The circadian clock gene Bmal1 facilitates cisplatin-induced renal injury and hepatization
Ontology highlight
ABSTRACT: Cisplatin is one of the most potent chemotherapy drugs to treat cancers, but its clinical application remains limited due to severe nephrotoxicity. Several approaches have been developed to minimize such side effects, notably including chronotherapy, a well-known strategy based on the circadian clock. However, the component of the circadian clock machinery that particularly responses to the cisplatin stimulation remains unknown, including its functions in cisplatin-induced renal injury. In our present study, we demonstrated that Bmal1, as a key clock gene, was induced by the cisplatin stimulation in the mouse kidney and cultured human HK-2 renal cells. Gain- and loss-of-function studies indicated that Bmal1 facilitated cisplatin-induced renal injury both in vivo and in vitro, by aggravating the cell apoptotic process. More importantly, RNA-seq analysis revealed that Bmal1 triggered the expression of hallmark genes involved in renal hepatization, a critical event accompanied by the injury. At the molecular level, Bmal1 activated the transcription of hepatization-associated genes through direct recruitment to the E-box motifs of their promoters. Our findings suggest that Bmal1, a pivotal mediator induced renal injury in response to cisplatin treatment, and the therapeutic intervention targeting Bmal1 in the kidney may be a promising strategy to minimize the toxic side-effects of cisplatin in its clinical applications.
Project description:Chronotherapy demands that patients are treated at a particular time of the day in order to maximize treatment effects and minimize side effects. Chronotherapy can be personalized by taking into account the patient's circadian rhythm as measured by a repetitive sampling of gene expression over the day. As a proof of concept, the submitted model links circadian gene expression to the diurnal toxicity profile of the cancer drug irinotecan. The model is based on MODEL2109140001; it implements a transcription-translation network model of the core clock and additional genes associated with irinotecan metabolism and links this to a model of the pharmacokinetics and -dynamics (PK-PD) of irinotecan. The submitted model refines network connections of the gene regulatory network and adds a treatment-induced increase in UGT1A1 and a transient increase in the apoptosis rate in response to treatment for the PK-PD part.
Project description:Circadian rhythmicity in renal function suggests a requirement for circadian adaptations in renal metabolism. We studied circadian changes in renal metabolic pathways using integrated transcriptomic, proteomic and metabolomic analysis performed on control mice and mice deficient in the circadian clock gene Bmal1 in the renal tubule (cKOt mice). Proteins were extracted from whole kidneys of 60 mice. Of these, 30 were conditional knockouts of Arntl (Bmal1) and 30 were of control genotype. They were housed under 12-hours light/12-hours dark cycles and were sacrificed at six different time points: zeitgeber time ZT 0, ZT 4, ZT 8, ZT 12, ZT 16, ZT 20 ( ZT 0 being the time of light on and ZT 12 the time of light off). Five replicates per genotype and time point were analysed.
Project description:The circadian clock controls the expression of nearly 50% of protein coding genes in mice, and most likely in humans as well. Therefore, disruption of the circadian clock is presumed to have serious pathological effects including cancer. However, epidemiological studies on individuals with circadian disruption because of night shift or rotating shift work have produced contradictory data not conducive to scientific consensus as to whether circadian disruption increases the incidence of breast, ovarian, prostate or colorectal cancers. Similarly, genetically engineered mice with clock disruption do not exhibit spontaneous or radiation-induced cancers at higher incidence than wild-type controls. Because many cellular functions including the cell cycle and cell division are, at least in part, controlled by the molecular clock components (CLOCK, BMAL1, CRYs, PERs), it has also been expected that appropriate timing of chemotherapy may increase the efficacy of chemotherapeutic drugs and ameliorate their side effect. However, empirical attempts at chronochemotherapy have not produced beneficial outcomes. Using mice without and with human tumor xenografts, sites of DNA damage and repair following treatment with the anticancer drug cisplatin have been mapped genome-wide at single nucleotide resolution and as a function of circadian time. The data indicate that mechanism-based studies such as these may provide information necessary for devising rational chronochemotherapy regimens.
Project description:In mammals, circadian clocks are strictly suppressed during early embryonic stages as well as pluripotent stem cells, by the lack of CLOCK/BMAL1 mediated circadian feedback loops. During ontogenesis, the innate circadian clocks emerge gradually at a late developmental stage, then, with which the circadian temporal order is invested in each cell level throughout a body. Meanwhile, in the early developmental stage, a segmented body plan is essential for an intact developmental process and somitogenesis is controlled by another cell-autonomous oscillator, the segmentation clock, in the posterior presomitic mesoderm (PSM). In the present study, focusing upon the interaction between circadian key components and the segmentation clock, we investigated the effect of the CLOCK/BMAL1 on the segmentation clock Hes7 oscillation, revealing that the expression of functional CLOCK/BMAL1 severely interferes with the ultradian rhythm of segmentation clock in induced PSM and gastruloids. RNA sequencing analysis showed that the premature expression of CLOCK/BMAL1 affects the Hes7 transcription and its regulatory pathways. These results suggest that the suppression of CLOCK/BMAL1-mediated transcriptional regulation during the somitogenesis may be inevitable for intact mammalian development.
Project description:Circadian rhythmicity in renal function suggests rhythmic adaptations in renal metabolism. To decipher the role of the circadian clock in renal metabolism, we studied diurnal changes in renal metabolic pathways using integrated transcriptomic, proteomic, and metabolomic analysis performed on control mice and mice with inducible deletion of the circadian clock regulator Bmal1 in the renal tubule (cKOt). With this unique resource, we demonstrated that ~30% RNAs, ~20% proteins and ~20% metabolites are rhythmic in kidneys of control mice. Several key metabolic pathways including NAD+ biosynthesis, fatty acid transport, carnitine shuttle, and b-oxidation displayed impairments in kidneys of cKOt, resulting in a perturbed mitochondrial activity. Carnitine reabsorption from the primary urine was one of the most impacted processes with a ~50% reduction in plasma carnitine levels and a parallel systemic decrease in tissues carnitine content. This suggests that the circadian clock in the renal tubule controls both kidney and systemic physiology.
Project description:Glioblastomas are highly lethal cancers, containing self-renewing glioblastoma stem cells (GSCs). Here, we show that GSCs, differentiated glioblastoma cells (DGCs), and normal brain cultures all displayed robust circadian rhythms, yet GSCs alone displayed exquisite dependence on core clock transcription factors, BMAL1 and CLOCK, for optimal cell growth. Downregulation of BMAL1 or CLOCK in GSCs induced cell cycle arrest and apoptosis. Chromatin immunoprecipitation revealed BMAL1 preferentially bound at metabolic genes in GSCs, associated with differences in active chromatin regions compared to NSCs. Targeting BMAL1 or CLOCK attenuated mitochondrial metabolic function and reduced expression of the tricarboxylic acid (TCA) cycle enzymes. Small molecule agonists of two independent BMAL1::CLOCK negative regulators, the Cryptochromes and REV-ERBs, downregulated stem cell factors and reduced GSC growth. Combination of Cryptochrome and REV-ERB agonists induced synergistic anti-tumor efficacy. Collectively, GSCs coopt circadian regulators beyond canonical circadian circuitry to promote stemness maintenance and metabolism, offering novel therapeutic paradigms.
Project description:Glioblastomas are highly lethal cancers, containing self-renewing glioblastoma stem cells (GSCs). Here, we show that GSCs, differentiated glioblastoma cells (DGCs), and normal brain cultures all displayed robust circadian rhythms, yet GSCs alone displayed exquisite dependence on core clock transcription factors, BMAL1 and CLOCK, for optimal cell growth. Downregulation of BMAL1 or CLOCK in GSCs induced cell cycle arrest and apoptosis. Chromatin immunoprecipitation revealed BMAL1 preferentially bound at metabolic genes in GSCs, associated with differences in active chromatin regions compared to NSCs. Targeting BMAL1 or CLOCK attenuated mitochondrial metabolic function and reduced expression of the tricarboxylic acid (TCA) cycle enzymes. Small molecule agonists of two independent BMAL1::CLOCK negative regulators, the Cryptochromes and REV-ERBs, downregulated stem cell factors and reduced GSC growth. Combination of Cryptochrome and REV-ERB agonists induced synergistic anti-tumor efficacy. Collectively, GSCs coopt circadian regulators beyond canonical circadian circuitry to promote stemness maintenance and metabolism, offering novel therapeutic paradigms.
Project description:Cryptochromes are negative transcriptional regulators of the circadian clock in mammals. It is not clear how reducing the level of endogenous CRY1 in mammals will affect circadian rhythm and the relation of such a decrease with apoptosis. Here, we discovered a molecule (M47) that destabilizes Cryptochrome 1 (CRY1) both in vitro and in vivo. The M47 selectively enhanced the degradation rate of CRY1 by increasing its ubiquitination and resulted in increasing the circadian period length of U2OS Bmal1-dLuc cells. In addition, subcellular fractionation studies from mice liver indicated that M47 increased degradation of the CRY1 in the nucleus. Furthermore, M47-mediated CRY1 reduction enhanced cisplatin-induced apoptosis in Ras-transformed p53 null fibroblast cells. Systemic repetitive administration of M47 increased the median lifespan of p53-/- mice by ~25%. Collectively our data suggest that M47 is a very promising molecule to treat forms of cancer depending on the p53 mutation.
Project description:The mammalian circadian clock is a molecular oscillator composed of a feedback loop that involves transcriptional activators CLOCK and BMAL1, and repressors Cryptochrome (CRY) and Period (PER). Here we show that a direct CLOCK-BMAL1 target gene, Gm129, is a novel regulator of the feedback loop. ChIP analysis revealed that the CLOCK:BMAL1:CRY1 complex strongly occupies the promoter region of Gm129. Both mRNA and protein levels of GM129 exhibit high amplitude circadian oscillations in mouse liver, and Gm129 gene encodes a nuclear-localized protein that directly interacts with BMAL1 and represses CLOCK:BMAL1 activity. In vitro and in vivo protein-DNA interaction results demonstrate that, like CRY1, GM129 functions as a repressor by binding to the CLOCK:BMAL1 complex on DNA. Although Gm129-/- or Cry1-/- Gm129-/- mice retain a robust circadian rhythm, the peaks of Nr1d1 and Dbp mRNAs in liver exhibit significant phase delay compared to control. Our results suggest that, in addition to CRYs and PERs, GM129 protein contributes to the transcriptional feedback loop by modulating CLOCK:BMAL1 activity as a transcriptional repressor. Examination of 3 transcriptional regulators in mouse liver