Prior investigations show that signaling activation through pattern recognition receptors can directly impact a number of inflammatory lung diseases. While toll-like receptor (TLR) 7 agonists have raised interest for their ability to inhibit allergen-induced pathological changes in experimental asthma conditions, the putative benefit of this treatment is limited by adverse effects. Our aim was to evaluate the therapeutic potential of two PEGylated purine-like compounds, TMX-302 and TMX-306, characterized by TLR7 partial agonistic activity; therefore, the compounds are expected to induce lower local and systemic adverse reactions. In vitro approaches and translation to murine models of obstructive and restrictive lung diseases were explored. In vitro studies with human PBMCs showed that both TMX-302 and TMX-306 marginally affects cytokine production as compared with equivalent concentrations of the TLR7 full agonist, TMX-202. The PEGylated compounds did not induce monocyte-derived DC maturation or B cell proliferation, differently from what observed after stimulation with TMX-202. Impact of PEGylated ligands on lung function and inflammatory changes was studied in animal models of acute lung injury, asthma, and silicosis following Lipopolysaccharide (LPS), allergen (ovalbumin), and silica inhalation, respectively. Subcutaneous injection of TMX-302 prevented LPS- and allergen-induced airway hyper-reactivity (AHR), leukocyte infiltration, and production of pro-inflammatory cytokines in the lung. However, intranasal instillation of TMX-302 led to neutrophil infiltration and failed to prevent allergen-induced AHR, despite inhibiting leukocyte counts in the BAL. Aerosolized TMX-306 given prophylactically, but not therapeutically, inhibited pivotal asthma features. Interventional treatment with intranasal instillation of TMX-306 significantly reduced the pulmonary fibrogranulomatous response and the number of silica particles in lung interstitial space in silicotic mice. These findings highlight the potential of TMX-306, emphasizing its value in drug development for lung diseases, and particularly silicosis.

No abstract

Cadmium is an important toxic environmental heavy metal. Several studies have demonstrated that a major site of cadmium toxicity in humans and in other animals is the proximal tubule of the kidney. A well established model for nefrotoxicity is the use of in vitro technique with proximal tubule epithelial cell lines, as LLC-PK1. Herein, we have the intention to study the possible protective effect of highdiluted CdCl2 solutions. In a blinding way, LLC-PK1 cells were pre-treated with highdiluted cadmium chloride in the potencies 10 cH, 15 cH and 20cH. After 4 days, these cells have received CdCl2 in a pre-determined toxic concentration. The cell viability was assessed by MTT assay. We have identified a protective effect of two CdCl2 highdiluted solutions, 10 cH and 20 cH, when cells were intoxicated by sublethal CdCl2 concentration. The results indicate that probably the highdilutions have an expressive action on cells in sublethal intoxication.

O sistema imune inato reconhece estruturas químicas dos vírus, ativando células capazes de bloquear a infecção viral, e ativa, também, o sistema imune adaptativo a desenvolver anticorpos que destroem ou imobilizam os vírus. De forma análoga, os componentes químicos de produtos naturais derivados de plantas e de leveduras podem agir como ativadores do sistema imune, ativando a defesa contra infecção viral. Neste trabalho, examinou-se diversos produtos naturais de alimentos e plantas medicinais, cujos componentes químicos, possivelmente, poderiam contribuir para a defesa contra SARS-CoV-2, o vírus que causa a COVID-19.