Molecular Genetics of Bartter Syndrome

Bartter syndrome (BS) is a heterogeneous disorder, caused by mutations in several genes which mostly encode proteins involved in ions transportation across renal cells in the thick ascending limb of the nephron. It is characterized by deficient renal reabsorption of sodium and chloride, which results in a group of certain symptoms. Different types of BS can be distinguished from different clinical manifestations, and most importantly, via analyzing possible affected gene(s) for its confirmation. A close associated syndrome which was primarily considered as a mild variant of BS, Gitelman syndrome (GS), is characterized by hypokalemic metabolic alkalosis with hypocalciuria, and hypomagnesemia. In this review, we discuss different features of BS and also GS, including clinical and genetic alterations which correspond to each type.  Keywords: Bartter Syndrome; Molecular Genetics; Child

First report of inherited thyroxine-binding globulin deficiency in Iran caused by a known de novo mutation in SERPINA7

Background Thyroxine-binding globulin (TBG) is the main transporter of thyroid hormones in human serum, encoded by the gene TBG (SERPINA7), located in long arm of X-chromosome (Xq21-q22). Deficiency of SERPINA7 (serum protease inhibitor, clade A alpha-1 antiproteinase, antitrypsin, member 7) leads to inherited TBG deficiency. Several mutations have been reported in the coding and noncoding regions of SERPINA7 in association with TGB deficiency. Methods Automated chemiluminescence immunoassays were used to determine TSH, free and total T4 and T3 (fT4, TT4, TT3) and TBG. Direct DNA sequencing identified the mutation in SERPINA7. Results We present a 3 and 4/12 year old boy, born premature, who was mismanaged as hypothyroidism before referral to our center, and was diagnosed with TBG deficiency at our center with a hemizygous substitution in exon 1, position c.347T > A, leading to replacement of isoleucine for arginine in position 96 (considering the first 20 amino acid signal peptide). Conclusion This known mutation, reported as the first SERPINA7 mutation in Iran, emphasizes the point that endocrinologists should pay more attention to inherited TBG to prevent unnecessary treatment

Terminal differentiation of villus tip enterocytes is governed by distinct Tgfβ superfamily members

The protective and absorptive functions of the intestinal epithelium rely on differentiated enterocytes in the villi. The differentiation of enterocytes is orchestrated by sub-epithelial mesenchymal cells producing distinct ligands along the villus axis, in particular Bmps and Tgfβ. Here, we show that individual Bmp ligands and Tgfβ drive distinct enterocytic programs specific to villus zonation. Bmp4 is expressed from the centre to the upper part of the villus and activates preferentially genes connected to lipid uptake and metabolism. In contrast, Bmp2 is produced by villus tip mesenchymal cells and it influences the adhesive properties of villus tip epithelial cells and the expression of immunomodulators. Additionally, Tgfβ induces epithelial gene expression programs similar to those triggered by Bmp2. Bmp2-driven villus tip program is activated by a canonical Bmp receptor type I/Smad-dependent mechanism. Finally, we establish an organoid cultivation system that enriches villus tip enterocytes and thereby better mimics the cellular composition of the intestinal epithelium. Our data suggest that not only a Bmp gradient but also the activity of individual Bmp drives specific enterocytic programs

Epithelial to mesenchymal transition trajectories in developmental and disease

Resumen del trabajo presentado al 19th International Congress of Developmental Biology, celebrado en El Algarve (Portugal) del 16 al 20 de octubre de 2022.The Epithelial to Mesenchymal transition (EMT) triggers cell plasticity during embryonic development and tissue repair, but it can also promote tumor progression and organ degeneration. The reactivation of EMT in the adult promotes cell dedifferentiation and profound remodeling of the epithelial program, leading to multiple phenotypes, observed in response to injury, during organ fibrosis and cancer cell dissemination. Despite recent advances, identifying universal EMT molecular signatures and understanding how EMT can instructs different outcomes have remained elusive due to the intrinsic complexity and heterogeneity of the process. We have dissected how EMT transcription factors (EMT-TFs) orchestrate TGFBinduced EMT including phenotypic and behavioral states. Further, we have combined lineage tracing and single-cell transcriptomics in three EMT contexts, namely the neural crest, renal fibrosis, and breast cancer to reveal conserved EMT transcription factor codes and signaling pathways that discriminate different EMT states. After inferring cellular trajectories, we have reconstructed the evolution of EMT phenotypic and functional states in all these contexts. Finally, multiplex labeling allowed to spatially allocate distinct EMT programs in mouse and human tumor samples. Altogether, this work unveils distinct EMT trajectories in development and disease, which should also help propase improved therapeutic strategies for organ fibrosis and cancer.Peer reviewe

Two distinct epithelial to mesenchymal transition programmes. Control invasion and inflammation in segregated tumour cell populations

Resumen del trabajo presentado al 19th Christmas Meeting del Instituto de Neurociencias (CSIC-UMH) celebrado el 21 de diciembre de 2022.Epithelial plasticity is at the core of crucial processes including embryonic cell migration, cancer progression, organ tibrosis and tissue repair. The epithelial to mesenchymal transition (EMT) triggers cell plasticity in all these contexts, highlighting its pleiotropy and intrinsic complcxity. Seminal studies have classified EMT states in cancer celllines and animal modcls. This varicty ofEMT phenotypes necds further investigation, particularly those relevant to the progression ofprevalent and dcvastating diseases such as cancer. Our objcctive is to analyse at single-cell level how different EMT states are established in tumours and if different EMT states pcrform different functions during tumour progression.Peer reviewe

A gene regulatory network to control EMT programs in development and disease

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 23-04-2019Esta tesis tiene embargado el acceso al texto completo hasta el 23-10-2020Epithelial to Mesenchymal Transition (EMT) plays pivotal roles during development and diseases like cancer and fibrosis, through the activation of several EMT transcription factor (EMT-TF) families, including Snail, Zeb, Twist and Prrx. Prior data from the laboratory showed that the patterns of PRRX1 and SNAIL1 expression were complementary in chicken embryos and cancer cells, and that their functions in EMT subprograms, such as the regulation of stemness, also seemed to be distinct. Here, after examining zebrafish, chicken and mouse embryos, we find that this complementary expression of Snail1 and Prrx1 is conserved during vertebrate development. Moreover, analyzing public single-cell RNA sequencing databases of breast, head-and-neck cancer or melanoma patients and from mouse pulmonary fibrosis, we confirmed that this complementary expression is also present in pathological EMTs. By studying the transcriptome of cancer cells, gain and loss of function experiments for the two EMT-TFs, and the use of animal models, we describe a novel gene regulatory network (GRN) where Snail1 and Prrx1 form a double-negative feedback loop, involving miR-15 family. We have found that this GRN triggers an expression switch from Snail1 to Prrx1, with Snail1 being an early-response gene to EMT-inducing signals, which is followed by the activation of Prrx1 that in turn attenuates Snail1 expression through miR-15 family. We have also validated this GRN in vitro and in vivo highlighting its relevance in development and diseaseLa transición epitelio-mesenquimática (EMT) desempeña un papel fundamental durante la embriogénesis y la progresión de enfermedades como el cáncer y la fibrosis, mediante la activación de varias familias de factores de transcripción inductores de la EMT (EMT-TF), incluyendo Snail, Zeb, Twist y Prrx. Resultados previos obtenidos en el laboratorio mostraron que los patrones de expresión de PRRX1 y SNAIL1 eran complementarios en embriones de pollo y células cancerosas, y que sus funciones en subprogramas de la EMT, como la regulación de la pluripotencia, también parecían ser distintas. En este estudio, tras examinar el patrón de expresión de estos EMT-TFs en embriones de pez cebra, de pollo y de ratón hemos encontrado que la expresión complementaria de Snail1 y Prrx1 está conservada en los distintos vertebrados. Además, el análisis de bases de datos públicas obtenidos tras la secuenciación del transcriptoma de células individuales (scRNA seq) de pacientes con cáncer de mama, cuello y cabeza, melanoma, y de ratones con fibrosis pulmonar, confirmamos que esta complementariedad también existe en los procesos de EMT patológicos. Tras el estudio del transcriptoma de células cancerosas y experimentos de ganancia y pérdida de función para los dos EMT-TF, junto con el uso de modelos animales, hemos encontrado una red de regulación génica (GRN) donde Snail1 y Prrx1 forman un bucle de retroalimentación negativo, involucrando a la familia miR-15. Esta red promueve un cambio de expresión de Snail1 a Prrx1, siendo Snail1 un gen de respuesta temprana a señales inductoras de EMT, que es seguida por la activación de Prrx1 que, a su vez, atenúa la expresión de Snail1 mediante la familia miR-15. Hemos validado este GRN in vitro e in vivo, revelando sus implicaciones en el desarrollo embrionario y la enfermedad

Distinct populations of crypt-associated fibroblasts act as signaling hubs to control colon homeostasis

Despite recent progress in recognizing the importance of mesenchymal cells for the homeostasis of the intestinal system, the current picture of how these cells communicate with the associated epithelial layer remains unclear. To describe the relevant cell populations in an unbiased manner, we carried out a single-cell transcriptome analysis of the adult murine colon, producing a high-quality atlas of matched colonic epithelium and mesenchyme. We identify two crypt-associated colonic fibroblast populations that are demarcated by different strengths of platelet-derived growth factor receptor A (Pdgfra) expression. Crypt-bottom fibroblasts (CBFs), close to the intestinal stem cells, express low levels of Pdgfra and secrete canonical Wnt ligands, Wnt potentiators, and bone morphogenetic protein (Bmp) inhibitors. Crypt-top fibroblasts (CTFs) exhibit high Pdgfra levels and secrete noncanonical Wnts and Bmp ligands. While the Pdgfralow cells maintain intestinal stem cell proliferation, the Pdgfrahigh cells induce differentiation of the epithelial cells. Our findings enhance our understanding of the crosstalk between various colonic epithelial cells and their associated mesenchymal signaling hubs along the crypt axis—placing differential Pdgfra expression levels in the spotlight of intestinal fibroblast identity

Investigating and comparing structural, electronic and optical properties of chi-3-Borophene in monolayer, nanoribbon and nanotube modes as a transparent metal

Investigating and comparing structural, electronic and optical properties of chi-3-Borophene in monolayer, nanoribbon and nanotube modes as a transparent metal. OpenMX - Vesta The density functional theory (DFT) was adopted to evaluate the electronic, structural, and optical properties of chi-3-borophene ML, BNRs, and BNTs structures using the OpenMX simulation package. Also, the effect of oxidation on the stability of borophene was studied. The cohesive energy of oxidized borophene (25% O-defected), (0,3) zigzag nanoribbon, (5,0) armchair nanoribbon, zigzag (12,0) and (16,0), and armchair (0,6) and (0,8) BNTs equaled 3.25, 3.24, 3.27, 3.41, 3.43, 3.43, and 3.44 eV, respectively, and their relative stability is as follows: pristine ML > (0,8) BNT > (0,6) BNT > (16,0) BNT > (12,0) BNT > (5,0) armchair NR > 25% O-defected borophene > (0,3) zigzag NR. We concluded that the adsorption of oxygen on boron ML is barrierless, and this reduces stability because any changes trying to buckle the structure lower its stability. However, growing borophene on the Ag (111) surface can help stabilize the structure. The material has a very high optical transparency, thus becoming a very good candidate in photovoltaic and touch screen applications. Specifically, zigzag BNTs have a nearly 100% optical transmission in visible, UV, and portions of the IR spectrum. The absorption coefficient is considerably decreased in (12,0) and (16,0) BNTs compared to armchair BNTs and borophene ML in the IR, visible, and UV spectrum. The refractive index is below unity for a wide range of energy between IR and UV for ML along the x-direction, (0,6), (0,8) BNTs, indicating superluminosity

Effect of β-glucan on serum levels of IL-12, hs-CRP, and clinical outcomes in multiple-trauma patients: A prospective randomized study �oklu travma hastalarda β �glukanın serum IL-12, hs-CRP de�erleri ve klinik sonuçları üzerine etkisi: Ileriye yönelik randomize çalı�ma

BACKGROUND: Trauma is associated with a profound immunological dysfunction. This predisposes patients to infections and adverse outcomes. β-glucan has been implicated in the initiation of anti-microbial immune response. The present study aimed to evaluate the effects of an enteral diet containing β-glucan on serum levels of IL-12 and highly-sensitive C-reactive protein (hs-CRP), occurrence of infection, and clinical outcomes in critically ill multiple-trauma patients. METHODS: Forty multiple-trauma patients requiring enteral nutrition for at least 10 days were randomly assigned to the intervention group (n=20) or the placebo group (n=20). The intervention group received a high-protein enteral diet providing 3 g β-glucan, and the control group received a similar diet, except for 3 g of maltodextrin as a placebo. Serum levels of IL-12 and hs-CRP were measured on days 0, 10, and 21. RESULTS: The β-glucan group showed significantly higher serum levels of IL-12 on day 21 compared to the control group. Infection frequency and duration of mechanical ventilation were significantly lower in the β-glucan group. A significant difference was found in the Sequential Organ Failure Assessment (SOFA) score in favor of the β-glucan group. No difference was found in the serum levels of hs-CRP, length of ICU stay, occurrence of infection, and mortality rates between the two groups. CONCLUSION: β-glucan may increase serum levels of IL-12, shorten the duration of mechanical ventilation, and reduce organ failure in critically ill multiple-trauma patients. © 2018 Turkish Association of Trauma and Emergency Surgery