Digested Cinnamon (Cinnamomum verum J. Presl) Bark Extract Modulates Claudin-2 Gene Expression and Protein Levels under TNFα/IL-1ß Inflammatory Stimulus.

Epigenetic changes, host-gut microbiota interactions, and environmental factors contribute to inflammatory bowel disease (IBD) onset and progression. A healthy lifestyle may help to slow down the chronic or remitting/relapsing intestinal tract inflammation characteristic of IBD. In this scenario, the employment of a nutritional strategy to prevent the onset or supplement disease therapies included functional food consumption. Its formulation consists of the addition of a phytoextract enriched in bioactive molecules. A good candidate as an ingredient is the Cinnamon verum aqueous extract. Indeed, this extract, subjected to a process of gastrointestinal digestion simulation (INFOGEST), exhibits beneficial antioxidant and anti-inflammatory properties in an in vitro model of the inflamed intestinal barrier. Here, we deepen the study of the mechanisms related to the effect of digested cinnamon extract pre-treatment, showing a correlation between transepithelial electrical resistance (TEER) decrement and alterations in claudin-2 expression under Tumor necrosis factor-α/Interleukin-1ß (TNF-α/IL-1) ß cytokine administration. Our results show that pre-treatment with cinnamon extract prevents TEER loss by claudin-2 protein level regulation, influencing both gene transcription and autophagy-mediated degradation. Hence, cinnamon polyphenols and their metabolites probably work as mediators in gene regulation and receptor/pathway activation, leading to an adaptive response against renewed insults.

Coffee-Derived Phenolic Compounds Activate Nrf2 Antioxidant Pathway in I/R Injury In Vitro Model: A Nutritional Approach Preventing Age Related-Damages.

Age-related injuries are often connected to alterations in redox homeostasis. The imbalance between free radical oxygen species and endogenous antioxidants defenses could be associated with a growing risk of transient ischemic attack and stroke. In this context, a daily supply of dietary antioxidants could counteract oxidative stress occurring during ischemia/reperfusion injury (I/R), preventing brain damage. Here we investigated the potential antioxidant properties of coffee-derived circulating metabolites and a coffee pulp phytoextract, testing their efficacy as ROS scavengers in an in vitro model of ischemia. Indeed, the coffee fruit is an important source of phenolic compounds, such as chlorogenic acids, present both in the brewed seed and in the discarded pulp. Therefore, rat brain endothelial cells, subjected to oxygen and glucose deprivation (OGD) and recovery (ogR) to mimic reperfusion, were pretreated or not with coffee by-products. The results indicate that, under OGD/ogR, the ROS accumulation was reduced by coffee by-product. Additionally, the coffee extract activated the Nrf2 antioxidant pathway via Erk and Akt kinases phosphorylation, as shown by increased Nrf2 and HO-1 protein levels. The data indicate that the daily intake of coffee by-products as a dietary food supplement represents a potential nutritional strategy to counteract aging.

Systemic Exposure to Air Pollution Induces Oxidative Stress and Inflammation in Mouse Brain, Contributing to Neurodegeneration Onset.

In northern Italy, biomass burning-derived (BB) particles and diesel exhaust particles (DEP) are considered the most significant contributors to ultrafine particle (UFP) emission. However, a comparison between their impact on different brain regions was not investigated until now. Therefore, male BALB/c mice were treated with a single or three consecutive intratracheal instillations using 50 µg of UFPs in 100 µL of isotonic saline solution or 100 µL of isotonic saline solution alone, and brains were collected and analyzed. Proteins related to oxidative stress and inflammation, as well as Alzheimer's disease markers, were examined in the hippocampus, cerebellum, and the rest of the brain (RoB). Histopathological examination of the brain was also performed. Moreover, correlations among different brain, pulmonary, and cardiovascular markers were performed, allowing us to identify the potentially most stressful UFP source. Although both acute exposures induced inflammatory pathways in mouse brain, only DEP showed strong oxidative stress. The sub-acute exposure also induced the modulation of APP and BACE1 protein levels for both UFPs. We observed that DEP exposure is more harmful than BB, and this different response could be explained by this UFP's different chemical composition and reactivity.

In Vivo Comparative Study on Acute and Sub-acute Biological Effects Induced by Ultrafine Particles of Different Anthropogenic Sources in BALB/c Mice.

Exposure to ultrafine particles (UFPs) leads to adverse effects on health caused by an unbalanced ratio between UFPs deposition and clearance efficacy. Since air pollution toxicity is first direct to cardiorespiratory system, we compared the acute and sub-acute effects of diesel exhaust particles (DEP) and biomass burning-derived particles (BB) on bronchoalveolar Lavage Fluid (BALf), lung and heart parenchyma. Markers of cytotoxicity, oxidative stress and inflammation were analysed in male BALB/c mice submitted to single and repeated intra-tracheal instillations of 50 µg UFPs. This in-vivo study showed the activation of inflammatory response (COX-2 and MPO) after exposure to UFPs, both in respiratory and cardiovascular systems. Exposure to DEP results also in pro- and anti-oxidant (HO-1, iNOS, Cyp1b1, Hsp70) protein levels increase, although, stress persist only in cardiac tissue under repeated instillations. Statistical correlations suggest that stress marker variation was probably due to soluble components and/or mediators translocation of from first deposition site. This mechanism, appears more important after repeated instillations, since inflammation and oxidative stress endure only in heart. In summary, chemical composition of UFPs influenced the activation of different responses mediated by their components or pro-inflammatory and pro-oxidative molecules, indicating DEP as the most damaging pollutant in the comparison.

Lipid Reshaping and Lipophagy Are Induced in a Modeled Ischemia-Reperfusion Injury of Blood Brain Barrier.

Ischemic-reperfusion (I/R) injury induced a remodeling of protein and lipid homeostasis, under oxidative stress and inflammatory status. Starvation occurring during I/R is a condition leading to autophagy activation, which allows abnormal material clearance or amino acid, or both, and fatty acid (FA) recycling essential for survival. This study investigated the lipid reshaping, peroxidation, and related-signaling pathways, in rat brain endothelial cells (RBE4) subjected to 3 h of oxygen and glucose deprivation (OGD) and restoration of standard condition (I/R in vitro model). Lipids and proteins were analyzed after 1 or 24 h of oxygen and nutrient restoration. Together with the oxidative stress and inflammatory status, I/R injury induced a reshaping of neutral lipids and biogenesis of lipid droplets (LD) with excessive lipid storage. The increase of LC3-II/LC3-I ratio, an autophagy marker, and LC3 co-localization with LD suggest the activation of lipophagy machinery to counteract the cell engulfment. Lipophagy leads to cholesterol ester (CE) hydrolysis, increasing free cholesterol (FC) secretion, which occurred by specific transporters or unconventional exocytosis pathways, or both. Here, we propose that an unconventional spreading of FC and other lipid metabolites may influence the neurovascular unit (NVU) cells, contributing to Blood brain barrier (BBB) alteration or adaptation, or both, to the cumulative effects of several transient ischemia.

New potent antibacterials against Gram-positive multiresistant pathogens: effects of side chain modification and chirality in linezolid-like 1,2,4-oxadiazoles.

The effects of side chain modification and chirality in linezolid-like 1,2,4-oxadiazoles have been studied to design new potent antibacterials against Gram-positive multidrug-resistant pathogens. The adopted strategy involved a molecular modelling approach, the synthesis and biological evaluation of new designed compounds, enantiomers separation and absolute configuration assignment. Experimental determination of the antibacterial activity of the designed (S)-1-((3-(4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl)-oxazolidin-2-one-5-yl)methyl)-3-methylthiourea and (S)-1-((3-(3-fluoro-4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl)-oxazolidin-2-one-5-yl)methyl)-3-methylthiourea against multidrug resistant linezolid bacterial strains was higher than that of linezolid.

Health-Related Lifestyles among University Students: Focusing on Eating Habits and Physical Activity.

The transition to higher education at University is a critical moment for young adults to acquire unhealthy habits regarding physical activity (PA) and adherence to a healthy diet. Negative behaviors might be maintained in the years to come with a major risk of suffering from a Non-Communicable Disease. This study aims to determine the relationship between diet and PA in the student community of University of Milano-Bicocca. Students between 18 and 30 years old completed an online survey (6949 students). Two analyses of covariance (ANCOVA), chi-square tests of independence, and a binomial logistic regression were performed to examine the relationship between adequacy of food consumption and PA, in association also with sociodemographic characteristics. Data show a strong correlation between behaviors analyzed, with a proportional positive association between PA and healthy diet. Nevertheless, a third of the sample students incur in incorrect habits for both diet and PA. Further, students performing intensive PA have the healthiest food consumption in general but the worst red meat and pork intake. Accordingly, men practice more PA but have a less adequate diet, exactly contrary to women. In conclusion, policies promoting consciousness of well-being would transform Universities into healthy hubs for virtuous habits.

Antitumor properties of substituted (αE)-α-(1H-indol-3-ylmethylene)benzeneacetic acids or amides.

A novel class of indole derivatives characterized by a (αE)-α-(1H-indol-3-ylmethylene)benzeneacetic acid or amide scaffold was synthesized. These derivatives, assayed for cell-growth inhibition activity against a panel of six different tumor cell lines, showed strong antiproliferative activity and selectivity mainly towards DU145 cell line. In particular, compounds 2d-m and 5 stand out for their cell growth inhibitory activity and, among them, compound 2d emerged for its selectivity towards DU145 with respect to other tested tumor cell lines. DU145 treated with 1µM of 2d for 72h showed p21(Cip1) induction and suppression of Akt signaling together with induction of Rb. From a computational point of view, two different approaches were used in order to study topology and electronic properties of the novel compounds and to shed light on their drug-likeness properties. Firstly, topological and electronic features of the compounds endowed with the most relevant biological activity were deepened; in parallel, some ADME properties like solubility and permeability were predicted.

Aß42 production in brain capillary endothelial cells after oxygen and glucose deprivation.

Although the diverse triggers of AD are still under debate, the hypothesis of the contribution of cerebrovascular deficiencies has emerged in recent years. Cerebrovascular dysfunction may precede cognitive decline and onset of neurodegeneration. Indeed, the toxic Aß(42) aggregates constituting senile plaques, one of AD hallmarks, is often detected as amorphous material or fine fibrils in the brain capillary of AD patients. Aß(42) causing cerebral microangiopathy might originate either from the circulating blood, the vessel wall itself or the brain parenchyma. In the present investigation we show, for the first time, that in rat brain capillary endothelial cells (RBE4), in vitro oxygen glucose deprivation treatment elicits 250% of Aß(42) peptide production increase through a mechanism that involves the hypoxia inducible factor-1-mediated ß-secretase (BACE1) up-regulation. Furthermore, we observed a time dependent increase of amyloid protein precursor (AßPP) gene and protein expression, confirming previous reports which established the existence of AßPP in the cerebrovascular domain. Our experimental evidences point out that ischemic events may directly contribute in brain capillary endothelial cells to the enhancement of the amyloidogenic metabolism, leading to intracellular deposition of Aß(42). This events may contribute to the impairment of Aß brain clearance and AD related blood brain barrier dysfunctions.

Transport and signaling through the phosphate-binding site of the yeast Pho84 phosphate transceptor.

A novel concept in eukaryotic signal transduction is the use of nutrient transporters and closely related proteins as nutrient sensors. The action mechanism of these "transceptors" is unclear. The Pho84 phosphate transceptor in yeast transports phosphate and mediates rapid phosphate activation of the protein kinase A (PKA) pathway during growth induction. We have now identified several phosphate-containing compounds that act as nontransported signaling agonists of Pho84. This indicates that signaling does not require complete transport of the substrate. For the nontransported agonist glycerol-3-phosphate (Gly3P), we show that it is transported by two other carriers, Git1 and Pho91, without triggering signaling. Gly3P is a competitive inhibitor of transport through Pho84, indicating direct interaction with its phosphate-binding site. We also identified phosphonoacetic acid as a competitive inhibitor of transport without agonist function for signaling. This indicates that binding of a compound into the phosphate-binding site of Pho84 is not enough to trigger signaling. Apparently, signaling requires a specific conformational change that may be part of, but does not require, the complete transport cycle. Using Substituted Cysteine Accessibility Method (SCAM) we identified Phe(160) in TMD IV and Val(392) in TMD VIII as residues exposed with their side chain into the phosphate-binding site of Pho84. Inhibition of both transport and signaling by covalent modification of Pho84(F160C) or Pho84(V392C) showed that the same binding site is used for transport of phosphate and for signaling with both phosphate and Gly3P. Our results provide to the best of our knowledge the first insight into the molecular mechanism of a phosphate transceptor.

Effects of PM2.5 Exposure on the ACE/ACE2 Pathway: Possible Implication in COVID-19 Pandemic.

Particulate matter (PM) is a harmful component of urban air pollution and PM2.5, in particular, can settle in the deep airways. The RAS system plays a crucial role in the pathogenesis of pollution-induced inflammatory diseases: the ACE/AngII/AT1 axis activates a pro-inflammatory pathway counteracted by the ACE2/Ang(1-7)/MAS axis, which in turn triggers an anti-inflammatory and protective pathway. However, ACE2 acts also as a receptor through which SARS-CoV-2 penetrates host cells to replicate. COX-2, HO-1, and iNOS are other crucial proteins involved in ultrafine particles (UFP)-induced inflammation and oxidative stress, but closely related to the course of the COVID-19 disease. BALB/c male mice were subjected to PM2.5 sub-acute exposure to study its effects on ACE2 and ACE, COX-2, HO-1 and iNOS proteins levels, in the main organs concerned with the pathogenesis of COVID-19. The results obtained show that sub-acute exposure to PM2.5 induces organ-specific modifications which might predispose to greater susceptibility to severe symptomatology in the case of SARS-CoV-2 infection. The novelty of this work consists in using a molecular study, carried out in the lung but also in the main organs involved in the disease, to analyze the close relationship between exposure to pollution and the pathogenesis of COVID-19.

Antioxidant and Anti-Inflammatory Effect of Cinnamon (Cinnamomum verum J. Presl) Bark Extract after In Vitro Digestion Simulation.

Cinnamon bark is widely used for its organoleptic features in the food context and growing evidence supports its beneficial effect on human health. The market offers an increasingly wide range of food products and supplements enriched with cinnamon extracts which are eliciting beneficial and health-promoting properties. Specifically, the extract of Cinnamomum spp. is rich in antioxidant, anti-inflammatory and anticancer biomolecules. These include widely reported cinnamic acid and some phenolic compounds, such asproanthocyanidins A and B, and kaempferol. These molecules are sensitive to physical-chemical properties (such as pH and temperature) and biological agents that act during gastric digestion, which could impair molecules' bioactivity. Therefore, in this study, the cinnamon's antioxidant and anti-inflammatory bioactivity after simulated digestion was evaluated by analyzing the chemical profile of the pure extract and digested one, as well as the cellular effect in vitro models, such as Caco2 and intestinal barrier. The results showed that the digestive process reduces the total content of polyphenols, especially tannins, while preserving other bioactive compounds such as cinnamic acid. At the functional level, the digested extract maintains an antioxidant and anti-inflammatory effect at the cellular level.

Lifestyle Profiles and Their Sociodemographic Correlate in an Academic Community Sample.

Promoting healthy behaviors throughout life is an essential prevention tool. Prior research showed that unhealthy behaviors tend to co-occur and interplay. However, which behaviors co-occur most frequently and which sociodemographic variables are associated with specific clusters of unhealthy behavior are still being determined. This study aimed to identify different lifestyle profiles and analyze their associations with sociodemographic factors in an Italian academic community to plan targeted initiatives to promote healthy lifestyles. A sample of 8715 adults from an Italian university (mean age = 26 years; range = 18-76; 30% male) participated in an online survey in 2019. Four health-related behaviors were evaluated: diet, physical activity, smoking, and alcohol consumption. Lifestyle profiles were identified through cluster analysis. Then, a multinomial logistic regression was performed to explore the association among lifestyle profiles, sociodemographic variables (age, gender, and academic role), and body mass index (BMI). Results showed that older age was associated with the probability of belonging to the profile characterized by smoke addiction and regular alcohol consumption but also with the healthiest diet. The younger the age, the greater the probability of belonging to the most physically active profile. Men were more likely than women to belong to the lifestyle profile with the most regular alcohol consumption and the highest physical activity. Lower BMI was associated with the most physically active profile. This study shed light on factors associated with different co-occurring health-related behaviors that should be considered in planning effective communication strategies and preventive health interventions within the academic community.

LSEA Evaluation of Lipid Mediators of Inflammation in Lung and Cortex of Mice Exposed to Diesel Air Pollution.

Airborne ultrafine particle (UFP) exposure is a great concern as they have been correlated to increased cardiovascular mortality, neurodegenerative diseases and morbidity in occupational and environmental settings. The ultrafine components of diesel exhaust particles (DEPs) represent about 25% of the emission mass; these particles have a great surface area and consequently high capacity to adsorb toxic molecules, then transported throughout the body. Previous in-vivo studies indicated that DEP exposure increases pro- and antioxidant protein levels and activates inflammatory response both in respiratory and cardiovascular systems. In cells, DEPs can cause additional reactive oxygen species (ROS) production, which attacks surrounding molecules, such as lipids. The cell membrane provides lipid mediators (LMs) that modulate cell-cell communication, inflammation, and resolution processes, suggesting the importance of understanding lipid modifications induced by DEPs. In this study, with a lipidomic approach, we evaluated in the mouse lung and cortex how DEP acute and subacute treatments impact polyunsaturated fatty acid-derived LMs. To analyze the data, we designed an ad hoc bioinformatic pipeline to evaluate the functional enrichment of lipid sets belonging to the specific biological processes (Lipid Set Enrichment Analysis-LSEA). Moreover, the data obtained correlate tissue LMs and proteins associated with inflammatory process (COX-2, MPO), oxidative stress (HO-1, iNOS, and Hsp70), involved in the activation of many xenobiotics as well as PAH metabolism (Cyp1B1), suggesting a crucial role of lipids in the process of DEP-induced tissue damage.

Abeta peptide toxicity is reduced after treatments decreasing phosphatidylethanolamine content in differentiated neuroblastoma cells.

We investigated whether the toxicity of oligomeric amyloid-beta peptide (Abeta1-42) upon differentiated human neuroblastoma SH-SY5Y cells, can be affected by changes of membrane lipid composition. An immunostaining technique, using lipids extracted from the cells and separated by thin layer chromatography, suggested that Abeta preferentially binds to phosphatidylethanolamine (PE), one of the major lipids in the cell extract. For this reason, we utilized treatments with putative inhibitors of phosphatidylethanolamine biosynthesis (choline, phosphocholine, R59949) to decrease its proportion in the cell membrane; choline treatment (2.5 mM, 24 h) showed the best performance, reducing phosphatidylethanolamine content from 5.7 to 3.3 µg phosphorous/mg protein. Either the extent of Abeta binding or its toxicity decreased onto choline-treated cells. These data may open the possibility to develop future strategies aiming to reduce Abeta toxicity in Alzheimer disease.

Study of the Antioxidant Effects of Coffee Phenolic Metabolites on C6 Glioma Cells Exposed to Diesel Exhaust Particles.

The contributing role of environmental factors to the development of neurodegenerative diseases has become increasingly evident. Here, we report that exposure of C6 glioma cells to diesel exhaust particles (DEPs), a major constituent of urban air pollution, causes intracellular reactive oxygen species (ROS) production. In this scenario, we suggest employing the possible protective role that coffee phenolic metabolites may have. Coffee is a commonly consumed hot beverage and a major contributor to the dietary intake of (poly) phenols. Taking into account physiological concentrations, we analysed the effects of two different coffee phenolic metabolites mixes consisting of compounds derived from bacterial metabolization reactions or phase II conjugations, as well as caffeic acid. The results showed that these mixes were able to counteract DEP-induced oxidative stress. The cellular components mediating the downregulation of ROS included extracellular signal-regulated kinase 1/2 (ERK1/2), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and uncoupling protein 2 (UCP2). Contrary to coffee phenolic metabolites, the treatment with N-acetylcysteine (NAC), a known antioxidant, was found to be ineffective in preventing the DEP exposure oxidant effect. These results revealed that coffee phenolic metabolites could be promising candidates to protect against some adverse health effects of daily exposure to air pollution.

Pin1 affects Tau phosphorylation in response to Abeta oligomers.

We show that in hippocampal cultured neurons, dephosphorylation of peptidyl-prolyl cis-trans isomerase Pin1 on Ser16 is occurring during the early stages of exposure to Abeta (1-42) oligomers. This occurrence, resulting in Pin1 activation, is paralleled by Tau(Thr231) dephosphorylation, probably due to Pin1-mediated Tau isomerisation. Indeed, in the presence of the specific Pin1 inhibitor juglone, Abeta-induced Tau(Thr231)dephosphorylation is prevented. The involvement of protein phosphatase 2A (PP2A) in dephosphorylation of isomerised Tau is shown by the co-treatment of neurons with Abeta (1-42) and okadaic acid, a PP2A inhibitor, leading to Tau(Thr231) hyperphosphorylation. We also report the modulation, via Pin1, of Ser199, Ser396, Ser400 and Ser404 phosphorylation state in response to Abeta treatment. Taken together, these data suggest for the first time that an early Pin1 response might be transiently evoked by Abeta 1-42 oligomers, preventing Tau hyperphosphorylation. This evidence highlights the role of Pin1 as Tau phosphorylation modulator during Alzheimer onset.

TrkA pathway activation induced by amyloid-beta (Abeta).

Amyloid-beta (Abeta), a cytotoxic fragment of Amyloid Precursor Protein (APP), has been implicated in the etiopathogenesis of Alzheimer's disease (AD). Since several neurotrophins signalling pathways may be activated in response to toxic insults, we investigated whether a similar response is triggered also by Abeta. After Abeta (25-35) peptide administration to cultured rat hippocampal neurons, the nerve growth factor (NGF) and its receptor (TrkA) mRNA expression is up-regulated. Moreover, we observe an increased cellular TrkA expression (4.5 fold) and NGF release in the culture medium (5-fold). Concomitantly, TrkA, Akt and glycogen synthase kinase 3beta (Gsk3beta) phosphorylation significantly increase. Interestingly, when cells were treated with Abeta (25-35) in the presence of blocking antibody against NGF, only a partial TrkA activation (2-fold) was observed. These results have been confirmed by using pathophysiological Abeta (1-42) oligomers. Our data provide the evidence that Abeta induces the TrkA pathway activation directly by itself and indirectly promoting NGF secretion.

Intranasal delivery of mesenchymal stem cell-derived extracellular vesicles exerts immunomodulatory and neuroprotective effects in a 3xTg model of Alzheimer's disease.

The critical role of neuroinflammation in favoring and accelerating the pathogenic process in Alzheimer's disease (AD) increased the need to target the cerebral innate immune cells as a potential therapeutic strategy to slow down the disease progression. In this scenario, mesenchymal stem cells (MSCs) have risen considerable interest thanks to their immunomodulatory properties, which have been largely ascribed to the release of extracellular vesicles (EVs), namely exosomes and microvesicles. Indeed, the beneficial effects of MSC-EVs in regulating the inflammatory response have been reported in different AD mouse models, upon chronic intravenous or intracerebroventricular administration. In this study, we use the triple-transgenic 3xTg mice showing for the first time that the intranasal route of administration of EVs, derived from cytokine-preconditioned MSCs, was able to induce immunomodulatory and neuroprotective effects in AD. MSC-EVs reached the brain, where they dampened the activation of microglia cells and increased dendritic spine density. MSC-EVs polarized in vitro murine primary microglia toward an anti-inflammatory phenotype suggesting that the neuroprotective effects observed in transgenic mice could result from a positive modulation of the inflammatory status. The possibility to administer MSC-EVs through a noninvasive route and the demonstration of their anti-inflammatory efficacy might accelerate the chance of a translational exploitation of MSC-EVs in AD.

Prion protein structure is affected by pH-dependent interaction with membranes: a study in a model system.

Interaction of full length recombinant hamster prion protein with liposomes mimicking lipid rafts or non-raft membrane regions was studied by circular dichroism, chemical cross-linking and sucrose gradient ultracentrifugation. At pH 7.0, the protein bound palmitoyloleoylphosphatidylcholine/cholesterol/sphingomyelin/monosialoganglioside GM1 (GM1) ganglioside liposomes but not palmitoyloleoylphosphatidylcholine alone (bound/free=0.33 and 0.01, respectively), maintaining the native alpha-helical structure and monomeric form. At pH 5.0, though still binding to quaternary mixtures, in particular GM1, the protein bound also to palmitoyloleoylphosphatidylcholine (bound/free 0.35) becoming unfolded and oligomeric. The pH-dependent interaction with raft or non-raft membranes might have implication in vivo, by stabilizing or destabilizing the protein.