Biology subjects

Cheng, C.-J.

Publications and source records attributed to Cheng, C.-J..

3 recordsLinked to original sources

bioRxiv2026

Dodecagon light-sheet fluorescence microscopy for large-volume imaging without striping artifacts

Light-sheet fluorescence microscopy (LSFM) has revolutionized biological imaging by enabling high spatial and temporal resolution with minimal photodamage. However, conventional LSFM techniques often suffer from striping artifacts in the resulting images due to light scattering and absorption within samples, leading to uneven illumination that negatively impacts the accuracy of subsequent image analyses. To address this limitation, we introduce dodecagon light-sheet fluorescence microscopy (dodecaLSFM), a novel approach that maximizes angular diversity to achieve homogeneous illumination and suppress striping artifacts. dodecaLSFM employs diffraction optics and cylindrical lenses to generate twelve light sheets, providing 360{degrees} omnidirectional illumination that significantly enhances illumination uniformity compared to traditional mSPIM, mDSLM, and ultramicroscopy systems, which use only one or two illumination planes. We demonstrate the effectiveness of dodecaLSFM by achieving high-resolution imaging of whole mouse brain vasculature following tissue clearing, allowing precise morphometric analysis of vascular networks without striping artifacts. Furthermore, we show that combining dodecaLSFM with expansion microscopy (ExM) enables whole-organ 3D imaging at cellular resolution. This novel approach provides an advanced, scalable solution for large-volume imaging, facilitating detailed structural and functional studies across diverse biological applications.

bioengineering↗

bioRxiv2025

Endoplasmic reticulum-mitochondrion disconnection promotesmetabolic reprogramming and cystogenesis in polycystic kidneydisease

Mutations in PKD1 and PKD2 cause autosomal-dominant polycystic kidney disease (ADPKD), characterized by fluid-filled cysts, aberrant cell proliferation, and widespread genetic and epigenetic remodeling. While mitochondrial dysfunction and metabolic shifts are central to disease progression, the mechanisms linking PKD mutations to these changes remain unclear. Here, we demonstrate that ER-mitochondria connectivity was disrupted in Pkd1- and Pkd2-deleted mice, preceding cyst formation. This disconnection induces mitochondrial stress, triggering epigenetic remodeling and transcriptional activation of pathways driving proliferation and metabolic reprogramming. Remarkably, restoring PKD function in the ER or pharmacologically enhancing ER-mitochondria connection ameliorates mitochondrial dysfunction, epigenetic shifts, and cystogenesis. These findings reveal a critical role for ER-localized PKD in maintaining mitochondrial integrity and transcriptional homeostasis. Mitochondrial dysfunction resulting from ER-mitochondria uncoupling emerges as a key driver of cystogenesis in ADPKD, and correcting this defect may offer a promising therapeutic strategy. SignificanceAutosomal dominant polycystic kidney disease (ADPKD) is the most prevalent monogenic cause of kidney failure, marked by fluid-filled cysts, aberrant cell proliferation, metabolic reprogramming, and extensive genetic and epigenetic alterations. The mechanisms by which loss-of-function mutations in PKD1 and PKD2 drive disease progression remain poorly understood. Here, we demonstrate that ER-mitochondria contacts are disrupted in Pkd-mutant mice prior to cyst formation. This disconnection induces mitochondrial dysfunction and epigenetic remodeling, which in turn promote metabolic reprogramming and cystogenesis. Restoration of PKD function in the ER or pharmacological enhancement of ER-mitochondria coupling mitigates these pathological changes. Our findings uncover a critical role for ER-mitochondria crosstalk in suppressing cystogenesis and identify a promising therapeutic target for ADPKD.

molecular biology↗

bioRxiv2024

Transport activity regulates mitochondrial bioenergetics and biogenesis in renal tubules

Renal tubules are featured with copious mitochondria and robust transport activity. Mutations in mitochondrial genes cause congenital renal tubulopathies, and changes in transport activity affect mitochondrial morphology, suggesting mitochondrial function and transport activity are tightly coupled. Current methods of using bulk kidney tissues or cultured cells to study mitochondrial bioenergetics are limited. Here, we optimized an extracellular flux analysis (EFA) to study mitochondrial respiration and energy metabolism using microdissected mouse renal tubule segments. EFA detects mitochondrial respiration and glycolysis by measuring oxygen consumption and extracellular acidification rates, respectively. We show that both measurements positively correlate with sample sizes of a few centimeter-length renal tubules. The thick ascending limbs (TALs) and distal convoluted tubules (DCTs) predominantly utilize glucose/pyruvate as energy substrates, whereas proximal tubules (PTs) are significantly much less so. Acute inhibition of TALs transport activity by ouabain treatment reduces basal and ATP-linked mitochondrial respiration. Chronic inhibition of transport activity by 2-week furosemide treatment or deletion of with-no-lysine kinase 4 (Wnk4) decreases maximal mitochondrial capacity. In addition, chronic inhibition downregulates mitochondrial DNA mass and mitochondrial length/density in TALs and DCTs. Conversely, gain-of-function Wnk4 mutation increases maximal mitochondrial capacity and mitochondrial length/density without increasing mitochondrial DNA mass. In conclusion, EFA is a sensitive and reliable method to investigate mitochondrial functions in isolated renal tubules. Transport activity tightly regulates mitochondrial bioenergetics and biogenesis to meet the energy demand in renal tubules. The system allows future investigation into whether and how mitochondria contribute to tubular remodeling adapted to changes in transport activity. Key pointsO_LIA positive correlation between salt reabsorption and oxygen consumption in mammalian kidneys hints at a potential interaction between transport activity and mitochondrial respiration in renal tubules. C_LIO_LIRenal tubules are heterogeneous in transport activity and mitochondrial metabolism, and traditional assays using bulk kidney tissues cannot provide segment-specific information. C_LIO_LIHere, we applied an extracellular flux analysis to investigate mitochondrial respiration and energy metabolism in isolated renal tubules. This assay is sensitive in detecting oxygen consumption and acid production in centimeter-length renal tubules and reliably recapitulates segment-specific metabolic features. C_LIO_LIAcute inhibition of transport activity reduces basal and ATP-linked mitochondrial respirations without changing maximal mitochondrial respiratory capacity. Chronic alterations of transport activity further adjust maximal mitochondrial respiratory capacity via regulating mitochondrial biogenesis or non-transcriptional mechanisms. C_LIO_LIOur findings support the concept that renal tubular cells finely adjust mitochondrial bioenergetics and biogenesis to match the new steady state of transport activity. C_LI

physiology↗