Michael S. Balzer
@balzer-lab.org
MD FASN | Nephrologist = kidney doc | #PeritonealDialysis aficionado | #ClinicianScientist @ChariteBerlin | Editorial Board member @JASN | #SingleCell | Determined to understand adaptation to kidney disease | #ERCStG | 🌐 https://balzer-lab.org
Classic Fred Luft #Nephrology 101 editorial on a study testing the effect of potassium supplement on natriuresis: Eliminating sodium with potassium 🔗 academic.oup.com/ndt/article/... #NephSky #MedSky 🧪
February 3, 2026 at 8:25 PM
Classic Fred Luft #Nephrology 101 editorial on a study testing the effect of potassium supplement on natriuresis: Eliminating sodium with potassium 🔗 academic.oup.com/ndt/article/... #NephSky #MedSky 🧪
The human data brought it home. Higher CTSD expr. in kidney tubules tracked w/ worse eGFR & more fibrosis. Patients on RAASi had lower CTSD. And a gene signature derived from enalapril-responsive cells stratified kidneys by outcomes, not diagnoses. Mechanism meeting prognosis is always satisfying.
January 8, 2026 at 12:55 PM
The human data brought it home. Higher CTSD expr. in kidney tubules tracked w/ worse eGFR & more fibrosis. Patients on RAASi had lower CTSD. And a gene signature derived from enalapril-responsive cells stratified kidneys by outcomes, not diagnoses. Mechanism meeting prognosis is always satisfying.
Spatial transcriptomics sealed it. In human DKD kidneys, CTSD⁺ connecting tubules and TREM2⁺ macrophages sit next to each other. Not metaphorically. Physically. When disease is present, their neighborhood expands. When RAAS signaling is suppressed, that neighborhood quiets down. Context matters.
January 8, 2026 at 12:54 PM
Spatial transcriptomics sealed it. In human DKD kidneys, CTSD⁺ connecting tubules and TREM2⁺ macrophages sit next to each other. Not metaphorically. Physically. When disease is present, their neighborhood expands. When RAAS signaling is suppressed, that neighborhood quiets down. Context matters.
Then came the immune system. Those CTSD⁺ distal cells were talking — loudly — to a specific macrophage population: TREM2⁺ resident macrophages. These macrophages were inflammatory, expanded in DKD, and shrank with enalapril treatment. This was epithelial–immune crosstalk, not collateral damage.
January 8, 2026 at 12:54 PM
Then came the immune system. Those CTSD⁺ distal cells were talking — loudly — to a specific macrophage population: TREM2⁺ resident macrophages. These macrophages were inflammatory, expanded in DKD, and shrank with enalapril treatment. This was epithelial–immune crosstalk, not collateral damage.
Digging deeper, we found a distinct population of CTSD⁺ connecting tubule cells. They sit between healthy and injured states. Not fully broken, not fully normal. Transitional. Plastic. Vulnerable. And enalapril selectively depleted this population. That was the first “oh wow” moment.
January 8, 2026 at 12:53 PM
Digging deeper, we found a distinct population of CTSD⁺ connecting tubule cells. They sit between healthy and injured states. Not fully broken, not fully normal. Transitional. Plastic. Vulnerable. And enalapril selectively depleted this population. That was the first “oh wow” moment.
One molecule kept showing up: cathepsin D (CTSD). Strongly induced in diabetic kidneys. Strongly suppressed by enalapril. And not everywhere — very specifically in a subset of distal nephron cells. This was not a generic injury marker. It looked like a state.
January 8, 2026 at 12:53 PM
One molecule kept showing up: cathepsin D (CTSD). Strongly induced in diabetic kidneys. Strongly suppressed by enalapril. And not everywhere — very specifically in a subset of distal nephron cells. This was not a generic injury marker. It looked like a state.
When we mapped the kidney cell by cell, the biggest enalapril “rescue” signal was not in proximal tubules. It was in the distal nephron. That alone made us stop and reread the plots twice.
January 8, 2026 at 12:52 PM
When we mapped the kidney cell by cell, the biggest enalapril “rescue” signal was not in proximal tubules. It was in the distal nephron. That alone made us stop and reread the plots twice.
Using long-term enalapril treatment in the ZSF1 rat DKD model, we confirmed the obvious first: blood pressure, albuminuria, fibrosis, injury markers all improved. So yes, the drug works. But where does it work? That question is where single-cell really earns its keep.
January 8, 2026 at 12:52 PM
Using long-term enalapril treatment in the ZSF1 rat DKD model, we confirmed the obvious first: blood pressure, albuminuria, fibrosis, injury markers all improved. So yes, the drug works. But where does it work? That question is where single-cell really earns its keep.
RAAS inhibitors have been used for decades. We all learned the story: glomeruli, proximal tubules, hemodynamics. But when we looked at this with single-cell resolution, the biology told a different story. Not louder. Just clearer. And it pointed us somewhere unexpected.
January 8, 2026 at 12:52 PM
RAAS inhibitors have been used for decades. We all learned the story: glomeruli, proximal tubules, hemodynamics. But when we looked at this with single-cell resolution, the biology told a different story. Not louder. Just clearer. And it pointed us somewhere unexpected.
Excited to share our recent JASN paper on enalapril effects in #DKD using #single-cell approaches.🧪
Thanks to the whole team @nephrointberlin.bsky.social @PennKidney, and @Bayer.
Special 🙏 to my mentor @ksusztak.bsky.social. Her insightful X thread is copied below.
🔗 t.ly/oNjkJ #NephSky #MedSky
Thanks to the whole team @nephrointberlin.bsky.social @PennKidney, and @Bayer.
Special 🙏 to my mentor @ksusztak.bsky.social. Her insightful X thread is copied below.
🔗 t.ly/oNjkJ #NephSky #MedSky
January 8, 2026 at 12:44 PM
Excited to share our recent JASN paper on enalapril effects in #DKD using #single-cell approaches.🧪
Thanks to the whole team @nephrointberlin.bsky.social @PennKidney, and @Bayer.
Special 🙏 to my mentor @ksusztak.bsky.social. Her insightful X thread is copied below.
🔗 t.ly/oNjkJ #NephSky #MedSky
Thanks to the whole team @nephrointberlin.bsky.social @PennKidney, and @Bayer.
Special 🙏 to my mentor @ksusztak.bsky.social. Her insightful X thread is copied below.
🔗 t.ly/oNjkJ #NephSky #MedSky
Check out a recent interesting case of C-H-BG syndrome from @nephrointberlin.bsky.social. A great example of how rare symptoms in a common disease can present with complex phenotypes.
#NephSky #MedSky 🧪
🔗 www.sciencedirect.com/science/arti...
#NephSky #MedSky 🧪
🔗 www.sciencedirect.com/science/arti...
January 3, 2026 at 12:44 PM
Check out a recent interesting case of C-H-BG syndrome from @nephrointberlin.bsky.social. A great example of how rare symptoms in a common disease can present with complex phenotypes.
#NephSky #MedSky 🧪
🔗 www.sciencedirect.com/science/arti...
#NephSky #MedSky 🧪
🔗 www.sciencedirect.com/science/arti...
December 23, 2025 at 11:16 AM
👏Fantastic to see @cetinsz.bsky.social from our team presenting insights into #single-cell transcriptomic patterns distinguishing recovery from non-recovery after #AKI. Exciting 🧪 at #KidneyWk Houston, TX! #MedSky #NephSky
November 6, 2025 at 11:24 PM
👏Fantastic to see @cetinsz.bsky.social from our team presenting insights into #single-cell transcriptomic patterns distinguishing recovery from non-recovery after #AKI. Exciting 🧪 at #KidneyWk Houston, TX! #MedSky #NephSky
❓Do we finally have a nodular sclerosis mouse model for DKD? 🔥Tour-de-force #kidneywk talk by @linkermannlab.bsky.social suggests so. 🧪 #NephSky #MedSky
November 6, 2025 at 9:37 PM
❓Do we finally have a nodular sclerosis mouse model for DKD? 🔥Tour-de-force #kidneywk talk by @linkermannlab.bsky.social suggests so. 🧪 #NephSky #MedSky
🔥 Huge congrats to @ksusztak.bsky.social & team on a landmark @natgenet.nature.com paper!
🚶♂️🐁🐀Cross-species 🫘kidney pathway dysregulation via #singlecell functional profiling of individual samples — opening new therapeutic avenues.
🔗 www.nature.com/articles/s41...
🧪 #NephSky #MedSky
🚶♂️🐁🐀Cross-species 🫘kidney pathway dysregulation via #singlecell functional profiling of individual samples — opening new therapeutic avenues.
🔗 www.nature.com/articles/s41...
🧪 #NephSky #MedSky
August 8, 2025 at 8:08 AM
🔥 Huge congrats to @ksusztak.bsky.social & team on a landmark @natgenet.nature.com paper!
🚶♂️🐁🐀Cross-species 🫘kidney pathway dysregulation via #singlecell functional profiling of individual samples — opening new therapeutic avenues.
🔗 www.nature.com/articles/s41...
🧪 #NephSky #MedSky
🚶♂️🐁🐀Cross-species 🫘kidney pathway dysregulation via #singlecell functional profiling of individual samples — opening new therapeutic avenues.
🔗 www.nature.com/articles/s41...
🧪 #NephSky #MedSky
July 1, 2025 at 2:52 PM
🎉🎈Congrats to all ASN 2025 🏆Lifetime & Midcareer awardees!
Well-deserved, @ksusztak.bsky.social @rkramann.bsky.social @genetickidneydoc.bsky.social, you are on 🔥!!!
#NephSky, #MedSky, #ERA25
Well-deserved, @ksusztak.bsky.social @rkramann.bsky.social @genetickidneydoc.bsky.social, you are on 🔥!!!
#NephSky, #MedSky, #ERA25
June 4, 2025 at 4:47 PM
🎉🎈Congrats to all ASN 2025 🏆Lifetime & Midcareer awardees!
Well-deserved, @ksusztak.bsky.social @rkramann.bsky.social @genetickidneydoc.bsky.social, you are on 🔥!!!
#NephSky, #MedSky, #ERA25
Well-deserved, @ksusztak.bsky.social @rkramann.bsky.social @genetickidneydoc.bsky.social, you are on 🔥!!!
#NephSky, #MedSky, #ERA25
📣Attention #NephSky #MedSky!
Inaugural #PeritonealDialysis 🧪research meeting incoming:
"1st International Meeting on Cellular & Molecular #PD Research"
📆July 4-5, 2025 @The Nucleus, 🛳️Kiel, Germany
🔗Program & registration: www.pdmeeting.skip-sh.de
👫@ispd.org @dgfn.bsky.social ERA/EDTA
Inaugural #PeritonealDialysis 🧪research meeting incoming:
"1st International Meeting on Cellular & Molecular #PD Research"
📆July 4-5, 2025 @The Nucleus, 🛳️Kiel, Germany
🔗Program & registration: www.pdmeeting.skip-sh.de
👫@ispd.org @dgfn.bsky.social ERA/EDTA
May 18, 2025 at 6:59 AM
📣Attention #NephSky #MedSky!
Inaugural #PeritonealDialysis 🧪research meeting incoming:
"1st International Meeting on Cellular & Molecular #PD Research"
📆July 4-5, 2025 @The Nucleus, 🛳️Kiel, Germany
🔗Program & registration: www.pdmeeting.skip-sh.de
👫@ispd.org @dgfn.bsky.social ERA/EDTA
Inaugural #PeritonealDialysis 🧪research meeting incoming:
"1st International Meeting on Cellular & Molecular #PD Research"
📆July 4-5, 2025 @The Nucleus, 🛳️Kiel, Germany
🔗Program & registration: www.pdmeeting.skip-sh.de
👫@ispd.org @dgfn.bsky.social ERA/EDTA
All quiet on the Western front?!
🧪Work in @jama.com network open shows that predicting #contrast-induced #nephropathy remains imprecise and models demonstrate considerable heterogeneity.
#NephSky #MedSky
🔗 jamanetwork.com/journals/jam...
🧪Work in @jama.com network open shows that predicting #contrast-induced #nephropathy remains imprecise and models demonstrate considerable heterogeneity.
#NephSky #MedSky
🔗 jamanetwork.com/journals/jam...
March 23, 2025 at 7:58 AM
All quiet on the Western front?!
🧪Work in @jama.com network open shows that predicting #contrast-induced #nephropathy remains imprecise and models demonstrate considerable heterogeneity.
#NephSky #MedSky
🔗 jamanetwork.com/journals/jam...
🧪Work in @jama.com network open shows that predicting #contrast-induced #nephropathy remains imprecise and models demonstrate considerable heterogeneity.
#NephSky #MedSky
🔗 jamanetwork.com/journals/jam...
🔥Inspiring keynote at the 1st Joint Mayo Charité Symposium by @asnkidney.bsky.social past president @susanquaggin.bsky.social on the golden era of #kidney health.
🫘🧪
#NephSky #MedSky @nephrointberlin.bsky.social
🫘🧪
#NephSky #MedSky @nephrointberlin.bsky.social
March 20, 2025 at 6:35 PM
🔥Inspiring keynote at the 1st Joint Mayo Charité Symposium by @asnkidney.bsky.social past president @susanquaggin.bsky.social on the golden era of #kidney health.
🫘🧪
#NephSky #MedSky @nephrointberlin.bsky.social
🫘🧪
#NephSky #MedSky @nephrointberlin.bsky.social
💵Funding opportunities for female postdoc🧪scientists in #STEM.
Calls for🇨🇭🇹🇷🇪🇬🇧🇷🇿🇦 and other countries still open.
#NephSky #MedSky #WomenInScience
@womeninmedicine.bsky.social
@women-in-stem.bsky.social
🔗https://www.forwomeninscience.com/challenge/show/120
Calls for🇨🇭🇹🇷🇪🇬🇧🇷🇿🇦 and other countries still open.
#NephSky #MedSky #WomenInScience
@womeninmedicine.bsky.social
@women-in-stem.bsky.social
🔗https://www.forwomeninscience.com/challenge/show/120
March 17, 2025 at 7:30 PM
💵Funding opportunities for female postdoc🧪scientists in #STEM.
Calls for🇨🇭🇹🇷🇪🇬🇧🇷🇿🇦 and other countries still open.
#NephSky #MedSky #WomenInScience
@womeninmedicine.bsky.social
@women-in-stem.bsky.social
🔗https://www.forwomeninscience.com/challenge/show/120
Calls for🇨🇭🇹🇷🇪🇬🇧🇷🇿🇦 and other countries still open.
#NephSky #MedSky #WomenInScience
@womeninmedicine.bsky.social
@women-in-stem.bsky.social
🔗https://www.forwomeninscience.com/challenge/show/120
Hey #NephSky #MedSky, today is #WorldKidneyDay!
Next generation of🫘kidney🧪scientists hard at work to raise awareness for #KidneyDisease, which affects >850 million people worldwide!
🧦 #SockItToKidneyDisease #KidneyAwareness
@kidney.org @asnkidney.bsky.social @theisn.org @nu-nephrology.bsky.social
Next generation of🫘kidney🧪scientists hard at work to raise awareness for #KidneyDisease, which affects >850 million people worldwide!
🧦 #SockItToKidneyDisease #KidneyAwareness
@kidney.org @asnkidney.bsky.social @theisn.org @nu-nephrology.bsky.social
March 13, 2025 at 7:30 AM
Hey #NephSky #MedSky, today is #WorldKidneyDay!
Next generation of🫘kidney🧪scientists hard at work to raise awareness for #KidneyDisease, which affects >850 million people worldwide!
🧦 #SockItToKidneyDisease #KidneyAwareness
@kidney.org @asnkidney.bsky.social @theisn.org @nu-nephrology.bsky.social
Next generation of🫘kidney🧪scientists hard at work to raise awareness for #KidneyDisease, which affects >850 million people worldwide!
🧦 #SockItToKidneyDisease #KidneyAwareness
@kidney.org @asnkidney.bsky.social @theisn.org @nu-nephrology.bsky.social
Attention European #NephSky #MedSky!
Call for abstracts: #JungeNiere 🫘renal 🧪research meeting for early career #ClinicianScientists. July 11-12, 2025 @uniregensburg.bsky.social (GER).
💰Travel grants for students, 🥾hiking &🍺Bavarian beer included!
junge-niere.jimdosite.com
M. Banas, S. Reichelt-Wurm
Call for abstracts: #JungeNiere 🫘renal 🧪research meeting for early career #ClinicianScientists. July 11-12, 2025 @uniregensburg.bsky.social (GER).
💰Travel grants for students, 🥾hiking &🍺Bavarian beer included!
junge-niere.jimdosite.com
M. Banas, S. Reichelt-Wurm
February 26, 2025 at 9:33 AM
Attention European #NephSky #MedSky!
Call for abstracts: #JungeNiere 🫘renal 🧪research meeting for early career #ClinicianScientists. July 11-12, 2025 @uniregensburg.bsky.social (GER).
💰Travel grants for students, 🥾hiking &🍺Bavarian beer included!
junge-niere.jimdosite.com
M. Banas, S. Reichelt-Wurm
Call for abstracts: #JungeNiere 🫘renal 🧪research meeting for early career #ClinicianScientists. July 11-12, 2025 @uniregensburg.bsky.social (GER).
💰Travel grants for students, 🥾hiking &🍺Bavarian beer included!
junge-niere.jimdosite.com
M. Banas, S. Reichelt-Wurm
Ever wondered about the genetic architecture of #kidney function?
🔥Fantastic🧪work & impressive resource by @ksusztak.bsky.social & team @science.org on convergent coding & regulatory GFR variants contributing to kidney disease via a genetic score card.
🔗 tinyurl.com/33yzf5wz
#NephSky #MedSky
🔥Fantastic🧪work & impressive resource by @ksusztak.bsky.social & team @science.org on convergent coding & regulatory GFR variants contributing to kidney disease via a genetic score card.
🔗 tinyurl.com/33yzf5wz
#NephSky #MedSky
February 7, 2025 at 1:16 PM
Ever wondered about the genetic architecture of #kidney function?
🔥Fantastic🧪work & impressive resource by @ksusztak.bsky.social & team @science.org on convergent coding & regulatory GFR variants contributing to kidney disease via a genetic score card.
🔗 tinyurl.com/33yzf5wz
#NephSky #MedSky
🔥Fantastic🧪work & impressive resource by @ksusztak.bsky.social & team @science.org on convergent coding & regulatory GFR variants contributing to kidney disease via a genetic score card.
🔗 tinyurl.com/33yzf5wz
#NephSky #MedSky