Related Articles

A first-in-human study of quantitative ultrasound to assess transplant kidney fibrosis

Kidney transplantation is the optimal treatment for renal failure. In the United States, a biopsy at the time of organ procurement is often used to assess kidney quality to decide whether it should be used for transplant. This assessment is focused on renal fibrotic burden, because fibrosis is an important measure of irreversible kidney injury. Unfortunately, biopsy at the time of transplant is plagued by problems, including bleeding risk, inaccuracies introduced by sampling bias and rapid sample preparation, and the need for round-the-clock pathology expertise. We developed a quantitative algorithm, called renal H-scan, that can be added to standard ultrasound workflows to quickly and noninvasively measure renal fibrotic burden in preclinical animal models and human transplant kidneys. Furthermore, we provide evidence that biopsy-based fibrosis estimates, because of their highly localized nature, are inaccurate measures of whole-kidney fibrotic burden and do not associate with kidney function post-transplant. In contrast, we show that whole-kidney H-scan fibrosis estimates associate closely with post-transplant renal function. Taken together, our data suggest that the addition of H-scan to standard ultrasound workflows could provide a safe, rapid and easy-to-perform method for accurate quantification of transplant kidney fibrotic burden, and thus better prediction of post-transplant renal outcomes.

Recommendations for mitochondria transfer and transplantation nomenclature and characterization

Intercellular mitochondria transfer is an evolutionarily conserved process in which one cell delivers some of their mitochondria to another cell in the absence of cell division. This process has diverse functions depending on the cell types involved and physiological or disease context. Although mitochondria transfer was first shown to provide metabolic support to acceptor cells, recent studies have revealed diverse functions of mitochondria transfer, including, but not limited to, the maintenance of mitochondria quality of the donor cell and the regulation of tissue homeostasis and remodelling. Many mitochondria-transfer mechanisms have been described using a variety of names, generating confusion about mitochondria transfer biology. Furthermore, several therapeutic approaches involving mitochondria-transfer biology have emerged, including mitochondria transplantation and cellular engineering using isolated mitochondria. In this Consensus Statement, we define relevant terminology and propose a nomenclature framework to describe mitochondria transfer and transplantation as a foundation for further development by the community as this dynamic field of research continues to evolve.

Sensory input, sex and function shape hypothalamic cell type development

Mammalian behaviour and physiology undergo major changes in early life. Young animals rely on conspecifics to meet their needs and start showing nutritional independence and sex-specific social interactions at weaning and puberty, respectively. How neuronal populations regulating homeostatic functions and social behaviours develop during these transitions remains unclear. We used paired transcriptomic and chromatin accessibility profiling to examine the developmental trajectories of neuronal populations in the hypothalamic preoptic region, where cell types with key roles in physiological and behavioural control have been identified1,2,3,4,5,6. These data show a marked diversity of developmental trajectories shaped by the sex of the animal, and the location and behavioural or physiological function of the corresponding cell types. We identify key stages of preoptic development, including early diversification, perinatal emergence of sex differences, postnatal maturation and refinement of signalling networks, and nonlinear transcriptional changes accelerating at the time of weaning and puberty. We assessed preoptic development in various sensory mutants and find a major role for vomeronasal sensing in the timing of preoptic cell type maturation. These results provide new insights into the development of neurons controlling homeostatic functions and social behaviours and lay ground for examining the dynamics of these functions in early life.

The 2023 EBMT report on hematopoietic cell transplantation and cellular therapies. Increased use of allogeneic HCT for myeloid malignancies and of CAR-T at the expense of autologous HCT

In 2023, 47,731 HCT (20,485 (42.9%) allogeneic and 27,246 (57.1%) autologous) in 43,902 patients were reported by 696 European centers. 6042 patients received advanced cellular therapies, 4888 of which were CAR-T. Compared to the previous year there was an increase in CAR-T (+52.5%), in allogeneic HCT (+7.8%) but none in autologous HCT (+0.4%). Main indications for allogeneic HCT were myeloid (11,748; 60.7%), lymphoid malignancies (4,850; 25.0%), and non-malignant disorders (2558; 13.2%). Use of allogeneic HCT increased for AML (+12.1%) and for NHL (+11.0%), particularly in T-NHL (+25.6%). Main indications for autologous HCT were lymphomas (7890; 32.2%), PCD (14,271; 58.2%), and solid tumors (1608; 6.6%) with recovering numbers for autoimmune diseases. In patients with allogeneic HCT, the use of sibling donors increased by +1.0%, haploidentical donors by +11.7%, and unrelated donors by +11.1%. Cord blood HCT decreased again by −5.4%. Pediatric HCT activity increased slightly (5455; +0.1%) with differences between allogeneic (4111; −0.5%) and autologous HCT (1344: +1.7%). Use of CAR-T increased to a cumulative total of 13,927 patients including patients treated for autoimmune diseases. Overall, numbers show a complete recovery from the pandemic dip with increased cellular therapy at the expense of autologous HCT. Allogeneic HCT activity focuses on myeloid malignancies.

Coupling of cell shape, matrix and tissue dynamics ensures embryonic patterning robustness

Tissue patterning coordinates morphogenesis, cell dynamics and fate specification. Understanding how precision in patterning is robustly achieved despite inherent developmental variability during mammalian embryogenesis remains a challenge. Here, based on cell dynamics quantification and simulation, we show how salt-and-pepper epiblast and primitive endoderm (PrE) cells pattern the inner cell mass of mouse blastocysts. Coupling cell fate and dynamics, PrE cells form apical polarity-dependent actin protrusions required for RAC1-dependent migration towards the surface of the fluid cavity, where PrE cells are trapped due to decreased tension. Concomitantly, PrE cells deposit an extracellular matrix gradient, presumably breaking the tissue-level symmetry and collectively guiding their own migration. Tissue size perturbations of mouse embryos and their comparison with monkey and human blastocysts further demonstrate that the fixed proportion of PrE/epiblast cells is optimal with respect to embryo size and tissue geometry and, despite variability, ensures patterning robustness during early mammalian development.

Responses

Your email address will not be published. Required fields are marked *