Biology subjects

Franco, I.

Publications and source records attributed to Franco, I..

4 recordsLinked to original sources

bioRxiv2026

Single genome analysis of normal cells identifies the early steps of kidney cancer.

Whole genome analyses have shown that every cell of the body accumulates thousands of genetic changes during a lifetime, with implications for cancer initiation. We have analyzed normal kidney cells from both healthy individuals and patients with the Von Hippel Lindau (VHL) syndrome, which predisposes to kidney cancer. Using a clonal-expansion method that enables the collection of high confidence genetic and gene expression data from the same cell, we define a new mutational signature that marks a specific subset of damage-activated proximal tubule cells, as well as 96% of clear cell renal cell carcinomas. The underlying mutational process is specifically active in highly transcribed DNA and impacts the occurrence of cancer driver variants in the VHL gene. Our data from normal cells, supported by in vitro experiments, point to perturbations of oxygen availability as a causative factor. These findings link hypoxia, a frequent endogenous stress in the normal renal tissue, to excessive mutation and cancer initiation.

cancer biology↗

bioRxiv2026

Small Molecule Regulation of CLOCK:BMAL1 DNA Binding Activity

CLOCK:BMAL1 is a bHLH-PAS transcription factor complex that utilizes its bHLH (basic helix-loop-helix) domains to bind E-box motifs in DNA and tandem PAS (PER-ARNT-SIM) domains to heterodimerize and interact with regulatory proteins to generate circadian rhythms. PAS domains are evolutionarily conserved modules that frequently bind small molecule ligands within buried cavities to perform sensory and signal transduction functions. CLOCK and BMAL1 PAS domains have cavities that could be leveraged to regulate the transcription factor, and consequently, the circadian clock. Using NMR spectroscopy, we identified small molecules that bind within a cavity inside the PAS-A domain of CLOCK and its paralog NPAS2, which sits at an important flexible junction in the structured core of the heterodimer. We identified a gatekeeping mutant in the core of CLOCK PAS-A that significantly decreased ligand binding affinity. High-pressure NMR studies showed that ligand binding or the gatekeeping mutant significantly stabilized the domain. Finally, we showed that ligands induced dose-dependent displacement of CLOCK:BMAL1 from DNA in vitro. Together, these data demonstrate that small molecules can regulate DNA binding by the circadian transcription factor CLOCK:BMAL1 through occupancy of a PAS domain cavity.

biochemistry↗

bioRxiv2025

Network-aware self-supervised learning enables high-content phenotypic screening for genetic modifiers of neuronal activity dynamics

High-throughput phenotypic screening has historically relied on manually selected features, limiting our ability to capture complex cellular processes, particularly neuronal activity dynamics. While recent advances in self-supervised learning have revolutionized the ability to study cellular morphology and transcriptomics, dynamic cellular processes have remained challenging to phenotypically profile. To address this limitation, we developed Plexus, a self-supervised model specifically designed to capture and quantify network-level neuronal activity dynamics. Unlike existing phenotyping tools that focus on static readouts, Plexus leverages a network-level cell encoding method, which enables it to efficiently encode dynamic neuronal activity data into rich representational embeddings. In turn, Plexus achieves state of the art performance in detecting phenotypic changes in neuronal activity. We validated Plexus using a comprehensive GCaMP6m simulation framework and demonstrated its enhanced ability to classify distinct neuronal activity phenotypes compared to traditional signal-processing approaches. To enable practical application, we integrated Plexus with a scalable experimental system utilizing human iPSC-derived neurons equipped with the GCaMP6m calcium indicator and CRISPR interference machinery. This integrated platform successfully identified nearly seventeen times as many distinct phenotypic changes in response to genetic perturbations compared to conventional signal processing methods, as demonstrated in a 52-gene CRISPRi screen across multiple iPSC lines. Using this framework, we identified potential genetic modifiers of aberrant neuronal activity in frontotemporal dementia, illustrating its utility for understanding complex neurological disorders.

bioinformatics↗

bioRxiv2024

Effects of SGLT2 Ablation or Inhibition on Corticosterone Secretion in High-Fat-Fed Mice: Exploring a Nexus with Cytokine Levels

Despite recent therapeutic advances, achieving optimal glycaemic control remains a challenge in managing Type 2 Diabetes (T2D). Sodium-glucose co-transporter type 2 (SGLT2) inhibitors have emerged as effective treatments by promoting urinary glucose excretion. However, the full scope of their mechanisms extends beyond glycaemic control. At present, their immunometabolic effects remain elusive. To investigate the effects of SGLT2 inhibition or deletion, we compared the metabolic and immune phenotype between high fat diet-fed control, chronically dapagliflozin-treated mice and total-body SGLT2/Slc5a2 knockout mice. SGLT2 null mice exhibited superior glucose tolerance and insulin sensitivity compared to control or dapagliflozin-treated mice, independent of glycosuria and body weight. Moreover, SGLT2 null mice demonstrated physiological regulation of corticosterone secretion, with lowered morning levels compared to control mice. Systemic cytokine profiling also unveiled significant alterations in inflammatory mediators, particularly interleukin 6 (IL-6). Furthermore, unbiased proteomic analysis demonstrated downregulation of acute-phase proteins and upregulation of glutathione-related proteins, suggesting a role in the modulation of antioxidant responses. Conversely, IL-6 increased SGLT2 expression in kidney HK2 cells suggesting a role for cytokines in the effects of hyperglycemia. Collectively, our study elucidates a potential interplay between SGLT2 activity, immune modulation, and metabolic homeostasis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=193 HEIGHT=200 SRC="FIGDIR/small/590099v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@140041forg.highwire.dtl.DTLVardef@1ceb1b7org.highwire.dtl.DTLVardef@f575b1org.highwire.dtl.DTLVardef@101d5b4_HPS_FORMAT_FIGEXP M_FIG C_FIG Article HighlightsO_LIThe role of Sodium-glucose co-transporter type 2 (SGLT2) in immunity regulation remains elusive, despite extensive research in SGLT2 inhibitors. C_LIO_LIWe sought to discern the effects of SGLT2 inhibition or deletion on metabolic and immune profiles in high-fat-fed mice, focussing on corticosterone regulation and cytokine alterations. C_LIO_LISGLT2 null mice exhibit enhanced insulin sensitivity, alongside physiologically regulated corticosterone levels and significant alterations in inflammatory cytokines, and we identified changes in protein expression suggestive of antioxidant modulation. C_LIO_LIOur findings emphasize the interplay between immune responses and metabolic regulation mediated by SGLT2 activity. C_LI

cell biology↗