OBJECTIVE: To investigate the intervention of melatonin (MT) in the expression of circadian genes in patients with pulmonary fibrosis and to analyze the mechanism by which it alleviates the progression of pulmonary fibrosis. METHODS: By utilizing the Gene Expression Omnibus (GEO) database, we identified differentially expressed circadian genes between patients with pulmonary fibrosis and controls. We analyzed the correlation between circadian genes and pulmonary function as well as genes related to pulmonary fibrosis. A bleomycin-induced mouse model of pulmonary fibrosis (BLM group) was constructed to observe the expression differences of PER2 and CRY2 by sequencing and immunohistochemical staining in the BLM group and after MT intervention (BLM+MT group). Hematoxylin and eosin (HE) staining and Masson staining were used to observe the effects of MT on fibrosis. We used Western blot to detect the expression of P-smad2/3 in lung epithelial cells induced by transforming growth factor β (TGF-β). Reverse transcription quantitative real-time PCR technology was employed to investigate the rhythmic expression changes of circadian genes in the control group, TGF-β group, and TGF-β+MT group. Finally, luzindole, a MT receptor antagonist, was used to intervene in TGF-β+MT group, and Western blot was used to explore the receptor dependence of MT in alleviating TGF-β-induced epithelial-mesenchymal transition. RESULTS: (1) Analysis of the GEO dataset (GSE) revealed a negative correlation between circadian genes PER2 and CRY2 and the expression of TGF-β, and a positive correlation with pulmonary function indicators in patients. (2) Transcriptome sequencing analysis of lung tissue in BLM group found that the expression of PER2 and CRY2 was significantly reduced compared with the normal group. Histopathological staining results showed that the lung tissue structure of the normal group was intact and clear, with thin alveolar septa; in the BLM group, there was a large increase in collagen fibers and disordered alveolar structure; compared with the BLM group, the BLM+MT group had reduced collagen fiber proliferation and inflammatory cell infiltration; the expression of PER2 and CRY2 in the BLM group was lower than in the normal group, and the expression in the BLM+MT group was increased compared with the BLM group. (3) In vitro lung epithelial cell experiments with TGF-β intervention showed that compared with the control group, the expression of P-smad2/3 increased in the TGF-β group, and MT intervention inhibited the inducing effect of TGF-β on P-smad2/3, while intervention with the MT receptor antagonist reversed this phenomenon. The results indicated that MT could inhibit the activation of the TGF-β pathway, and this process was dependent on MT receptors. (4) The 48-hour rhythm experiment in lung epithelial cells showed that the mRNA rhythm of PER2 and CRY2 in the TGF-β+MT group was close to 24 hours and showed a trend towards restoring the rhythm of the control group, while the addition of the MT receptor blocker tended to make the rhythm duration and amplitude of both groups approach that of the TGF-β group. CONCLUSION MT, by binding to its receptors, can restore the periodic expression of the circadian genes PER2 and CRY2, thereby inhibiting the activation of the TGF-β classical pathway and suppressing the pathological process of epithelial-mesenchymal transition in pulmonary fibrosis. This finding provides new molecular targets and potential therapeutic strategies for the treatment of pulmonary fibrosis.
Melatonin/pharmacology* ; Animals ; Mice ; Pulmonary Fibrosis/chemically induced* ; Bleomycin ; Humans ; Transforming Growth Factor beta/metabolism* ; Period Circadian Proteins/metabolism* ; Smad3 Protein/genetics* ; Disease Models, Animal ; Lung/pathology* ; Cryptochromes/metabolism* ; Smad2 Protein/genetics* ; Epithelial Cells/metabolism* ; Mice, Inbred C57BL

OBJECTIVETo investigate the effect and regulatory mechanism of clock gene Per1 on the proliferation,apoptosis,migration,and invasion of human oral squamous carcinoma SCC15 cells.

METHODSRNA interference was used to knock down Per1 gene in human oral squamous cell carcinoma SCC15 cell line. Changes of cell proliferation and apoptosis were analyzed by flow cytometry. Transwell assay was carried out to assess cell migration and invasion. Real-time polymerase chain reaction was used to detect the mRNA expressions of Ki-67, murine double minute 2 (MDM2), c-Myc, p53, Bax, Bcl-2, metalloproteinase (MMP)2, MMP9, and vascular endothelial growth factor (VEGF).

RESULTSshRNA-mediated knockdown of Per1 promoted the proliferation, migration and invasion capacity, and inhibited cell apoptosis capacity of SCC15 cells (all P<0.05). Additionally, Per1 knockdown also increased the mRNA expressions of Ki-67, MDM2, Bcl-2, MMP2, and MMP9 and decreased the mRNA expressions of c-Myc, p53, and Bax (all P<0.05); however, the VEGF mRNA expression did not differ significantly after Per1 knockdown (P>0.05).

CONCLUSIONSClock gene Perl can regulate important tumor-related genes downstream such as Ki-67, MDM2, c-Myc, p53, Bax, Bcl-2, MMP2, and MMP9, and the aberrant expression of Per1 can affect tumor cell proliferation,apoptosis,migration and invasion. An in-depth study of Per1 may further clarify the mechanism of tumorigenesis and tumor development and thus provides new effective molecular targets for cancer treatment.

Apoptosis ; Carcinoma, Squamous Cell ; metabolism ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Gene Knockdown Techniques ; Humans ; Ki-67 Antigen ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Period Circadian Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Proto-Oncogene Proteins c-mdm2 ; metabolism ; Proto-Oncogene Proteins c-myc ; metabolism ; RNA Interference ; Real-Time Polymerase Chain Reaction ; Tumor Suppressor Protein p53 ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVEThis study investigates the circadian variation rules of the clock gene Per2 and clock-controlled genes of vascular endothelial growth factor (VEGF), Ki67, c-Myc, and P53 in different stages of carcinogenesis in buccal mucosa carcinoma and their roles in the development of buccal mucosa carcinoma.

METHODSNinety Syrian golden hamsters were housed under. 12 h light/12 h dark cycles. Dimethylbenzanthracene (DMBA) was used to establish the carcinoma model by smearing the golden hamster buccal mucosa. Before DMBA painting and after 6 and 14 weeks, the hamsters were sacrificed at six time points within a period of 24 h (i.e., 4, 8, 12, 16, 20, and 24 h after light onset), and the normal buccal mucosa, precancerous lesions, and cancer tissues were simultaneously obtained. Hematoxylin and eosin stained sections were prepared to observe the canceration of each tissue. Real time polymerase chain reaction was used to detect the mRNA expression of Per2, VEGF, Ki67, c-Myc, and P53. Cosine analysis was employed to determine the circadian-rhythm variations of Per2, VEGF, Ki67, c-Myc, and P53 mRNA expression in terms of median, amplitude, and acrophase.

RESULTSThe expression of Per2, VEGF, P53, and c-Myc mRNA in three different stages appeared with circadian rhythms (P<0.05), whereas the Ki67 mRNA was expressed with circadian rhythm only in normal and precancerous lesion stages (P<0.05). The midline-estimating statistic of rhythms (MESORs) of Per2 and P53 mRNA were significantly down-regulated with the development of cancer (P<0.05), whereas the MESORs of VEGF, c-Myc, and Ki67 mRNA were up-regulated (P<0.05). The amplitude of P53 mRNA significantly decreased with the development of cancer (P<0.05). Moreover, compared with the normal group, the amplitudes of Per2, VEGF, Ki67, and c-Myc mRNA significantly increased in precancerous lesions and cancer tissue (P<0.05). In precancerous stage, the acrophases of Per2, VEGF, and c-Myc mRNA were earlier than that in the normal group, whereas that of Ki67 and P53 mRNA were delayed.

CONCLUSIONThe circadian-rhythm characteristics of the clock gene Per2 and clock-controlled gene expression of VEGF, Ki67, c-Myc, and P53 mRNA have changed with the occurrence and development of carcinoma.

9,10-Dimethyl-1,2-benzanthracene ; Animals ; Carcinogenesis ; Carcinoma, Squamous Cell ; metabolism ; Circadian Rhythm ; Cricetinae ; Mesocricetus ; Mouth Mucosa ; metabolism ; Mouth Neoplasms ; metabolism ; Neoplasm Staging ; Period Circadian Proteins ; genetics ; metabolism ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A

OBJECTIVETo identify protein-protein interaction partners of PER1 (period circadian protein homolog 1), key component of the molecular oscillation system of the circadian rhythm in tumors using bacterial two-hybrid system technique.

METHODSHuman cervical carcinoma cell Hela library was adopted. Recombinant bait plasmid pBT-PER1 and pTRG cDNA plasmid library were cotransformed into the two-hybrid system reporter strain cultured in a special selective medium. Target clones were screened. After isolating the positive clones, the target clones were sequenced and analyzed.

RESULTSFourteen protein coding genes were identified, 4 of which were found to contain whole coding regions of genes, which included optic atrophy 3 protein (OPA3) associated with mitochondrial dynamics and homo sapiens cutA divalent cation tolerance homolog of E. coli (CUTA) associated with copper metabolism. There were also cellular events related proteins and proteins which are involved in biochemical reaction and signal transduction-related proteins.

CONCLUSIONIdentification of potential interacting proteins with PER1 in tumors may provide us new insights into the functions of the circadian clock protein PER1 during tumorigenesis.

Base Sequence ; Cell Line, Tumor ; Escherichia coli ; genetics ; metabolism ; Humans ; Molecular Sequence Data ; Neoplasms ; genetics ; metabolism ; Period Circadian Proteins ; genetics ; metabolism ; Protein Binding ; Proteins ; genetics ; metabolism ; Two-Hybrid System Techniques

Circadian clocks are the endogenous oscillators that harmonize a variety of physiological processes within the body. Although many urinary functions exhibit clear daily or circadian variation in diurnal humans and nocturnal rodents, the precise mechanisms of these variations are as yet unclear. In the present study, we demonstrate that Per2 promoter activity clearly oscillates in neonate and adult bladders cultured ex vivo from Per2::Luc knock-in mice. In subsequent experiments, we show that multiple local oscillators are operating in all the bladder tissues (detrusor, sphincter and urothelim) and the lumbar spinal cord (L4-5) but not in the pontine micturition center or the ventrolateral periaqueductal gray of the brain. Accordingly, the water intake and urine volume exhibited daily and circadian variations in young adult wild-type mice but not in Per1-/- Per2-/- mice, suggesting a functional clock-dependent nature of the micturition rhythm. Particularly in PDK mice, the water intake and urinary excretion displayed an arrhythmic pattern under constant darkness, and the amount of water consumed and excreted significantly increased compared with those of WT mice. These results suggest that local circadian clocks reside in three types of bladder tissue and the lumbar spinal cord and may have important roles in the circadian control of micturition function.
Animals ; *Circadian Clocks ; Drinking ; Mice ; Organ Specificity ; Periaqueductal Gray/metabolism/physiology ; Period Circadian Proteins/genetics/*metabolism ; Pons/metabolism/physiology ; Spinal Cord/*metabolism/physiology ; Urinary Bladder/innervation/metabolism/*physiology ; Urination

OBJECTIVETo detect the expression of Per2 in non-small cell lung cancer (NSCLC), and analyze its clinical significance.

METHODSThe expression of Per2 was determined in 60 NSCLC and 20 normal lung tissues by immunohistochemical assay, and the relationship between Per2 expression and clinicopathological features was analyzed.

RESULTSThe positive expression rates of Per2 in NSCLC and normal lung tissues were 71.7% and 95.0%, respectively (P < 0.05). The expression of Per2 in NSCLC was correlated with pathological differentiation and TNM stage (P < 0.05).

CONCLUSIONThe expression of Per2 in NSCLC is decreased. The negative expression of Per2 may contribute to the development and invasion in NSCLC.

Adult ; Aged ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; surgery ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; metabolism ; pathology ; surgery ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Grading ; Neoplasm Staging ; Period Circadian Proteins ; metabolism ; Smoking

OBJECTIVETo investigate the effect of acute heat stress on the day-night circadian gene Per2 mRNA expression in the liver of rats.

METHODSMale Wistar rats were randomly divided into two groups and exposed to heat at 32 degrees celsius; or to a room temperature at 24 degrees celsius; (control). After 7 days of heat exposure, the body temperature was measured by telemetry. The relative weight of the pituitary and adrenal glands was determined after the exposure, and liver Per2 mRNA expression level was detected using RT-PCR.

RESULTSAcute heat stress did not obviously affect body temperature or body weight of the rats. Seven days of heat exposure increased the relative weight of the pituitary and adrenal glands and significantly lowered Per2 mRNA expression level at night.

CONCLUSIONAcute heat stress can interfere with the day-night circadian gene Per2 mRNA expression in rats.

Adrenal Glands ; Animals ; Body Temperature ; Body Weight ; Heat-Shock Response ; genetics ; Liver ; metabolism ; Male ; Organ Size ; Period Circadian Proteins ; genetics ; metabolism ; Pituitary Gland ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the clinical significance of promoter methylation status of hPer3 gene in acute myeloid leukemia (AML) patients and the in vitro effect of decitabine (DCA) on AML cell lines HL-60 and U937.

METHODSThe promoter methylation status of hPer3 gene and mRNA expression levels in bone marrow of 206 AML and 40 iron deficiency anemia (IDA) patients (as control) were detected by methylation specific PCR (MS-PCR) and real-time PCR (RT-PCR). The HL-60 and U937 cell lines were treated with different concentrations of DCA for 48 and 72 h. The inhibition rates of cell proliferation were detected by methyl thiazolyl tetrazolium (MTT); the early apoptosis rates by staining with Annexin V and PI; the CD14 and CD11b expressions by flow cytometry (FCM); the promoter methylation status of hPer3 gene by MS-PCR; and the hPer3 mRNA expressions levels by RT-PCR.

RESULTSThe promoter methylation rates of hPer3 in newly diagnosed (ND) group, partial remission(PR) group, complete remission (CR) group, relapse (R) group and control group were 93.65% (59/63), 54.39% (31/57), 24.66% (18/73), 61.54% (8/13) and 0% (0/40), and the hPer3 mRNA expression levels were 0.19 ± 0.08, 6.28 ± 2.11, 52.76 ± 14.17, 8.18 ± 4.36, 75.03 ± 18.16, respectively. There was a significant statistic difference between any two group (P < 0.01) excepting for between PR and R group (P > 0.05). After DCA treatment, the promoter hypermethylation status of hPer3 was reduced and the mRNA and CD14, CD11b expression levels were up regulated in a dose dependent manner with an induction of cell apoptosis.

CONCLUSIONSPromotor methylation status and mRNA expression of hPer3 gene may be indicators for evaluating AML. DCA can induce the expression of hPer3 gene and cells apoptosis in AML.

Adolescent ; Adult ; Aged ; Azacitidine ; analogs & derivatives ; pharmacology ; Cell Proliferation ; DNA Methylation ; Female ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Period Circadian Proteins ; genetics ; Promoter Regions, Genetic ; U937 Cells ; Young Adult

OBJECTIVETo investigate the molecular biological mechanism of chronoexercise regulating circadian.

METHODSExpressions of mPer1 and mPer2 in the diencephalon of golden hamster were determined 2 hours after acute exhaustive exercise (circadian time 6) by quantitative RT-PCR.

RESULTSChronoexercise at CT6 significantly decreased expressions of mPer1 and mPer2 in the diencephalon of golden hamster.

CONCLUSIONInhibitory effect of chronoexercise on Per1 and Per2 mRNA levels in the diencephalon of golden hamster at CT6 may be achieved transcription-translation-based autoregulatory negative feedback loop.

Animals ; Circadian Rhythm ; physiology ; Cricetinae ; Gene Expression ; Period Circadian Proteins ; genetics ; metabolism ; Physical Conditioning, Animal ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction