IPF pathogenesis is dependent upon TGFß induction of IGF-1.

Pathogenic fibrotic diseases, including idiopathic pulmonary fibrosis (IPF), have some of the worst prognoses and affect millions of people worldwide. With unclear etiology and minimally effective therapies, two-thirds of IPF patients die within 2-5 years from this progressive interstitial lung disease. Transforming Growth Factor Beta (TGFß) and insulin-like growth factor-1 (IGF-1) are known to promote fibrosis; however, myofibroblast specific upregulation of IGF-1 in the initiation and progression of TGFß-induced fibrogenesis and IPF have remained unexplored. To address this, the current study (1) documents the upregulation of IGF-1 via TGFß in myofibroblasts and fibrotic lung tissue, as well as its correlation with decreased pulmonary function in advanced IPF; (2) identifies IGF-1's C1 promoter as mediating the increase in IGF-1 transcription by TGFß in pulmonary fibroblasts; (3) determines that SMAD2 and mTOR signaling are required for TGFß-dependent Igf-1 expression in myofibroblasts; (4) demonstrates IGF-1R activation is essential to support TGFß-driven profibrotic myofibroblast functions and excessive wound healing; and (5) establishes the effectiveness of slowing the progression of murine lung fibrosis with the IGF-1R inhibitor OSI-906. These findings expand our knowledge of IGF-1's role as a novel fibrotic-switch, bringing us one step closer to understanding the complex biological mechanisms responsible for fibrotic diseases and developing effective therapies.

SIRT7-mediated modulation of glutaminase 1 regulates TGF-ß-induced pulmonary fibrosis.

In the current work we show that the profibrotic actions of TGF-ß are mediated, at least in part, through a metabolic maladaptation in glutamine metabolism and how the inhibition of glutaminase 1 (GLS1) reverses pulmonary fibrosis. GLS1 was found to be highly expressed in fibrotic vs normal lung fibroblasts and the expression of profibrotic targets, cell migration, and soft agar colony formation stimulated by TGF-ß required GLS1 activity. Moreover, knockdown of SMAD2 or SMAD3 as well as inhibition of PI3K, mTORC2, and PDGFR abrogated the induction of GLS1 by TGF-ß. We further demonstrated that the NAD-dependent protein deacetylase, SIRT7, and the FOXO4 transcription factor acted as endogenous brakes for GLS1 expression, which are inhibited by TGF-ß. Lastly, administration of the GLS1 inhibitor CB-839 attenuated bleomycin-induced pulmonary fibrosis. Our study points to an exciting and unexplored connection between epigenetic and transcriptional processes that regulate glutamine metabolism and fibrotic development in a TGF-ß-dependent manner.

Fatty acid synthase is required for profibrotic TGF-ß signaling.

Evidence is provided that the fibroproliferative actions of TGF-ß are dependent on a metabolic adaptation that sustains pathologic growth. Specifically, profibrotic TGF-ß signaling is shown to require fatty acid synthase (FASN), an essential anabolic enzyme responsible for the de novo synthesis of fatty acids. With the use of pharmacologic and genetic approaches, we show that TGF-ß-stimulated FASN expression is independent of Smad2/3 and is mediated via mammalian target of rapamycin complex 1. In the absence of FASN activity or protein, TGF-ß-driven fibrogenic processes are reduced with no apparent toxicity. Furthermore, as increased FASN expression was also observed to correlate with the degree of lung fibrosis in bleomycin-treated mice, inhibition of FASN was examined in a murine-treatment model of pulmonary fibrosis. Remarkably, inhibition of FASN not only decreased expression of profibrotic targets, but lung function was also stabilized/improved, as assessed by peripheral blood oxygenation.-Jung, M.-Y., Kang, J.-H., Hernandez, D. M., Yin, X., Andrianifahanana, M., Wang, Y., Gonzalez-Guerrico, A., Limper, A. H., Lupu, R., Leof, E. B. Fatty acid synthase is required for profibrotic TGF-ß signaling.

Profibrotic up-regulation of glucose transporter 1 by TGF-ß involves activation of MEK and mammalian target of rapamycin complex 2 pathways.

TGF-ß plays a central role in the pathogenesis of fibroproliferative disorders. Defining the exact underlying molecular basis is therefore critical for the development of viable therapeutic strategies. Here, we show that expression of the facilitative glucose transporter 1 (GLUT1) is induced by TGF-ß in fibroblast lines and primary cells and is required for the profibrotic effects of TGF-ß. In addition, enhanced GLUT1 expression is observed in fibrotic areas of lungs of both patients with idiopathic pulmonary fibrosis and mice that are subjected to a fibrosis-inducing bleomycin treatment. By using pharmacologic and genetic approaches, we demonstrate that up-regulation of GLUT1 occurs via the canonical Smad2/3 pathway and requires autocrine activation of the receptor tyrosine kinases, platelet-derived and epidermal growth factor receptors. Engagement of the common downstream effector PI3K subsequently triggers activation of the MEK and mammalian target of rapamycin complex 2, which cooperate in regulating GLUT1 expression. Of note, inhibition of GLUT1 activity and/or expression is shown to impair TGF-ß-driven fibrogenic processes, including cell proliferation and production of profibrotic mediators. These findings provide new perspectives on the interrelation of metabolism and profibrotic TGF-ß signaling and present opportunities for potential therapeutic intervention.-Andrianifahanana, M., Hernandez, D. M., Yin, X., Kang, J.-H., Jung, M.-Y., Wang, Y., Yi, E. S., Roden, A. C., Limper, A. H., Leof, E. B. Profibrotic up-regulation of glucose transporter 1 by TGF-ß involves activation of MEK and mammalian target of rapamycin complex 2 pathways.

Profibrotic TGFß responses require the cooperative action of PDGF and ErbB receptor tyrosine kinases.

Transforming growth factor ß (TGFß) has significant profibrotic activity both in vitro and in vivo. This reflects its capacity to stimulate fibrogenic mediators and induce the expression of other profibrotic cytokines such as platelet-derived growth factor (PDGF) and epidermal growth factor (EGF/ErbB) ligands. Here we address both the mechanisms by which TGFß induced ErbB ligands and the physiological significance of inhibiting multiple TGFß-regulated processes. The data document that ErbB ligand induction requires PDGF receptor (PDGFR) mediation and engages a positive autocrine/paracrine feedback loop via ErbB receptors. Whereas PDGFRs are essential for TGFß-stimulated ErbB ligand up-regulation, TGFß-specific signals are also required for ErbB receptor activation. Subsequent profibrotic responses are shown to involve the cooperative action of PDGF and ErbB signaling. Moreover, using a murine treatment model of bleomycin-induced pulmonary fibrosis we found that inhibition of TGFß/PDGF and ErbB pathways with imatinib plus lapatinib, respectively, not only prevented myofibroblast gene expression to a greater extent than either drug alone, but also essentially stabilized gas exchange (oxygen saturation) as an overall measure of lung function. These observations provide important mechanistic insights into profibrotic TGFß signaling and indicate that targeting multiple cytokines represents a possible strategy to ameliorate organ fibrosis dependent on TGFß.

Comparison of the effects of different infant formulas on the growth and development and intestinal flora of infants.

The purpose of this study was to compare the effects of different infant formulas on the growth and development, sleep, allergy symptoms, and intestinal flora of infants. A total of 428 infants participated in the study. Breastfeeding (BF) was used as the control, and the remaining subjects were randomly assigned to the full goat milk protein formula group (FGM), partial goat milk protein formula group (PGM), and cow milk formula group (M). During the 6-month feeding experiment, data on the growth, sleep, allergy symptoms, and intestinal flora of infants were collected using questionnaires, anthropometric measurements, and biochemical examinations. In general, the basic information of the participants was consistent among the groups. There were no differences in infant weight, length, or head circumference among the groups (p > .05). The sleep time of infants in the formula-fed groups was longer than that of the breastfeeding group at baseline (p < .05), but there were no differences at mid-term or outcome (p > .05). The incidence of allergic symptoms continued to decrease, and the total scores of allergic symptoms did not differ among the groups (p > .05). The relative abundance of intestinal Bifidobacteriaceae in the PGM group was lower than that in the other groups (p < .05). There was no difference in the ß-diversity of intestinal flora between formula-fed and breastfed infants (p > .05). There were strong correlations in the composition of the main intestinal flora at the family level between the formula and breastfeeding groups. This study showed that within 6 months of feeding, there were no significant differences in the growth and development, allergic symptoms, or intestinal flora of the infants among the groups.

Hypoglycemic Effects and Mechanisms of Buckwheat-Oat-Pea Composite Flour in Diabetic Rats.

Nutritional intervention is a basic way to prevent and treat diabetes mellitus. Appropriate whole grain intake daily is recommended. The study aimed to explore the feasibility of a kind of buckwheat-oat-pea composite flour (BOP, quality ratio of buckwheat:oats:peas = 6:1:1) as a stable food substitution and its underlying mechanisms. High-fat food (HFD) and streptozotocin injection were used to induce diabetes in rats, and buckwheat, oats, and three different doses of BOP were added to the HFD separately for diet intervention. The whole study lasted for 10 weeks, and the glucose tolerance test, lipids, liver injury, and gut microbiota were evaluated in the last week. The diabetic rat model was successfully induced. The BOP significantly changed the glucose and lipids metabolism, decreased liver injury, and changed the composition of the gut microbiota of diabetic rats. The outcomes of the current study revealed that BOP is a potential stable food substitution.

As a Staple Food Substitute, Oat and Buckwheat Compound Has Health-Promoting Effects for Diabetic Rats.

Dietary intervention is crucial for the prevention and control of diabetes. China has the largest diabetic population in the world, yet no one dietary strategy matches the eating habits of the Chinese people. To explore an effective and acceptable dietary pattern, this study uses oat and buckwheat compound (OBC) as a staple food substitute and explored its effects on diabetic Sprague-Dawley rats. The model of diabetic rats was established by combining high-calorie feed and streptozotocin (STZ) injection. The dietary intervention for the seven groups, including a normal control group, a model control group, a metformin control group, a wheat flour control group, and three OBC groups with different doses, started from the beginning of the experiment and lasted for 11 weeks, two consecutive injections of STZ in small doses were operated at the 6th week. General states, glucose metabolism, and lipid metabolism indexes were measured. Antioxidant and inflammatory indexes and pathologic changes of kidney and liver tissues were tested. Changes in kidney and ileum ultramicrostructure were detected. What's more, ileal epithelial tight junction proteins and gut microbiota were analyzed. Significant decreases in fasting blood glucose (FBG), glucose tolerance, serum insulin, and insulin resistance were observed in rats intervened with OBC, and these rats also showed a higher level of superoxide dismutase (SOD) together with improved lipid metabolism, attenuated inflammation, and liver and kidney injuries. In addition, in OBC groups, the intestinal barrier was improved, and the disturbance of gut microbiota was reduced. These results suggest that OBC has health-promoting effects for diabetic rats, and since oat and buckwheat are traditionally consumed grains in China, OBC could be a potential and easy-to-accept staple food substitute for the dietary pattern for Chinese.

Sugar Content of Market Beverages and Children's Sugar Intake from Beverages in Beijing, China.

(1) Background: This study aims to find the sugar content of market beverages and estimate the sugar intake from beverages among students in Beijing. (2) Methods: Using snapshotting, we collected the sugar content of beverages through their packages or nutrition labels. Combined with the statistic of student beverage consumption, we estimated students' sugar intake. (3) Results: The median sugar content of total beverages was 9.0 g/100 mL, among which the fruits/vegetable juices and beverages had the highest sugar content (10.0 g/100 mL). Sugar content in most beverages in Beijing was generally higher than the recommendations, and fruit/vegetable juices and beverages exceeded the most. The median of sugar intake from beverages among students was 5.3 g/d, and the main sources were fruit/vegetable juices and beverages, protein beverages and carbonated beverages. Sugar intake from beverages differed according to gender, age and living area. Higher sugar intake was found among boys, older students and rural students. (4) Conclusions: Sugar content in market beverages in Beijing were high. Gender, age and residence were the influencing factors of sugar intake. Targeted measures should be taken to decrease the sugar content in beverages, especially the fruit/vegetable juices and beverages and the sugar intake among students.

Polymeric antibacterial materials: design, platforms and applications.

Over the past decades, the morbidity and mortality caused by pathogen invasion remain stubbornly high even though medical care has increasingly improved worldwide. Besides, impacted by the ever-growing multidrug-resistant bacterial strains, the crisis owing to the abuse and misuse of antibiotics has been further exacerbated. Among the wide range of antibacterial strategies, polymeric antibacterial materials with diversified synthetic strategies exhibit unique advantages (e.g., their flexible structural design, processability and recyclability, tuneable platform construction, and safety) for extensive antibacterial fields as compared to low molecular weight organic or inorganic antibacterial materials. In this review, polymeric antibacterial materials are summarized in terms of four structure styles and the most representative material platforms to achieve specific antibacterial applications. The superiority and defects exhibited by various polymeric antibacterial materials are elucidated, and the design of various platforms to elevate their efficacy is also described. Moreover, the application scope of polymeric antibacterial materials is summarized with regard to tissue engineering, personal protection, and environmental security. In the last section, the subsequent challenges and direction of polymeric antibacterial materials are discussed. It is highly expected that this critical review will present an insight into the prospective development of antibacterial functional materials.

Effects of transgenic Bacillus Thuringiensis maize (2A-7) on the growth and development in rats.

This study aimed to determine the effects of genetically modified insect-resistant maize (2A-7) on the growth and development in developing rats. Rats were fed a diet formulated with 2A-7 maize and were compared with rats fed a diet formulated with non-transgenic maize (CK group) and rats fed AIN-93G diet (BC group). 2A-7 maize was formulated into diets at ratios of 82.4% (H group) and 20.6% (L group); non-transgenic maize was formulated into diets at a ratio of 82.4%. From the first day of pregnancy, adult rats were divided into four groups and fed with the above four diets, respectively. Weaning on postnatal day 21, the diets of offspring were consistent with their parents. The results showed that body weight, hematology, serum biochemistry, organ weight, organ coefficients and allergenicity of offspring fed with 2A-7 maize were comparable with those in the CK and BC groups. In physiological and behavioral development experiments, there was no statistically significant difference among groups. Although mCry1Ab proteins were detected in organs and serum, no histopathological changes were observed among groups. In conclusion, A-7 maize cause no treatment-related adverse effects on offspring, indicating that 2A-7 maize is safe for developing rats.

A charged second-site mutation in the fusion peptide rescues replication of a mutant avian sarcoma and leukosis virus lacking critical cysteine residues flanking the internal fusion domain.

The entry process of the avian sarcoma and leukosis virus (ASLV) family of retroviruses requires first a specific interaction between the viral surface (SU) glycoproteins and a receptor on the cell surface at a neutral pH, triggering conformational changes in the viral SU and transmembrane (TM) glycoproteins, followed by exposure to low pH to complete fusion. The ASLV TM glycoprotein has been proposed to adopt a structure similar to that of the Ebola virus GP2 protein: each contains an internal fusion peptide flanked by cysteine residues predicted to be in a disulfide bond. In a previous study, we concluded that the cysteines flanking the internal fusion peptide in ASLV TM are critical for efficient function of the ASLV viral glycoproteins in mediating entry. In this study, replication-competent ASLV mutant subgroup A [ASLV(A)] variants with these cysteine residues mutated were constructed and genetically selected for improved replication capacity in chicken fibroblasts. Viruses with single cysteine-to-serine mutations reverted to the wild-type sequence. However, viruses with both C9S and C45S (C9,45S) mutations retained both mutations and acquired a second-site mutation that significantly improved the infectivity of the genetically selected virus population. A charged-amino-acid second-site substitution in the TM internal fusion peptide at position 30 is preferred to rescue the C9,45S mutant ASLV(A). ASLV(A) envelope glycoproteins that contain the C9,45S and G30R mutations bind the Tva receptor at wild-type levels and have improved abilities to trigger conformational changes and to form stable TM oligomers compared to those of the C9,45S mutant glycoprotein.

Study on the release behaviors of berberine hydrochloride based on sandwich nanostructure and shape memory effect.

Nanofibrous drug delivery systems (DDSs) recently have attracted remarkable interest, especially their potential to program dosage of the encased drug intelligently. Despite this, the exploration of efficient strategy to precisely program drug release from nanofibrous DDS still remains a significant challenge. In this study, we electrospun a near-body temperature (Ttrans ≈ 42 °C) sensitive shape memory polyurethane in three stages through sequential electrospinning technology, and prepared a sort of sandwich structural membrane, comprising of top, inner and bottom layers, wherein a natural antibacterial agent, berberine hydrochloride (BCH), was imbedded inside the middle layer. As demonstrated by the results obtained from tensile testing and morphology characterization, the prepared sandwich structural membrane and the nanofibrous membrane with homogenous structure exhibited not only desirable mechanical properties but also surface morphologies. In addition, the release period can be significantly prolonged in virtue of the sandwich structure. As revealed by the experiment of in vitro drug release, it took nearly 144 h to release 80 wt% BCH from sandwich structural membrane, while as little as 72 h was observed to release the same amount of BCH from that with homogenous structure. More interestingly, the encapsulated BCH is capable to be released in a controlled manner owning to the thermo-sensitive shape memory effect, and the release rate of BCH can be accelerated by stretching and fixing the nanofibrous membranes into certain ratios prior to release. Collectively, this study provides a facile strategy to design and prepare a reliable and smart DDS, i.e. sandwich structural membrane, which may enhance the availability of BCH and also intelligently avoid the bacterial infection.

A single-amino-acid substitution in the TvbS1 receptor results in decreased susceptibility to infection by avian sarcoma and leukosis virus subgroups B and D and resistance to infection by subgroup E in vitro and in vivo.

The avian sarcoma and leukosis virus (ASLV) family of retroviruses contains five highly related envelope subgroups (A to E) thought to have evolved from a common viral ancestor in the chicken population. Three genetic loci in chickens determine the susceptibility or resistance of cells to infection by the subgroup A to E ASLVs. Some inbred lines of chickens display phenotypes that are somewhere in between either efficiently susceptible or resistant to infection by specific subgroups of ASLV. The tvb gene encodes the receptor for subgroups B, D, and E ASLVs. The wild-type Tvb(S1) receptor confers susceptibility to subgroups B, D, and E ASLVs. In this study, the genetic defect that accounts for the altered susceptibility of an inbred chicken line, line M, to infection by ASLV(B), ASLV(D), and ASLV(E) was identified. The tvb gene in line M, tvb(r2), encodes a mutant Tvb(S1) receptor protein with a substitution of a serine for a cysteine at position 125 (C125S). Here, we show that the C125S substitution in Tvb(S1) significantly reduces the susceptibility of line M cells to infection by ASLV(B) and ASLV(D) and virtually eliminates susceptibility to ASLV(E) infection both in cultured cells and in the incidence and growth of avian sarcoma virus-induced sarcomas in chickens. The C125S substitution significantly reduces the binding affinity of the Tvb(S1) receptor for the subgroup B, D, and E ASLV envelope glycoproteins. These are the first results that demonstrate a possible role of the cysteine-rich domain 3 in the function of the Tvb receptors.

Mutations in Both the Surface and Transmembrane Envelope Glycoproteins of the RAV-2 Subgroup B Avian Sarcoma and Leukosis Virus Are Required to Escape the Antiviral Effect of a Secreted Form of the TvbS3 Receptor †.

The subgroup A through E avian sarcoma and leukosis viruses ASLV(A) through ASLV(E) are a group of highly related alpharetroviruses that have evolved to use very different host protein families as receptors. We have exploited genetic selection strategies to force the replication-competent ASLVs to naturally evolve and acquire mutations to escape the pressure on virus entry and yield a functional replicating virus. In this study, evolutionary pressure was exerted on ASLV(B) virus entry and replication using a secreted for of its Tvb receptor. As expected, mutations in the ASLV(B) surface glycoprotein hypervariable regions were selected that knocked out the ability for the mutant glycoprotein to bind the sTvbS3-IgG inhibitor. However, the subgroup B Rous associated virus 2 (RAV-2) also required additional mutations in the C-terminal end of the SU glycoprotein and multiple regions of TM highlighting the importance of the entire viral envelope glycoprotein trimer structure to mediate the entry process efficiently. These mutations altered the normal two-step ASLV membrane fusion process to enable infection.

Programmable Release of Berberine Chloride Hydrate from Shape Memory Fibers Prepared from Core-Sheath Wet-Spinning Technology.

Smart wet-spun fibers for highly programmable release of therapeutic drug have been rarely reported. Herein, thermalresponsive composite fibers were successfully prepared by core-sheath wet-spinning technology in present study. They consisted of a model drug of natural antibacterial berberine chloride hydrate (BCH) and a drug carrier of temperature responsive shape memory polyurethane (SMPU). The obtained composite fibers featured with well-controlled microscopic morphologies, exhibiting significantly enhanced thermal stability and superb mechanical properties. In vitro drug release test and corresponding release kinetics study were performed for investigation of BCH's release behavior. Results demonstrated that the release behaviors of BCH from the core-sheath fibers were pH-dependent, influenced by both diffusion from pore channels and the solubility of BCH in the release mediums, and BCH imbedded only in core part showed a longer release period compared with that in both core and sheath parts of the composite fibers. More importantly, the release rate of BCH can be simply controlled by changing the initial shapes of fibers through stretching and fixation of the stretched deformations. Furthermore, the antibacterial durability of the smart composites fibers was demonstrated and tracked according to the growth inhibition against both negative E. coli and positive S. aureus bacteria strains. All these results suggest that the developed composite fibers can be promising candidates as smart drug delivery vehicles for highly adjustable doses of target drugs towards practical applications.

Hexokinase 2 couples glycolysis with the profibrotic actions of TGF-ß.

Metabolic dysregulation in fibroblasts is implicated in the profibrotic actions of transforming growth factor-ß (TGF-ß). Here, we present evidence that hexokinase 2 (HK2) is important for mediating the fibroproliferative activity of TGF-ß both in vitro and in vivo. Both Smad-dependent and Smad-independent TGF-ß signaling induced HK2 accumulation in murine and human lung fibroblasts through induction of the transcription factor c-Myc. Knockdown of HK2 or pharmacological inhibition of HK2 activity with Lonidamine decreased TGF-ß-stimulated fibrogenic processes, including profibrotic gene expression, cell migration, colony formation, and activation of the transcription factors YAP and TAZ, with no apparent effect on cellular viability. Fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) exhibited an increased abundance of HK2. In a mouse model of bleomycin-induced lung fibrosis, Lonidamine reduced the expression of genes encoding profibrotic markers (collagenΙα1, EDA-fibronectin, α smooth muscle actin, and connective tissue growth factor) and stabilized or improved lung function as assessed by measurement of peripheral blood oxygenation. These findings provide evidence of how metabolic dysregulation through HK2 can be integrated within the context of profibrotic TGF-ß signaling.

Facile Fabrication of Sandwich Structural Membrane With a Hydrogel Nanofibrous Mat as Inner Layer for Wound Dressing Application.

A common problem existing in wound dressing is to integrate the properties of against water erosion while maintaining a high water-uptake capacity. To tackle this issue, we imbedded one layer of hydrogel nanofibrous mat into two hydrophobic nanofibrous mats, thereafter, the sandwich structural membrane (SSM) was obtained. Particularly, SSM is composed of three individual nanofibrous layers which were fabricated through sequential electrospinning technology, including two polyurethane/antibacterial agent layers, and one middle gelatin/rutin layer. The obtained SSM is characterized in terms of morphology, component, mechanical, and functional performance. In addition to the satisfactory antibacterial activity against Staphylococcus aureus and Escherichia coli, and antioxidant property upon scavenging DPPH free radicals, the obtained SSM also shows a desirable thermally regulated water vapor transmission rate. More importantly, such SSM can be mechanically stable and keep its intact morphology without appearance damage while showing a high water-absorption ratio. Therefore, the prepared sandwich structural membrane with hydrogel nanofibrous mat as inner layer can be expected as a novel wound dressing.

Genetic Variation in the H19-IGF2 Cluster Might Confer Risk of Developing Impaired Renal Function.

The H19-IGF2 imprinted gene region could be implicated in the risk of developing impaired renal function (IRF). Our aim was to determine the association of several common H19-IGF2 variants and IRF in a cohort of elderly healthy individuals. The study involved 675 individuals >65 years of age, 184 with type 2 diabetes mellitus (T2DM), and 105 with IRF (estimated glomerular filtration rate [eGFR] <60). They were genotyped for two common H19 single nucleotide polymorphisms (SNPs) (rs2839698 and rs10732516), one H19-IGF2 intergenic indel (rs201858505), and one indel in the 3'UTR of the IGF2. For the H19 SNPs, we also determined the allele present in the methylated chromosome through genotyping the DNA digested with a methylation-sensitive endonuclease. None of the four H19-IGF2 variants was associated with IRF in our cohort. We found a significantly higher frequency of the 3'UTR IGF2 deletion (D) in the eGFR <60 group (p = 0.01; odds ratio = 1.16, 95% confidence interval = 1.10-2.51). This association was independent of age and T2DM, two strong predictors of IRF. In conclusion, a common indel variant in the 3'UTR of the IGF2 gene was associated with the risk of IRF. This association could be explained by the role of IGF2 in podocyte survival, through regulation of IGF2 expression by differential binding of miRNAs to the indel sequences. Functional studies should be necessary to clarify this issue.

Basolateral delivery of the type I transforming growth factor beta receptor is mediated by a dominant-acting cytoplasmic motif.

Delivery of biomolecules to the correct subcellular locales is critical for proper physiological function. To that end, we have previously determined that type I and II transforming growth factor beta (TGF-ß) receptors (TßRI and TßRII, respectively) localize to the basolateral domain in polarized epithelia. While TßRII targeting was shown to be regulated by sequences between amino acids 529 and 538, the analogous region(s) within TßRI is unknown. To address that question, sequential cytoplasmic TßRI truncations and point mutations identified a targeting motif between residues 158 and 163 (VxxEED) required for basolateral TßRI expression. Further studies documented that receptor internalization, down-regulation, direct recycling, or Smad signaling were unaffected by motif mutations that caused TßRI mislocalization. However, inclusion of amino acids 148-217 containing the targeting motif was able to direct basolateral expression of the apically sorted nerve growth factor receptor (NGFR, p75; extracellular and transmembrane regions) in a dominant manner. Finally, coexpression of apically targeted type I and type II TGF-ß receptors mediated Smad3 signaling from the apical membrane of polarized epithelial cells. These findings demonstrate that the absence of apical TGF-ß signaling in normal epithelia is primarily a reflection of domain-specific receptor expression and not an inability to couple with the signaling machinery.