A modified version of CRISPR-Cas9 has enabled, for the first time, the efficient integration of a large transgene capable of inactivating entire chromosomes into one of the three copies of chromosome 21 in Down syndrome-derived cells. The goal is to silence the extra copy to limit the gene-dosage imbalance that drives many features of trisomy 21. Researchers at Beth Israel Deaconess Medical Center turned to XIST, the long noncoding RNA responsible for the natural silencing of the X chromosome in females. Using this strategy, they achieved integration efficiencies of 20% to 40% and a partial reduction in the overexpression of chromosome 21 genes.

Genes that are switched on or off in the human brain differ between men and women. Moreover, these differences are not uniform. They vary across cortical regions and cell types. Scientists at the National Institute of Mental Health (NIMH) and the National Institute on Aging (NIA) used single-cell sequencing and unveiled distinct gene expression patterns regulated by hormones and sex chromosomes. This detailed map of the brain’s molecular biology shows how women and men switch on and off more than 3,000 brain genes differently and expands the catalogue of X chromosome genes that escape inactivation.

The loss of regenerative capacity in mammals over the course of evolution may be linked to certain environmental conditions rather than to a genetic limitation. Tissue stiffness around an amputated area, oxygen availability, or epigenetic regulation could determine this ability, according to two simultaneously published but independent studies published in Science, as reported by BioWorld yesterday.

The loss of regenerative capacity in mammals over the course of evolution may be linked to certain environmental conditions rather than to a genetic limitation. Tissue stiffness around an amputated area, oxygen availability, or epigenetic regulation could determine this ability, according to two simultaneously published but independent studies published in Science today.

A smart polymer contact lens measures intraocular pressure (IOP) in real time and automatically releases medication into the eye when IOP goes beyond a critical limit. This technological advance, developed by scientists at the Terasaki Institute for Biomedical Innovation (TIBI), could enable personalized glaucoma therapy, avoiding poor patient adherence to their prescribed regimen and eliminating the need for bulky electronic devices. Animal models tolerate it well and, although the load is concentrated at the edges of the lens, it is still unknown how it could affect visual acuity.

A smart polymer contact lens measures intraocular pressure (IOP) in real time and automatically releases medication into the eye when IOP goes beyond a critical limit. This technological advance, developed by scientists at the Terasaki Institute for Biomedical Innovation, could enable personalized glaucoma therapy.

Certain cancers, such as triple-negative breast cancer, produce antibodies that, although they help fight the tumor, can cross the blood-brain barrier and alter the function of NMDA receptors (NMDAR) in the brain, which are essential for neuronal signaling. Scientists at Cold Spring Harbor Laboratory (CSHL) have identified their origin and described how this process is linked to the maturation of these antibodies, which can activate or inhibit the receptor, causing neurological and psychiatric symptoms.

Parkinson’s disease is a progressive neurodegenerative disorder best known for its motor symptoms. However, a proportion of patients also develop dementia as the condition advances. Yet the biological divide between those who experience this cognitive decline and those who do not has remained an open question. Are they different conditions or simply stages of the same disease?

Microglia play a central role in the neuroinflammation associated with Alzheimer’s disease (AD). At the 20th International Conference on Alzheimer’s and Parkinson’s Diseases (AD/PD), scientists focused on TREM2, a microglial receptor that regulates immune responses, exploring new ways to address neuroinflammation. 

Microglia play a central role in the neuroinflammation associated with Alzheimer’s disease (AD). These cells act as the brain’s immune system and respond to damage signals such as amyloid accumulation. When the process starts, the initial microglial response can be protective. However, in later stages, this response becomes dysfunctional and contributes to disease progression. At the 20th International Conference on Alzheimer’s and Parkinson’s Diseases (AD/PD), scientists focused on TREM2, a microglial receptor that regulates immune responses, exploring new ways to address neuroinflammation.