PATHOLOGY: Structural-protein Scrum Knocks Down Nerve Cells
The protein tau is involved in Alzheimer’s disease and other forms of dementia, but exactly how the protein inflicts damage in the brain is still unknown. A study from the lab of Mel Feany, published online Dec. 24 in Nature Cell Biology, introduces a new connection: tau interacts directly with an important structural protein in cells, actin. In a fruit fly model of tau-induced neurodegeneration, the team found that tau causes filaments of actin to bundle and accumulate in neurons, which may be a novel mechanism of disease.

CELL BIOLOGY: Study Adds Feather to mRNA Cap
A team of HMS researchers has added a surprising twist to the story of how mRNAs make their exodus from the nucleus into the cytoplasm. Nascent mRNAs are unwieldy and vulnerable molecules that must be capped, spliced, and inspected before leaving the nucleus. Proteins associated with the cap have been shown to help splice and inspect the mature mRNAs, but their multitasking was thought to stop there. It now appears that cap-associated proteins also play a role in the export of mRNA. The findings by Robin Reed (left), Hong Cheng, and colleagues appear in the Dec. 29 Cell.

IMMUNOLOGY: Lymph Node Cells Mimic Thymus to Induce Immune Tolerance
Cells that make up the framework of lymph nodes appear to actively protect the body from its own immune cells, says a paper in the February Nature Immunology from the lab of Shannon Turley. Stromal cells in lymph nodes catch and destroy passing self-reactive T cells by producing a broad range of proteins found in far-flung tissues and organs. The discovery may lead to a better understanding of how the immune system polices itself and how self-tolerance breaks down in autoimmune diseases, such as type 1 diabetes and multiple sclerosis.

AMBULATORY CARE: Findings Cast Doubt on Association of Benzodiazepines with Hip Fractures
For more than 15 years, benzodiazepine use among the elderly has been linked to hip fractures due to falls. But the evidence has never been firm. In fact, a study in the Jan. 16 Annals of Internal Medicine by Anita Wagner, Stephen Soumerai, and colleagues has found no evidence for the connection. The researchers consequently urge a reexamination of state and federal policies limiting the drugs’ use, which were established because of the purported risk.