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Biology subjects

Goudin, N.

Publications and source records attributed to Goudin, N..

6 recordsLinked to original sources

A cilia-dependent inflammatory programme links bacterial detection to kidney disease

The primary cilium is a microtubule-based sensory organelle projecting from the plasma membrane of most mammalian cells. Genetic defects in ciliary components cause chronic kidney disease (CKD) characterized by heightened production of inflammatory and fibrogenic mediators by tubular epithelial cells. Yet, whether this reflects a physiological role of the primary cilium remains unknown. Here, we show that primary cilia on kidney tubular cells bind uropathogenic Escherichia coli and, in response to bacterial components, initiate a fibro-inflammatory program reminiscent of CKD. Integrating single-cell transcriptomics with conditional mouse models, we observed that epithelial cilia orchestrate a similar fibro-inflammatory response in the absence of infection during CKD. This convergence reveals a shared cilia-dependent signalling axis governing both host-pathogen responses and CKD progression. Mechanistically, cilia ablation selectively impairs tubular responses to ADP-heptose, a pathogen-associated molecular pattern that activates NF-{kappa}B via the cytosolic innate immune receptor ALPK1. In human kidney organoids, ADP-heptose induces robust fibro-inflammation, and genetic or pharmacological inhibition of ALPK1 attenuates this response in a rodent CKD model. Together, these findings identify primary cilia as central orchestrators of a fibro-inflammatory program linking pathogen detection to kidney disease progression.

physiology↗

Therapeutic splice modulation of COL4A5 reinstates collagen IV assembly in an organoid model of X-linked Alport syndrome

Kidney organoids are an emerging tool for disease modeling, especially genetic diseases. Among them, X-linked Alport syndrome (XLAS) is a hematuric nephropathy affecting the glomerular basement membrane (GBM) secondary to pathogenic variations in the COL4A5 gene encoding the 5 subunit of type IV collagen [5(IV)]. In patients carrying pathogenic variations affecting splicing, the use of antisense oligonucleotides (ASOs) offers immense therapeutic hope. In this study, we develop a framework combining the use of patient-derived cells and kidney organoids to provide evidence of the therapeutic efficacy of ASOs in XLAS patients. Using multiomics analysis, we describe the development of GBM in wild-type and mutated human kidney organoids. We show that GBM maturation is a dynamic process, which requires long organoid culture. Then, using semi-automated quantification of 5(IV) at basement membranes in organoids carrying the splicing variants identified in patients, we demonstrate the efficacy of ASO treatment for 5(IV) restoration. These data contribute to our understanding of the development of GBM and pave the way for a therapeutic screening platform for patients.

genetics↗

Evaluation of Prostaglandin Receptor Agonists and Eupatilin in the Context of Nephronophthisis

BackgroundPrimary cilia are sensory antennas that are present on the majority of quiescent vertebrate cells where they mediate key signaling during development and in response to environmental stimuli. Defects in primary cilia result in a group of heterogeneous inherited disorders with overlapping phenotypes, called ciliopathies. Nephronophthisis is an autosomal recessive tubulo-interstitial kidney ciliopathy with more than 25 identified genes called NPHP. Presently, no treatment exists beyond supportive care and kidney transplant, underscoring the need for novel therapies. MethodsUsing a phenotypic screening approach in cultured cell lines, we previously identified prostaglandin analogues as candidate therapeutic molecules based on their ability to rescue ciliogenesis defects in kidney tubular cells from NPHP1 patients. Here, we have investigated the potential beneficial effects of ROCK inhibitors and Eupatilin, similarly identified by other groups in different NPHP contexts, in kidney cells from NPHP1 and IQCB1/NPHP5 patients as well as in a zebrafish NPHP mutant line (traf3ip1/ift54). ResultsEupatilin partially rescued NPHP1-associated ciliogenesis defects. Transcriptomic analyses pointed out that cell cycle progression was inhibited by Eupatilin, likely explaining its broad effects on cilia assembly. Interestingly, while ciliary defects also observed in NPHP5 patient cells were rescued by both prostaglandins and Eupatilin, only prostaglandin analogues were able to reduce pronephric cysts size in the used nphp zebrafish model. ConclusionOur study indicates that these molecules can show beneficial effects across genetic contexts and shed light on their potential as therapeutic interventions for nephronophthisis.

cell biology↗

Pharmacological cAMP stimulation via prostaglandin receptors rescues ciliary defects in CEP290-deficient patient and mouse models

The retinas sensitivity to light depends on the primary cilium of photoreceptors, known as the outer segment (OS). OS defects are a primary cause of inherited retinal dystrophies (IRDs) and can also indicate wider ciliary dysfunctions. One such IRD is Leber congenital amaurosis type 10 (LCA10), which occurs as a monosymptomatic retinal disease or the presenting symptom of syndromic ciliopathies within the Senior-Loken-Joubert-Meckel spectrum. LCA10 patients are born blind but retain dormant photoreceptors for decades, offering the potential for reactivation. AAV-based gene therapies for IRDs cannot accommodate the large CEP290 gene, prompting the search for innovative treatments. LCA10 is caused by mutations in CEP290, which plays a vital role in ciliation, similar to cAMP signaling. Utilizing fibroblasts displaying variable CEP290 mutations and associated ciliary defects, we show that exposure to Taprenepag, a specific PGE2 receptor agonist, substantially stimulated cAMP synthesis and consistently improved cilia formation and elongation. We also found that intraperitoneal injection of Taprenepag in mice reached the retina and slowed retinal degeneration, promoting OS formation, and improving light sensitivity in a Cep290 mutant mouse. These findings demonstrate the potential of Taprenepag to treat the CEP290-related visual dysfunction and suggest evaluation for other CEP290-related organ issues and ciliopathies.

genetics↗

Abnormal autophagy is a critical mechanism in TANGO2-related rhabdomyolysis

Patients with pathogenic variants in the TANGO2 gene suffer from severe and recurrent rhabdomyolysis (RM) episodes precipitated by fasting. Since starvation promotes autophagy induction, we wondered whether TANGO2-related muscle symptoms result from autophagy insufficiency to meet cellular demands in stress conditions. Autophagy functioning was analyzed in vitro, in primary skeletal muscle cells from TANGO2 patients in basal and fasting conditions. In addition, we developed a tango2 morphant zebrafish model to assess the effect of tango2 knockdown (KD) on locomotor function and autophagy efficiency in vivo. We report that TANGO2 mutations are associated with decreased LC3-II levels upon starvation in primary muscle cells, but not in fibroblasts. In zebrafish larvae, tango2 knockdown induces locomotor defects characterized by reduced evoked movements which are exacerbated by exposure to atorvastatin, a compound known to cause RM. Importantly, RM features of tango2 KD are also associated with autophagy and mitophagy defects in zebrafish. Calpeptin treatment, a known activator of autophagy, is sufficient to rescue the locomotor properties, thanks to its beneficial effect on autophagy functioning in zebrafish and independently to its effect on calpain activity. LC3-II levels of primary muscle cells of TANGO2 patients are also improved by calpeptin treatment. Overall, we demonstrate that TANGO2 plays an important role in autophagy, and that autophagy efficiency is critical to prevent RM, thus giving rise to new therapeutic perspectives in the prevention of these life-threatening episodes in TANGO2 pathology.

cell biology↗

The Pentose Phosphate Pathway constitutes a major metabolic hub in pathogenic Francisella

Metabolic pathways are now considered as intrinsic virulence attributes of pathogenic bacteria and hence represent potential targets for anti-bacterial strategies. Here, we addressed the role of the pentose phosphate pathway (PPP) and its connections with other metabolic pathways in the pathophysiology of Francisella novicida. The involvement of the PPP in Francisella intracellular life cycle was first demonstrated with the study of PPP inactivation mutants. Indeed, inactivation of tktA, rpiA or rpe genes, severely impaired intramacrophagic multiplication during the first 24 hours. Time-lapse video microscopy demonstrated that rpiA and rpe mutants were able to resume late intracellular bacterial multiplication. To get further insight into the links between the PPP and other metabolic networks of the bacterium, we next performed a thorough proteo-metabolomic analysis of these mutants. We show that the PPP constitutes a major bacterial metabolic hub with multiple connections with glycolysis, tricarboxylic acid cycle and other pathways, such as fatty acid degradation and sulfur metabolism. Hence, our study highlights how the PPP is instrumental to Francisella pathogenesis and growth in its intracellular niche.

microbiology↗