Arginine Glycine Research Articles (Page 1)

Nano-theranostics using biodegradable polymers are effective for the diagnosis and treatment of intractable cancers; however, there is a need for technology that controls bioavailability and biodegradability without compromising biocompatibility. In this study, peptide nanoparticles (NPs) with controlled particle size and biodegradability were prepared by ionizing radiation and loaded with imaging agents and anticancer drugs to develop novel nano-theranostics for pancreatic cancer diagnosis and treatment. Peptides composed of histidine, glycine, glutamic acid, and an arginine–glycine–aspartic acid motif were synthesized by the solid-phase synthesis method. Their aqueous solutions were irradiated with γ-rays to produce NPs with a particle size of less than 50 nm, enabling penetration of the pancreatic cancer stroma. The radiation crosslinking of peptides, with or without the arginine–glycine–aspartic acid motif, in water was investigated by pulse radiolysis. Peptide NPs loaded with fluorescent labeling or magnetic resonance imaging agents were efficiently taken up by pancreatic cancer cells. Cisplatin-loaded peptide NPs produced by higher-dose irradiation suppress drug-release rates owing to their lower biodegradability. In conclusion, peptide NPs with controllable particle size and biodegradability were produced by ionizing radiation and loaded with fluorescent labeling agents, magnetic resonance imaging agents, and anticancer drugs to develop a new nano-theranostics drug for pancreatic cancer diagnosis and treatment.

Malaria remains a global health crisis, with Plasmodium resistance underscoring the urgent need for advanced drug delivery strategies. To overcome the limitations of oral antimalarials, such as hepatic first-pass metabolism and insufficient drug accumulation in parasites, intestinal M cell-mediated lymphatic transport and Plasmodium-triggered drug release are effective strategies. Plasmodium parasites maintain a weakly acidic intracellular environment with high levels of glutathione (GSH). Polydopamine (PDA) remains stable in the gastrointestinal tract and degrades in the parasite’s weakly acidic, GSH-rich environment, making PDA nanoliposomes (PNLs) a promising oral delivery system for Plasmodium-responsive drug release. Additionally, cyclic arginine–glycine–aspartic acid (cRGD) can specifically target intestinal M cells, promoting lymphatic transport and thereby reducing the first-pass effect. We developed cRGD- and PDA-modified nanoliposomes (cRPNLs) to address the challenges associated with oral administration and loaded them with a disulfide bond (–SS–)-modified dihydroartemisinin (DHA) prodrug (DSSC) to simultaneously deplete GSH and induce lethal oxidative stress, thereby offering an enhanced antimalarial mechanism. In vitro, cRPNLs exhibited pH- and GSH-responsive DHA release. Ex vivo fluorescent imaging confirmed that cRPNLs targeted Peyer’s patches with minimal distribution in the liver. Crucially, both PNLs and cRPNLs reduced GSH levels in infected erythrocytes and elevated ROS by 2.0-fold, outperforming unmodified DHA. Pharmacokinetic and in vivo antimalarial pharmacodynamic studies revealed that cRPNLs exhibited significantly higher exposure and Plasmodium inhibition rates compared to PNLs and free DHA. These results highlight cRPNLs as a potent oral nanoplatform that combines M cell-mediated lymphatic uptake with parasite-triggered drug release, significantly improving antimalarial efficacy.

Dry eye disease (DED) is characterized by chronic inflammation and an unstable tear film. Stem cells have shown potential for DED treatment, but the main challenge lies in improving cell delivery effectiveness. Here, we developed eye drops for autoimmune DED treatment using porous arginine–glycine–aspartic acid (RGD)–modified alginate microcarriers with mesenchymal stem/stromal cells (MSCs) (RGD-Alg@MSCs). These microcarriers provided a favorable microenvironment for large-scale cell expansion while maintaining stemness with ideal mechanical properties for ocular application. In vitro, RGD-Alg@MSCs demonstrated significantly enhanced therapeutic effects compared to conventional MSCs, including improved cell viability, reduced apoptosis and reactive oxygen species, and enhanced release of immunomodulatory factors. Transcriptomic analysis revealed distinct molecular mechanisms underlying these enhanced therapeutic effects. In the mouse model, RGD-Alg@MSCs exhibited prolonged ocular retention and enhanced tear production, promoted corneal healing, and suppressed inflammation by inhibiting dendritic cell activation and TH17 differentiation. Our microcarrier system substantially improves stem cell delivery efficiency for treating autoimmune DED.

Ewing sarcoma, the second most common pediatric bone and soft tissue cancer, is caused by aberrant fusion of the RNA‐binding protein EWS (EWS) low‐complexity domain (EWSLCD) to the DNA‐binding domain of the transcription factor friend leukemia integration 1 (FLI1). The resulting fusion, EWS::FLI1, directly interacts with and engages in a dynamic interplay with EWS that drives tumorigenesis and regulates the function of both proteins. While EWSLCD is known to promote self‐association, the role of the RNA‐binding domains (RBDs) of EWS, which include arginine–glycine–glycine (RGG) repeat regions and a structured RNA‐recognition motif (RRM), remains less well understood. Here, we investigate the interplay between EWSLCD and RBDs using biomolecular condensation assays, microscopy, nuclear magnetic resonance (NMR) spectroscopy, and molecular simulations. Our studies reveal that RBDs differentially influence EWSLCD condensate formation and suggest that electrostatics and polypeptide‐chain length likely contribute to this interaction. NMR spectroscopy and molecular dynamics simulations further demonstrate that EWSLCD and the central RNA‐binding region, comprising the RRM and RGG2 domains, engage in transient, non‐specific interactions that are broadly distributed across both regions and involve diverse residue types. Specifically, tyrosine, polar residues, and proline within EWSLCD preferentially interact with arginine, glycine, and proline residues in the RBD. Atomistic simulations of EWS confirm that the full‐length protein exhibits a similar interaction profile with conserved chemical specificity, supporting a model in which a network of weak, distributed interdomain contacts underlies EWS self‐association. Together, these findings provide molecular insight into the mechanisms of EWS condensate formation and lay the groundwork for understanding how interdomain interactions regulate EWS and EWS::FLI1 function.

Retinal neovascularization diseases cause vision impairment due to abnormal blood vessel growth in the retina. Current treatments, including repeated intraocular anti–vascular endothelial growth factor injections, are invasive and often lead to discomfort and complicated hemorrhages. Here, we developed a noninvasive nanozyme eye drop capable of penetrating the fundus to eliminate reactive oxygen species (ROS) and thereby inhibit neovascularization. The nanozyme eye drops consist of liposomes formed by fluorinated and arginine–glycine–aspartic acid–modified phospholipids, which enhance the penetration of ocular barriers. The encapsulated superoxide dismutase–catalase cascade nanozyme within these liposomes allows for efficient ROS scavenging. In vitro and in vivo studies demonstrate that these nanozyme eye drops achieve deep retinal tissue penetration, alleviate oxidative stress, restore mitochondrial function, and suppress aberrant insulin-like growth factor binding protein 6 signaling, thereby inhibiting pathological neovascularization. Enhanced ocular bioavailability and minimal toxicity further underscore its promise as a safe and effective noninvasive treatment for retinal neovascularization diseases.

Amyloid-β (Aβ) fibrillation is a spontaneous, thermodynamic process governed by nucleation and elongation. While many studies have explored the ability of engineered nanomaterials (ENMs) to modulate Aβ fibrillation, such as inhibitors, promoters, and dual-modulators, the key physicochemical property of ENMs that determines this behavior remains unclear. In this study, we developed a comprehensive library of ENMs with well-controlled physicochemical properties, including surface charges, morphologies, and hydrophilicity, to systematically investigate their effects on Aβ40 fibrillation. We identified hydrophilicity as the primary determinant of ENM-mediated modulation, rather than surface charge or morphology. Thioflavin T (ThT) kinetics assays indicated that hydrophilic ENMs exhibited bidirectional modulation, both promoting and inhibiting fibrillation depending on concentration. This bidirectional effect results from a competition between accelerated nucleation and decelerated elongation. While hydrophobic ENMs exhibited only unidirectional inhibition from the initial nucleation phase, two-dimensional-NMR (2D-NMR) mechanism studies indicated that this difference resulted from specific interactions with Aβ40 residues. Hydrophilic ENMs targeted hydrophilic residues involved in elongation, including Arginine R5, Glycine G9, G25, G33, G37, and G38, Lysine K28, and Alanine A30, while hydrophobic ENMs bound to hydrophobic residues critical for nucleation, such as I31. These findings provide mechanistic insight into NP-peptide interactions and lay a foundation for the rational design of nanomaterials to modulate amyloid fibrillation.

Chronic hydrocephalus following aneurysmal subarachnoid hemorrhage (SAH) is a complication that can lead to deterioration in neurological status and cognitive impairment. Our recent clinical study reported that a high concentration of plasma fibulin-5 (FBLN5), a matricellular protein, was associated with the occurrence of chronic hydrocephalus after SAH. This study aimed to investigate whether and how FBLN5 was associated with hydrocephalus during acute to later phases of SAH in mice. C57BL/6 male mice underwent sham or filament perforation SAH modeling, and vehicle or two dosages (0.01 and 0.1 μg) of short or long recombinant FBLN5 (rFBLN5) were randomly administrated by an intracerebroventricular injection. Neurobehavioral tests, measurements of the degree of ventricular enlargement, Western blotting, and immunohistochemical staining were performed to evaluate hydrocephalus 24 and 48 h after SAH. After SAH, ventricular dilatation did not occur at 24 h but developed at 48 h, and both doses of long rFBLN5 with an arginine–glycine–aspartic acid domain suppressed ventricular dilatation at 48 h after SAH. Long rFBLN5 also decreased phosphorylated p38 in the brain parenchyma and prevented post-SAH increases in perivascular macrophages, as well as microglia activation in the brain parenchyma at 48 h after SAH. Although further research is required to clarify the detailed mechanism, this study demonstrated for the first time that exogenous administration of FBLN5 may have a protective effect against ventricular dilatation after experimental SAH.

Responses in green alga Trentepohlia to ultraviolet-B (UV-B) radiation: Physiological and metabolic implications for stress adaptation.

Salt-sensitive hypertension (SSH) is a major risk factor for cardiovascular disease, but its metabolic mechanisms remain unclear. This study investigates the plasma metabolic profile of SSH patients to identify potential therapeutic targets. Additionally, SSH patients were identified through an oral salt-loading test. Plasma metabolomics was performed by utilizing GC-MS and LC-MS, followed by network correlation analysis, pathway enrichment, receiver operating characteristic analysis, and linear regression analysis. The findings were validated in Dahl salt-sensitive (SS) rats, with glycine supplementation evaluated as a potential therapeutic intervention. Firstly, plasma metabolomics illustrated distinct metabolic alterations in SSH patients, with substantially increased levels of fumaric acid, pyruvat,e and lactic acid, as well as significantly decreased levels of glycine, leucine and β-alanine (p < 0.05). Additionally, Glycine and β-alanine levels decreased by 61% and 68% compared to the control group. Secondly, pathway enrichment analysis identified disruptions in amino acid metabolism, particularly Arginine biosynthesis pathway, TCA pathway, glycine, serine, and threonine metabolism pathways were significantly enriched (p < 0.05). Correlation network analysis identified fumarate as a hub metabolite in the pathophysiology of SSH. Glycine showed the highest predictive value for SSH (AUC = 94.6181%) and was negatively correlated with blood pressure. Finally, glycine supplementation in SS rats substantially reduced salt-induced hypertension (p < 0.001) by improving renal amino acid metabolism and enhancing nitric oxide production. This study identifies glycine as a crucial metabolic target for SSH intervention. Glycine supplementation effectively alleviates SSH in animal models, indicating its potential for clinical applications. Future research should focus on exploring glycine-based therapies in clinical trials. Intervention targets and validation of salt-sensitive hypertension.

The present work evaluates whether buffalo and cattle have different sequences of luteinizing hormone receptor (LHr) and glyceraldehyde 3-phosphate dehydrogenase (GADPDH) genes. DNA was extracted from the peripheral blood of 38 animals (17 buffaloes and 21 cows) and the ovarian granulosa cells of 13 cows. Primers used for amplification were reported in the literature. The PCR products obtained were analyzed via electrophoresis on 1.5% agarose gels and sequenced via the Sanger technique. The electropherograms were analyzed via DNA Baser software, and the sequences were aligned via MEGA5 software. The quality of the electropherograms was evaluated via UGENE software.The edited contigs corresponding to the GAPDH gene were 100 nucleotides long, whereas those of the LHR gene reached 151 nucleotides. The most relevant changes were observed in the following positions: valine for isoleucine at position 65; asparagine for cysteine at position 67; alanine for glycine at position 70; threonine for proline at position 72; glycine for arginine at position 88; and alanine for aspartic acid at position 89. In the analyzed region, a variation was identified at position 446, where buffaloes preferentially present threonine, whereas in cows, alanine or valine.It is reported for the first time that there are differences in the LHr and GAPDH genes between buffaloes and cattle. The bioinformatic analysis of these sequences may explain whether the changes may affect the function of the genes and whether these may be responsible for the differences observed in the reproduction of the species analyzed.

Antioxidant and anti-aging effect of queen bee larvae (Apis mellifera) protein hydrolysates in Drosophila melanogaster.

BackgroundDestruction of the blood–spinal cord barrier (BSCB) following spinal cord injury (SCI) can result in various harmful cytokines, neutrophils, and macrophages infiltrating into the injured site, causing secondary damage. Growing evidence shows that M2 macrophages and their small extracellular vesicles (sEVs) contribute to tissue repair in various diseases.Methods and ResultsIn our previous proteomics‐based analysis of protein expression profiles in M2 macrophages and their sEVs (M2‐sEVs), the proteoglycan perlecan, encoded by HSPG2, was found to be upregulated in M2‐sEVs. Perlecan is a crucial component of basement membranes, playing a vital role in stabilising BSCB homeostasis and functions through its interactions with other matrix components, growth factors, and receptors. Here, we verified the high levels and remarkable therapeutic effect of M2‐sEV‐derived perlecan on the permeability of spinal cord microvascular endothelial cells exposed to oxygen glucose deprivation and reoxygenation in vitro. We also decorated the surface of M2‐sEVs with a fusion protein comprising the N‐terminus of Lamp2 and arginine glycine aspartic acid (RGD) peptides, which have an affinity for integrin αvβ3 and are primarily present on neovascular endothelium surfaces. In SCI model mice, these RGD‐M2‐sEVs accumulated at injured sites, promoting BSCB restoration. Finally, we identified M2‐sEV‐derived perlecan as a key player in regulating BSCB integrity and functional recovery post‐SCI.ConclusionOur results indicate that RGD‐M2‐sEVs promote BSCB restoration by transporting perlecan to neovascular endothelial cells, representing a potential strategy for SCI treatment.Key pointsPerlecan, a crucial component of basement membranes that plays a vital role in stabilising BSCB homeostasis and functions, was found to be upregulated in M2‐sEVs.M2‐sEVs decorated with RGD peptide can effectively target the neovascular endothelium surfaces at the injured spinal cord site.RGD‐M2‐sEVs promote BSCB restoration by transporting perlecan to neovascular endothelial cells, representing a potential strategy for SCI treatment.

Apatinib potentiates doxorubicin with cRGD-functionalized pH-senstive micelles against glioma

RNA binding proteins (RBPs) are enriched in phase separated biomolecular assemblies across cell types. These RBPs often harbor arginine–glycine rich RGG motifs, which can drive phase separation, and can preferentially interact with RNA G-quadruplex (G4) structures, particularly in the neuron. Increasing evidence underscores the important role that RNA sequence and structure play in contributing to the form and function of protein condensates, however, less is known about the role of G4 RNAs and their interaction with RGG domains specifically. In this study we focused on the model protein, Fragile X mental retardation protein (FMRP), to investigate how G4-containing RNA sequences impact the phase behavior and material properties of condensates. FMRP is implicated in the development of Fragile X Syndrome, and is enriched in neuronal granules where it is thought to aid in mRNA trafficking and translational control. Here, we examined RNA sequences with increasing G content and G4 propensity in complex with the RGG-containing low complexity region (LCR) of FMRP. We found, that while increasing G content triggers aggregation of poly-arginine, all RNA sequences supported phase separation into liquid droplets with FMRP-LCR. Combining microrheology, and fluorescence recovery after photobleaching, we measured a moderate increase in viscosity and decrease in dynamics for increasing G-content, and detected no measurable increase in elasticity as a function of G4 structure. Additionally, we found that while methylation of FMRP decreased RNA binding affinity, this modification did not impact condensate material properties suggesting that RNA sequence/structure can play a greater role than binding affinity in determining the emergent properties of condensates. Together, this work lends much needed insight into the ways in which G-rich RNA sequences tune the assembly, dynamics and material properties of protein/RNA condensates and/or granules.

While genetic engineering has offered new strategies for regulating stem cell differentiation, the efficacy varies in cells with different phenotypes or lineage commitments, leading to inconsistent differentiation outcomes and uncertainty in regenerative medicine. To address this issue, we employ a Y-shaped DNA (Y-DNA) as a nanomaterial to phenotype-specifically regulate differentiation of human mesenchymal stem cells (hMSCs). Y-DNA is composed of three DNA strands with complementary sequences and different roles. The Y-DNA designed in the present study can be uniquely activated by miR-106a-5p, a microRNA preferentially expressed in adipogenesis-biased hMSCs. Upon activation, the Y-DNA disassembles, releasing an antisense oligonucleotide that inhibits expression of cofilin, which serves as a key regulator to enhance adipogenic differentiation, and thus, prevents hMSCs from undergoing osteogenic differentiation. The key regulatory role of cofilin in hMSC differentiation is verified at the single-cell level on arginine–glycine–aspartate microislands under the nonfouling background of poly(ethylene glycol) hydrogels. Our strategy effectively redirects these cells towards osteogenic differentiation by inhibiting adipogenic differentiation, demonstrating dose dependence with high specificity, selectivity, and low toxicity. hMSCs cultured in a dual induction medium (a mixture of adipogenic medium and osteogenic medium) show enhanced osteogenic differentiation after transfection with the nanostructured Y-DNA. This approach addresses the challenge of cell heterogeneity in bone regeneration, offering a promising solution for precise control over stem cell fate. The ability of Y-DNA to specifically target cells with a propensity for adipogenic differentiation and to reprogram their lineage commitment has significant implications for the field of regenerative medicine, particularly in applications requiring enhanced purity of cell differentiation outcomes.

Diagnosis and Prognosis of aGVHD By Metabolic Biomarkers after Allogeneic Hematopoietic Stem Cell Transplantation

A covalent assembly strategy was developed to construct agold nanocluster-based nano-assembly (AuNCNA) in a controllable manner, using Au8 nanocluster as node and 5,10,15,20-tetra(4-alkynylphenyl)porphine (TEPP) as ligand. Subsequently, the tripeptide arginine glycine aspartic acid (RGD) peptide is further modified via clicking reaction to build a multi-functional nanoplatform (AuNCNA@RGD) that can integrate the targeted fluorescence imaging and efficient photodynamic therapy (PDT). The strong interregulation of Au8 nanocluster and TEPP results in AuNCNA@RGD exhibiting three distinct advantages: (i) TEPP plays an important role in stabilizing the Au8 nanocluster and keeping the active site fixed within the framework, thereby enhancing stability of Au8 nanocluster; (ii) Au8 nanocluster possess adjustable energy level, which can accelerate the transfer of photogenerated charge and prevent the recombination of electrons and holes, thus improving thephotosensitivity of TEPP for PDT; (iii) AuNCNA exhibits bright fluorescence emission that facilitates RGD-assisted targeted tumor imaging. This work expands the construction method of AuNC assembly, and this assembly method is versatile and can flexibly transform different organic ligands to construct various AuNC-based functional nanomaterials.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are devastating neurodegenerative diseases with no effective cure. GGGGCC repeat expansion in C9orf72 is the most common genetic cause of both ALS and FTD. A key pathological feature of C9orf72 related ALS/FTD is the presence of abnormal dipeptide repeat proteins translated from GGGGCC repeat expansion, including poly Glycine-Arginine (GR). In this study, we observed that (GR)50 conferred significant mitochondria damage and cytotoxicity. Metformin, the most widely used clinical drug, successfully relieved (GR)50 induced mitochondrial damage and inhibited (GR)50 related cytotoxicity. Further research revealed metformin effectively restored mitochondrial function by upregulating AKT phosphorylation in (GR)50 expressed cells. Taken together, our results indicated restoring mitochondrial function with metformin may be a rational therapeutic strategy to reduce poly(GR) toxicity in C9orf72 ALS/FTD patients.

Background: Near-infrared (NIR) phototheranostics provide promising noninvasive imaging and treatment for head and neck squamous cell carcinoma (HNSCC), capitalizing on its adjacency to skin or mucosal surfaces. Activated by laser irradiation, targeted NIR fluorophores can selectively eradicate cancer cells, harnessing the power of synergistic photodynamic therapy and photothermal therapy. However, there is a paucity of NIR bioprobes showing tumor-specific targeting and effective phototheranosis without hurting surrounding healthy tissues. Methods: We engineered a tumor-specific bifunctional NIR bioprobe designed to precisely target HNSCC and induce phototheranosis using bioconjugation of a cyclic arginine-glycine-aspartic acid (cRGD) motif and zwitterionic polymethine NIR fluorophore. The cytotoxic effects of cRGD-ZW800-PEG were measured by assessing heat and reactive oxygen species (ROS) generation upon an 808-nm laser irradiation. We then determined the invivo efficacy of cRGD-ZW800-PEG in the FaDu xenograft mouse model of HNSCC, as well as its biodistribution and clearance, using a customized portable NIR imaging system. Results: Real-time NIR imaging revealed that intravenously administered cRGD-ZW800-PEG targeted tumors rapidly within 4 h postintravenous injection in tumor-bearing mice. Upon laser irradiation, cRGD-ZW800-PEG produced ROS and heat simultaneously and exhibited synergistic photothermal and photodynamic effects on the tumoral tissue without affecting the neighboring healthy tissues. Importantly, all unbound bioprobes were cleared through renal excretion. Conclusions: By harnessing phototheranosis in combination with tailored tumor selectivity, our targeted bioprobe ushers in a promising paradigm in cancer treatment. It promises safer and more efficacious therapeutic avenues against cancer, marking a substantial advancement in the field.

Adsorbed molecules can modulate the behavior of magnesium (Mg) and Mg alloy in biomedical applications. The interaction regularity and mechanism of biomolecules (such as amino acids, dipeptides, and tripeptide) on a Mg(0001) surface, the influence of dipole correction, and the effects of alloying elements and electronic structure were investigated in this study using first-principles calculations. Specifically, the adsorption energy (Eads) of functional groups (-NH2, -COOH and -CN3H4), amino acids (arginine (Arg), glycine (Gly), and aspartic acid (Asp)), dipeptides (arginine–glycine (Arg-Gly), glycine–aspartic acid (Gly-Asp), and arginine–aspartic acid (Arg-Asp)), and arginine–glycine–aspartic acid (RGD) tripeptide were systematically calculated. Dipole correction slightly enhanced the interaction between molecules and Mg surfaces, but the Eads trend remained unchanged. The addition of alloying elements improved the interaction of molecules and Mg-based alloy surfaces. This study will be of fundamental importance in understanding the interaction regularity of molecules on Mg and Mg-based alloy surfaces and provide possibilities for surface modification design of biomedical materials.