The circadian clock plays a critical role in regulating various physiological processes, including gene expression, metabolic regulation, immune response, and the sleep-wake cycle in living organisms. Post-translational modifications (PTMs) are crucial regulatory mechanisms to maintain the precise oscillation of the circadian clock. By modulating the stability, activity, cell localization and protein-protein interactions of core clock proteins, PTMs enable these proteins to respond dynamically to environmental and intracellular changes, thereby sustaining the periodic oscillations of the circadian clock. Different types of PTMs exert their effects through distincting molecular mechanisms, collectively ensuring the proper function of the circadian system. This review systematically summarized several major types of PTMs, including phosphorylation, acetylation, ubiquitination, SUMOylation and oxidative modification, and overviewed their roles in regulating the core clock proteins and the associated pathways, with the goals of providing a theoretical foundation for the deeper understanding of clock mechanisms and the treatment of diseases associated with circadian disruption.
Protein Processing, Post-Translational/physiology* ; Circadian Rhythm/physiology* ; Humans ; Animals ; CLOCK Proteins/physiology* ; Circadian Clocks/physiology* ; Phosphorylation ; Acetylation ; Ubiquitination ; Sumoylation

The aim of this study was to investigate the contribution of lung zinc ions to pathogenesis of lung ischemia/reperfusion (I/R) injury in rats. Male Sprague Dawley (SD) rats were randomly divided into control group, lung I/R group (I/R group), lung I/R + low-dose zinc chloride group (LZnCl₂+I/R group), lung I/R + high-dose ZnCl₂ group (HZnCl₂+I/R group), lung I/R + medium-dose ZnCl₂ group (MZnCl₂+I/R group) and TPEN+MZnCl₂+I/R group (n = 8 in each group). Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the concentration of zinc ions in lung tissue. The degree of lung tissue injury was analyzed by observing HE staining, alveolar damage index, lung wet/dry weight ratio and lung tissue gross changes. TUNEL staining was used to detect cellular apoptosis in lung tissue. Western blot and RT-qPCR were used to determine the protein expression levels of caspase-3 and ZIP8, as well as the mRNA expression levels of zinc transporters (ZIP, ZNT) in lung tissue. The mitochondrial membrane potential (MMP) of lung tissue was detected by JC-1 MMP detection kit. The results showed that, compared with the control group, the lung tissue damage, lung wet/dry weight ratio and alveolar damage index were significantly increased in the I/R group. And in the lung tissue, the concentration of Zn²⁺ was markedly decreased, while the cleaved caspase-3/caspase-3 ratio and apoptotic levels were significantly increased. The expression levels of ZIP8 mRNA and protein were down-regulated significantly, while the mRNA expression of other zinc transporters remained unchanged. There was also a significant decrease in MMP. Compared with the I/R group, both MZnCl₂+I/R group and HZnCl₂+I/R group exhibited significantly reduced lung tissue injury, lung wet/dry weight ratio and alveolar damage index, increased Zn²⁺ concentration, decreased ratio of cleaved caspase-3/caspase-3 and apoptosis, and up-regulated expression levels of ZIP8 mRNA and protein. In addition, the MMP was significantly increased in the lung tissue. Zn²⁺ chelating agent TPEN reversed the above-mentioned protective effects of medium-dose ZnCl₂ on the lung tissue in the I/R group. The aforementioned results suggest that exogenous administration of ZnCl₂ can improve lung I/R injury in rats.
Animals ; Reperfusion Injury/pathology* ; Male ; Rats, Sprague-Dawley ; Rats ; Chlorides/administration & dosage* ; Lung/pathology* ; Zinc Compounds/administration & dosage* ; Apoptosis/drug effects* ; Caspase 3/metabolism* ; Cation Transport Proteins/metabolism*

Objective To investigate whether Liuwei Dihuang Pills enhances the antigen cross-presenting ability of dendritic cell(DC)by increasing gap junctional intercellular communication(GJIC),and to explore the mechanisms involved.Methods Western Blot and immunofluorescence were used to observe the effects of Liuwei Dihuang Pills-containing serum on the expression and membrane localisation of gap junction protein connexin43(Cx43)in mouse melanoma cells(B16);Calcein-AM/DiI fluorescence tracer assay was used to observe the effects of Liuwei Dihuang Pills-containing serum on the function of GJIC in B16 cells;flow cytometry was used to observe the role of GJIC in the enhancement of DC antigen presenting ability by Liuwei Dihuang Pills-containing serum;and propidium iodide(PI)/Hoechst staining assay was used to observe the immunocidal effect of CD8+ T-lymphocytes.Results Western Blot and immunofluorescence experiments showed that Liuwei Dihuang Pills-containing serum led to the up-regulation of Cx43 expression;fluorescence tracer experiments proved that the GJIC function of B16 cells was significantly enhanced by Liuwei Dihuang Pills-containing serum;flow cytometry analyses showed that the DC antigen-presenting ability was enhanced by Liuwei Dihuang Pills-containing serum;and the results of PI/Hoechst staining showed that the immuno-killing effect of CD8+T-cells was more significant after the intervention of Liuwei Dihuang Pills-containing serum in B16-OVA.Conclusion Liuwei Dihuang Pills improve the GJIC function by up-regulating the Cx43 expression of melanoma cells,and then enhance the cross-presenting ability of DCs thus activating stronger CD8+ T-cell immunocidal responses.

Objective: To investigate the prevalence of suicidal ideation among MSM, and to explore the influence of perceived social support and depression on suicidal ideation and the possible pathway. Methods: MSM who are ≥18 years, HIV-negative, and ever had sex with men (oral sex/anal sex) in the last year participated in is study. Cross-sectional survey and convenient sampling method were used to recruit MSM through a male social interaction platform Blued 7.5 software from December 2020 to March 2021, with a questionnaire survey. Demographic questionnaire, Perceived Social Support Questionnaire and Center for Epidemiologic Studies Depression Scale were employed to collect data. Mplus 8.3 was used for data analysis. Results: Among 1 394 eligible MSM participants, 25.7% (358/1 394) had suicidal ideation. Perceived social support could have a direct effect on suicidal ideation (β=-0.11, P=0.009), and an indirect effect on suicidal ideation through depression (β=-0.18, P<0.001). Conclusions: Suicidal ideation was found to be lower in MSM with a higher level of perceived social support and a lower level of depression. Using social media to improve MSM's perceived social support and reduce depressive symptoms might be an effective means to prevent suicidal ideation.
Cross-Sectional Studies ; Depression/epidemiology* ; Homosexuality, Male ; Humans ; Male ; Sexual Behavior ; Sexual and Gender Minorities ; Social Support ; Suicidal Ideation

Deficits in the clearance of amyloid β protein (Aβ) by the peripheral system play a critical role in the pathogenesis of sporadic Alzheimer's disease (AD). Impaired uptake of Aβ by dysfunctional monocytes is deemed to be one of the major mechanisms underlying deficient peripheral Aβ clearance in AD. In the current study, flow cytometry and biochemical and behavioral techniques were applied to investigate the effects of polysaccharide krestin (PSK) on AD-related pathology in vitro and in vivo. We found that PSK, widely used in therapy for various cancers, has the potential to enhance Aβ uptake and intracellular processing by human monocytes in vitro. After administration of PSK by intraperitoneal injection, APP/PS1 mice performed better in behavioral tests, along with reduced Aβ deposition, neuroinflammation, neuronal loss, and tau hyperphosphorylation. These results suggest that PSK holds promise as a preventive agent for AD by strengthening the Aβ clearance by blood monocytes and alleviating AD-like pathology.
Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor/metabolism* ; Animals ; Cognition ; Disease Models, Animal ; Mice ; Mice, Transgenic ; Monocytes/pathology* ; Polysaccharides/therapeutic use* ; Proteoglycans

Objective: To investigate whether large conductance calcium-activated potassium channel (BK(Ca)) was involved in the migration of pericytes (PC) in the mice of senile cochlear stria vascularis capillaries PC. Methods: C57BL/6J mice were divided into 3-month (n=10) and 12-month groups (n=10). Auditory brainstem response (ABR) was used to test the hearing threshold of each group. The immunofluorescence was used to detect the expression changes of osteopontin (OPN) and β-BK(Ca) channels on cochlear stria vascularis PC. The morphological changes of perivascular cells in cochlea were observed by transmission electron microscope (TEM). Cell experiment: The PC, which were in the stria vascularis of the cochlea were primary cultured and identified. A cell senile model was made with D-gal. The appropriate intervention concentration of low galactose (D-gal) was determined by CCK8. β-galactosidase (SA-β-gal) staining was used to evaluate the cell decrept level. The change of BK(Ca) channels current on PC were recorded by whole cell patch clamp technique. The expression of BK(Ca) channels on PC was detected by immunofluorescence. The migration and invasion ability of two groups were detected by using Scratch test and Transwell. The levels of OPN and β-BK(Ca) channels were detected by Western blot. SPSS 22.0 software was used to analyze the data. Results: The ABR threshold in the 12-month group was higher than 3-month group (t=12.66, P<0.01). In the 12-month group, the expression of β-BK(Ca) channel was lower and the expression of OPN was increased (t=14.64, P<0.01; t=20.73, P<0.01). In TEM, cochlear stria vascularis PC were tightly connected to endothelial cells in 3-month group, while PC were loosely connected to endothelial cells or PC soma were separated from the capillary in 12-month group. Cell experiment: The positive rate of PC in the primary cultured cochlear stria vascularis is above 95%. Compared with the SA-β-gal stained cells in the control group, the positive rate of 15 mg/ml D-gal intervention PC was 85% (t=36.90, P<0.01). Whole cell patch clamp BK(Ca) channels current decreased in the D-gal group compared with the young group PC (t=12.18, P<0.05). The OPN expression in the senile group was higher than control group (t=16.30, P<0.01), while the β-BK(Ca) channels expression was decreased (t=11.98, P<0.01; t=15.72, P<0.05), and migration ability raised (t=7.91, P<0.01;t=7.59, P<0.01). After intervened of BK(Ca) channels specific blocker IBTX in the D-gal group, the expression of OPN and migration were increased (t=4.26, P<0.05; t=5.88, P<0.01; t=21.97, P<0.01). Conclusion: PC migration capacity were increased during the senile period, and the expression of β-BK(Ca) channel was decreased. The administration of IBTX, a specific blocker of BK(Ca) channel, at the cell level could increase the migration capacity, suggesting that BK(Ca) might be involved in the migration of PC in the stria vascularis of the aging cochlea.
Aging ; Animals ; Cochlea ; Endothelial Cells ; Large-Conductance Calcium-Activated Potassium Channels ; Mice ; Mice, Inbred C57BL ; Pericytes ; Stria Vascularis

Objective: To predict B cell and T cell epitopes of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins. Methods: The sequences of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins which were derived from Orientia tsutsugamushi were analyzed by SOPMA, DNAstar, Bcepred, ABCpred, NetMHC, NetMHC II and IEDB. The 58-kDa tertiary structure model was built by MODELLER9.17. Results: The 22-kDa B-cell epitopes were located at positions 194-200, 20-26 and 143-154, whereas the T-cell epitopes were located at positions 154-174, 95-107, 17-25 and 57-65. The 47-kDa protein B-cell epitopes were at positions 413-434, 150-161 and 283-322, whereas the T-cell epitopes were located at positions 129-147, 259-267, 412-420 and 80-88. The 56-kDa protein B-cell epitopes were at positions 167-173, 410-419 and 101-108, whereas the T-cell epitopes were located at positions 88-104, 429-439, 232-240 and 194-202. The 58-kDa protein B-cell epitopes were at positions 312-317, 540-548 and 35-55, whereas the T-cell epitopes were located at positions 415-434, 66-84 and 214-230. Conclusions: We identified candidate epitopes of 22-kDa, 47-kDa, 56-kDa and 58-kDa proteins from Orientia tsutsugamushi. In the case of 58-kDa, the dominant antigen is displayed on tertiary structure by homology modeling. Our findings will help target additional recombinant antigens with strong specificity, high sensitivity, and stable expression and will aid in their isolation and purification.

OBJECTIVE: To study whether the Bmi-1 gene can be a biomarker for analysis of clinical risk stratification and prognosis of ALL patients. METHODS: The expression level of Bmi-1 gene in bone marrow samples from 127 cases of newly diagnosed ALL was detected by qRT-PCR, at the same time the expression level of Bmi-1 protein in bone marrow samples from above-mentioned cases was detected by Western blot. The collected samples were divided into 3 groups: high, intermediate and low risk according to clinical risk stratfication, the relationship between Bmi-1 expression and risk grade of ALL patients was analyzed; at the same time the collected samples were divided into 2 groups: prednisone good response (PGR) and prednisone poor respouse (PPR) according to the sensitivity of prednison test, and the sensitivily to prednisone in 2 groups was compared; moreover, the collected samples were divided into 2 groups: high level and low level according to median of Bmi-1 level, and the relation of Bmi-1 level with prognosis of patients was analyzed by using the Kaplan-Meier method. RESULTS: The expression level of Bmi-1 in low risk group was lowest, while that in high risk group was highest, however that in intermediat risk group was between the low and high risk groups, statistical analysis showed significant difference (P＜0.05). The expression level of Bmi-1 in PPR group was significantly higher than that in PGR group (P＜0.001). The Kaplan-Meier analysis showed that the RFS rate in Bmi-1 high expression group was significantly lower than that in Bmi-1 low expression group (73.0% vs 90.6%) (P＜0.001). CONCLUSION The Bmi-1 can be used as a molecular marker for the analysis of chinical risk and prognosis of pediatric ALL.
Biomarkers ; Child ; Humans ; Kaplan-Meier Estimate ; Polycomb Repressive Complex 1 ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prednisone ; Prognosis

OBJECTIVE: To investigate whether the down-regulation of miR-125b can reverse the drug-resistence of doxorubicine-resistant leukemia cell lines or not, so as to explore a new method for treatment of drug-resistant leukemia patients. METHODS: The expression levels of miR125b in doxorubicine drug-sensitive and doxorubicine drug-resistant leukemia cell lines.HL-60, K562 and HL-60/Dox, the K562/Dox were detected by using RT-qPCR; the up-regulation or inhibition of miR-1256 expression in HL-60/Dox were performed by electroporation transfection, then the viability of cells treated with doxorubicine of different concentration was detected by CCK-8 method, the proliferation inhibition curve of cells was drawed, and the IC was calculated. RESULTS: The miR-125b expression was obviously up-regulated in drug-resistant cell lines HL-60/DOX and K562/DOX, as compared with HL-60 and K562 cell lines. The miR-125b expression level in HL-60/DOX and K562/DOX cells was 15 times and 5 times higher than that in HL-60 and K562 cells, respectively. The up-regulating or inhibiting expression of miR-125b in HL-60/DOX cells found that the proliferation inhibition rate in cells transfected with miR-125b mimic significantly decreased, compared with control group (P<0.01), while the proliferation inhibition rate in cells transfected with miR-125b inhibitor significantly increased, compared with control group(P<0.01). CONCLUSION The miR-125b expression in HL-60/Dox and K562/Dox cells has been up-regulated, down-regulation of miR-125b expression can reverse the drug resistance of leukemia cells to doxorubicine.
Down-Regulation ; Doxorubicin ; Drug Resistance, Neoplasm ; Humans ; K562 Cells ; Leukemia ; MicroRNAs

Fructus Arctii is a traditional Chinese medicine. The main counterfeit species are the seeds of Arctium tomentosum, Onopordum acanthium, Silybum marianum, Saussurea costus, Amorpha fruticosa. Traditional identification methods or molecular barcoding techniques can identify Fructus Arctii and its counterfeit species. However, the identification of the mixture of it and its spurious species is rarely reported. In this paper, we sequenced the ITS2 sequences of Fructus Arctii and 5 kinds of spurious species mix powder by high-throughput sequencing to identify the mixed powder species and providing new ideas for the identification of Fructus Arctii mix powder. The total DNA in mixed powder was extracted, and the ITS2 sequences in total DNA was amplified. Paired-end sequencing was performed on the DNA fragment of the community using the Illumina MiSeq platform. The sequence was analyzed by the software FLASH, QIIME and GraPhlAn etc. The results showed that the high quality ITS2 sequences of 39910 mix samples were obtained from the mixed samples, of which the total ITS2 sequence of the samples genus was 34 935. Phylogenetic analysis showed that the samples contained Fructus Arctii, A. tomentosum, O. acanthium, S. marianum, S. costus and A. fruticosa. Using ITS2 sequences as DNA barcodes, high-throughput sequencing technology can be used to detect the Fructus Arctii and its spurious specie in mixed powder, which can provide reference for the quality control, safe use of medicinal materials of Fructus Arctii and the identification of mixed powder of traditional Chinese medicine.
Arctium ; chemistry ; classification ; DNA Barcoding, Taxonomic ; DNA, Plant ; genetics ; DNA, Ribosomal Spacer ; genetics ; Drug Contamination ; Drugs, Chinese Herbal ; standards ; Fabaceae ; Fruit ; High-Throughput Nucleotide Sequencing ; Milk Thistle ; Onopordum ; Phylogeny ; Saussurea