Publications by authors named "Branko Stefanovic"

Motile cilia on the cell surface produce fluid flows in the body and abnormalities in motile cilia cause primary ciliary dyskinesia. Dynein axonemal assembly factor 6 (DNAAF6), a causative gene of primary ciliary dyskinesia, was isolated as an interacting protein with La ribonucleoprotein 6 (LARP6) that regulates ciliogenesis in multiciliated cells (MCCs). In MCCs of Xenopus embryos, LARP6 and DNAAF6 were colocalized in biomolecular condensates termed dynein axonemal particles and synergized to control ciliogenesis.

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A predictive analysis of the conservative scoliosis treatment is necessary, in which a 3D model of an optimal treatment algorithm is a basic part in the design of a prosthetic corset. Since CAD technology has proven to be very useful in the field of prosthetics and orthotics, we used an open-source software to plan the correction of the scoliotic curve on a virtual model of the subject's torso. The shape of the scoliosis was simplified by means of a directional polygon, which was drawn in a reverse manner depending on the directional arcs of the scoliotic curve.

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Background & Aims: A number of genetic polymorphisms have been associated with susceptibility to or protection against non-alcoholic fatty liver disease (NAFLD), but the underlying mechanisms remain unknown. Here, we focused on the rs738409 C>G single nucleotide polymorphism (SNP), which produces the I148M variant of patatin-like phospholipase domain-containing protein 3 (PNPLA3) and is strongly associated with NAFLD.

Methods: To enable mechanistic dissection, we developed a human pluripotent stem cell (hPSC)-derived multicellular liver culture by incorporating hPSC-derived hepatocytes, hepatic stellate cells, and macrophages.

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Central nervous system (CNS) trauma activates a persistent repair response that leads to fibrotic scar formation within the lesion. This scarring is similar to other organ fibrosis in many ways; however, the unique features of the CNS differentiate it from other organs. In this review, we discuss fibrotic scar formation in CNS trauma, including the cellular origins of fibroblasts, the mechanism of fibrotic scar formation following an injury, as well as the implication of the fibrotic scar in CNS tissue remodeling and regeneration.

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Excessive synthesis of type I collagen is a hallmark of fibrotic diseases. Binding of La-related protein 6 (LARP6) to the 5' stem-loop (5'SL) of collagen mRNAs regulates their translation leading to an unnaturally elevated rate of collagen biosynthesis in fibrosis. Previous work suggested that LARP6 needs two domains to form stable complex with 5'SL RNA, the La domain and the juxtaposed RNA recognition motif (RRM), jointly called the La-module.

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Mechanistic aspects of type I procollagen biosynthesis in cells are poorly understood. To provide more insight into this process we designed a system to directly image type I procollagen biogenesis by co-expression of fluorescently labeled full size procollagen α1(I) and one α2(I) polypeptides. High resolution images show that collagen α1(I) and α2(I) polypeptides are produced in coordination in discrete structures on the ER membrane, which we termed the collagenosomes.

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Case Description: Conventional methods for producing custom prosthetic fingers are time-consuming, can be uncomfortable for the patient, and require a skilled prosthetist. The subject was a 40-year-old male with congenital absence of the thumb and related metacarpal bone on the right non-dominant hand, anomaly of the lengths of individual upper limb segments, and contracture of the elbow joint. This hand presentation made it impossible for him to perform thumb opposition, which is a very important function for common daily activities.

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Fibrosis is a major medical problem caused by excessive synthesis of the extracellular matrix, composed predominantly of type I collagen, in various tissues. There are no approved antifibrotic drugs, and the major obstacle in finding clinically relevant compounds is the lack of specificity of current experimental drugs for type I collagen. Here we describe the discovery of a lead compound that specifically inhibited secretion of type I collagen by fibroblasts in culture at IC = 4.

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Background: Although keloids have been empirically treated with steroids and radiation, evidence-based radiation parameters for keloid therapy are lacking.

Objective: To determine evidence-based radiation parameters for blocking keloid fibroblast proliferation in vitro and apply them to patients.

Methods: The effects of various radiation parameters and steroids on cell proliferation, cell death, and collagen production in keloid explants and fibroblasts were evaluated with standard assays.

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Fibrosis is defined by excessive production of type I collagen in various organs. Excessive type I collagen production in fibrosis is stimulated by binding of RNA protein LARP6 to the structural element of collagen mRNAs, the 5' stem loop (5'SL). The LARP6-dependent regulation is specific for type I collagen and critical for fibrosis development.

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Fibrosis is characterized by excessive production of type I collagen. Biosynthesis of type I collagen in fibrosis is augmented by binding of protein LARP6 to the 5' stem-loop structure (5'SL), which is found exclusively in type I collagen mRNAs. A high throughput screen was performed to discover inhibitors of LARP6 binding to 5'SL, as potential antifibrotic drugs.

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Background: La-related protein 6 (LARP6) is an evolutionally conserved RNA-binding protein. Vertebrate LARP6 binds the 5' stem-loop found in mRNAs encoding type I collagen to regulate their translation, but other target mRNAs and additional functions for LARP6 are unknown. The aim of this study was to elucidate an additional function of LARP6 and to evaluate the importance of its function during development.

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Excessive deposition of type I collagen causes fibrotic diseases. Binding of La ribonucleoprotein domain family, member 6 (LARP6) to collagen mRNAs regulates their translation and is necessary for high type I collagen expression. Here we show that mTORC1 phosphorylates LARP6 on S348 and S409.

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Background: Idiopathic Pulmonary Fibrosis (IPF) is a lethal lung disease of unknown etiology. A major limitation in transcriptomic profiling of lung tissue in IPF has been a dependence on snap-frozen fresh tissues (FF). In this project we sought to determine whether genome scale transcript profiling using RNA Sequencing (RNA-Seq) could be applied to archived Formalin-Fixed Paraffin-Embedded (FFPE) IPF tissues.

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Type I collagen is the most abundant structural protein in all vertebrates, but its constitutive rate of synthesis is low due to long half-life of the protein (60-70 days). However, several hundred fold increased production of type I collagen is often seen in reparative or reactive fibrosis. The mechanism which is responsible for this dramatic upregulation is complex, including multiple levels of regulation.

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La ribonucleoprotein domain family, member 6 (LARP6) is the RNA binding protein, which regulates translation of collagen mRNAs and synthesis of type I collagen. Posttranslational modifications of LARP6 and how they affect type I collagen synthesis have not been studied. We show that in lung fibroblasts LARP6 is phosphorylated at 8 serines, 6 of which are located within C-terminal domain.

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Overproduction of type I collagen is associated with a wide range of fibrotic diseases as well as surgical failure such as in glaucoma filtration surgery (GFS). Its modulation is therefore of clinical importance. Valproic acid (VPA) is known to reduce collagen in a variety of tissues with unclear mechanism of action.

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Type I collagen is composed of 2 polypeptides, α1(I) and α2(I), which fold into triple helix. Collagen α1(I) and α2(I) mRNAs have a conserved stem-loop structure in their 5' UTRs, the 5'SL. LARP6 binds the 5'SL to regulate type I collagen expression.

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Type I collagen is extracellular matrix protein composed of two α1(I) and one α2(I) polypeptides that fold into triple helix. Collagen polypeptides are translated in coordination to synchronize the rate of triple helix folding to the rate of posttranslational modifications of individual polypeptides. This is especially important in conditions of high collagen production, like fibrosis.

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Fibroproliferative diseases are one of the leading causes of death worldwide. They are characterized by reactive fibrosis caused by uncontrolled synthesis of type I collagen. There is no cure for fibrosis and development of therapeutics that can inhibit collagen synthesis is urgently needed.

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Regulatory Factor X (RFX) transcription factors are important for development and are likely involved in the pathogenesis of serious human diseases including ciliopathies. While seven RFX genes have been identified in vertebrates and several RFX transcription factors have been reported to be regulators of ciliogenesis, the role of RFX7 in development including ciliogenesis is not known. Here we show that RFX7 in Xenopus laevis is expressed in the neural tube, eye, otic vesicles, and somites.

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Collagen content in atherosclerotic plaque is a hallmark of plaque stability. Our earlier studies showed that insulin-like growth factor-1 (IGF-1) increases collagen content in atherosclerotic plaques of Apoe(-/-) mice. To identify mechanisms we investigated the effect of IGF-1 on the la ribonucleoprotein domain family member 6 (LARP6).

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Type I collagen is the most abundant protein in the human body and is composed of two α1(I) and one α2(I) polypeptides which assemble into a triple helix. For the proper assembly of the collagen triple helix, the individual polypeptides must be translated in coordination. Here, we show that serine-threonine kinase receptor-associated protein (STRAP) is tethered to collagen mRNAs by interaction with LARP6.

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