Current status and challenges in drug discovery against the globally important zoonotic cryptosporidiosis

The zoonotic cryptosporidiosis is globally distributed,one of the major diarrheal diseases in humans and animals.Cryptosporidium oocysts are also one of the major environmental concerns,making it a pathogen that fits well into the One Health concept.Despite its importance,fully effective drugs are not yet available.Anti-cryptosporidial drug discovery has historically faced many unusual challenges attributed to unique parasite biology and technical burdens.While significant progresses have been made recently,anti-cryptosporidial drug discovery still faces a major obstacle:identification of systemic drugs that can be absorbed by patients experiencing watery diarrhea and effectively pass through electron-dense(ED)band at the parasite-host cell interface to act on the epicellular parasite.There may be a need to develop an in vitro assay to effectively screen hits/leads for their capability to cross ED band.In the meantime,non-systemic drugs with strong mucoadhesive properties for extended gastrointestinal exposure may represent another direction in developing anti-cryptosporidial therapeutics.For developing both systemic and non-systemic drugs,a non-ruminant animal model exhibiting diarrheal symptoms suitable for routine evaluation of drug absorption and anti-cryptosporidial efficacy may be very helpful.

Aspirin alleviates endothelial gap junction dysfunction through inhibition of NLRP3inflammasome activation in LPS-induced vascular injury

The loss of endothelial connective integrity and endothelial barrier dysfunction can lead to increased vascular injury, which is related to the activation of endothelial inflammasomes. There are evidences that low concentrations of aspirin can effectively prevent cardiovascular diseases. We hypothesized that low-dose aspirin could ameliorate endothelial injury by inhibiting the activation of NLRP3 inflammasomes and ultimately prevent cardiovascular diseases. Microvascular endothelial cells were stimulated by lipopolysaccharide(2 μg/mL) and administrated by 0.1–2 mmol/L aspirin. The wild type mice were stimulated with LPS(100 μg/kg/day), and 1 h later treated with aspirin(12.5, 62.5, or125 mg/kg/day) and dexamethasone(0.0182 mg/kg/day) for 7 days. Plasma and heart were harvested for measurement of ELISA and immunofluorescence analyses. We found that aspirin could inhibit NLRP3 inflammasome formation and activation in vitro in dose-dependent manner and has correlation between the NLRP3 inflammasome and the ROS/TXNIP pathway. We also found that low-concentration aspirin could inhibit the formation and activation of NLRP3 inflammasome and restore the expression of theendothelial tight junction protein zonula occludens-1/2(ZO1/2). We assume that aspirin can ameliorate the endothelial layer dysfunction by suppressing the activation of NLRP3 inflammasome.