Biology subjects

Serra-Marques, A.

Publications and source records attributed to Serra-Marques, A..

4 recordsLinked to original sources

bioRxiv2026

NINTEDANIB AND PIRFENIDONE AFFECT GROWTH AND DIFFERENTIATION OF HUMAN ALVEOLAR TYPE 2 CELLS

BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease characterized by epithelial cell senescence. Pirfenidone and nintedanib are approved drugs for the treatment of IPF. They significantly slow disease progression, but their mechanisms of action, especially on alveolar type 2 (AT2) cells, are poorly understood. We addressed this question by evaluating colony formation and growth of human AT2 cells co-cultured with fibroblasts in organoid culture in the presence of pirfenidone and nintedanib. We further evaluated molecular changes induced by these drugs via single cell RNA-seq of treated organoids. MethodsAT2 cells isolated from normal donor lungs or IPF patients were mixed with human fibroblasts in 3D culture and grown in the absence or presence of pirfenidone or nintedanib. After 14 days in culture, the organoids were quantified and cells extracted from Matrigel for single cell RNA-seq. ResultsAT2 cell organoids cultured in the presence of pirfenidone or nintedanib resulted in increased colony formation and, in the case of nintedanib, in larger colonies. We observed that untreated or pirfenidone treated AT2 cells lost surfactant protein C (SFTPC) expression and acquired an expression profile consistent with keratin (KRT)17high/KRT5- basaloid cells, whereas a larger proportion of nintedanib treated cells retained SFTPC expression. In contrast, AT2 cells treated with TGF{beta} inhibitor exhibited intermediate (SFTPC-/KRT17low) gene expression profile. ConclusionThese results suggest that nintedanib maintains an AT2-like expression state in culture and acts proximal to TGF{beta}. Conflict of Interest StatementPJW was supported by grants from Boehringer Ingelheim, Roche, Sanofi, Pliant and Arda Therapeutics and received personal fees from Boehringer Ingelheim and Sanofi. None of these companies had a role in the design or analysis of the study or in the writing of the manuscript. ASM, GP, JRR and DG are employees of Genetech. The other authors have no conflicts of interest to declare.

cell biology↗

bioRxiv2021

Angiomotin isoform 2 promotes binding of PALS1 to KIF13B at the base of primary cilia and suppresses ciliary elongation

The kinesin-3 motor KIF13B functions in endocytosis, vesicle transport, and regulation of ciliary length and signaling. Direct binding of the membrane-associated guanylate kinase (MAGUK) DLG1 to KIF13Bs MAGUK-binding stalk (MBS) domain relieves motor autoinhibition and promotes microtubule plus end-directed cargo transport. Here we characterize Angiomotin isoform 2 (Ap80) as a novel KIF13B interactor that promotes binding of another MAGUK, the polarity protein and Crumbs complex component PALS1, to KIF13B. Live cell imaging analysis indicated that Ap80 is concentrated at the base of primary cilia and recruits PALS1 to this site, but is not itself a cargo of KIF13B. Consistent with a ciliary function for Ap80, its depletion led to elongated primary cilia while its overexpression caused ciliary shortening. Our results suggest that Ap80 may specifically activate KIF13B cargo binding at the base of primary cilia to regulate ciliary length.

cell biology↗

bioRxiv2020

The mitotic protein NuMA plays a spindle-independent role in nuclear formation and mechanics

Eukaryotic cells typically form a single, round nucleus after mitosis, and failures to do so can compromise genomic integrity. How mammalian cells form such a nucleus remains incompletely understood. NuMA is a spindle protein whose disruption results in nuclear fragmentation. What role NuMA plays in nuclear integrity, or whether its perceived role stems from its spindle function, is unclear. Here, we use live imaging to demonstrate that NuMA plays a spindle-independent role in forming a single, round nucleus. NuMA keeps the decondensing chromosome mass compact at mitotic exit, and promotes a mechanically robust nucleus. NuMAs C-terminus binds DNA in vitro and chromosomes in interphase, while its coiled-coil acts as a regulatory and structural hub: it prevents NuMA from binding chromosomes at mitosis, regulates its nuclear mobility and is essential for nuclear formation. Thus, NuMA plays a long-range structural role in building and maintaining an intact nucleus, as it does for the spindle, playing a protective role over the cell cycle.

cell biology↗

bioRxiv2020

Concerted action of kinesin-1 KIF5B and kinesin-3 KIF13B promotes efficient transport of exocytotic vesicles to microtubule plus ends

Intracellular transport relies on multiple kinesins, but it is poorly understood which kinesins are present on particular cargos, what their contributions are and whether they act simultaneously on the same cargo. Here, we show that Rab6-positive secretory vesicles are transported from the Golgi apparatus to the cell periphery by kinesin-1 KIF5B and kinesin-3 KIF13B, which determine the location of secretion events. KIF5B plays a dominant role, whereas KIF13B helps Rab6 vesicles to reach freshly polymerized microtubule ends, to which KIF5B binds poorly, likely because its cofactors, MAP7-family proteins, are slow in populating these ends. Sub-pixel localization demonstrated that during microtubule plus-end directed transport, both kinesins localize to the vesicle front and can be engaged on the same vesicle. When vesicles reverse direction, KIF13B relocates to the middle of the vesicle, while KIF5B shifts to the back, suggesting that KIF5B but not KIF13B undergoes a tug-of-war with a minus-end directed motor.

cell biology↗