Search Results (93)

Snakebites are a significant public health problem in many tropical and subtropical regions, causing extensive morbidity and mortality. Traditional snake antivenoms face multiple challenges, including allergenicity, high production costs, and logistical difficulties, highlighting the urgent need for new therapeutic approaches. This pilot study explores the potential of oligopeptides as therapeutic inhibitors targeting the neurotoxic sites of ammodytoxin A (AtxA; PDB: 3G8G) from Vipera ammodytes. We selected two sense oligopeptides to represent critical neurotoxic regions of AtxA as targets for inhibition by complementary antisense peptides. Utilizing a heuristic antisense peptide design based on the molecular recognition theory, we modeled two antisense oligopeptides as complementary counterparts for each sense oligopeptide. The modeled sense and antisense peptides were commercially synthesized, and their binding affinities were evaluated using spectrofluorometric titrations. The determined dissociation constants (K_D) were in the range of 1–10 μM for all sense–antisense pairs, revealing relatively strong binding affinities. Confirmation of sense–antisense peptide binding prompted further investigation into their potential binding to the native target protein through global docking simulations using the HPEPDOCK web server. The results highlight the applicability of molecular recognition theory in the development of antisense peptides that could change therapeutic strategies in various biomedical fields. Further studies are needed to investigate the therapeutic efficacy and broader applications of these peptides. Full article

Alzheimer’s disease (AD) is a debilitating neurodegenerative disorder marked by progressive cognitive decline and memory loss, impacting millions of people around the world. The apolipoprotein E4 (ApoE4) allele is the most prominent genetic risk factor for late-onset AD, dramatically increasing disease susceptibility and accelerating onset compared to its isoforms ApoE2 and ApoE3. ApoE4’s unique structure, which arises from single-amino-acid changes, profoundly alters its function. This review examines the critical interplay between ApoE4 and microglia—the brain’s resident immune cells—and how this relationship contributes to AD pathology. We explore the molecular mechanisms by which ApoE4 modulates microglial activity, promoting a pro-inflammatory state, impairing phagocytic function, and disrupting lipid metabolism. These changes diminish microglia’s ability to clear amyloid-beta peptides, exacerbating neuroinflammation and leading to neuronal damage and synaptic dysfunction. Additionally, ApoE4 adversely affects other glial cells, such as astrocytes and oligodendrocytes, further compromising neuronal support and myelination. Understanding the ApoE4–microglia axis provides valuable insights into AD progression and reveals potential therapeutic targets. We discuss current strategies to modulate ApoE4 function using small molecules, antisense oligonucleotides, and gene editing technologies. Immunotherapies targeting amyloid-beta and ApoE4, along with neuroprotective approaches to enhance neuronal survival, are also examined. Future directions highlight the importance of personalized medicine based on individual ApoE genotypes, early biomarker identification for risk assessment, and investigating ApoE4’s role in other neurodegenerative diseases. This review emphasizes the intricate connection between ApoE4 and microglial dysfunction, highlighting the necessity of targeting this pathway to develop effective interventions. Advancing our understanding in this area holds promise for mitigating AD progression and improving outcomes for those affected by this relentless disease. Full article

As a popular tool for gene function characterization and gene therapy, RNA interference (RNAi)-based gene silencing has been increasingly explored for potential applications to control invasive species. At least two major hurdles exist when applying this approach to invasive plants: (1) the design and screening of species- and gene-specific biomacromolecules (i.e., gene-silencing agents or GSAs) made of DNA, RNA, or peptides that can suppress the expression of target genes efficiently, and (2) the delivery vehicle needed to penetrate plant cell walls and other physical barriers (e.g., leaf cuticles). In this study, we investigated the cell-penetrating peptide (CPP)-mediated delivery of multiple types of GSAs (e.g., double-stranded RNA (dsRNA), artificial microRNA (amiRNA), and antisense oligonucleotide (ASO)) to knock down a putative phytoene desaturase (PDS) gene in the invasive common reed (Phragmites australis spp. australis). Both microscopic and quantitative gene expression evidence demonstrated the CPP-mediated internalization of GSA cargos and transient suppression of PDS expression in both treated and systemic leaves up to 7 days post foliar application. Although various GSA combinations and application rates and frequencies were tested, we observed limitations, including low gene-silencing efficiency and a lack of physiological trait alteration, likely owing to low CPP payload capacity and the incomplete characterization of the PDS-coding genes (e.g., the recent discovery of two PDS paralogs) in P. australis. Our work lays a foundation to support further research toward the development of convenient, cost-effective, field-deployable, and environmentally benign gene-silencing technologies for invasive P. australis management. Full article

Therapeutic nucleic acids (TNAs) including antisense oligonucleotides (ASOs) and small interfering RNA (siRNA) have emerged as promising treatment strategies for a wide variety of diseases, offering the potential to modulate gene expression with a high degree of specificity. These small, synthetic nucleic acid-like molecules provide unique advantages over traditional pharmacological agents, including the ability to target previously “undruggable” genes. Despite this promise, several biological barriers severely limit their clinical efficacy. Upon administration, TNAs primarily enter cells through endocytosis, becoming trapped inside membrane-bound vesicles known as endosomes. Studies estimate that only 1–2% of TNAs successfully escape endosomal compartments to reach the cytosol, and in some cases the nucleus, where they bind target mRNA and exert their therapeutic effect. Endosomal entrapment and inefficient nuclear localization are therefore critical bottlenecks in the therapeutic application of TNAs. This review explores the current understanding of TNA endosomal escape and nuclear transport along with strategies aimed at overcoming these challenges, including the use of endosomal escape agents, peptide-TNA conjugates, non-viral delivery vehicles, and nuclear localization signals. By improving both endosomal escape and nuclear localization, significant advances in TNA-based therapeutics can be realized, ultimately expanding their clinical utility. Full article

Otitis media (OM) is a frequent disease with incidence rate of 5300 cases per 100,000 people. Recent studies showed that polymicrobial biofilm formation represents a significant pathogenic mechanism in recurrent and chronic forms of OM. Biofilm enables bacteria to resist antibiotics that would typically be recommended in guidelines, contributing to the ineffectiveness of current antimicrobial strategies. Given the challenges of successfully treating bacterial biofilms, there is an growing interest in identifying novel and effective compounds to overcome antibacterial resistance. The objective of this review was to provide an overview of the novel compounds with antibiofilm effects on bacterial biofilm formed by clinical isolates of OM. The systematic review included studies that evaluated antibiofilm effect of novel natural or synthetic compounds on bacterial biofilm formed from clinical isolates obtained from patients with OM. The eligibility criteria were defined using the PICOS system: (P) Population: all human patients with bacterial OM; (I) Intervention: novel natural or synthetic compound with biofilm effect; (C) Control standard therapeutic antimicrobial agents or untreated biofilms, (O) Outcome: antibiofilm effect (biofilm inhibition, biofilm eradication), (S) Study design. The PRISMA protocol for systematic reviews and meta-analysis was followed. From 3564 potentially eligible studies, 1817 duplicates were removed, and 1705 were excluded according to defined exclusion criteria. A total of 41 studies with available full texts were retrieved by two independent authors. Fifteen articles were selected for inclusion in the systematic review which included 125 patients with OM. A total of 17 different novel compounds were examined, including N-acetyl-L-cysteine (NAC), tea tree oil, xylitol, eugenol, Aloe barbadensis, Zingiber officinale, Curcuma longa, Acacia arabica, antisense peptide nucleic acids, probiotics Streptococcus salivarius and Streptococcus oralis, Sodium 2-mercaptoethanesulfonate (MESNA), bioactive glass, green synthesized copper oxide nanoparticles, radish, silver nanoparticles and acetic acid. Staphylococcus aureus was the most commonly studied pathogen, followed by Pseudomonas aeruginosa and Haemophilus influenzae. Biofilm inhibition only by an examined compound was assessed in six studies; biofilm eradication in four studies, and both biofilm inhibition and biofilm eradication were examined in five studies. This systematic review indicates that some compounds like NAC, prebiotics, nanoparticles and MESNA that have significant effects on biofilm are safe and could be researched more extensively for further clinical use. However, a lack of data about reliable and efficient compounds used in therapy of different types of otitis media still remains in the literature. Full article

Cell-penetrating peptides (CPPs) are promising carriers to effectively transport antisense oligonucleotides (ASOs), including peptide nucleic acids (PNAs), into bacterial cells to combat multidrug-resistant bacterial infections, demonstrating significant therapeutic potential. Streptococcus suis, a Gram-positive bacterium, is a major bacterial pathogen in pigs and an emerging zoonotic pathogen. In this study, through the combination of super-resolution structured illumination microscopy (SR-SIM), flow cytometry analysis, and toxicity analysis assays, we investigated the suitability of four CPPs for delivering PNAs into S. suis cells: HIV-1 TAT efficiently penetrated S. suis cells with low toxicity against S. suis; (RXR)₄XB had high penetration efficiency with inherent toxicity against S. suis; (KFF)₃K showed lower penetration efficiency than HIV-1 TAT and (RXR)₄XB; K8 failed to penetrate S. suis cells. HIV-1 TAT-conjugated PNA specific for the essential gyrase A subunit gene (TAT-anti-gyrA PNA) effectively inhibited the growth of S. suis. TAT-anti-gyrA PNA exhibited a significant bactericidal effect on serotypes 2, 4, 5, 7, and 9 strains of S. suis, which are known to cause human infections. Our study demonstrates the potential of CPP-ASO conjugates as new antimicrobial compounds for combating S. suis infections. Furthermore, our findings demonstrate that applying SR-SIM and flow cytometry analysis provides a convenient, intuitive, and cost-effective approach to identifying suitable CPPs for delivering cargo molecules into bacterial cells. Full article

G-quadruplexes (G4s) are non-canonical nucleic acid secondary structures that have gathered significant interest in medicinal chemistry over the past two decades due to their unique structural features and potential roles in a variety of biological processes and disorders. Traditionally, research efforts have focused on stabilizing G4s, while in recent years, the attention has progressively shifted to G4 destabilization, unveiling new therapeutic perspectives. This review provides an in-depth overview of recent advances in the development of small molecules, starting with the controversial role of TMPyP4. Moreover, we described effective metal complexes in addition to G4-disrupting small molecules as well as good G4 stabilizing ligands that can destabilize G4s in response to external stimuli. Finally, we presented antisense strategies as a promising approach for destabilizing G4s, with a particular focus on 2′-OMe antisense oligonucleotide, peptide nucleic acid, and locked nucleic acid. Overall, this review emphasizes the importance of understanding G4 dynamics as well as ongoing efforts to develop selective G4-unfolding strategies that can modulate their biological function and therapeutic potential. Full article

Metabolic syndrome prevalence is between 24 and 27% and poses a significant risk for the development of atherosclerotic cardiovascular disease (ASCVD), type 2 diabetes (T2D), or other comorbidities. Currently, no drugs are approved for metabolic syndrome treatment itself, so the risk factors are treated with therapies approved for cardiac and metabolic conditions. These are approved drugs for dyslipidemia treatment such as statins and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, cornerstone antihypertensive drugs, or novel class glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1 RA) for T2D and overweight or obesity treatment. We have also evaluated new pharmacological interventions in clinical development that have reached Phase 2 and/or Phase 3 randomized clinical trials (RCTs) for the management of the risk factors of metabolic syndrome. In the pipeline are glucose-dependent insulinotropic polypeptide (GIP), GLP-1, glucagon receptor (GCGR), amylin agonists, and a combination of the latter for T2D and overweight or obesity treatment. Non-entero-pancreatic hormone-based therapies such as ketohexokinase (KHK) inhibitor, growth differentiation factor 15 (GDF15) agonists, monoclonal antibodies (mAbs) as activin type II receptors (ActRII) inhibitors, and a combination of anti-α-myostatin (GFD8) and anti-Activin-A (Act-A) mAbs have also reached Phase 2 or 3 RCTs in the same indications. Rilparencel (Renal Autologous Cell Therapy) is being evaluated in patients with T2D and chronic kidney disease (CKD) in a Phase 3 trial. For dyslipidemia treatment, novel PCSK9 inhibitors (oral and subcutaneous) and cholesteryl ester transfer protein (CETP) inhibitors are in the final stages of clinical development. There is also a surge of a new generation of an antisense oligonucleotide (ASO) and small interfering RNA (siRNA)-targeting lipoprotein(a) [Lp(a)] synthesis pathway that could possibly contribute to a further step forward in the treatment of dyslipidemia. For resistant and uncontrolled hypertension, aldosterone synthase inhibitors and siRNAs targeting angiotensinogen (AGT) messenger RNA (mRNA) are promising new therapeutic options. It would be interesting if a few drugs in clinical development for metabolic syndrome such as 6-bromotryptophan (6-BT), vericiguat, and INV-202 as a peripherally-acting CB1 receptor (CB1r) blocker would succeed in finally gaining the first drug approval for metabolic syndrome itself. Full article

HIV-1 has an antisense gene overlapping env that encodes the ASP protein. ASP functions are still unknown, but it has been associated with gp120 in the viral envelope and membrane of infected cells, making it a potential target for immune response. Despite this, immune response patterns against ASP are poorly described and can be influenced by the high genetic variability of the env gene. To explore this, we analyzed 100k HIV-1 ASP sequences from the Los Alamos HIV sequence database using phylogenetic, Shannon entropy (Hs), and logo tools to study ASP variability in worldwide and Brazilian sequences from the most prevalent HIV-1 subtypes in Brazil (B, C, and F1). Data obtained in silico guided the design and synthesis of 15-mer overlapping peptides through spot synthesis on cellulose membranes. Peptide arrays were screened to assess IgG and IgM responses in pooled plasma samples from HIV controllers and individuals with acute or recent HIV infection. Excluding regions with low alignment accuracy, several sites with higher variability (Hs > 1.5) were identified among the datasets (25 for worldwide sequences, 20 for Brazilian sequences). Among sites with Hs < 1.5, sequence logos allowed the identification of 23 other sites with subtype-specific signatures. Altogether, amino acid variations with frequencies > 20% in the 48 variable sites identified were included in 92 peptides, divided into 15 sets, representing near full-length ASP. During the immune screening, the strongest responses were observed in three sets, one in the middle and one at the C-terminus of the protein. While some sets presented variations potentially associated with epitope displacement between IgG and IgM targets and subtype-specific signatures appeared to impact the level of response for some peptides, signals of cross-reactivity were observed for some sets despite the presence of B/C/F1 signatures. Our data provides a map of ASP regions preferentially targeted by IgG and IgM responses. Despite B/C/F1 subtype signatures in ASP, the amino acid variation in some areas preferentially targeted by IgM and IgG did not negatively impact the response against regions with higher immunogenicity. Full article

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder that is caused by mutations in the survival motor neuron 1 (SMN1) gene, hindering the production of functional survival motor neuron (SMN) proteins. Antisense oligonucleotides (ASOs), a versatile DNA-like drug, are adept at binding to target RNA to prevent translation or promote alternative splicing. Nusinersen is an FDA-approved ASO for the treatment of SMA. It effectively promotes alternative splicing in pre-mRNA transcribed from the SMN2 gene, an analog of the SMN1 gene, to produce a greater amount of full-length SMN protein, to compensate for the loss of functional protein translated from SMN1. Despite its efficacy in ameliorating SMA symptoms, the cellular uptake of these ASOs is suboptimal, and their inability to penetrate the CNS necessitates invasive lumbar punctures. Cell-penetrating peptides (CPPs), which can be conjugated to ASOs, represent a promising approach to improve the efficiency of these treatments for SMA and have the potential to transverse the blood–brain barrier to circumvent the need for intrusive intrathecal injections and their associated adverse effects. This review provides a comprehensive analysis of ASO therapies, their application for the treatment of SMA, and the encouraging potential of CPPs as delivery systems to improve ASO uptake and overall efficiency. Full article

During mammalian heart development, the clustered genes encoding peptide hormones, Natriuretic Peptide A (NPPA; ANP) and B (NPPB; BNP), are transcriptionally co-regulated and co-expressed predominately in the atrial and ventricular trabecular cardiomyocytes. After birth, expression of NPPA and a natural antisense transcript NPPA-AS1 becomes restricted to the atrial cardiomyocytes. Both NPPA and NPPB are induced by cardiac stress and serve as markers for cardiovascular dysfunction or injury. NPPB gene products are extensively used as diagnostic and prognostic biomarkers for various cardiovascular disorders. Membrane-localized guanylyl cyclase receptors on many cell types throughout the body mediate the signaling of the natriuretic peptide ligands through the generation of intracellular cGMP, which interacts with and modulates the activity of cGMP-activated kinase and other enzymes and ion channels. The natriuretic peptide system plays a fundamental role in cardio-renal homeostasis, and its potent diuretic and vasodilatory effects provide compensatory mechanisms in cardiac pathophysiological conditions and heart failure. In addition, both peptides, but also CNP, have important intracardiac actions during heart development and homeostasis independent of the systemic functions. Exploration of the intracardiac functions may provide new leads for the therapeutic utility of natriuretic peptide-mediated signaling in heart diseases and rhythm disorders. Here, we review recent insights into the regulation of expression and intracardiac functions of NPPA and NPPB during heart development, homeostasis, and disease. Full article

Cancer stem cells (CSCs) represent a subpopulation within tumors that promote cancer progression, metastasis, and recurrence due to their self-renewal capacity and resistance to conventional therapies. CSC-specific markers and signaling pathways highly active in CSCs have emerged as a promising strategy for improving patient outcomes. This review provides a comprehensive overview of the therapeutic targets associated with CSCs of solid tumors across various cancer types, including key molecular markers aldehyde dehydrogenases, CD44, epithelial cellular adhesion molecule, and CD133 and signaling pathways such as Wnt/β-catenin, Notch, and Sonic Hedgehog. We discuss a wide array of therapeutic modalities ranging from targeted antibodies, small molecule inhibitors, and near-infrared photoimmunotherapy to advanced genetic approaches like RNA interference, CRISPR/Cas9 technology, aptamers, antisense oligonucleotides, chimeric antigen receptor (CAR) T cells, CAR natural killer cells, bispecific T cell engagers, immunotoxins, drug-antibody conjugates, therapeutic peptides, and dendritic cell vaccines. This review spans developments from preclinical investigations to ongoing clinical trials, highlighting the innovative targeting strategies that have been informed by CSC-associated pathways and molecules to overcome therapeutic resistance. We aim to provide insights into the potential of these therapies to revolutionize cancer treatment, underscoring the critical need for a multi-faceted approach in the battle against cancer. This comprehensive analysis demonstrates how advances made in the CSC field have informed significant developments in novel targeted therapeutic approaches, with the ultimate goal of achieving more effective and durable responses in cancer patients. Full article

The low efficiency of in vivo transfection of a few fibres revealed a novel tissue network that temporally amplified growth stimulation in the entire regenerating rat soleus muscle. This acupuncture-like effect was demonstrated when the fibres began to grow after complete fibre degradation, synchronous inflammation, myoblast and myotube formation. Neonatal sarcoplasmic/endoplasmic reticulum ATPase (SERCA1b) was first detected in this system. The neonatal, fast and slow SERCA isoforms displayed consequent changes with innervation and differentiation, recapitulating events in muscle development. In vivo transfection of myotubes with plasmids expressing dominant negative Ras or a calcineurin inhibitor peptide (Cain/cabin) proved that expression of the slow myosin heavy chain and the slow muscle type SERCA2a are differentially regulated. In vivo transfection of a few nuclei of myotubes with dnRas or SERCA1b shRNA stimulated fibre size growth in the whole regenerating muscle but only until the full size had been reached. Growth stimulation by Ras and SERCA1b antisense was abolished by co-transfection of Cain or with perimuscular injection of IL4 antibody. This revealed a novel signalling network resembling scale-free networks which, starting from transfected fibre myonuclei as “hubs”, can amplify growth stimulation uniformly in the entire regenerating muscle. Full article

A total of nine TIDES (pepTIDES and oligonucleoTIDES) were approved by the FDA during 2023. The four approved oligonucleotides are indicated for various types of disorders, including amyotrophic lateral sclerosis, geographic atrophy, primary hyperoxaluria type 1, and polyneuropathy of hereditary transthyretin-mediated amyloidosis. All oligonucleotides show chemically modified structures to enhance their stability and therapeutic effectiveness as antisense or aptamer oligomers. Some of them demonstrate various types of conjugation to driving ligands. The approved peptides comprise various structures, including linear, cyclic, and lipopeptides, and have diverse applications. Interestingly, the FDA has granted its first orphan drug designation for a peptide-based drug as a highly selective chemokine antagonist. Furthermore, Rett syndrome has found its first-ever core symptoms treatment, which is also peptide-based. Here, we analyze the TIDES approved in 2023 on the basis of their chemical structure, medical target, mode of action, administration route, and common adverse effects. Full article

To meet unmet medical needs, middle-to-large molecules, including peptides and oligonucleotides, have emerged as new therapeutic modalities. Owing to their middle-to-large molecular sizes, middle-to-large molecules are not suitable for oral absorption, but there are high expectations around orally bioavailable macromolecular drugs, since oral administration is the most convenient dosing route. Therefore, extensive efforts have been made to create bioavailable middle-to-large molecules or develop absorption enhancement technology, from which some successes have recently been reported. For example, Rybelsus^® tablets and Mycapssa^® capsules, both of which contain absorption enhancers, were approved as oral medications for type 2 diabetes and acromegaly, respectively. The oral administration of Rybelsus and Mycapssa exposes their pharmacologically active peptides with molecular weights greater than 1000, namely, semaglutide and octreotide, respectively, into systemic circulation. Although these two medications represent major achievements in the development of orally absorbable peptide formulations, the oral bioavailability of peptides after taking Rybelsus and Mycapssa is still only around 1%. In this article, we review the approaches and recent advances of orally bioavailable middle-to-large molecules and discuss challenges for improving their oral absorption. Full article