Stem cell implantation is a step closer to becoming the next strategy against Parkinson's disease. Two clinical trials, one in phase I and the other in phase I/II, have demonstrated their safety and potential to restore dopamine production in the brains of patients with this currently incurable neurodegenerative condition. The number of participants in the study is still small, and further research is needed to demonstrate the clinical benefits of these cell therapies.

Six main cell types form glioblastomas, the most aggressive brain cancer due to its high rate of recurrence. Of these six, quiescent cancer stem cells are responsible for resistance to therapy and the reappearance of the tumor, according to a study that identified the six groups and highlighted the importance of these stem cells for the design of more effective therapies.

Phagocytosis – eliminating millions of dead cells every day – requires specialized cells such as macrophages, the true professionals, which migrate to engulf waste and dying cells. But they are not the only ones that can perform this task, as scientists at Howard Hughes Medical Institute (HHMI) discovered when they investigated hair follicle stem cells (HFSCs), a tissue in constant regeneration, to clarify how dying cells are detected and cleared in the epithelium and the mesenchyme.

Researchers in Japan were able to transfer genes from jellyfish into common fruit flies and discovered that the transferred gene suppressed an age-related intestinal issue in the flies. The findings suggest that studying genes specific to animals with high regenerative capability like jellyfish may uncover new mechanisms for rejuvenating stem cell function and extending the healthy lifespan of unrelated organisms.

The word “niche” implies a specialized environment. But to Fiona Doetsch, the stem cell niche is anything but. For brain stem cells, “the whole organism is the niche,” Doetsch told the audience at the third plenary session of the International Society for Stem Cell Research (ISSCR) annual meeting in Hamburg this week. It’s a surprising idea at first, given the brain’s protection from many circulating substances via a series of barriers, including the blood-brain barrier and the blood-cerebrospinal fluid barrier.

Japanese researchers have transplanted human induced pluripotent stem cells (iPSCs) in a primate model of myocardial infarction and were able to restore heart muscle and function in monkeys. Developed by Tokyo-based Heartseed Inc., the grafted iPSCs consist of clusters of purified heart muscle cells (cardiomyocyte spheroids) that are injected into the myocardial layer of the heart. Published in Circulation on April 26, 2024, the study showed that the cardiomyocyte spheroids survived long term and showed improved contractile function with low occurrence of post-transplant arrhythmias.

Investigators at the Chinese Academy of Sciences have generated a chimeric monkey by injecting an embryonic stem cell into the morula, which is an extremely early embryo consisting of 16 to 32 cells. The animal survived for only 10 days, and it is not the first live birth of a chimeric primate. But it is the first such chimera with contributions from an embryonic stem cell, and that stem cell contributed a far higher proportion of cells in the newborn than have been achieved in previous attempts at creating chimeras.

The development of an embryo in its early stages involves a series of processes in which cells interact and organize to form tissues. In humans, these stages are studied with animal models, stem cells and cell aggregates that mimic natural development phases, or with human embryos, depending on their availability and a strict protocol. Now, in back-to-back papers published online in Nature, scientists from Yale University and the University of Cambridge have two new embryonic models formed from human stem cells to study development after embryo implantation in the uterus.

An international team of researchers has created two bat stem cell lines that reveal an unusual number of viral sequences in bat cells compared with those of other mammals. Writing in an article posted online Feb. 21, 2023, in Cell, the scientists suggested that the unusual amount of viral genetic material found in the bat stem cells could explain why these mammals are largely unaffected by most viral infections, despite being able to transmit them.

The first in vivo cell atlas of senescent tissue in skeletal muscle has identified the damaging properties of these cells and explained why they block muscle regeneration. According to a study at Pompeu Fabra University led by scientists from Altos Labs Inc., cell damage caused the senescence of the cells, which secreted toxic substances into the surrounding microenvironment, causing fibrosis and preventing tissue regeneration.