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.

A group of scientists from Basel University Hospital have designed an antibody-drug conjugate (ADC) that eliminated blood cancer cells without attacking healthy hematopoietic stem cells (HSCs), which they modified by base editing and transplanted to renew an altered blood system. They achieved this by focusing on the panhematopoietic marker CD45.

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.

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.

Iron regulates the metabolism of hematopoietic stem cells (HSCs) and acts as a genetic control of their fate, preserving their identity and regenerative capacity during tissue maintenance and repair. A group of scientists at Albert Einstein College of Medicine has described the key components of a molecular pathway that iron regulates. “What we are proposing here with this mechanism is that iron serves like a switchboard and a sensor,” senior author Britta Will told BioWorld. Will is at the Department of Oncology, the Cell Biology Department, and the Ruth and David Gottesman Institute for Stem Cell Research and Regenerative Medicine at Albert Einstein College of Medicine.

Reprogramming techniques to generate functional neurons could improve neurodegeneration in the future. A group of researchers from the Institute for Stem Cell Research (ISF) in Germany have found the pathways that play a role in improving the conversion of astrocytes into neurons.

The generation of in vitro small blood vessels mimicking the alterations of cerebral small vessel disease (CSVD) allowed a British research group to identify a way to seal leaks to treat conditions such as stroke or vascular dementia. The inhibition of matrix metalloproteinases (MMPs), enzymes that participate in the formation of new vessels, restored the normal union of the cells, preventing the permeability of the system.

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.

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.

Scientists at the Guangzhou Institutes of Biomedicine and Health have developed a humanized kidney at the mesonephros stage in pig embryos up to day 28 of gestation. It is the first time that this has been achieved in chimeric xenotransplants.