Sam the Mensan

11/01/2025

In the Pits
Cells don’t always have everything they need in-house. So, they receive deliveries including metabolites, hormones and proteins from elsewhere. This cargo is taken up via a process called clathrin-mediated endocytosis. Pits coated in the structural protein clathrin form on the surface of a cell’s membrane to collect the required goods and then pinch off into sacs. Here, researchers investigate the 'machinery' underpinning this operation, focusing on the protein CCDC32, which interacts with the clathrin coating and is mutated in the congenital disease cardio-facio-neuro-developmental syndrome. Using a type of electron microscopy (PREM) that 'unroofs' the clathrin-coated structures, they showed that in cells with reduced amounts of CCDC32 (pictured, right), there were fewer dome- (green) and spherical-shaped (orange) pits and more flat, clathrin-coated structures (blue) compared to normal cells (left). They also revealed the disease-causing mutant of CCDC32 prevents endocytosis in cells grown in a dish, so confirming a key role for CCDC32 in this cellular uptake process.

Written by Lux Fatimathas

Image from work by Ziyan Yang and colleagues
NHC Key Laboratory of Birth Defect Research and Prevention,Hengyang Medical School , , Hengyang, China; Chan Zuckerberg Biohub, San Francisco, CA, USA Chan Zuckerberg Biohub Network
Video contributed by the authors and originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
Published in eLife (reviewed preprint), August 2025

Originally on bpod.org.uk/archive/2025/9/22
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In the Pits - Biomedical pictures for September 2025.

11/01/2025

Reason for Lupus
PLD4 protein is an enzyme that normally modulates components of the immune system including Toll-like receptor pathways. Finding a mutation in the PLD4 gene that knocks out its function in a subset of patients with the autoimmune disease systemic lupus erythematosus reveals for the first time the importance of PLD4 deficiency in human disease, and points to a target for treatments

Image from work by Qintao Wang, Honghao Zhu, Xiangwei Sun, Changming Zhang and Shuangyue Ma, and colleagues
Liangzhu Laboratory, Zhejiang University, Hangzhou, China Zhejiang University
Image contributed by the authors and originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
Published in Nature, September 2025

Originally on bpod.org.uk/archive/2025/9/19
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Reason for Lupus - Biomedical pictures for September 2025.

11/01/2025

Feeding Frenzy
Bacteria, viruses, fungi and even cancer cells are all on the menu for macrophages. These immune cells ‘eat’ their targets through a process called phagocytosis. Too much phagocytosis, however, can be problematic and is implicated in disease processes such as neurodegeneration. Researchers investigate how phagocytosis goes into overdrive by focusing on the SNARE protein syntaxin-2. SNAREs help macrophages form the phagosome, the structure that engulfs microbes and unwelcome cells. In mouse macrophages with reduced amounts of syntaxin-2, phagocytosis of beads coated with an ‘eat me’ signal increased, as revealed by scanning electron microscopy (pictured, right), when compared to normal macrophages (left). However, when these mutant cells phagocytosed E.coli, they were less able to digest the bacteria. Syntaxin-2 is, therefore, a key player for ingestion and digestion and may prove to be a good target for combating excessive phagocytosis in disease.

Written by Lux Fatimathas

Image from work by Suman Samanta and colleagues
Dept of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal; Dept of Zoology, Institute of Science, Banaras Hindu University - Varanasi, Varanasi, India
Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
Published in Journal of Cell Science, August 2025

Originally on bpod.org.uk/archive/2025/9/8
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Feeding Frenzy - Biomedical pictures for September 2025.

11/01/2025

Hair Cell Roots
Variants in the gene encoding enzyme MSRB3 are associated with an inherited deafness disorder. This study finds out why: MSRB3 is necessary for the maintenance and proper maturation of the inner ear's hair cells and their 'hair', the sterocilia that transduce sound to the brain as electrical signals

Image from work by Gowri Nayak & Elodie M. Richard, and colleagues

Department of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH Cincinnati Children's
; Department of Otorhinolaryngology Head and Neck Surgery, , University of Maryland School of Medicine, Baltimore, MD, USA
Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in and on the cover of Disease Models & Mechanisms, August 2025

Originally on bpod.org.uk/archive/2025/9/9
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Hair Cell Roots - Biomedical pictures for September 2025.

11/01/2025

11/01/2025

Leaflets and Signals
Multifunctional brain cells called astrocytes have delicate projections called leaflets which envelop neuron-neuron synapses (connections). Using volumetric high-resolution electron microscopy and two-photon Ca2+ (which signifies electrical activity) imaging, this study reveals without damaging their structure the details of how the astrocyte leaflets integrate signals from multiple synapses from different neurons

Still from a video from work by Lucas Benoit, Ines Hristovska and Nicolas Liaudet, and colleagues
University Grenoble Alpes, Inserm U1216, Grenoble Institut Neurosciences, Grenoble, France Université Grenoble Alpes
; Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland Université de Lausanne
Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
Published in Cell, September 2025

Originally on bpod.org.uk/archive/2025/10/9
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Leaflets and Signals - Biomedical pictures for October 2025.