Virus-pathogen interactions improve water quality along the Middle Route of the South-to-North Water Diversion Canal.

Bacterial pathogens and viruses are the leading causes of global waterborne diseases. Here, we discovered an interesting natural paradigm of water "self-purification" through virus-pathogen interactions over a 1432 km continuum along the Middle Route of the South-to-North Water Diversion Canal (MR-SNWDC) in China, the largest water transfer project in the world. Due to the extremely low total phosphorus (TP) content (ND-0.02 mg/L) in the MR-SNWDC, the whole canal has experienced long-lasting phosphorus (P) limitation since its operation in 2015. Based on 4443 metagenome-assembled genomes (MAGs) and 40,261 nonredundant viral operational taxonomic units (vOTUs) derived from our recent monitoring campaign, we found that residential viruses experiencing extreme P constraints had to adopt special adaptive strategies by harboring smaller genomes to minimize nucleotide replication, DNA repair, and posttranslational modification costs. With the decreasing P supply downstream, bacterial pathogens showed repressed environmental fitness and growth potential, and a weakened capacity to maintain P acquisition, membrane formation, and ribonucleotide biosynthesis. Consequently, the unique viral predation effects under P limitation, characterized by enhanced viral lytic infections and an increased abundance of ribonucleotide reductase (RNR) genes linked to viral nuclear DNA replication cycles, led to unexpectedly lower health risks from waterborne bacterial pathogens in the downstream water-receiving areas. These findings highlighted the great potential of water self-purification associated with virus-pathogen dynamics for water-quality improvement and sustainable water resource management.

An Shen Ding Zhi Ling Alleviates Symptoms of Attention Deficit Hyperactivity Disorder via Anti-Inflammatory Effects in Spontaneous Hypertensive Rats.

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset chronic neurobehavioral disorder, with multiple genetic and environmental risk factors. Chronic inflammation may be critical for the progression of ADHD. An Shen Ding Zhi Ling (ASDZL) decoction, a traditional Chinese medicine prescription, is clinically used in ADHD treatment. In this study, we investigated the effects and underlying anti-inflammatory mechanisms of ASDZL in young spontaneously hypertensive rats (SHRs), a widely used model of ADHD. SHRs were divided into the SHR model group (vehicle), atomoxetine group (4.56 mg/kg/day) and ASDZL group (21.25 g/kg/day), and orally administered for four weeks. Wistar Kyoto rats were used as controls (vehicle). We found that ASDZL significantly controlled hyperactivity and impulsivity, and improved spatial memory of SHRs in the open field test and Morris water maze test. ASDZL reduced the pro-inflammatory factors interleukin (IL)-1ß, IL-4, IL-6, tumor necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1 and increased anti-inflammatory factor IL-10 in SHRs, and decreased the activation of microglia, astrocytes and mast cells in the prefrontal cortex (PFC) and hippocampus. Furthermore, the results indicated that ASDZL inhibited the neuroinflammatory response by protecting the integrity of the blood-brain barrier and suppressing the mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB signaling pathways of SHRs. In conclusion, these findings revealed that ASDZL attenuated ADHD symptoms in SHRs by reducing neuroinflammation.

[Regulatory effect of Shudihuang on expressions of BDNF/TrkB and NRG-3 in prefrontal cortex and striatum of ADHD model rats].

To observe the effect of Shudihuang on behaviors and expression of BDNF/TrkB and NRG-3 in prefrontal cortex and striatum of attention deficit hyperactivity disorder (ADHD) model rats. Thirty 4-week-old spontaneous hypertension rats (SHR) were randomly divided into model group, methylphenidate hydrochloride (MPH, 2 mg·kg⁻¹·d⁻¹) and Shudihuang group (2.4 g·kg⁻¹·d⁻¹). Another 10 Wistar-Kyoto (WKY) rats were selected as normal control group. The 0.5% CMC-Na solution was administered to model group and WKY rats (2 mL·kg⁻¹·d⁻¹). All of the rats were treated for 4 weeks. The open field test was performed at the 14th and 28th days after gavage, in order to evaluate the spontaneous and impulsive behaviors. Subsequently, gene and protein expressions of BDNF/TrkB and NRG-3 were tested by RT-qPCR and Western blot. Compared with model group, MPH and Shudihuang groups showed significant reduction in total distance, mean velocity and central distance in the open field test (P<0.05), and Shudihuang group displayed a shorter central distance than MPH group (P<0.05). RT-qPCR and Western blot analysis indicated that expressions of BDNF/TrkB and NRG-3 were lower in prefrontal cortex and striatum of SHR compared with WKY rats. Four weeks later after administration, both Shudihuang and MPH significantly elevated mRNA and protein expressions of BDNF/TrkB and NRG-3 (P<0.05).In conclusion, neurodevelopmental disorder mediated by BDNF/TrkB and NRG-3 was closely related with SHR rats' behaviors. Shudihuang may ameliorate the spontaneous and impulsive behaviors by up-regulating the expressions of BDNF/TrkB and NRG-3 and improving growth and maturation of neurons in SHR.