Effects of the Rho GTPase-activating toxin CNF1 on fibroblasts derived from Rett syndrome patients: A pilot study.

The bacterial product CNF1, through its action on the Rho GTPases, is emerging as a modulator of crucial signalling pathways involved in selected neurological diseases characterized by mitochondrial dysfunctions. Mitochondrial impairment has been hypothesized to have a key role in paramount mechanisms underlying Rett syndrome (RTT), a severe neurologic rare disorder. CNF1 has been already reported to have beneficial effects in mouse models of RTT. Using human RTT fibroblasts from four patients carrying different mutations, as a reliable disease-in-a-dish model, we explored the cellular and molecular mechanisms, which can underlie the CNF1-induced amelioration of RTT deficits. We found that CNF1 treatment modulates the Rho GTPases activity of RTT fibroblasts and induces a considerable re-organization of the actin cytoskeleton, mainly in stress fibres. Mitochondria of RTT fibroblasts show a hyperfused morphology and CNF1 decreases the mitochondrial mass leaving substantially unaltered the mitochondrial dynamic. From a functional perspective, CNF1 induces mitochondrial membrane potential depolarization and activation of AKT in RTT fibroblasts. Given that mitochondrial quality control is altered in RTT, our results are suggestive of a reactivation of the damaged mitochondria removal via mitophagy restoration. These effects can be at the basis of the beneficial effects of CNF1 in RTT.

Association of Polygenic Risk Score and Bacterial Toxins at Screening Colonoscopy with Colorectal Cancer Progression: A Multicenter Case-Control Study.

Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and its incidence is correlated with infections, chronic inflammation, diet, and genetic factors. An emerging aspect is that microbial dysbiosis and chronic infections triggered by certain bacteria can be risk factors for tumor progression. Recent data suggest that certain bacterial toxins implicated in DNA attack or in proliferation, replication, and death can be risk factors for insurgence and progression of CRC. In this study, we recruited more than 300 biopsy specimens from people undergoing colonoscopy, and we analyzed to determine whether a correlation exists between the presence of bacterial genes coding for toxins possibly involved in CRC onset and progression and the different stages of CRC. We also analyzed to determine whether CRC-predisposing genetic factors could contribute to bacterial toxins response. Our results showed that CIF toxin is associated with polyps or adenomas, whereas pks+ seems to be a predisposing factor for CRC. Toxins from Escherichia coli as a whole have a higher incidence rate in adenocarcinoma patients compared to controls, whereas Bacteroides fragilis toxin does not seem to be associated with pre-cancerous nor with cancerous lesions. These results have been obtained irrespectively of the presence of CRC-risk loci.

The Escherichia coli protein toxin cytotoxic necrotizing factor 1 induces epithelial mesenchymal transition.

Some toxigenic bacteria produce protein toxins with carcinogenic signatures, which either directly damage DNA or stimulate signalling pathways related to cancer. So far, however, only a few of them have been proved to favour the induction or progression of cancer. In this work, we report that the Rho-activating Escherichia coli protein toxin, cytotoxic necrotising factor 1 (CNF1), induces epithelial to mesenchymal transition (EMT) in intestinal epithelial cells. EMT is a crucial step in malignant tumour conversion and invasiveness. In the case of CNF1, it occurs by up-regulation of the transcription factors ZEB1 and Snail1, delocalisation of E-cadherin and ß-catenin, activation of the serine/threonine kinase mTOR, accelerated wound healing, and invasion. However, our results highlight that nontransformed epithelial cells entail the presence of inflammatory factors, in addition to CNF1, to acquire a mesenchymal-like behaviour. All this suggests that the surrounding microenvironment, as well as the cell type, dramatically influences the CNF1 ability to promote carcinogenic traits.

Bearberry identification by a multidisciplinary study on commercial raw materials.

Herbal species different from the official bearberry, Arctostaphylos uva-ursi, are sold through conventional markets and also through non-controlled Internet websites, putting consumer safety at risk owing to the lack of quality control. Recently, Arctostaphylos pungens has become one of the most used species as a raw material for herbal medicines and dietary supplements in the place of official bearberry, a plant used for the treatment of various urinary disorders. A fingerprint identification based on an integrated application of different analytical techniques (HPTLC, NMR, HPLC-DAD and LC-ESI-MS) is here described to distinguish A. uva-ursi from A. pungens. The HPTLC and HPLC-DAD fingerprints resulted the simplest methods to differentiate the two species, whereas LC-ESI-MS was more useful to quantify arbutin, the main component of bearberry, and to evaluate its different content in the two species. This multidisciplinary study showed for the first time a specific phytochemical fingerprint of the new species A. pungens.

Chemical fingerprinting of Equisetum arvense L. using HPTLC densitometry and HPLC.

Equisetum arvense L. is a herbaceous medicinal plant, commonly known as horsetail, whose extracts have been reported to possess diuretic and haemostatic properties. The aim of this study was to evaluate the use of fingerprint chromatographic methods on commercially available raw materials or preparations of E. arvense L. in order to ascertain their quality and identify possible adulterants using HPLC and HPTLC densitometry. Two chromatographic methods were used to determine the chemical fingerprints of E. arvense and other allied species. The first was based on HPTLC identification followed by densitometric measurement at 350 nm. The second was based on HPLC separation. The ease of sample preparation and the possibility of simultaneous analysis of several samples in a short time make HPTLC a method of choice for the comprehensive quality evaluation of herbal products.

Chemical fingerprinting of Lawsonia inermis L. using HPLC, HPTLC and densitometry.

INTRODUCTION: Lawsonia inermis L. is a natural red colouring agent, commonly named "Henna", which is used to dye skin and hair. The aim of this study was to evaluate the quality of L. inermis that is commercially available as a raw plant material or preparation in order to guarantee good quality products. OBJECTIVE: To develop a simple protocol for the qualification of different samples labelled as L. inermis by using the HPTLC densitometry method and to identify possible adulterations with other plants. METHODOLOGY: Samples of leaves of L. inermis were extracted with methanol. Two chromatographic methods were developed to determine the chemical fingerprinting of L. inermis. The first was based on HPTLC identification followed by densitometric measurements at 337 nm. The second was based on RP-HPLC separation with gradient elution and photodiode array detection at 337 nm. Samples of Cassia obovata Collad., and Indigofera tinctoria L., were treated in the same way. RESULTS: The simplicity of the sample preparation, and the possibility of analysing several samples of herbal products simultaneously in a short time, make HPTLC the method of choice. The HPTLC method was feasible for the comprehensive quality evaluation of herbal products. From the comparison of their "fingerprint", it was possible to detect substitution of plants that are different from those declared on the label. CONCLUSION: The HPTLC may be used as a rapid method by which to control the quality of raw plant materials and formulations based on the title plant.