By the time of clinical diagnosis, these tumours exhibit a degree of genetic and cellular heterogeneity that provides few clues to the mechanisms that initiate and drive gliomagenesis. Here, to explore the early steps in gliomagenesis, we utilized conditional gene deletion and lineage tracing in tumour mouse models, coupled with serial magnetic resonance imaging, to initiate and then closely track tumour formation.

Bone marrow niches orchestrate stem-cell hierarchy and immune tolerance.

Stem cells reside in specialized microenvironments, termed niches, at several different locations in tissues. The differential functions of heterogeneous stem cells and niches are important given the increasing clinical applications of stem-cell transplantation and immunotherapy. Whether hierarchical structures among stem cells at distinct niches exist and further control aspects of immune tolerance is unknown.

Epidemic Zika virus strains from the Asian lineage induce an attenuated fetal brain pathogenicity.

The 2015-2016 Zika virus (ZIKV) outbreak in the Americas revealed the ability of ZIKV from the Asian lineage to cause birth defects, generically called congenital Zika syndrome (CZS). Notwithstanding the long circulation history of Asian ZIKV, no ZIKV-associated CZS cases were reported prior to the outbreaks in French Polynesia (2013) and Brazil (2015). Whether the sudden emergence of CZS resulted from an evolutionary event of Asian ZIKV has remained unclear.

DDX18 coordinates nucleolus phase separation and nuclear organization to control the pluripotency of human embryonic stem cells.

Pluripotent stem cells possess a unique nuclear architecture characterized by a larger nucleus and more open chromatin, which underpins their ability to self-renew and differentiate. Here, we show that the nucleolus-specific RNA helicase DDX18 is essential for maintaining the pluripotency of human embryonic stem cells. Using techniques such as Hi-C, DNA/RNA-FISH, and biomolecular condensate analysis, we demonstrate that DDX18 regulates nucleolus phase separation and nuclear organization by interacting with NPM1 in the granular nucleolar component, driven by specific nucleolar RNAs.

Generation of a selective senolytic platform using a micelle-encapsulated Sudan Black B conjugated analog.

The emerging field of senolytics is centered on eliminating senescent cells to block their contribution to the progression of age-related diseases, including cancer, and to facilitate healthy aging. Enhancing the selectivity of senolytic treatments toward senescent cells stands to reduce the adverse effects associated with existing senolytic interventions. Taking advantage of lipofuscin accumulation in senescent cells, we describe here the development of a highly efficient senolytic platform consisting of a lipofuscin-binding domain scaffold, which can be conjugated with a senolytic drug via an ester bond.

Structural and functional determination of peptide versus small molecule ligand binding at the apelin receptor.

We describe a structural and functional study of the G protein-coupled apelin receptor, which binds two endogenous peptide ligands, apelin and Elabela/Toddler (ELA), to regulate cardiovascular development and function. Characterisation of naturally occurring apelin receptor variants from the UK Genomics England 100,000 Genomes Project, and AlphaFold2 modelling, identifies T89 as important in the ELA binding site, and R168 as forming extensive interactions with the C-termini of both peptides. Base editing to introduce an R/H168 variant into human stem cell-derived cardiomyocytes demonstrates that this residue is critical for receptor binding and function.

Astrocyte-derived PTN alleviates deficits in hippocampal neurogenesis and cognition in models of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease that results in motor, sensory, cognitive, and affective deficits. Hippocampal demyelination, a common occurrence in MS, is linked to impaired cognitive function and mood. Despite this, the precise mechanisms underlying cognitive impairments in MS remain elusive.

Early detection of high blood pressure from natural speech sounds with graph diffusion network.

This study presents an innovative approach to cuffless blood pressure prediction by integrating speech and demographic features. With a focus on non-invasive monitoring, especially in remote regions, our model harnesses speech signals and demographic data to accurately estimate blood pressure. We found a strong correlation between our predictive model and early-stage high blood pressure, highlighting its potential for early detection.