Mastodawn

Jorge Ferrer Dec 20, 2023

We are hiring in @CRGenomica!

Early-career Group Leader in Health Genomics – support for 9 yrs to lead a lab focused on any interest within the broad area of Health Genomics

Spread the word!

https://recruitment.crg.eu/content/jobs/position/junior-group-leader-position-medical-genomics

Jorge Ferrer Apr 15, 2023

RT @EfsunArdaLab
The claim that beta cells arise from duct progenitors in the adult pancreas seems to have a zombie-like quality 🧟 repeatedly reemerging despite the overwhelming evidence against it @1jorgeferrer has a great thread explaining it all https://twitter.com/1jorgeferrer/status/1644256545214021633

Jorge Ferrer on Twitter

““Matters Arising”: Are new insulin-producing beta cells continuously being generated from duct progenitors in the adult pancreas? This question has huge implications for regenerative medicine https://t.co/IMPexcf0nC https://t.co/d5PXTonvH4 Thread below”

Twitter

Jorge Ferrer Apr 7, 2023

RT @MorghanLucas
Thrilled to share our new method, Nano-tRNAseq, a @nanopore direct #RNA sequencing approach that simultaneously quantifies tRNA abundances and modifications. If you’re interested in sequencing other small RNA types with nanopore, this method might interest you 1/ 🧵 https://twitter.com/naturebiotech/status/1644054775376277504

Nature Biotechnology on Twitter

“Quantitative analysis of tRNA abundance and modifications by nanopore RNA sequencing https://t.co/MXngiA66xT”

Twitter

Jorge Ferrer Apr 7, 2023

RT @msanderlab
@1jorgeferrer analyzes recent study claiming that beta cells regenerate from ducts. This question has been extensively studied for decades with overwhelming evidence against beta cells arising from ducts. We summarized the evidence in this review:
https://www.nature.com/articles/ncb3309 https://twitter.com/1jorgeferrer/status/1644256545214021633

Stem cells versus plasticity in liver and pancreas regeneration - Nature Cell Biology

Sander and colleagues discuss recent evidence for and against the roles of stem cells versus the plasticity of mature cell types in response to injury during regeneration of the adult liver and pancreas.

Nature

Show thread

Jorge Ferrer Apr 7, 2023

Thanks to Yuval Dor (not in twitter, glad to co-lead with him), Judith Magenheim, Miguel A. Maestro, @JanelKopp, @NadavSharon3, Pedro Herrera, @TheMeltonLab, Charlie Murtaugh, Guoqiang Gu, @msanderlab

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Jorge Ferrer Apr 7, 2023

9/
This time its hard to say “we are excited to share a new publication” because this type of study is not particularly fun. But we felt it was very important for the field. We have respect for the authors though we disagree with that paper

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Jorge Ferrer Apr 7, 2023

8/
Our conclusion is that this cannot be considered evidence that adult duct progenitors contribute to new beta cells in these conditions

Of course this is all based on mouse. New technologies, maybe single cell mutational analysis, may enable testing this in human

Show thread

Jorge Ferrer Apr 7, 2023

7/
We illustrate how this affects results by segregating G. et al´s image channels and recounting.
There is a response to our “matters arising” with new results and corrections, but no co-localizations to address this central problem... the Cre lines mark somatostatin cells

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Jorge Ferrer Apr 7, 2023

6/ Most somatostatin+ delta cells have thin elongated shapes (http://shorturl.at/otxRW)
G. et al did not simultaneously co-stain SMS, INS, reporter and nuclei. We show that if SMS+ reporter+ cells are surrounded by INS+ cells and only INS is stained, they appear to be INS+ cells

Show thread

Jorge Ferrer Apr 7, 2023

5/ So how can all this be reconciled with the G. et al findings?
The main issue is that ngn3 and hnf1b Cre lines used by G. et al are not specific to duct cells or putative progenitors. Both directly mark islet somatostatin+ cells profusely, as well as a lower number of b cells