Phenotyping of cancer-associated somatic mutations in the BCL2 transmembrane domain.

The BCL2 family of proteins controls cell death by modulating the permeabilization of the mitochondrial outer membrane through a fine-tuned equilibrium of interactions among anti- and pro-apoptotic members. The upregulation of anti-apoptotic BCL2 proteins represents an unfavorable prognostic factor in many tumor types due to their ability to shift the equilibrium toward cancer cell survival. Furthermore, cancer-associated somatic mutations in BCL2 genes interfere with the protein interaction network, thereby promoting cell survival. A range of studies have documented how these mutations affect the interactions between the cytosolic domains of BCL2 and evaluate the impact on cell death; however, as the BCL2 transmembrane interaction network remains poorly understood, somatic mutations affecting transmembrane regions have been classified as pathogenic-based solely on prediction algorithms. We comprehensively investigated cancer-associated somatic mutations affecting the transmembrane domain of BCL2 proteins and elucidated their effect on membrane insertion, hetero-interactions with the pro-apoptotic protein BAX, and modulation of cell death in cancer cells. Our findings reveal how specific mutations disrupt switchable interactions, alter the modulation of apoptosis, and contribute to cancer cell survival. These results provide experimental evidence to distinguish BCL2 transmembrane driver mutations from passenger mutations and provide new insight regarding selecting precision anti-tumor treatments.

Exploring the neuroprotective potential of antimicrobial peptides from Dinoponera quadriceps venom against pentylenetetrazole-induced seizures in vivo.

Epilepsy affects around 50 million people worldwide and 30% of patients have difficulty controlling the disease. The search for substances that can fill the existing gaps in the treatment of epilepsy is of great importance. Arthropod venoms are promising sources for this purpose due to the presence of small peptides that modulate the activity of ion channels and neuron receptors. The aim of this study was to investigate dinoponeratoxins from the Dinoponera quadriceps ant venom (M-PONTX-Dq3a, M-PONTX-Dq3b and M-PONTX-Dq3c) as potential anticonvulsants. We evaluated them in a seizure model induced by pentylenetetrazole (PTZ) in male swiss mice. Interestingly, intraperitoneal treatment with each peptide increased the time until the first seizure and the percentage of survival, with M-PONTX-Dq3b showing the best results. M-PONTX-Dq3a was discarded due to the appearance of some signs of toxicity with the increase in malondialdehyde (MDA) levels in the striatum. Both, M-PONTX-Dq3b and M-PONTX-Dq3c decreased iNOS and TNF-α in the hippocampus. Notably, M-PONTX-Dq3c treatment decreased the levels of MDA and nitrite in the cortex and hippocampus. Our results indicate that, M-PONTX-Dq3b and M-PONTX-Dq3c have anticonvulsant activity and exhibit anti-inflammatory effects in epilepsy, offering new perspectives for biopharmaceutical development.

Rational design of a trypanocidal peptide derived from Dinoponera quadriceps venom.

Chagas disease is caused by the parasite Trypanosoma cruzi and affects millions of people worldwide, having no effective cure. The main sanitary emergency is related to patients with chronic infection, which accumulate comorbidities causing patient death. However, actual chemotherapeutic treatments do not effectively address the chronic forms of the disease. Invertebrates are a relevant source of antimicrobial peptides (AMPs) as part of the innate immune system for their protection. The AMP M-PONTX-Dq3a, isolated from the Dinoponera quadriceps ant venom, has shown very effective antimicrobial and trypanocidal activities. Although M-PONTX-Dq3a has better activity that the current therapies, the peptide length has limited its possibilities to reach clinical application. In this investigation, we aimed to dissect the trypanocidal effect of M-PONTX-Dq3a fragments and to study the activity of substituted analogs, to improve not only peptide trypanocidal activity and bioavailability, but also production costs. Our studies have led to the identification of two smaller peptides, M-PONTX-Dq3a [1-15] and [Lys]3-M-PONTX-Dq3a [3-153-15 with similar trypanocidal activities that the parent peptide has against the three forms of T. cruzi benznidazole-resistant Y strain. Both peptides represent promising candidates to develop novel and effective trypanocidal bio-therapeutic agents, opening new avenues for the treatment of chronic patients.

Nanodevices for the Efficient Codelivery of CRISPR-Cas9 Editing Machinery and an Entrapped Cargo: A Proposal for Dual Anti-Inflammatory Therapy.

In this article, we report one of the few examples of nanoparticles capable of simultaneously delivering CRISPR-Cas9 gene-editing machinery and releasing drugs for one-shot treatments. Considering the complexity of inflammation in diseases, the synergistic effect of nanoparticles for gene-editing/drug therapy is evaluated in an in vitro inflammatory model as proof of concept. Mesoporous silica nanoparticles (MSNs), able to deliver the CRISPR/Cas9 machinery to edit gasdermin D (GSDMD), a key protein involved in inflammatory cell death, and the anti-inflammatory drug VX-765 (GSDMD45CRISPR-VX-MSNs), were prepared. Nanoparticles allow high cargo loading and CRISPR-Cas9 plasmid protection and, thus, achieve the controlled codelivery of CRISPR-Cas9 and the drug in cells. Nanoparticles exhibit GSDMD gene editing by downregulating inflammatory cell death and achieving a combined effect on decreasing the inflammatory response by the codelivery of VX-765. Taken together, our results show the potential of MSNs as a versatile platform by allowing multiple combinations for gene editing and drug therapy to prepare advanced nanodevices to meet possible biomedical needs.

Dinoponera quadriceps venom as a source of active agents against Staphylococcus aureus.

Staphylococcus aureus is a highly virulent pathogen, capable of biofilm formation and responsible for thousands of deaths each year. The prevalence of Methicillin-Resistant S. aureus (MRSA) strains has increased in recent years and thus, the development of new antibiotics has become necessary. Antimicrobial Peptides (AMPs) are effective against a variety of multidrug-resistant bacteria and low levels of resistance have been reported regarding these molecules. Dinoponera quadriceps ant venom (DqV) has been described regarding its effect against S. aureus. In this study, we have evaluated the antibacterial effect of DqV-AMPs, the dinoponeratoxins (DNTxs), against Methicillin-Sensitive and a Methicillin-Resistant S. aureus strains. Our results show DNTx M-PONTX-Dq3a as a potent inhibitor of both strains, being able to prevent biofilm formation at low micromolar range (0.78-3.12 µM). It also showed a short-time effect through membrane disruption. M-PONTX-Dq3a opens up new perspectives for the prevention of biofilm formation through the development of anti-adhesive surface coatings on medical devices, as well as the treatment of resistant strains in skin or soft tissue infections.