Crosstalk between Gut Sensory Ghrelin Signaling and Adipose Tissue Sympathetic Outflow Regulates Metabolic Homeostasis.

The stomach-derived orexigenic hormone ghrelin is a key regulator of energy homeostasis and metabolism in humans. The ghrelin receptor, growth hormone secretagogue receptor 1a (GHSR), is widely expressed in the brain and gastrointestinal vagal sensory neurons, and neuronal GHSR knockout results in a profoundly beneficial metabolic profile and protects against diet-induced obesity (DIO) and insulin resistance. Here we show that in addition to the well characterized vagal GHSR, GHSR is robustly expressed in gastrointestinal sensory neurons emanating from spinal dorsal root ganglia. Remarkably, sensory neuron GHSR deletion attenuates DIO through increased energy expenditure and sympathetic outflow to adipose tissue independent of food intake. In addition, neuronal viral tract tracing reveals prominent crosstalk between gut non-vagal sensory afferents and adipose sympathetic outflow. Hence, these findings demonstrate a novel gut sensory ghrelin signaling pathway critical for maintaining energy homeostasis.

Citrinin as a potential anti-cancer therapy: A comprehensive review.

Citrinin (CIT) is a polyketide-derived mycotoxin, which is produced by many fungal strains belonging to the gerena Monascus, Aspergillus, and Penicillium. It has been postulated that mycotoxins have several toxic mechanisms and are potentially used as antineoplastic agents. Therefore, the present study carried out a systematic review, including articles from 1978 to 2022, by collecting evidence in experimental studies of CIT antiplorifactive activity in cancer. The Data indicate that CIT intervenes in important mediators and cell signaling pathways, including MAPKs, ERK1/2, JNK, Bcl-2, BAX, caspases 3,6,7 and 9, p53, p21, PARP cleavage, MDA, reactive oxygen species (ROS) and antioxidant defenses (SOD, CAT, GST and GPX). These factors demonstrate the potential antitumor drug CIT in inducing cell death, reducing DNA repair capacity and inducing cytotoxic and genotoxic effects in cancer cells.

Antidiabetic, Antiglycation, and Antioxidant Activities of Ethanolic Seed Extract of Passiflora edulis and Piceatannol In Vitro.

The objective of this work was to investigate the antidiabetic, antiglycation, and antioxidant potentials of ethanolic extract of seeds of Brazilian Passiflora edulis fruits (PESE), a major by-product of the juice industry, and piceatannol (PIC), one of the main phytochemicals of PESE. PESE, PIC, and acarbose (ACB) exhibited IC50 for alpha-amylase, 32.1 ± 2.7, 85.4 ± 0.7, and 0.4 ± 0.1 µg/mL, respectively, and IC50 for alpha-glucosidase, 76.2 ± 1.9, 20.4 ± 7.6, and 252 ± 4.5 µg/mL, respectively. The IC50 of PESE, PIC, and sitagliptin (STG) for dipeptidyl-peptidase-4 (DPP-4) was 71.1 ± 2.6, 1137 ± 120, and 0.005 ± 0.001 µg/mL, respectively. PESE and PIC inhibited the formation of advanced glycation end-products (AGE) with IC50 of 366 ± 1.9 and 360 ± 9.1 µg/mL for the initial stage and 51.5 ± 1.4 and 67.4 ± 4.6 µg/mL for the intermediate stage of glycation, respectively. Additionally, PESE and PIC inhibited the formation of ß-amyloid fibrils in vitro up to 100%. IC50 values for 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging activity of PESE and PIC were 20.4 ± 2.1, and 6.3 ± 1.3 µg/mL, respectively. IC50 values for scavenging hypochlorous acid (HOCl) were similar in PESE, PIC, and quercetin (QCT) with values of 1.7 ± 0.3, 1.2 ± 0.5, and 1.9 ± 0.3 µg/mL, respectively. PESE had no cytotoxicity to the human normal bronchial epithelial (BEAS-2B), and alpha mouse liver (AML-12) cells up to 100 and 50 µg/mL, respectively. However, 10 µg/mL of the extract was cytotoxic to non-malignant breast epithelial cells (MCF-10A). PESE and PIC were found to be capable of protecting cultured human cells from the oxidative stress caused by the carcinogen NNKOAc at 100 µM. The in vitro evidence of the inhibition of alpha-amylase, alpha-glucosidase, and DPP-4 enzymes as well as antioxidant and antiglycation activities, warrants further investigation of the antidiabetic potential of P. edulis seeds and PIC.

Alpha-Terpineol as Antitumor Candidate in Pre-Clinical Studies.

BACKGROUND: Alpha-terpineol is monoterpene alcohol with anti-tumor activity against different tumor cell lines (lung, breast, leukemias and colorectal) through blockage of NF-kB expression, which play an important role in tumor cells growth. OBJECTIVE: Evaluate the antitumor activity of alpha-terpineol in murine Sarcoma 180 cell line. METHODS: For the tests, different cytotoxic and genotoxic assays were used, including Trypan blue, cytokinesis- blocked micronucleus assay, comet assay, agarose gel DNA fragmentation, flow cytometry and cell viability using fluorescence. Ascitic fluid cells from sarcoma 180 were obtained from Mus musculus peritoneal cavity and Alpha-terpineol was tested at 100, 250 and 500 µg/mL. Doxorubicin and Cisplatin were used as positive controls. RESULTS: Cytotoxic effects of alpha-terpineol were found in all concentrations tested, reducing cell viability in 50.9; 38.53; 30.82% at 100, 250 and 500 µg/mL, respectively. Alpha-terpineol induced genotoxic effects due to DNA fragmentation (increased frequency and index of damage), and was clastogenic by increased micronuclei formation, nucleoplasmic bridges and nuclear buds. DNA fragmentation and increased cell death indicated that alpha-terpineol can cause early, late, and necrotic apoptosis. CONCLUSION: Our data indicate that alpha-terpineol has antitumor activity revealed by cytogenetic mechanisms and / or loss of cell membrane integrity.

Antiproliferative and Genotoxic Action of an Underexploited Organoteluran Derivative on Sarcoma 180 Cells.

BACKGROUND: The search for novel metallic chemical compounds with toxicogenic effects has been of great importance for more efficient cancer treatment. OBJECTIVE: The study evaluated the cytotoxic, genotoxic and mutagenic activity of organoteluran RF07 in the S-180 cell line. METHODS: The bioassays used were cell viability with 3-(4,5-dimethyl-2-thiazole)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test, evaluation of apoptosis and necrosis using fluorescence and flow cytometry, cytokinesisblock micronucleus test and comet assay. The compound was tested at 1; 2.5 and 5µM. RESULTS: The results showed the cytotoxicity of RF07 at concentrations of 2.5, 5, 10 and 20µM when compared to the negative control. For genotoxicity tests, RF07 showed effects in all concentrations assessed by increased index and frequencies of damage and mutagenic alterations. The compound was also cytotoxic due to the significant decrease in the nuclear division index, with significant values of apoptosis and necrosis. The results of fluorescence and flow cytometry showed apoptosis as the main type of cell death caused by RF07 at 5µM, which is thought to avoid an aggressive immune response of the organism. CONCLUSION: In addition to cytotoxic and genotoxic effects, RF07 creates good perspectives for future antitumor formulations.

Complex Landscape of Germline Variants in Brazilian Patients With Hereditary and Early Onset Breast Cancer.

Pathogenic variants in known breast cancer (BC) predisposing genes explain only about 30% of Hereditary Breast Cancer (HBC) cases, whereas the underlying genetic factors for most families remain unknown. Here, we used whole-exome sequencing (WES) to identify genetic variants associated to HBC in 17 patients of Brazil with familial BC and negative for causal variants in major BC risk genes (BRCA1/2, TP53, and CHEK2 c.1100delC). First, we searched for rare variants in 27 known HBC genes and identified two patients harboring truncating pathogenic variants in ATM and BARD1. For the remaining 15 negative patients, we found a substantial vast number of rare genetic variants. Thus, for selecting the most promising variants we used functional-based variant prioritization, followed by NGS validation, analysis in a control group, cosegregation analysis in one family and comparison with previous WES studies, shrinking our list to 23 novel BC candidate genes, which were evaluated in an independent cohort of 42 high-risk BC patients. Rare and possibly damaging variants were identified in 12 candidate genes in this cohort, including variants in DNA repair genes (ERCC1 and SXL4) and other cancer-related genes (NOTCH2, ERBB2, MST1R, and RAF1). Overall, this is the first WES study applied for identifying novel genes associated to HBC in Brazilian patients, in which we provide a set of putative BC predisposing genes. We also underpin the value of using WES for assessing the complex landscape of HBC susceptibility, especially in less characterized populations.

Hereditary breast and ovarian cancer: assessment of point mutations and copy number variations in Brazilian patients.

BACKGROUND: Germ line mutations in BRCA1 and BRCA2 (BRCA1/2) and other susceptibility genes have been identified as genetic causes of hereditary breast and ovarian cancer (HBOC). To identify the disease-causing mutations in a cohort of 120 Brazilian women fulfilling criteria for HBOC, we carried out a comprehensive screening of BRCA1/2, TP53 R337H, CHEK2 1100delC, followed by an analysis of copy number variations in 14 additional breast cancer susceptibility genes (PTEN, ATM, NBN, RAD50, RAD51, BRIP1, PALB2, MLH1, MSH2, MSH6, TP53, CDKN2A, CDH1 and CTNNB1). METHODS: Capillary sequencing and multiplex ligation-dependent probe amplification (MLPA) were used for detecting point mutations and copy number variations (CNVs), respectively, for the BRCA1 and BRCA2 genes; capillary sequencing was used for point mutation for both variants TP53 R337H and CHEK2 1100delC, and finally array comparative genomic hybridization (array-CGH) was used for identifying CNVs in the 14 additional genes. RESULTS: The positive detection rate in our series was 26%. BRCA1 pathogenic mutations were found in 20 cases, including two cases with CNVs, whereas BRCA2 mutations were found in 7 cases. We also found three patients with the TP53 R337H mutation and one patient with the CHEK2 1100delC mutation. Seven (25%) pathogenic mutations in BRCA1/2 were firstly described, including a splice-site BRCA1 mutation for which pathogenicity was confirmed by the presence of an aberrant transcript showing the loss of the last 62 bp of exon 7. Microdeletions of exon 4 in ATM and exon 2 in PTEN were identified in BRCA2-mutated and BRCA1/2-negative patients, respectively. CONCLUSIONS: In summary, our results showed a high frequency of BRCA1/2 mutations and a higher prevalence of BRCA1 (64.5%) gene. Moreover, the detection of the TP53 R337H variant in our series and the fact that this variant has a founder effect in our population prompted us to suggest that all female breast cancer patients with clinical criteria for HBOC and negative for BRCA1/2 genes should be tested for the TP53 R337H variant. Furthermore, the presence of genomic structural rearrangement resulting in CNVs in other genes that predispose breast cancer in conjunction with BRCA2 point mutations demonstrated a highly complex genetic etiology in Brazilian breast cancer families.

Breakpoint characterization of a novel large intragenic deletion of MUTYH detected in a MAP patient: case report.

BACKGROUND: MUTYH-associated polyposis (MAP) is a recessive, hereditary, colorectal cancer-predisposing syndrome caused by biallelic mutations in the MUTYH gene. Most MUTYH pathogenic variants are missense mutations, and until recently no gross genomic deletions had been described. CASE PRESENTATION: We have identified a large deletion in the MUTYH gene: a > 4.2 kb deletion encompassing exons 4-16. This is the second description of this rearrangement, which has been recently described as the first large deletion in this gene. The clinically suspected MAP patient was homozygous for this mutation and presented with no amplification products for 14 exons of MUTYH on initial screening. Deletion breakpoints were refined to base pair level through array comparative genomic hybridization (aCGH) analysis followed by sequencing. The identified breakpoints were located within intron 3 and 146 bp downstream of the 3' end of the gene, with the presence of an AluJr element adjacent to the distal breakpoint. The presence of a 2 bp insertion at the junction suggests the involvement of the non-homologous end joining (NHEJ) repair mechanism, possibly facilitated by rearrangement-promoting elements. Examination of the MUTYH locus revealed a high Alu density that may make this region prone to rearrangements. CONCLUSION: Large deletions are a possible mechanism for loss of function of the MUTYH gene, and investigation of such mutations may be important in identifying causative mutations in MAP patients.