The Soy-Derived Peptide Lunasin Inhibits Invasive Potential of Melanoma Initiating Cells

Lunasin is a 44 amino acid peptide with multiple functional domains including an aspartic acid tail, an RGD domain, and a chromatin-binding helical domain. We recently showed that Lunasin induced a phenotype switch of cancer initiating cells (CIC) out of the stem compartment by inducing melanocyte-associated differentiation markers while simultaneously reducing stem-cell-associated transcription factors. In the present study, we advance the hypothesis that Lunasin can reduce pools of melanoma cells with stem cell-like properties, and demonstrate that Lunasin treatment effectively inhibits the invasive potential of CICs in vitro as well as in vivo in a mouse experimental metastasis model. Mice receiving Lunasin treatment had significantly reduced pulmonary colonization after injection of highly metastatic B16-F10 melanoma cells compared to mice in the control group. Mechanistic studies demonstrate that Lunasin reduced activating phosphorylations of the intracellular kinases FAK and AKT as well as reduced histone acetylation of lysine residues in H3 and H4 histones. Using peptides with mutated activity domains, we functionally demonstrated that the RGD domain is necessary for Lunasin uptake and its ability to inhibit oncosphere formation by CICs, thus confirming that Lunasin’s ability to affect CICs is at least in part due to the suppression of integrin signaling. Our studies suggest that Lunasin represents a unique anticancer agent that could be developed to help prevent metastasis and patient relapse by reducing the activity of CICs which are known to be resistant to current chemotherapies

Lunasin—a multifunctional anticancer peptide from soybean

Lunasin is a bioactive peptide that was originally isolated from soybean and has since been shown to have a number of biological activities, including both cancer chemopreventive and therapeutic activities. Our recent focus has been on determining the range of cancer types that lunasin can affect and the mechanism of action against specific cancers. We recently found that lunasin has significant therapeutic activity against non-small cell lung cancer (NSCLC) both in vitro and in vivo. Mechanistic studies using lunasin-sensitive and lunasin-resistant NSCLC cell lines revealed the lunasin blocks cell proliferation by inhibiting cell cycle progression at the G1/S phase interface and that this inhibition was associated with reduced Akt signaling. In addition, we found that these effects were linked to the inhibition of integrin signaling through αv-containing integrins. Our results provide strong support for the hypothesis that direct effects on integrin signaling represent a major mode of action responsible for lunasin’s anticancer activity.

GPCR-mediated calcium and cAMP signaling determines psychosocial stress susceptibility and resiliency

ストレスに強い脳と弱い脳のメカニズム解明 --うつ病の脳のしくみ解明へ前進--. 京都大学プレスリリース. 2023-04-06.Chronic stress increases the risk of developing psychiatric disorders, including mood and anxiety disorders. Although behavioral responses to repeated stress vary across individuals, the underlying mechanisms remain unclear. Here, we perform a genome-wide transcriptome analysis of an animal model of depression and patients with clinical depression and report that dysfunction of the Fos-mediated transcription network in the anterior cingulate cortex (ACC) confers a stress-induced social interaction deficit. Critically, CRISPR-Cas9–mediated ACC Fos knockdown causes social interaction deficits under stressful situation. Moreover, two classical second messenger pathways, calcium and cyclic AMP, in the ACC during stress differentially modulate Fos expression and regulate stress-induced changes in social behaviors. Our findings highlight a behaviorally relevant mechanism for the regulation of calcium- and cAMP-mediated Fos expression that has potential as a therapeutic target for psychiatric disorders related to stressful environments

Direct measurement of radial strain in the inner-half layer of the left ventricular wall in hypertensive patients

SummaryBackgroundTwo-dimensional speckle tracking echocardiography (2D-STE) is a novel technology that directly measures regional left ventricular (LV) wall contraction. This study aimed to directly measure inner-layer thickening (radial strain) of the LV using 2D-STE, and to examine the relationship between radial strain and the degree of hypertrophy.MethodsThe study enrolled 63 untreated hypertensive patients with normal geometry (N group, n=32) or concentric hypertrophy (CH group, n=31), classified according to LV mass index (LVMI) and relative wall thickness (RWT). Thirty normotensive subjects (C group, n=30) served as controls. Radial strain (ɛ) in the inner half (ɛi) and all layers of the LV wall (ɛa) were calculated from the LV short-axis view by 2D-STE.ResultsLV ejection fraction did not differ significantly among the groups. However, ɛi and ɛa were significantly lower in the CH group compared with the C and N groups (p<0.01). A ratio of ɛi to ɛa was significantly lower in the CH group compared with the C and N groups (p<0.01). A multivariate regression model that included midwall fractional shortening, E/e′, LVMI, RWT, and LV ejection fraction showed that LVMI (p=0.002) and RWT (p=0.014) were independent predictors (R2=0.59) of ɛi.ConclusionRadial strain in the inner half layer of the LV wall decreases in parallel with the degrees of LV concentricity and hypertrophy in hypertensive patients. Radial strain in the inner half layer may identify subtle systolic dysfunction even in hypertensive patients with preserved LV chamber function

Virus induced gene silencing in Antirrhinum majus using the Cucumber mosaic virus vector : Functional analysis of the AINTEGUMENTA (Am-ANT) gene of A. majus

The Arabidopsis gene AINTEGUMENTA (At-ANT) functions in cell proliferation and organ growth. The ANT protein has two copies of the AP2 domains, R1 and R2. Recently, a partial cDNA sequence of the At-ANT homolog in Antirrhinum majus (Am-ANT) was reported (Delgado-Benarroch et al., 2009). Here, we used virus-induced gene silencing (VIGS) to analyze the function of the reported Am-ANT. We then determine the open reading frame (ORF) of Am-ANT and its predicted amino acid sequence. We induced VIGS using Cucumber mosaic virus (CMV-A1) and suppressed the level of Am-ANT mRNA and noted any phenotypic changes. The function of Am-ANT was very similar to that of At-ANT. The A1:ANT-infected Antirrhinum plants had smaller floral organs and leaves, even though cell sizes were unchanged in flowers and larger in leaves. The CMV-based VIGS showed that the cloned Am-ANT gene was indeed functional in cell proliferation and organ growth as observed for At-ANT. In A. majus, CMV vector provide great advantages for analysis of gene functions

Lunasin—a multifunctional anticancer peptide from soybean

Lunasin is a bioactive peptide that was originally isolated from soybean and has since been shown to have a number of biological activities, including both cancer chemopreventive and therapeutic activities. Our recent focus has been on determining the range of cancer types that lunasin can affect and the mechanism of action against specific cancers. We recently found that lunasin has significant therapeutic activity against non-small cell lung cancer (NSCLC) both in vitro and in vivo. Mechanistic studies using lunasin-sensitive and lunasin-resistant NSCLC cell lines revealed the lunasin blocks cell proliferation by inhibiting cell cycle progression at the G1/S phase interface and that this inhibition was associated with reduced Akt signaling. In addition, we found that these effects were linked to the inhibition of integrin signaling through αv-containing integrins. Our results provide strong support for the hypothesis that direct effects on integrin signaling represent a major mode of action responsible for lunasin’s anticancer activity. </p

The 2b proteins of Cucumber mosaic virus generally have the potential to differentially induce necrosis on Arabidopsis

Plant viral symptoms are rarely explained by direct molecular interaction between a viral protein and a host factor, but rather understood as a consequence of arms race between host RNA silencing and viral silencing suppressors. However, we have recently demonstrated that the 2b protein (2b) of Cucumber mosaic virus (CMV) HL strain could bind to Arabidopsis catalase that is important in scavenging cellular hydrogen peroxide, leading to the induction of distinct necrosis on Arabidopsis. Because we previously used virulent strains of subgroup I CMV in the study, we here further analyzed mild strains of subgroup II CMV, which share 70 to 80% sequence homology with subgroup I, to understand whether the necrosis induction is a general phenomenon to compromise host defense system mediated by catalase in the pathosystem of any CMV strains and Arabidopsis. Based on the results, we concluded that 2bs of subgroup II could also bind to catalase, resulting in decrease in catalase activity and weak necrosis on Arabidopsis. Because the 2b-catalase interaction did not prevent CMVs from spreading, it may eventually operate in favor of CMV

A Viral Satellite RNA Induces Yellow Symptoms on Tobacco by Targeting a Gene Involved in Chlorophyll Biosynthesis using the RNA Silencing Machinery

Symptoms on virus-infected plants are often very specific to the given virus. The molecular mechanisms involved in viral symptom induction have been extensively studied, but are still poorly understood. Cucumber mosaic virus (CMV) Y satellite RNA (Y-sat) is a non-coding subviral RNA and modifies the typical symptom induced by CMV in specific hosts; Y-sat causes a bright yellow mosaic on its natural host Nicotiana tabacum. The Y-sat-induced yellow mosaic failed to develop in the infected Arabidopsis and tomato plants suggesting a very specific interaction between Y-sat and its host. In this study, we revealed that Y-sat produces specific short interfering RNAs (siRNAs), which interfere with a host gene, thus inducing the specific symptom. We found that the mRNA of tobacco magnesium protoporphyrin chelatase subunit I (ChlI, the key gene involved in chlorophyll synthesis) had a 22-nt sequence that was complementary to the Y-sat sequence, including four G-U pairs, and that the Y-sat-derived siRNAs in the virus-infected plant downregulate the mRNA of ChlI by targeting the complementary sequence. ChlI mRNA was also downregulated in the transgenic lines that express Y-sat inverted repeats. Strikingly, modifying the Y-sat sequence in order to restore the 22-nt complementarity to Arabidopsis and tomato ChlI mRNA resulted in yellowing symptoms in Y-sat-infected Arabidopsis and tomato, respectively. In 5'-RACE experiments, the ChlI transcript was cleaved at the expected middle position of the 22-nt complementary sequence. In GFP sensor experiments using agroinfiltration, we further demonstrated that Y-sat specifically targeted the sensor mRNA containing the 22-nt complementary sequence of ChlI. Our findings provide direct evidence that the identified siRNAs derived from viral satellite RNA directly modulate the viral disease symptom by RNA silencing-based regulation of a host gene