David Angeles

Currently at #TERMIS2025, sitting at an award plenary, and though the speaker has done amazing science and is a great speaker, 100% of the data she presented is 2008-2018. Why? I can read all of these papers. The point of conferences used to be to show cutting edge work.

Super excited to get this out. This collab started a few years ago and is the first paper from it. Here, with experimental and computational approaches we:

1. establish that cell villages can be just as accurate (one might argue more accurate!) than arrayed-based designs

bsky.app/profile/bior...

The Bay Area Reporter front page, 13 August 1998. The headline ‘No obits’ is written in red above the lead story.

27 years ago, two years after the introduction of effective HIV treatment, the Bay Area Reporter, San Francisco’s lesbian and gay community newspaper, ran ‘No Obits’ as its headline.
It was the first edition not to report an AIDS death in almost 15 years.

Potatoes have their roots in ancient tomatoes Knowing potatoes’ origin story could help future-proof the crucial crop against climate threats.

🗃️
A history mystery solved: where do potatoes come from?

Nine million years ago, as the Andes were rising, a tomato cross pollinated a plant from the S. etuberosum lineage. Each plant contributed a gene, that together enabled underground stems to form tubers.

www.sciencenews.org/article/pota...

huh.

What does it say if you see circles at the bottom and rectangles at the top? Asking for a friend...

@saramostafavi.bsky.social (@Genentech) & I (@Stanford) r excited to announce co-advised postdoc positions for candidates with deep expertise in ML for bio (especially sequence to function models, causal perturbational models & single cell models). See details below. Pls RT 1/

My biggest question: he showed a regeneration suppression program that is AP polarized. How does this work when injuries happen at the P end? What about lateral injuries? Is there a lateral program?

He shows that in planarian species that cannot regenerate, knocking down these “regeneration suppressors” restores their ability to regenerate. Awesome.

Next he did a screen and found genes that mediate this suppression in the tail allegedly. claims they are working through regulating differentiated tissue turnover
rates.

ok. what does this systemic response do and why is it needed?

He performed a smart series of cutting experiments to show an inhibitory program of regeneration is likely encoded in the posterior segment and is erk mediated.

how does the injury passage through the body? in cases of Anterior wounds, it’s through Erk signaling using the longitudinal muscles. unclear how he showed that. I was pretty far away and the talk went by fast.

planarians have stem cells known as neoblasts. really cool cells. bo is talking about planarians regeneration. however, only proximal neoblasts to the wound activate initially. later, the rest of the body activates a secondary response. I missed what "activation" entails.

BO WANG, Stanford

Identifying and understanding regeneration suppressors

#isscr2025

She said humans dont have a recognizable blastema. I am not sure why she is saying that… blastema to me means regenerative, proliferative tissue, i don't know if blastemas have a molecular/cellular definition (missing in humans).

Fascinating study of human regeneration.

#isscr2025

mass spec of exudate shows different proteins secreted at different stages

an important point is that is that re-epithelialization happens at the end of regeneration. in axolots, it happens earlier, after coagulation.

coagulation is early and closes wound. next, fingers grow a granular tissue that looks raw, blistery. in proliferation we see more normal growth but the shape and texture is all wrong. the final stage reconfigures the finger to form the correct structures and final cell types.

They identified four different stages of regrowth: coagulation, hypergranulation, proliferation and epithelialization.

Note: she pointed out antibiotics are unnecessary because the regenerative program involves a lot of immune mobilization, highly antibacterial!

A leading hypothesis for the limits of regeneration has been immunity--this throws a bit of a wrench in that.

wow. they set up a program to recruit injured folks to a trial where they collected exudate, encased the finger in a transparent casing, and where the injury was neither disinfected nor antibiotic treated. 2 sets of xrays for fingertips.

salamanders can regrow limbs in 40 days. upon amputation, the wound closes quickly. then it forms an apical epithelial cap, under which is a proliferative tissue, this tissue forms the blastema, and the regeneration program is on.

Note: human fingertips can regenerate even in older folks.

up next @tatianasg.bsky.social

shared and distinct mechanisms in salamander limb and human fingertip regeneration.

now… do they proliferate in injury settings? EdU pulse! And yea! these cells proliferate post injury especially at 28D post injury. Beautiful work and ongoing.

They found some tiny muscle cells stain for pax7, right morphology for stem cells, developed tools to study them (found an ab). now isolating them they have proliferative and stem cell characteristics

ALBERT ERNESTO ALMADA Quiescent preexisting cells in skeletal muscle heal tail injuries in anole lizards 🦎

after tail amputation you see a thing called a blastema forming, muscle only starts to reappear after ~28 days of growth though.

#isscr2025

now can we reprogram human astrocytes into glial bridge cells? She says yes. Four factors reprogram astrocytes into bridge cells. She didn't disclose the factors. In vitro characterization looks like cells are behaving as expected. Preliminary in vivo looks good.

there is a specific subset of astrocytes that mediate injury recovery. comparative transcriptomics identifies a “homologous” cell type in human embryonic glial progenitors.

but what pathways mediate the recovery process in zfish? unsurprisingly, EMT is important.

astrocytes exist along a continuum of proinflammatory and normal states. She says we cannot yet identify these by sequencing.

zebrafish can recover from spinal cord injury at early ages through a cell type called glial bridge cells, related to astrocytes

Yesterday i didn't post my conference notes. Let's catch up.

animal models in regeneration.

MAYSSA MOKALLED washington u in st louis - approaches to spinal cord regeneration. a critical challenge in spinal cord therapies is in providing physical support for implanted neurons.
#isscr2025

speechless. wow!