A novel gut-restricted RIPK1 inhibitor, SZ-15, ameliorates DSS-induced ulcerative colitis.

As a key mediator of cell death and inflammation, receptor-interacting protein kinase 1 (RIPK1) responds to a broad set of inflammatory and pro-death stimuli in human diseases. Inhibitors targeting RIPK1 are being investigated for the treatment of a wide range of human diseases, including ulcerative colitis. In the present study, we designed, synthesized, and investigated the anti-necroptosis and RIPK1-inhibition effects of SZ-15-a symmetrical high-molecular-weight (>500 Da) compound. SZ-15 effectively inhibited necroptosis in U937 and HT-29 cells at concentrations of 1 nM and 10 nM, respectively, and SZ-15 at a concentration of 10 nM almost completely blocked RIPK1, RIPK3, and mixed-lineage kinase domain-like (MLKL) protein phosphorylation induced by necrosis inducers. SZ-15 suppressed the pro-necroptosis function of RIPK1 by downregulating the mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. The activities of SZ-15 were effectively restricted to the gut: The percent recovery of the parent form of SZ-15 in mouse feces was 85.75%. Nevertheless, SZ-15 was effectively absorbed and detected in colon tissues after 1 h at a concentration of 3335 ± 868 ng/g, indicating that membrane permeability was maintained. SZ-15 alleviated dextran sulfate sodium (DSS)-induced ulcerative colitis in vivo by decreasing TNF-α, IL-1ß, IL-22, and IL-6 mRNA expression in colonic tissues. Our preclinical study describes a novel gut-restricted RIPK1 inhibitor that shows great potential for use in the clinical treatment of ulcerative colitis.

[Clinical effect of Nd:YAP laser in periodontal regeneration surgery].

PURPOSE: To evaluate the clinical effect of Nd:YAP laser in periodontal regeneration surgery. METHODS: Four weeks after primary periodontal treatment, 48 patients, 60 teeth with bone defect and probing depth(PD) ≥6 mm, bleeding on probing (BOP)(+), were randomly divided into two groups. Patients in the experimental group were treated with Nd:YAP laser combined with periodontal regeneration surgery, while patients in the control group were treated with conventional periodontal regeneration surgery alone. Visual analogue scale(VAS) score was used to evaluate the pain degree of patients 24 hours and 3 days after surgery. The probing depth(PD) and clinical attachment loss(CAL) were examined before and 6 months after surgery, and preoperative and postoperative X-ray images of the two groups were observed and compared. SPSS 26.0 software package was used for statistical analysis. RESULTS: Twenty-four hours and 3 days after surgery, the pain in the experimental group was significantly less than that in the control group (P<0.001), and PD and CAL levels in the two groups were significantly lower 6 months after surgery than before surgery (P<0.001). There was no significant difference in PD and CAL between the two groups before surgery, and the difference was statistically significant 6 months after surgery(P<0.001). X-ray images showed different degrees of new bone formation in alveolar bone defects in the two groups 6 months after surgery. CONCLUSIONS: The application of Nd:YAP laser in periodontal regeneration surgery can reduce postoperative pain and improve the surgical efficacy.

Effect of Hybrid Blood Purification Treatment on Secondary Hyperparathyroidism for Maintenance Hemodialysis Patients.

OBJECTIVE: This study aims to investigate the effects of hybrid blood purification treatment on secondary hyperparathyroidism for maintenance hemodialysis (HD) patients. METHODS: A total of 40 patients were randomly divided into 2 groups: HD combined with hemoperfusion (HD + HP) group (n = 20) and HD group (n = 20). Changes in intact parathyroid hormone (iPTH) in these 2 groups were compared before and after treatment, and iPTH levels in the HD + HP group were monitored before and after treatment. RESULTS: iPTH, ß2 microglobulin (ß2-MG), and cystatin C (CysC) levels were significantly lower in the HD + HP group than in the HD group (p < 0.05), iPTH levels were significantly higher than at the first day after treatment (p < 0.05), and iPTH level was significantly higher (p < 0.05). CONCLUSION: The clearance effects of HD + HP on iPTH, ß2-MG, and CysC are better than HD alone. Treatment with HD + HP every 2 weeks is recommended for maintenance HD patients.

Lysosomal Proteolysis Is Associated With Exercise-Induced Improvement of Mitochondrial Quality Control in Aged Hippocampus.

Exercise improves cognitive function in older adults, but the underlying mechanism is largely unknown. Both lysosomal degradation and mitochondrial quality control decline with age. We hypothesized that exercise ameliorates age-related cognitive decline through the improvement of mitochondrial quality control in aged hippocampus, and this effect is associated with lysosomal proteolysis. Sixteen to eighteen-month old male Sprague Dawley rats underwent swim exercise training for 10 weeks. The exercise regimen prevented cognitive decline in aged rats, reduced oxidative stress, and rejuvenated mitochondria in the aged hippocampus. Exercise training promoted mitochondrial biogenesis, increased mitochondrial fusion and fission, and activated autophagy/mitophagy in aged hippocampal neurons. Lysosomal inhibitor chloroquine partly blocked beneficial effects of exercise on cognitive function, oxidative stress, autophagy/mitophagy, and mitochondrial quality control in aged rats. These results suggest that preservation of cognitive function by long-term exercise is associated with improvement of mitochondrial quality control in aged hippocampus and that lysosomal degradation is required for this process. Our findings suggest that exercise training or pharmacological regulation of mitochondrial quality control and lysosomal degradation may be effective strategies for slowing down age-related cognitive decline.

Recombinant expression, purification and antimicrobial activity of a novel antimicrobial peptide PaDef in Pichia pastoris.

The antimicrobial peptide PaDef was isolated from Mexican avocado fruit and was reported to inhibit the growth of Escherichia coli and Staphylococcus aureus in 2013. In this study, an N-terminal 6 × His tagged recombinant PaDef (rPaDef) with a molecular weight of 7.5 KDa, for the first time, was expressed as a secreted peptide in Pichia pastoris. The optimal culture condition for rPaDef expression was determined to be incubation with 1.5% methanol for 72 h at 28 °C under pH 6.0. Under this condition, the amount of the rPaDef accumulation reached as high as 79.6 µg per 1 ml of culture medium. Once the rPaDef peptide was purified to reach a 95.7% purity using one-step nickel affinity chromatography, its strong and concentration-dependent antimicrobial activity was detected to be against a broad-spectrum of bacteria of both Gram-negative and Gram-positive. The growth of these bacterial pathogens was almost completely inhibited when the rPaDef peptide was at a concentration of as low as 90 µg/ml. In summary, our data showed that rPaDef derived from Mexican avocado fruit can be expressed and secreted efficiently when P. pastoris was used as a cell factory. This is the first report on heterologous expression of PaDef in P. pastoris and the approach described holds great promise for antibacterial drug development.

Preservation of Cognitive Function by Lepidium meyenii (Maca) Is Associated with Improvement of Mitochondrial Activity and Upregulation of Autophagy-Related Proteins in Middle-Aged Mouse Cortex.

Maca has been used as a foodstuff and a traditional medicine in the Andean region for over 2,000 years. Recently the neuroprotective effects of maca also arouse interest of researchers. Decrease in mitochondrial function and decline in autophagy signaling may participate in the process of age-related cognitive decline. This study aimed to investigate if maca could improve cognitive function of middle-aged mice and if this effect was associated with improvement of mitochondrial activity and modulation of autophagy signaling in mouse cortex. Fourteen-month-old male ICR mice received maca powder administered by gavage for five weeks. Maca improved cognitive function, motor coordination, and endurance capacity in middle-aged mice, accompanied by increased mitochondrial respiratory function and upregulation of autophagy-related proteins in cortex. Our findings suggest that maca is a newly defined nutritional plant which can improve mitochondrial function and upregulate autophagy-related proteins and may be an effective functional food for slowing down age-related cognitive decline.

Expression, purification and initial characterization of a novel recombinant antimicrobial peptide Mytichitin-A in Pichia pastoris.

Mytichitin-A is an antimicrobial peptide isolated from the serum of Mytilus coruscus and is reported to inhibit bacterial growth as tested on several Gram-positive bacteria. To produce large quantity of Mytichitin-A to further investigate its biological activity, nucleotide sequence encoding a recombinant 6 × His-Mytichitin-A (rMytichitin-A) peptide was synthesized and inserted into the inducible yeast expression vector pPICZαA. With the availability of such an expression vector called pPICZαA-Mytichitin-A, we transformed Pichia pastoris GS115 cells with a SacI-linearized pPICZαA-Mytichitin-A by electroporation. Transgenic strains secreting rMytichitin-A with a molecular weight of approximate 10 KDa as expected were obtained. The optimal culture condition for rMytichitin-A expression was determined to be 1.0% methanol induction, 96 h incubation at 28 °C and the amount of rMytichitin-A reached 45.5 µg/ml. The percentage of rMytichitin-A was estimated to be 73.6% of the total protein. After rMytichitin-A was purified using nickel ions affinity chromatography, approximate 9.1 mg pure rMytichitin-A was obtained from 500 ml of cell culture medium with 97.8% purity. More importantly, both the culture supernatant and purified rMytichitin-A inhibited the growth of Gram-positive bacteria, especially Staphylococcus aureus and Bacillus subtilis with a minimum inhibition concentration of as low as 31 and 48 µg/ml, respectively. Differently from the native protein, however, the rMytichitin-A is not active against Gram-negative bacteria. Taken together, this is the first report on the heterologous expression of Mytichitin-A in P. pastoris. Our study showed that P. pastoris is an effective expression system for producing large quantities of biologically active Mytichitin-A for both research and application purposes.

The epigenetically-regulated miR-663 targets H-ras in K-562 cells.

miR-663 is a tumour suppressor that is potentially regulated by modification of CpG islands. Whether aberrant methylation is one of the reasons for miR-663 down-regulation in some malignant cells and whether miR-663 targets oncogenes warrants further research. In the present study, we report that the CpG islands in the upstream region of pre-miR-663 are aberrantly methylated in the k-562 cell line and in the white blood cells of some chronic myelogenous leukaemia patients, and also that H-ras is one of the genes targeted by miR-663. Over-expression of miR-663 may suppress proliferation of the k-562 cell line in part by enhancing cell apoptosis.

[Microwave radiation decreases the expressions of occludin and JAM-1 in rats].

OBJECTIVE: To explore the changes in the expressions of the tight junction related protein occludin and junctional adhesion molecule-1 (JAM-1) of the blood-testis barrier and their significance in rats after microwave radiation. METHODS: Eighty male Wistar rats were exposed to microwave radiation with average power density of 0, 10, 30 and 100 mW/cm2 for five minutes, and dynamic changes in the expressions of testicular occludin and JAM-1 were observed by Western blot and image analysis at 6 h, 1 d, 3 d, 7 d and 14 d after the radiation. RESULTS: There was a significant down-regulation in the expression of the occludin protein at 3 - 7 d, 6 h - 7 d and 6 h - 14 d (P < 0. 05), as well as in that of JAM-1 at 3 - 7 d, 1 - 7 d and 1-14 d (P < 0.05) after exposure to 10, 30 and 100 mW/cm2 microwave radiation. CONCLUSION: The decreased protein expressions of occludin and JAM-1 may play an important role in the microwave radiation induced-damage to the blood-testis barrier.

[Effect of microwave radiation on primary cultured Sertoli cells].

OBJECTIVE: To explore whether microwave radiation may cause injury of primary cultured Sertoli cells. METHODS: The model of primary cultured Sertoli cells in vitro was established, which was radiated by microwave with average power density 0, 30 and 100 mW/cm(2) for five minutes. The changes of cell cycle, apoptosis and death, and intracellular Ca2+ concentration in the Sertoli cells were measured at sixth hours through Annexin V-PI double labeling and Fluo-3-AM labeling, flow cytometry combined with laser scanning confocal microscopy after microwave exposure. RESULTS: The numbers of Sertoli cells were obviously reduced in G0-G1 and G2-M phase (62.57% +/- 3.22% and 8.25% +/- 1.75%) and increased in S phase (29.17% +/- 4.87%) compared with the control groups (79.18% +/- 0.24%, 11.17% +/- 0.50% and 9.64% +/- 0.62%) (P < 0.05 or P < 0.01), but the changes of rate of apoptosis and death and intracellular Ca2+ concentration showed no difference at 6 h after exposure to 30 mW/cm(2) microwave. There was a significant increase in the Sertoli cell counts of G0-G1 phase (87.69% +/- 1.32%), and decrease in the Sertoli cell counts of G2-M and S phase (7.41% +/- 0.60% and 4.87% +/- 0.91%) (P < 0.01). There was also a significant increase in intracellular Ca2+ concentration and rate of apoptosis and death (P < 0.05 or P < 0.01) at 6 h after exposure to 100 mW/cm(2) microwave. CONCLUSION: 100 mW/cm(2) microwave radiation may cause growth inhibition and increase of apoptosis and death in the primary cultured Sertoli cells. The increase of intracellular Ca2+ concentration is one of the injury mechanisms.

[High power microwave radiation damages blood-testis barrier in rats].

OBJECTIVE: To determine the effect of high power microwave (HPM) radiation on the structure and function of blood-testis barrier (BTB) in rats. METHODS: One hundred and sixty-six male Wistar rats were treated by heart perfusion of lanthanum-glutaraldehyde solution and tail vein injection of evans blue (EB) at 6 h, 1, 3, 7 and 14 d after exposed to 0, 10, 30 and 100 mW/cm2 HPM radiation for 5 minutes, the structural change of BTB and distribution of lanthanum or EB observed through the light microscope, electron microscope and laser scanning confocal microscopy (LSCM). RESULTS: Testicular interstitial edema, vascular congestion or hyperemia with accumulation of plasma proteins and red blood cells in the inner compartment of seminiferous tubules were observed after exposure to HPM. The above-mentioned pathological changes were aggravated at 1-7 d and relieved at 14 d after radiation, obviously more severe in the 30 and 100 mW/cm2 exposure groups than in the 10 mW/cm2. Both lanthanum precipitation and EB were deposited in the inner compartment. CONCLUSION: HPM radiation may damage the structure and increase the permeability of BTB.

[Status quo of the researches on the biological effect of electromagnetic radiation on the testis and epididymal sperm].

The testis is highly sensitive to electromagnetic radiation. Sperm is the passer of male genetic material and electromagnetic radiation may cause structural and functional injury to the testis, including motility reduction, abnormality increase and ultrastructural alteration of epididymal sperm. Energy metabolism disorder in spermatogenic cells, enhancement of lipid peroxidation in the testis, excessive expression of inflammatory factors and abnormality of genetic transcription may be responsible for injury to the testis and epididymal sperm. This paper reviews the progress made in this field and the preventive measures against the injury.