The period detection of the biological rhythms is one ofthe hot topics in the research of chronobiology,which will help to understand the mechanism of pathological changes and how the function of the clock genes affect the organism and thus guide clinical drug administration and treatment timely.Some new methods for detecting the periods of the biological rhythms,including Lomb-Scargle periodogram,spectral analysis based on Cosinor method(e.g.Percent Rhythm Spectrum and Reverse EHiptie Spectrum),and the Maximum Entropy Spectral Analysis(MESA),ale introduced in this paper.Advantages and disadvantages of the methods ale reviewed and some suggestions to the research in the future are also proposed.These methods provide promising approaches for detecting the precise periods of the biological rhythms and discovering the rule of the changes of the biological rhythms.

Aim To evaluate the effect of paeonol on the activity of tyrosinase and provide experimental evidence for the treatment of hyperpigmentation disorders. Methods Tyrosinase activity was estimated by measuring the oxidation rate of L-3,4-dihydroxyphenylalanine (L-Dopa). The inhibitory effects of paeonol on the activity of mushroom tyrosinase and Michaelis-Menten kinetics were deduced from the Lineweaver-Burk plots. Results The inhibitory concentration of paeonol leading to 50% enzyme Paeonol is a potential mixed inhibitor of mushroom tyrosinase. The mixed inhibition function may originate from its ability to form a Schiff base with a primary amino group and to chelate copper at the active site of tyrosinase.

Objective:To evaluate the effect of dexmedetomidine on pyroptosis in mice with acute renal injury induced by endotoxin and the relationship with miRNA-223-3p.Methods:Thirty-two clean-grade healthy male ICR mice, aged 8-12 weeks, weighing 20-25 g, were divided into 4 groups ( n=8 each) using the random number table method: control group (group C), lipopolysaccharide (LPS) group (group L), LPS plus dexmedetomidine group (group LD), and LPS plus dexmedetomidine plus atipamezole group (group LDT). The model of acute renal injury induced by endotoxin was established by intraperitoneal injection of LPS 400 μg/kg, followed by intraperitoneal injection of LPS 10 mg/kg 8 h later.Dexmedetomidine 40 μg/kg was intraperitoneally injected once every 2 h for 3 times in total starting from 30 min after establishing the model in group LD.Atipamezole 750 μg/kg was intraperitoneally injected immediately after establishing the model, and 30 min later dexmedetomidine 40 μg/kg was intraperitoneally injected once every 2 h for 3 times in total in group LDT.The equal volume of normal saline was intraperitoneally injected in group C. Blood samples were collected from the heart at 24 h after establishing the model, and serum creatinine (Cr) and blood urea nitrogen (BUN) concentrations were measured with an automatic biochemical analyzer.The animals were sacrificed and the left kidney tissues were obtained for microscopic examination of pathological changes after HE staining (with a light microscope) and for determination of the expression of caspase-1 p20, NOD-like receptor thermoprotein structural domain-related protein 3 (NLRP3) and ASC protein and mRNA (by quantitative real-time polymerase chain reaction and Western blot), contents of interleukin-1beta (IL-1β) and IL-18 (by enzyme-linked immunosorbent assay), and rate of pyroptosis in renal cortical cells (by TUNEL). Results:Compared with group C, the concentrations of serum Cr and BUN were significantly increased, the expression of NLRP3, caspase-1 p20 and ASC protein and mRNA in the renal tissues was up-regulated, the contents of IL-1β and IL-18 were increased, the rate of pyroptosis in renal cortical cells was increased ( P<0.05), no significant change was found in the expression of miRNA-223-3p ( P>0.05), and pathological changes of kidney were accentuated in group L. Compared with group L, the concentrations of serum Cr and BUN were significantly decreased, the expression of NLRP3, caspase-1 p20 and ASC protein and mRNA in the renal tissues was down-regulated, the contents of IL-1β and IL-18 were decreased, the rate of pyroptosis in renal cortical cells was decreased, the expression of miRNA-223-3p was up-regulated ( P<0.05), and pathological changes of kidney were attenuated in group LD.Compared with group LD, the concentrations of serum Cr and BUN were significantly increased, the contents of IL-1β and IL-18 were increased, the expression of NLRP3, caspase-1 p20 and ASC protein and mRNA in the renal tissues was up-regulated, the rate of pyroptosis in renal cortical cells was increased, the expression of miRNA-223-3p was down-regulated ( P<0.05), and the pathological changes of kidney were accentuated in group LDT. Conclusion:The mechanism by which dexmedetomidine reduces acute renal injury may be related to up-regulating the expression of miRNA-223-3p and inhibiting pyroptosis in mice.

Objective:To evaluate the relationship between Sestrin2 and mitochondrial DNA (mtDNA)-NOD-like receptor associated protein 3 (NLRP3) inflammasome pathway during endotoxin-induced myocardial injury in mice.Methods:One hundred and eighty-four clean-grade healthy male ICR mice, aged 8-12 weeks, weighing 20-25 g, were used in this study. One hundred and sixty-eight mice were divided into 7 groups ( n=24 each) using the random number table method: normal control group (N group), lipopolysaccaride(LPS) group (L group), mtDNA group, LPS+ mtDNA group (M group), normal control+ negative control adeno-associated virus (AAV-NC)group (NC group), LPS+ mtDNA+ AAV-NC group (MC group), and LPS+ mtDNA+ Sestrin2 overexpression adeno-associated virus (AAV-Sestrin2) group (MSgroup). Another 10 mice were used to detect the transfection effect of AAV-Sestrin2, and the left 6 mice were used for mtDNA extraction. The model of endotoxemia was developed by intraperitoneal injection of LPS 10 mg/kg. mtDNA 5 mg/kg was intraperitoneally injected in mtDNA group, and mtDNA 5 mg/kg was intraperitoneally injected at 30 min after LPS injection in M group.AAV-Sestrin2 150 μl was injected via the tail vein in MS group, and the equal volume of AAV-NC was injected via the tail vein in MC and NC groups. Four weeks after virus injection, LPS 10 mg/kg was intraperitoneally injected and 30 min later mtDNA 5 mg/kg was intraperitoneally injected in MS and MC groups. Blood samples were collected at 24 h after LPS injection for determination of serum creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) activities (by biochemical assay), concentrations of serum cardiac troponin I (cTnI), interleukin-18 (IL-18) and interleukin-1beta (IL-1β)(by enzyme-linked immunesorbent assay), and expression of mtDNA (by quantitative real-time polymerase chain reaction). The animals were sacrificed after the end of blood sampling and myocardial tissues were obtained for determination of the contents of reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and adenosine triphosphate (ATP) and expression of NOD-like receptor associated protein 3 (NLRP3), active subunit p20 of caspase-1 (caspase-1p20) and apoptosis-associated microprotein (ASC) in myocardial tissues (by Western blot) and for microscopic examination of the pathological changes after HE staining (with a light microscope). Results:Compared with N group, the levels of CK-MB, LDH, cTnI, IL-1β and IL-18 in serum were significantly increased, the expression of mtDNA was up-regulated, the ROS content in myocardial tissues was increased, the T-AOC and ATP contents in myocardial tissues were decreased, the expression of NLRP3, caspase-1p20 and ASC in the myocardial tissues was up-regulated( P<0.05), and the pathological changes of myocardial tissues were aggravated in L group and mtDNA group.Compared with L group and mtDNA group, the levels of CK-MB, LDH, cTnI, IL-1β and IL-18 in serum were significantly increased, the expression of mtDNA was up-regulated, the ROS content in myocardial tissues was increased, the T-AOC and ATP contents in myocardial tissues were decreased, the expression of NLRP3, caspase-1p20 and ASC in the myocardial tissues was up-regulated( P<0.05), and the pathological changes of myocardial tissues were aggravated in M group. Compared with M group, the levels of CK-MB, LDH, cTnI, IL-1β and IL-18 in serum were significantly decreased, the expression of mtDNA was down-regulated, the ROS content in myocardial tissues was decreased, the T-AOC and ATP contents in myocardial tissues were increased, the expression of NLRP3, caspase-1p20 and ASC in the myocardial tissues was down-regulated( P<0.05), and the pathological changes of myocardial tissues were significantly attenuated in MS group. Conclusions:Sestrin2 can reduce endotoxin-induced myocardial injury in mice by alleviating mitochondrial damage, inhibiting oxidative stress, protecting mtDNA from oxidative damage, and then inhibiting mtDNA-NLRP3 inflammasome pathway.

Objective:To explore the clinical significance of the expression of nuclear factor of activated T cells 5 (NFAT5) in esophageal cancer tissues and the effect of the expression of knock-down esophageal cancer cells on their migration ability.Methods:The expression of NFAT5 in tissues of 26 patients with esophageal cancer and their adjacent tissues was detected by immunohistochemistry. Esophageal cancer cells ECA109 were divided into experimental group and control group. The experimental group ECA109 cells were transfected with NFAT5-siRNA plasmid, and the control group ECA109 cells were transfected with MOCK-siRNA plasmid. The mRNA content of NFAT5 was detected by fluorescence quantitative PCR. The expression of NFAT5, TLR4 and MyD88 proteins in the experimental group and control group were detected by Western blot. Transwell assay and cell scratch assay were used to detect the migration ability of the experimental group and the NC group.Results:Immunohistochemical test results showed that the positive rate of NFAT5 in esophageal cancer tissues was 80.77% (21 cases/26 cases) , and the expression rate was 15.38% (4 cases/26 cases) in corresponding adjacent tissues. The positive rate of NFAT5 protein in esophageal cancer tissues was significantly higher than that in adjacent tissues ( P<0.001) . The NFAT5 mRNA content of ECA109 cells in experimental group and control group decreased after transfection with corresponding siRNA. The protein expression levels of NFAT5, TLR4 and MyD88 in ECA109 cells in the experimental group were 0.28±0.08, 0.31±0.13 and 0.41±0.14, respectively. The protein expression levels of NFAT5, TLR4 and MyD88 in ECA109 cells in control group were 0.95±0.15, 0.84±0.22 and 1.04±0.26, respectively. The expression of TLR4 and MyD88 in esophageal cancer ECA109 cells decreased significantly ( P<0.05) . The scratch healing rate of esophageal cancer ECA109 cells was 52.67%±5.21% in the experimental group and 82.91%±7.26 % in the control group. Transwell experiment results showed that the number of successfully migrated cells in the experimental group was (35±5) , and the number of successfully migrated cells in the control group was (92±13) . The results showed that the migration ability of esophageal cancer ECA109 cells was significantly decreased after low expression of NFAT5 ( P<0.01) . Conclusions:The expression of NFAT5 is significantly increased in esophageal cancer tissues, and the expression of NFAT5 may be related to the malignant degree of esophageal cancer. Moreover, NFAT5 affects the migration ability of esophageal cancer cells by regulating TLR4/MyD88 signaling pathway.