Xu Zhou lab @ BCH & HMS
xuzhoulab.bsky.social
Xu Zhou lab @ BCH & HMS
@xuzhoulab.bsky.social
AP @BostonChildrens @harvardmed AM @broadinstitute
inflammation, tissue biology, quant.&systems immunology #1stGen #ImmigrantScientists #NewPI
Super excited to see our recent @cellcellpress.bsky.social paper featured in a Life Metabolism preview! Huge thanks to Christoopher Glass @ucsdmedschool.bsky.social for the thoughtful highlight. 🔗 academic.oup.com/lifemeta/adv...
#inflammation #macrophage #chromatin #pH #biomolecularcondensates
September 19, 2025 at 3:31 PM
last but not least, BRD4 are broadly expressed in different cell types. We found consistent pH-dependent regulation across immune, stromal, epithelial and tumor cells, including both mouse and human. More examples are accumulating in-house. feel free to dm / email me if anybody is interested.
July 22, 2025 at 2:15 PM
we hypothesize that BRD4 condensates could function as an internal pH meter to gauge cellular state linked to inflammatory activation and metabolism, by controlling the expression of key metabolic genes. 22/n
July 22, 2025 at 2:12 PM
and a similar response happens in vivo! 21/n
July 22, 2025 at 2:09 PM
As immune activation tends to increase intracellular and extracellular acidification, we turned to look at what happens just with LPS stimulation. And it is sufficient to reduce BRD4 condensates in vitro 20/n
July 22, 2025 at 2:07 PM
for anybody who is curious what make a gene dependent or not on BRD4 condensates: we don't have the answer yet, but we found that pH-sensitive genes seem to have the most recruitment of BRD4 to their enhancers. In another words, BRD4 recruitment might be a predictor of pH-sensitive expression.19/n
July 22, 2025 at 2:06 PM
disruption of BRD4 condensates leads to disruption of MED1 condensates, which likely explains the suppressed the inflammatory activation in macrophages (more to come about these mechanisms!) 18/n
July 22, 2025 at 2:05 PM
surprisingly, we found that only histidine residues in selective regions of BRD4-IDR are required for pH sensitivity, and that consecutive histidine can give rise to pH-sensitivity in biomolecular condensates at physiological pH range.
17/n
July 22, 2025 at 2:02 PM
Swapping histidines (ph sensitive around 6-7) to alanine can reverse the pH-dependent regulation on transcriptional condensates. 16/n
July 22, 2025 at 2:01 PM
This response is regulated by enriched and conserved histidines on BRD4-IDR 15/n
July 22, 2025 at 2:00 PM
with suggestions from reviewers, we brought up our game to super-resolution microscopy to characterize the changes of native BRD4 condensates with STED scope & thanks to help from Krishnan Raghunathan and Thiagarajah lab👍
July 22, 2025 at 1:59 PM
@bsabari.bsky.social @richardyonck.com @whiteheadinstitute.bsky.social Arup Chakraborty @mitpress.bsky.social among other pioneers in biomolecular #condensates showed that BRD4 forms transcriptional condensates. We found that these condensates native to macrophages are disrupted by acidic pH. 13/n
July 22, 2025 at 1:57 PM
Based on features of the disordered loop in yeast SNF5. Diana Leung in my lab did an in silico screening and found mammalian BRD4 as putative pH sensor. Happy to chat about the bioinformatic work if anyone is interested. 12/n
July 22, 2025 at 1:51 PM
But how does it happen? We tested differential signaling, protein translation, global epigenetic modification etc. all proven wrong. a few good years of negative data 10/n
July 22, 2025 at 1:49 PM
this analysis suggested that inflammatory genes partition into functions for immediate microbial defense and propagations of inflammatory cascade in a pH-dependent manner 9/n
July 22, 2025 at 1:48 PM
And even more surprise, pH-dependent response is independent of well-known pH sensors in macrophages. To understand better how it happens, we developed a #deconvolution model to quantify how pH and immune signals interact to activate each gene.
Alert 🔥 A computational pipeline will be online soon.
July 22, 2025 at 1:47 PM
Thanks so much for constructive suggestions from anonymous reviewers. We confirmed the protein level expression for many inflammatory effectors. The pH-dependent regulation was confirmed at protein level, such as for interferon-b and IL-6. 7/n
July 22, 2025 at 1:44 PM
to our surprise, acidic ph regulates a switch-like gene-specific inflammatory response in macrophages. with many interesting genes repressed or more induced at low pH #cytokine #IFN 6/n
July 22, 2025 at 1:42 PM
These ideas are also derived from our earlier discussion
annualreviews.org/content/jour...
and our recent review focusing on pH with
Stephanie Hajjar
July 22, 2025 at 1:40 PM
It started with a simple idea. Inflammation is both beneficial and pathological. This balance demands calibration by both the threat and the cost. Bc deviation from homeostasis represents a cost, sensing it can feedback to immune system 3/n
@rmedzhitov.bsky.social
science.org/doi/10.1126/...
July 22, 2025 at 1:38 PM
Beyond excited to share our #NewPaper in @cellcellpress.bsky.social! Inflamed environments acidify intracellular #pH. BRD4 senses this via transcriptional condensates, tuning #macrophage responses to match demand and consequences of #inflammation authors.elsevier.com/sd/article/S...
July 22, 2025 at 1:24 PM
Despite all kinds of chaos, nothing beats a hotpot celebration of Lunar New Year with my lab family! Happy the year of snake! Year of slytherin! 🎉🎊🎆🍲
January 29, 2025 at 4:11 PM
Happy holidays to everyone! Just celebrated 2024 with the amazing group of people who made me want to go to work everyday, full of surprises and excitement! Looking forward to 2025 of Zhou lab #labholiday @bostonchildrens.bsky.social @harvardmed.bsky.social
December 22, 2024 at 1:35 AM