Gut dysbiosis impairs intestinal renewal and lipid absorption in Scarb2 deficiency-associated neurodegeneration.

Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease (GD) and Parkinson's disease (PD). Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.

Integrated Computational and Experimental Framework for Inverse Screening of Candidate Antibacterial Nanomedicine.

Nanomedicine is promising for disease prevention and treatment, but there are still many challenges that hinder its rapid development. A major challenge is to efficiently seek candidates with the desired therapeutic functions from tremendously available materials. Here, we report an integrated computational and experimental framework to seek alloy nanoparticles from the Materials Project library for antibacterial applications, aiming to learn the inverse screening concept from traditional medicine for nanomedicine. Because strong peroxidase-like catalytic activity and weak toxicity to normal cells are the desired material properties for antibacterial usage, computational screening implementing theoretical prediction models of catalytic activity and cytotoxicity is first conducted to select the candidates. Then, experimental screening based on scanning probe block copolymer lithography is used to verify and refine the computational screening results. Finally, the best candidate AuCu3 is synthesized in solution and its antibacterial performance over other nanoparticles against S. aureus and E. coli. is experimentally confirmed. The results show the power of inverse screening in accelerating the research and development of antibacterial nanomedicine, which may inspire similar strategies for other nanomedicines in the future.

Plant-soil feedback regulates the trade-off between phosphorus acquisition pathways in Pinus elliottii.

Plant-soil feedback (PSF) is conventionally characterized by plant biomass growth, yet it remains unclear how PSF affects plant nutrient acquisition strategies (e.g., nutrient absorption and nutrient resorption) associated with plant growth, particularly under changing soil environments. A greenhouse experiment was performed with seedlings of Pinus elliottii Englem and conditioned soils of monoculture plantations (P. elliottii and Cunninghamia lanceolata Hook). Soil sterilization was designed to test plant phosphorus (P) acquisition strategy with and without native soil fungal communities. Soils from P. elliottii and C. lanceolata plantations were used to explore the specific soil legacy effects on two different P acquisition pathways (absorption and resorption). Phosphorus addition was also applied to examine the separate and combined effects of soil abiotic factors and soil fungal factors on P acquisition pathways. Due to diminished mycorrhizal symbiosis, PSF prompted plants to increasingly rely on P resorption under soil sterilization. In contrast, P absorption was employed preferentially in the heterospecific soil, where species-specific pathogenic fungi could not affect P absorption. Higher soil P availability diluted the effects of soil fungal factors on the trade-off between the two P acquisition pathways in terms of the absolute PSF. Moreover, P addition plays a limited role in terms of the relative PSF and does not affect the direction and strength of relative PSF. Our results reveal the role of PSF in regulating plant P acquisition pathways and highlight the interaction between mycorrhizal and pathogenic fungi as the underlying mechanism of PSF.

[Effects of polydatin on ALT, AST, TNF-alpha, and COX-2 in sepsis model mice].

OBJECTIVE: To investigate the protective effects of polydatin on sepsis-induced acute liver injury (ALI) in mice, and to preliminarily study its mechanisms. METHODS: The sepsis model was established using cecal ligation and puncture (CLP).A sham-operation control group was also set up. Polydatin (50, 100, and 300 mg/kg, respectively) was administrated to mice 1 h before CLP. The survival and liver injury were evaluated subsequently per 6 h after CLP. The survived mice were scarified 24 h later. The serum and the liver tissue sample were collected. The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected by colorimetric method. The content of tumor necrosis factor-alpha (TNF-alpha) was assayed by ELISA. The cyclooxygenase-2 (COX-2) expression in the liver tissue was detected by Western blot. The pathological changes of the hepatic tissue were analyzed by hematoxylin and eosin stain. RESULTS: The mortality of mice reached as high as 50% at 24 h after CLP. The biochemical indices and the pathological changes of the liver tissue showed obvious lesion. The success rate of modeling was 90%. Compared with the sham-operation control group, the serum ALT,AST activity, the TNF-alpha content, and the hepatic COX-2 protein expression markedly increased in the CLP group (P < 0.01). Polydatin improved the sepsis-induced mortality dose-dependently, inhibited increased ALT, AST activity and TNF-alpha, decreased the hepatic COX-2 protein expression, and attenuated the pathological injury of the liver (P < 0.05). CONCLUSION: Polydatin could effectively protect sepsis-induced ALI, which might be achieved possibly through inhibiting serum TNF-alpha production and hepatic COX-2 expression.

Protective effects of asiaticoside on septic lung injury in mice.

Asiaticoside (AS), a major triterpenoid saponin component isolated from Centella asiatica, has been described to exhibit antioxidant and anti-inflammatory activities. The present study aimed to determine the protective effects and the underlying mechanisms of AS on septic lung injury induced by cecal ligation and puncture (CLP). Mice were pretreated with the AS (45 mg/kg) or AS as well as GW9662 at 1h before CLP, the survival, lung injury, inflammatory mediators and signaling molecules, and Peroxisome proliferator-activated receptor-γ (PPAR-γ) were determined 24 h after CLP. The results showed that AS significantly decreased CLP-induced the mortality, lung pathological damage, the infiltration of mononuclear, polymorphonuclear (PMN) leucocytes and total proteins. Moreover, AS inhibited CLP-induced the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB), the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein in lung tissues, and the production of serum tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Interestingly, the expression of PPAR-γ protein in lung tissue was up-regulated by AS. Furthermore, GW9662 (the inhibitor of PPAR-γ) significantly reversed these beneficial effects of AS in septic mice. These findings suggest that AS could effectively protect from septic lung injury induced by CLP and the underlying mechanisms might be related to up-regulation of PPAR-γ expression to some extent, which inhibits MAPKs and NF-κB pathway.

[Protective effects of asiaticoside on sepsis-induced acute kidney injury in mice].

OBJECTIVE: The present study is to investigate the protective effects of asiaticoside on sepsis-induced acute kidney injury in mice. METHOD: With the sepsis induced by cecal ligation and puncture (CLP), forty eight kunming mice were randomly divided into four groups as sham operated, CLP treated, CLP + asiaticoside 15, 45 mg x kg(-1) groups. General conditions and the amount of dead rate of mice were observed. The BUN and Cr levels were observed by the kits. IL-6 in serum was assayed by enzyme-linked immunosorbent assay (ELISA). Kidney tissues were harvested for determination of iNOS expression by Western blotting analysis. The pathologic changes were observed under electron microscope via hematoxylin-eosin (HE) stain. RESULT: Compared with CLP group, the death rate, the levels of BUN, Cr, IL-6, and iNOS protein expression of asiaticoside groups were significantly reduced. The pathologic changes in kidney tissues induced by sepsis were significantly attenuated dose-dependently by asiaticoside under electron microscope. CONCLUSION: Asiaticoside has protective effects against sepsis-induced acute kidney injury, which were probably associated with the inhibition of IL-6 in serum and iNOS protein in kidney tissues.

Anti-inflammatory mechanism of total glycosides of Acanthopanax Giraldii.

OBJECTIVE: To study the anti-inflammatory mechanisms of total glycosides of Acanthopanax Giraldii (TGA). METHODS: The changes of prostaglandin E(2)(PGE(2)), tumor necrosis factor (TNF-alpha), nitric oxide (NO), and expressions of COX-1 mRNA and COX-2 mRNA in BALB/c mouse macrophages were observed by the radioimmunoassay, ELISA and nitric acid reduction and RT-PCR in the presence or absence of TGA. RESULTS: (1) TGA could significantly decrease the production of PGE(2)and NO in mouse peritoneal macrophages. The inhibitory rate to LPS-induced PGE(2)production was 87% (TGA 100 mg/L, P<0.05, vs. LPS) and 62% (TGA 20 mg/L, P<0.05, vs. LPS), respectively. The inhibitory rate of NO production in mouse peritoneal macrophages was 49% (TGA 100 mg/L, P<0.05, vs. LPS) and 21% (TGA 20 mg/L, P<0.05 vs. LPS), respectively. TGA could not inhibit LPS-induced TNF-alpha production in mouse peritoneal macrophages. (2) TGA also inhibited the expression of COX-1 and COX-2 mRNA in RAW264.7 cells. The inhibitory rate of TGA to COX-1 mRNA was 22% (TGA 100 mg/L, P<0.05, vs. blank). The inhibitory rate of TGA to COX-2 mRNA was 55% (TGA 20 mg/L, P<0.05, vs. LPS) and 100% (TGA 100 mg/L, P<0.01 vs. LPS), respectively. CONCLUSION: The anti-inflammatory mechanisms of TGA for inhibiting the production of NO and PGE(2)are through inhibiting COX-2 mRNA expression without TNF-alpha changes.