Chlorin e6-Conjugated Mesoporous Titania Nanorods as Potential Nanoplatform for Photo-Chemotherapy.

Photodynamic therapy (PDT) has developed as an efficient strategy for cancer treatment. PDT involves the production of reactive oxygen species (ROS) by light irradiation after activating a photosensitizer (PS) in the presence of O2. PS-coupled nanomaterials offer additional advantages, as they can merge the effects of PDT with conventional enabling-combined photo-chemotherapeutics effects. In this work, mesoporous titania nanorods were surface-immobilized with Chlorin e6 (Ce6) conjugated through 3-(aminopropyl)-trimethoxysilane as a coupling agent. The mesoporous nanorods act as nano vehicles for doxorubicin delivery, and the Ce6 provides a visible light-responsive production of ROS to induce PDT. The nanomaterials were characterized by XRD, DRS, FTIR, TGA, N2 adsorption-desorption isotherms at 77 K, and TEM. The obtained materials were tested for their singlet oxygen and hydroxyl radical generation capacity using fluorescence assays. In vitro cell viability experiments with HeLa cells showed that the prepared materials are not cytotoxic in the dark, and that they exhibit photodynamic activity when irradiated with LED light (150 W m-2). Drug-loading experiments with doxorubicin (DOX) as a model chemotherapeutic drug showed that the nanostructures efficiently encapsulated DOX. The DOX-nanomaterial formulations show chemo-cytotoxic effects on Hela cells. Combined photo-chemotoxicity experiments show enhanced effects on HeLa cell viability, indicating that the conjugated nanorods are promising for use in combined therapy driven by LED light irradiation.

Unexpected diagnosis: large hemangioma in the interatrial septum.

BACKGROUND: Cardiac hemangiomas are very uncommon benign primary tumors. They are usually located preferentially in the right atrium and their location in the interatrial septum is extremely rare. CASE PRESENTATION: We report the case of a 41-year-old patient who was admitted due to a stroke. The transthoracic echocardiogram revealed a large mass in the right atrium adhered to the interatrial septum. Suspecting an atrial myxoma, surgical intervention was performed confirming that the mass extended within the thickness of the interatrial septum, protruding into the right atrial cavity. The histologic report confirmed a hemangioma. CONCLUSIONS: Cardiac hemangiomas are rare primary tumors and are usually misdiagnosed as other cardiac tumors. Histopathological examination is essential for a definitive diagnosis.

Metabolomics approach for phenolic compounds profiling of soursop (Annona muricata L.) fruit during postharvest storage.

INTRODUCTION: Soursop (Annona muricata L.) is a crop with medicinal properties and numerous bioactive compounds. Ripening is a complex process that regulates fruit quality and changes in metabolite content, such as flavonoids, polyphenols, and organic acids. OBJECTIVES: This study aimed to analyze the phenolic profiling of soursop fruit ripening. METHODS: The metabolic changes in different days of storage of soursop fruits were investigated using a semi-metabolomic approach based on ultra-performance liquid chromatography coupled to electrospray ionization quadrupole-time of flight mass spectrometry (UPLC-ESI-QTOF-MS). Further, multivariate analysis such as supervised partial least squares discriminant analysis (PLS-DA) was conducted to identify differential metabolites. RESULTS: A total of 68 metabolites were identified in soursop fruit during postharvest storage. A higher number of metabolites were identified in the Day zero (D0) compared to the Day one (D1), Day three (D3), and Day five (D5), belonging to flavonoids, other polyphenols, phenolic acids, and organic acids. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the pathways of flavone and flavonol biosynthesis, flavonoid biosynthesis, and biosynthesis of secondary metabolites were mostly enriched. Additionally, we included all the compounds and their postharvest storage in the public Phenolics profile database. CONCLUSIONS: Here, we show that the stage of ripening has a significant effect on the phenolic content, highlighting the point of cut (D0) and the onset of senescence (D5). The findings of this study provide new insights into the soursop fruit quality and may contribute to the identification of metabolic markers for its storage.

Treatment of infantile-onset Pompe disease in a rat model with muscle-directed AAV gene therapy.

OBJECTIVE: Pompe disease (PD) is caused by deficiency of the lysosomal enzyme acid α-glucosidase (GAA), leading to progressive glycogen accumulation and severe myopathy with progressive muscle weakness. In the Infantile-Onset PD (IOPD), death generally occurs <1 year of age. There is no cure for IOPD. Mouse models of PD do not completely reproduce human IOPD severity. Our main objective was to generate the first IOPD rat model to assess an innovative muscle-directed adeno-associated viral (AAV) vector-mediated gene therapy. METHODS: PD rats were generated by CRISPR/Cas9 technology. The novel highly myotropic bioengineered capsid AAVMYO3 and an optimized muscle-specific promoter in conjunction with a transcriptional cis-regulatory element were used to achieve robust Gaa expression in the entire muscular system. Several metabolic, molecular, histopathological, and functional parameters were measured. RESULTS: PD rats showed early-onset widespread glycogen accumulation, hepato- and cardiomegaly, decreased body and tissue weight, severe impaired muscle function and decreased survival, closely resembling human IOPD. Treatment with AAVMYO3-Gaa vectors resulted in widespread expression of Gaa in muscle throughout the body, normalizing glycogen storage pathology, restoring muscle mass and strength, counteracting cardiomegaly and normalizing survival rate. CONCLUSIONS: This gene therapy holds great potential to treat glycogen metabolism alterations in IOPD. Moreover, the AAV-mediated approach may be exploited for other inherited muscle diseases, which also are limited by the inefficient widespread delivery of therapeutic transgenes throughout the muscular system.

Arginine reprograms metabolism in liver cancer via RBM39.

Metabolic reprogramming is a hallmark of cancer. However, mechanisms underlying metabolic reprogramming and how altered metabolism in turn enhances tumorigenicity are poorly understood. Here, we report that arginine levels are elevated in murine and patient hepatocellular carcinoma (HCC), despite reduced expression of arginine synthesis genes. Tumor cells accumulate high levels of arginine due to increased uptake and reduced arginine-to-polyamine conversion. Importantly, the high levels of arginine promote tumor formation via further metabolic reprogramming, including changes in glucose, amino acid, nucleotide, and fatty acid metabolism. Mechanistically, arginine binds RNA-binding motif protein 39 (RBM39) to control expression of metabolic genes. RBM39-mediated upregulation of asparagine synthesis leads to enhanced arginine uptake, creating a positive feedback loop to sustain high arginine levels and oncogenic metabolism. Thus, arginine is a second messenger-like molecule that reprograms metabolism to promote tumor growth.

DPP9 Comes of Age: Highly Selective Inhibitors Promise New Therapeutic Opportunities.

Dipeptidyl peptidase-like protein 9 (DPP9) is emerging as a promising drug target for the treatment of hematological diseases. Two novel DPP9 inhibitors with nanomolar affinity and unprecedented selectivity to DPP9 over DPP8 have been discovered, paving the way for future progress in DPP9-mediated treatments.

Insight into the Role of Active Site Protonation States and Water Molecules in the Catalytic Inhibition of DPP4 by Vildagliptin.

Vildagliptin (VIL) is an antidiabetic drug that inhibits dipeptidyl peptidase-4 (DPP4) through a covalent mechanism. The molecular bases for this inhibitory process have been addressed experimentally and computationally. Nevertheless, relevant issues remain unknown such as the roles of active site protonation states and conserved water molecules nearby the catalytic center. In this work, molecular dynamics simulations were applied to examine the structures of 12 noncovalent VIL-DPP4 complexes encompassing all possible protonation states of three noncatalytic residues (His126, Asp663, Asp709) that were inconclusively predicted by different computational tools. A catalytically competent complex structure was only achieved in the system with His126 in its ε-form and nonconventional neutral states for Asp663/Asp709. This complex suggested the involvement of one water molecule in the catalytic process of His740/Ser630 activation, which was confirmed by QM/MM simulations. Our findings support the suitability of a novel water-mediated mechanism in which His740/Ser630 activation occurs concertedly with the nucleophilic attack on VIL and the imidate protonation by Tyr547. Then, the restoration of His740/ Tyr547 protonation states occurs via a two-water hydrogen bonding network in a low-barrier process, thus describing the final step of the catalytic cycle for the first time. Additionally, two hydrolytic mechanisms were proposed based on the hydrogen bonding networks formed by water molecules and the catalytic residues along the inhibitory mechanism. These findings are valuable to unveil the molecular features of the covalent inhibition of DPP4 by VIL and support the future development of novel derivatives with improved structural or mechanistic profiles.

Interaction of a viral insulin-like peptide with the IGF-1 receptor produces a natural antagonist.

Lymphocystis disease virus-1 (LCDV-1) and several other Iridoviridae encode viral insulin/IGF-1 like peptides (VILPs) with high homology to human insulin and IGFs. Here we show that while single-chain (sc) and double-chain (dc) LCDV1-VILPs have very low affinity for the insulin receptor, scLCDV1-VILP has high affinity for IGF1R where it can antagonize human IGF-1 signaling, without altering insulin signaling. Consequently, scLCDV1-VILP inhibits IGF-1 induced cell proliferation and growth hormone/IGF-1 induced growth of mice in vivo. Cryo-electron microscopy reveals that scLCDV1-VILP engages IGF1R in a unique manner, inducing changes in IGF1R conformation that led to separation, rather than juxtaposition, of the transmembrane segments and hence inactivation of the receptor. Thus, scLCDV1-VILP is a natural peptide with specific antagonist properties on IGF1R signaling and may provide a new tool to guide development of hormonal analogues to treat cancers or metabolic disorders sensitive to IGF-1 without affecting glucose metabolism.

Bacillus mojavensis enhances the antioxidant defense mechanism of soursop (Annona muricata L.) fruits during postharvest storage.

Rapid softening of soursop (Annona muricata L.) fruit results in postharvest losses. Bacillus genus is one of the most studied antagonistic biological control agents against postharvest diseases. Nevertheless, information about how this bacterium acts on the fruits is still not understood. The objective of this study aims to gain an insight into the effect of Bacillus mojavensis on the activity and gene expression of antioxidant defense enzymes in soursop fruits during postharvest storage. Our findings indicate different responses in the fruits inoculated with B. mojavensis at biochemical and molecular levels. On day one, fruits inoculated with B. mojavensis presented a mean value of 79.09 GAE/100 gFW in total phenols, and higher superoxide dismutase (SOD) and catalase (CAT) activities (1.35 and 1.78-fold higher, respectively). On the other hand, on the third day of storage, the ferric reducing/antioxidant power (FRAP) reached its highest level, including an increase in the expression of SOD, and PPO genes by 18.7-fold and 4.5-fold in fruits inoculated with B. mojavensis. Finally, on the fifth day of storage, soursop fruits inoculated with B. mojavensis had the highest mean values for 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH·), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS· +), with values of 194.68 EAA/100 gFW, and 172.33 EAA/100 gFW, respectively. Indeed, higher polyphenol oxidase (PPO), and peroxidase (POD) activities (2.17-fold and 1.27-fold higher, respectively) were recorded compared to the control fruits. We show that depending on the stage of ripening, the antagonist bacteria B. mojavensis enhanced the antioxidant capacity, enzymatic activity, and gene expression of soursop fruits.

Salpianthus macrodontus Extracts, a Novel Source of Phenolic Compounds with Antibacterial Activity against Potentially Pathogenic Bacteria Isolated from White Shrimp.

This study aimed to evaluate the antibacterial activity in vitro of Salpianthus macrodontus and Azadirachta indica extracts against potentially pathogenic bacteria for Pacific white shrimp. Furthermore, the extracts with higher inhibitory activity were analyzed to identify compounds responsible for bacterial inhibition and evaluate their effect on motility and biofilm formation. S. macrodontus and A. indica extracts were prepared using methanol, acetone, and hexane by ultrasound. The minimum inhibitory concentration (MIC) of the extracts was determined against Vibrio parahaemolyticus, V. harveyi, Photobacterium damselae and P. leiognathi. The polyphenol profile of those extracts showing the highest bacterial inhibition were determined. Besides, the bacterial swimming and swarming motility and biofilm formation were determined. The highest inhibitory activity against the four pathogens was found with the acetonic extract of S. macrodontus leaf (MIC of 50 mg/mL for Vibrio spp. and 25 mg/mL for Photobacterium spp.) and the methanol extract of S. macrodontus flower (MIC of 50 mg/mL for all pathogens tested). Both extracts affected the swarming and swimming motility and the biofilm formation of the tested bacteria. The main phenolic compounds related to Vibrio bacteria inhibition were naringin, vanillic acid, and rosmarinic acid, whilst hesperidin, kaempferol pentosyl-rutinoside, and rhamnetin were related to Photobacterium bacteria inhibition.

AAV-mediated BMP7 gene therapy counteracts insulin resistance and obesity.

Type 2 diabetes, insulin resistance, and obesity are strongly associated and are a major health problem worldwide. Obesity largely results from a sustained imbalance between energy intake and expenditure. Therapeutic approaches targeting metabolic rate may counteract body weight gain and insulin resistance. Bone morphogenic protein 7 (BMP7) has proven to enhance energy expenditure by inducing non-shivering thermogenesis in short-term studies in mice treated with the recombinant protein or adenoviral vectors encoding BMP7. To achieve long-term BMP7 effects, the use of adeno-associated viral (AAV) vectors would provide sustained production of the protein after a single administration. Here, we demonstrated that treatment of high-fat-diet-fed mice and ob/ob mice with liver-directed AAV-BMP7 vectors enabled a long-lasting increase in circulating levels of this factor. This rise in BMP7 concentration induced browning of white adipose tissue (WAT) and activation of brown adipose tissue, which enhanced energy expenditure, and reversed WAT hypertrophy, hepatic steatosis, and WAT and liver inflammation, ultimately resulting in normalization of body weight and insulin resistance. This study highlights the potential of AAV-BMP7-mediated gene therapy for the treatment of insulin resistance, type 2 diabetes, and obesity.

Evolucion del control metabolico en niños y adolescentes con diabetes tipo 1, luego del aislamiento implementado durante la pandemia por Covid-19 / Evolution of metabolic control in children and adolescents with tipe 1 diabetes, isolation implemented during the covid-19 pandemic

Introducción: la cuarentena adoptada durante la pandemia por COVID-19 significó grandes cambios en el cuidado de los pacientes con diabetes, pudiendo afectar el control metabólico. Objetivos: evaluar si existieron modificaciones en el control metabólico en menores de 18 años con diabetes tipo 1, seguidos en el Servicio de Nutrición y Diabetes del Hospital General de Niños Pedro de Elizalde (HGNPE), luego de las medidas de aislamiento social implementadas durante la pandemia por COVID-19. Estimar la frecuencia de complicaciones agudas y la variación del puntaje Z de Índice de masa corporal (IMC). Materiales y métodos: estudio observacional, longitudinal, retrospectivo. Se incluyeron pacientes de 1 a 18 años con diabetes tipo 1 de más de un año de evolución, con seguimiento regular en el HGNPE, que hayan sido evaluados, con determinación de hemoglobina glicosilada, entre diciembre de 2019 y marzo de 2020 (precuarentena). De estos pacientes, aquellos que asistieron a un control posterior, entre diciembre de 2020 y marzo de 2021, fueron considerados para un análisis comparativo. Resultados: se incluyeron 88 pacientes, de los cuales 59 se realizaron un control en el segundo período. La HbA1c inicial fue de 8,8% (IIC 25-75= 7,42-9,4) y la posterior de 8,3% (IIC 25-75= 7,2-9,95), el puntaje z de IMC inicial fue de 0,35 ± 1,02 y el posterior de 0,37 ± 0,97, siendo en ambos casos diferencias no significativas. Presentó complicaciones agudas el 15% (n= 9) de los pacientes. Conclusión: no se encontraron cambios significativos de la HbA1c y del puntaje z de IMC entre los períodos comparados

Introduction: the lock down during the COVID-19 pandemic meant great changes in the care of patients with diabetes, which could affect metabolic control. Objectives: to assesse whether there were changes in metabolic control in children under 18 years of age with type 1 diabetes followed up in the Nutrition and Diabetes Service of the Pedro de Elizalde Children's General Hospital (HGNPE), after the social isolation measures implemented during the COVID-19 pandemic and estimate the frequency of acute complications and the variation of the Z-score of Body Mass Index (BMI). Materials and methods: longitudinal, retrospective, observational study. Patients aged 1 to 18 years old with type 1 diabetes of more than one year of evolution, with regular follow-up in the HGNPE, who had been evaluated, with determination of glycosylated hemoglobin, between December 2019 and March 2020 (pre-quarantine) and between December 2020 and March2021. Of these patients, those who attended a subsequent control between December 2020 and March 2021 were considered for a comparative analysis. Results: 88 patients were included, of which 59 underwent a control in the second period. The initial HbA1c was 8,8% (IIC 25-75 = 7,42-9,4) and the subsequent one was 8,3% (IIC 25-75 = 7,2-9,95), the z-score of initial BMI was 0,35 ± 1,02 and the subsequent one was 0,37 ± 0,97, with non-significant differences in both cases. 15% (n = 9) of the patients had acute complications. Conclusion: no significant changes were found in HbA1c and BMI z-score between the periods compared

DIVERSIDAD GENÉTICA DE POBLACIONES DE GUANÁBANA (Annona muricata L.) EN NAYARIT, MÉXICO MEDIANTE MARCADORES SSR Y SRAP / Genetic diversity of soursop populations (Annona muricata L.) in Nayarit, Mexico using SSR and SRAP markers

RESUMEN La guanábana (Annona muricata L.) es un cultivo de importancia económica para Nayarit, México. Los frutos han tenido una excelente aceptación en el mercado regional, dificultando su comercialización a lugares lejanos porque la producción es altamente perecedera, aunado a que los árboles de los huertos de guanábana son en su mayoría ecotipos o fenotipos sin ningún plan de mejoramiento genético. Debido a la falta de variedades comerciales y de un banco de germoplasma, es importante conocer la diversidad genética para identificar y seleccionar genotipos; una de las herramientas para este propósito es el uso de marcadores moleculares. El objetivo de esta investigación fue analizar la diversidad genética de guanábana de las principales zonas productoras de Nayarit. Se extrajo ADN genómico de hojas de guanábana, las cuales fueron recolectadas de 11 huertos (poblaciones) de las siguientes zonas: Compostela (cinco poblaciones), Tepic (tres poblaciones) y San Blas (tres poblaciones). Posteriormente, se realizó un análisis mediante marcadores moleculares SSR y SRAP. Los resultados indicaron que los SSR no mostraron polimorfismo entre las poblaciones. Por otro lado, en los marcadores SRAP se obtuvieron 116 loci polimórficos con un promedio de porcentaje de loci polimórfico (P) entre las zonas productoras de 29,55 %. Asimismo, se realizó un AMOVA, el cual mostró que el mayor porcentaje de varianza se encuentra dentro de las poblaciones. Además, los análisis de agrupamiento demostraron la formación de tres grupos independientes. Por tanto, se obtuvo una alta homocigocidad y baja diversidad genética de guanábana entre las zonas y poblaciones estudiadas.

ABSTRACT Soursop (Annona muricata L.) is a crop of economic importance for Nayarit, Mexico. Soursop fruits have had an excellent acceptance in the regional market, making it difficult its commercialization to distant places because the production is highly perishable, in addition to the fact that the trees in the soursop orchards are mostly ecotypes or phenotypes without any genetic improvement plan. Due to the lack of commercial varieties and a germplasm bank, it is important to know the genetic diversity to identify and select genotypes; one of the tools for this purpose is the use of molecular markers. The objective of this research was to analyze the genetic diversity of soursop in the main producing areas of Nayarit. Genomic DNA was extracted from soursop leaves from 11 orchards (populations) in the following areas: Compostela (five populations), Tepic (three populations) and San Blas (three populations). Subsequently, we performed molecular analysis using SSR and SRAP molecular markers. The results indicated that the SSRs showed no polymorphism between the populations. On the other hand, we found 116 polymorphic loci in the SRAP markers with an average percentage of polymorphic loci (P) among the producing areas of 29.55 %. Likewise, an AMOVA was performed, showing that the highest percentage of variance is found within the populations. Furthermore, cluster analyzes demonstrated the formation of three independent groups. Therefore, a high homozygosity and low genetic diversity of soursop were obtained between the areas and populations studied.

Amikacin potentiator activity of zinc complexed to a pyrithione derivative with enhanced solubility.

Resistance to amikacin in Gram-negatives is usually mediated by the 6'-N-acetyltransferase type Ib [AAC(6')-Ib], which catalyzes the transfer of an acetyl group from acetyl CoA to the 6' position of the antibiotic molecule. A path to continue the effective use of amikacin against resistant infections is to combine it with inhibitors of the inactivating reaction. We have recently observed that addition of Zn2+ to in-vitro enzymatic reactions, obliterates acetylation of the acceptor antibiotic. Furthermore, when added to amikacin-containing culture medium in complex to ionophores such as pyrithione (ZnPT), it prevents the growth of resistant strains. An undesired property of ZnPT is its poor water-solubility, a problem that currently affects a large percentage of newly designed drugs. Water-solubility helps drugs to dissolve in body fluids and be transported to the target location. We tested a pyrithione derivative described previously (Magda et al. Cancer Res 68:5318-5325, 2008) that contains the amphoteric group di(ethyleneglycol)-methyl ether at position 5 (compound 5002), a modification that enhances the solubility. Compound 5002 in complex with zinc (Zn5002) was tested to assess growth inhibition of amikacin-resistant Acinetobacter baumannii and Klebsiella pneumoniae strains in the presence of the antibiotic. Zn5002 complexes in combination with amikacin at different concentrations completely inhibited growth of the tested strains. However, the concentrations needed to achieve growth inhibition were higher than those required to achieve the same results using ZnPT. Time-kill assays showed that the effect of the combination amikacin/Zn5002 was bactericidal. These results indicate that derivatives of pyrithione with enhanced water-solubility, a property that would make them drugs with better bioavailability and absorption, are a viable option for designing inhibitors of the resistance to amikacin mediated by AAC(6')-Ib, an enzyme commonly found in the clinics.

Treatment of skeletal and non-skeletal alterations of Mucopolysaccharidosis type IVA by AAV-mediated gene therapy.

Mucopolysaccharidosis type IVA (MPSIVA) or Morquio A disease, a lysosomal storage disorder, is caused by N-acetylgalactosamine-6-sulfate sulfatase (GALNS) deficiency, resulting in keratan sulfate (KS) and chondroitin-6-sulfate accumulation. Patients develop severe skeletal dysplasia, early cartilage deterioration and life-threatening heart and tracheal complications. There is no cure and enzyme replacement therapy cannot correct skeletal abnormalities. Here, using CRISPR/Cas9 technology, we generate the first MPSIVA rat model recapitulating all skeletal and non-skeletal alterations experienced by patients. Treatment of MPSIVA rats with adeno-associated viral vector serotype 9 encoding Galns (AAV9-Galns) results in widespread transduction of bones, cartilage and peripheral tissues. This led to long-term (1 year) increase of GALNS activity and whole-body correction of KS levels, thus preventing body size reduction and severe alterations of bones, teeth, joints, trachea and heart. This study demonstrates the potential of AAV9-Galns gene therapy to correct the disabling MPSIVA pathology, providing strong rationale for future clinical translation to MPSIVA patients.

Differential Responses of Antioxidative System during the Interaction of Soursop Fruits (Annona muricata L.) and Nectria haematococca at Postharvest Storage.

Soursop fruit (Annona muricata L.) production is diminished by the attack of pathogens such as Nectria haematococca. However, the fruit-pathogen interaction at the biochemical and molecular levels is still unknown. The objective of this study was to analyze the response of the soursop fruit to the presence of N. haematococca during postharvest storage. Soursop fruits were inoculated with the pathogen and total phenolic compounds, antioxidant capacity by Ferric reducing/antioxidant power (FRAP), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS•+), and 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH•), as well as enzymatic activity and transcript levels of polyphenol oxidase (PPO) and superoxide dismutase (SOD), were evaluated at 1, 3, and 5 days of storage. The noninoculated fruits were the controls of the experiment. The highest total phenol content was recorded on day one in the inoculated fruits. FRAP, ABTS, and DPPH activity presented the highest values on day three in the control fruits. Inoculated fruits recorded the highest PPO activity on day five and a five-fold induction in the PPO transcript on day three. SOD activity showed a decrease during the days of storage and 10-fold induction of SOD transcript on day three in the inoculated fruits. Principal component analysis showed that total phenols were the variable that contributed the most to the observed variations. Furthermore, a positive correlation between total phenols and SOD activity, PPO expression, and SOD expression, as well as between DPPH and FRAP, was recorded. The results showed a differential response in antioxidant capacity, enzymatic activity, and gene expression during the interaction of soursop fruits-N. haematococca at postharvest storage.

Rational Design of Novel Glycomimetic Peptides for E-Selectin Targeting.

E-selectin is a cell-adhesion receptor with specific recognition capacity toward sialo-fucosylated Lewis carbohydrates present in leukocytes and tumor cells. E-selectin interactions mediate the progress of inflammatory processes and tumor metastasis, which aroused the interest in using this protein as a biomolecular target to design glycomimetic inhibitors for active targeting or therapeutic purposes. In this work, we report the rational discovery of two novel glycomimetic peptides targeting E-selectin based on mutations of the reference selectin-binding peptide IELLQAR. Sixteen single or double mutants at Ile1, Leu3, Leu4, and Arg7 residues were evaluated as potential candidates for E-selectin targeting using 50 ns molecular dynamics (MD) simulations. Nine peptides showing a stable association with the functional pocket were modified by adding a cysteine residue to the N-terminus to confer versatility for further chemical conjugation. Subsequent 50 ns MD simulations resulted in five cysteine-modified peptides with retained or improved E-selectin binding potential. Then, 300 ns accelerated MD (aMD) simulations were used to examine the binding properties of the best five cysteine-modified peptides. CIEELQAR and CIELFQAR exhibit the most selective association with the functional pocket of E-selectin, as revealed by potential of mean force profiles. Microscale thermophoresis experiments confirmed the E-selectin binding capacity of the selected peptides with KD values in the low micromolar range (CIEELQAR KD = 35.0 ± 1.4 µM; CIELFQAR KD = 16.4 ± 0.7 µM), which are 25-fold lower than the reported value for the native ligand sLex (KD = 878 µM). Our findings support the potential of CIEELQAR and CIELFQAR as novel E-selectin-targeting peptides with high recognition capacity and versatility for chemical conjugation, which are critical for enabling future applications in active targeting.

BMP7 overexpression in adipose tissue induces white adipogenesis and improves insulin sensitivity in ob/ob mice.

BACKGROUND/OBJECTIVES: During obesity, hypertrophic enlargement of white adipose tissue (WAT) promotes ectopic lipid deposition and development of insulin resistance. In contrast, WAT hyperplasia is associated with preservation of insulin sensitivity. The complex network of factors that regulates white adipogenesis is not fully understood. Bone morphogenic protein 7 (BMP7) can induce brown adipogenesis, but its role on white adipogenesis remains to be elucidated. Here, we assessed BMP7-mediated effects on white adipogenesis in ob/ob mice. METHODS: BMP7 was overexpressed in either WAT or liver of ob/ob mice using adeno-associated viral (AAV) vectors. Analysis of gene expression, histological and morphometric alterations, and metabolites and hormones concentrations were carried out. RESULTS: Overexpression of BMP7 in adipocytes of subcutaneous and visceral WAT increased fat mass, the proportion of small-size adipocytes and the expression of adipogenic and mature adipocyte genes, suggesting induction of adipogenesis irrespective of fat depot. These changes were associated with reduced hepatic steatosis and improved insulin sensitivity. In contrast, liver-specific overproduction of BMP7 did not promote WAT hyperplasia despite BMP7 circulating levels were similar to those achieved after genetic engineering of WAT. CONCLUSIONS: This study unravels a new autocrine/paracrine role of BMP7 on white adipogenesis and highlights that BMP7 may modulate WAT plasticity and increase insulin sensitivity.

Polyamidoamine-based nanovector for the efficient delivery of methotrexate to U87 glioma cells.

The purpose of this study was to design a polyamidoamine (PAMAM)-based nanovector for the efficient delivery of methotrexate to U87 glioma cells. To this end, 0-100% acetylated PAMAM dendrimers of the fourth generation were synthesized and evaluated using drug encapsulation measurements, molecular dynamics simulations, neurotoxicity assays and neuronal internalization experiments. The best system was tested as a nanovector for methotrexate delivery to U87 glioma cells. The authors found that 25% acetylated PAMAM dendrimers of the fourth-generation combine low intrinsic toxicity, large drug complexation capacity and efficient internalization into hippocampal neurons. Nanovector complexation enhances the cytotoxic response of methotrexate against U87 glioma cells compared with free drug solutions. In conclusion, 25% acetylated PAMAM dendrimers of the fourth-generation increase drug uptake by glioma cells and thereby act as efficient nanovectors for methotrexate delivery.

Interdimeric Curvature in Tubulin-Tubulin Complexes Delineates the Microtubule-Destabilizing Properties of Plocabulin.

Plocabulin is a novel microtubule (MT) destabilizer agent with potent antineoplastic activity. This compound binds to the maytansine site at the longitudinal interface between tubulin dimers and exerts a hinge-like effect that disrupts normal microtubule assembly. Plocabulin has emerged as a valuable model for the rational design of novel MT destabilizers because of its unique structural and mechanistic features. To make progress on this matter, detailed molecular-level understanding of the ligand-protein interactions responsible for plocabulin association and the conformation and energetic effects arising from plocabulin binding on the longitudinal interaction between tubulin dimers must be provided. In this work, fully atomistic MD simulations and MM/GBSA binding free-energy calculations were used to examine the association of plocabulin to one or two tubulin dimers in longitudinal arrangement. Our results revealed that plocabulin binding is favored by the addition of a second tubulin dimer and that this ligand promotes the assembly of curved tetrameric arrangements with strengthened longitudinal interdimeric interactions compared to ligand-free systems. The applicability of these findings to the rational discovery of novel MT destabilizers was tested using MD and MM/GBSA calculations as filtering tools to narrow the results of virtual screening among an FDA-approved drug database. Our results confirmed that tight-binding ligands do not necessarily exert the expected conformational and energetic effects on longitudinal tubulin-tubulin interactions, which is a matter to consider in future design strategies.