CLOCK and BMAL1 stabilize and activate RHOA to promote F-actin formation in cancer cells

Traumatic brain injury-induced disruption of the circadian clock

Disturbances in the circadian rhythm have been reported in patients following traumatic brain injury (TBI). However, the rhythmic expression of circadian genes in peripheral blood leukocytes (PBL) following TBI has not yet been studied. The messenger ribonucleic acid (mRNA) expression of period 1 (Per1), Per2, Per3, cryptochrome 1 (Cry1), Cry2, brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (Bmal1), and circadian locomotor output cycles kaput (Clock) was quantified in PBLs from sham-operated rats and rats with acute subdural hematoma (ASDH) over a 48-h period. The rectal temperature of the animals was measured every 4 h over 2 days. The mesor, rhythm, amplitude, and acrophase were estimated using cosinor analysis. Cosinor analysis revealed that Per2, Cry1, and Bmal1 mRNAs were rhythmically expressed in the PBLs of sham-operated rats. In contrast, fluctuations in rhythmic expression were not observed following ASDH. The rectal temperature of sham-operated rats also exhibited rhythmicity. ASDH rats had a disrupted rectal temperature rhythm, a diminished amplitude, and an acrophase shift. TBI with ASDH results in dysregulated expression of some circadian genes and changes in body temperature rhythm. Further research is required to understand the pathophysiology of altered circadian networks following TBI. KEY MESSAGES: First to investigate the mRNA expression of circadian genes in PBLs of ASDH rats. ASDH rats had disrupted rhythmicity of Per2, Cry1, and Bmal1 mRNA expression. Cosinor analysis showed that ASDH rats had a disrupted rectal temperature rhythm.

Scinderin promotes glioma cell migration and invasion via remodeling actin cytoskeleton

BACKGROUND

Glioma is one of the most common intracranial tumors, characterized by invasive growth and poor prognosis. Actin cytoskeletal rearrangement is an essential event of tumor cell migration. The actin dynamics-related protein scinderin (SCIN) has been reported to be closely related to tumor cell migration and invasion in several cancers.

AIM

To investigate the role and mechanism of SCIN in glioma.

METHODS

The expression and clinical significance of SCIN in glioma were analyzed based on public databases. SCIN expression was examined using real-time quantitative polymerase chain reaction and Western blotting. Gene silencing was performed using short hairpin RNA transfection. Cell viability, migration, and invasion were assessed using cell counting kit 8 assay, wound healing, and Matrigel invasion assays, respectively. F-actin cytoskeleton organization was assessed using F-actin staining.

RESULTS

SCIN expression was significantly elevated in glioma, and high levels of SCIN were associated with advanced tumor grade and wild-type isocitrate dehydrogenase. Furthermore, SCIN-deficient cells exhibited decreased proliferation, migration, and invasion in U87 and U251 cells. Moreover, knockdown of SCIN inhibited the RhoA/focal adhesion kinase (FAK) signaling to promote F-actin depolymerization in U87 and U251 cells.

CONCLUSION

SCIN modulates the actin cytoskeleton via activating RhoA/FAK signaling, thereby promoting the migration and invasion of glioma cells. This study identified the cancer-promoting effect of SCIN and provided a potential therapeutic target for the treatment of glioma.

Circadian clock and lipid metabolism disorders: a potential therapeutic strategy for cancer

Recent research has emphasized the interaction between the circadian clock and lipid metabolism, particularly in relation to tumors. This review aims to explore how the circadian clock regulates lipid metabolism and its impact on carcinogenesis. Specifically, targeting key enzymes involved in fatty acid synthesis (SREBP, ACLY, ACC, FASN, and SCD) has been identified as a potential strategy for cancer therapy. By disrupting these enzymes, it may be possible to inhibit tumor growth by interfering with lipid metabolism. Transcription factors, like SREBP play a significant role in regulating fatty acid synthesis which is influenced by circadian clock genes such as BMAL1, REV-ERB and DEC. This suggests a strong connection between fatty acid synthesis and the circadian clock. Therefore, successful combination therapy should target fatty acid synthesis in addition to considering the timing and duration of drug use. Ultimately, personalized chronotherapy can enhance drug efficacy in cancer treatment and achieve treatment goals.

CLOCK inhibits the proliferation of porcine ovarian granulosa cells by targeting ASB9

BACKGROUND

Clock circadian regulator (CLOCK) is a core factor of the mammalian biological clock system in regulating female fertility and ovarian physiology. However, CLOCK's specific function and molecular mechanism in porcine granulosa cells (GCs) remain unclear. In this study, we focused on CLOCK's effects on GC proliferation.

RESULTS

CLOCK significantly inhibited cell proliferation in porcine GCs. CLOCK decreased the expression of cell cycle-related genes, including CCNB1, CCNE1, and CDK4 at the mRNA and protein levels. CDKN1A levels were upregulated by CLOCK. ASB9 is a newly-identified target of CLOCK that inhibits GC proliferation; CLOCK binds to the E-box element in the ASB9 promoter.

CONCLUSIONS

These findings suggest that CLOCK inhibits the proliferation of porcine ovarian GCs by increasing ASB9 level.

BMAL1/p53 mediating bronchial epithelial cell autophagy contributes to PM2.5-aggravated asthma

BACKGROUND

Fine particulate matter (PM2.5) is associated with increased incidence and severity of asthma. PM2.5 exposure disrupts airway epithelial cells, which elicits and sustains PM2.5-induced airway inflammation and remodeling. However, the mechanisms underlying development and exacerbation of PM2.5-induced asthma were still poorly understood. The aryl hydrocarbon receptor nuclear translocator-like protein 1 (BMAL1) is a major circadian clock transcriptional activator that is also extensively expressed in peripheral tissues and plays a crucial role in organ and tissue metabolism.

RESULTS

In this study, we found PM2.5 aggravated airway remodeling in mouse chronic asthma, and exacerbated asthma manifestation in mouse acute asthma. Next, low BMAL1 expression was found to be crucial for airway remodeling in PM2.5-challenged asthmatic mice. Subsequently, we confirmed that BMAL1 could bind and promote ubiquitination of p53, which can regulate p53 degradation and block its increase under normal conditions. However, PM2.5-induced BMAL1 inhibition resulted in up-regulation of p53 protein in bronchial epithelial cells, then increased-p53 promoted autophagy. Autophagy in bronchial epithelial cells mediated collagen-I synthesis as well as airway remodeling in asthma.

CONCLUSIONS

Taken together, our results suggest that BMAL1/p53-mediated bronchial epithelial cell autophagy contributes to PM2.5-aggravated asthma. This study highlights the functional importance of BMAL1-dependent p53 regulation during asthma, and provides a novel mechanistic insight into the therapeutic mechanisms of BMAL1. Video Abstract.

Major roles of the circadian clock in cancer

Circadian rhythms are natural rhythms that widely exist in all creatures, and regulate the processes and physiological functions of various biochemical reactions. The circadian clock is critical for cancer occurrence and progression. Its function is regulated by metabolic activities, and the expression and transcription of various genes. This review summarizes the composition of the circadian clock; the biological basis for its function; its relationship with, and mechanisms in, cancer; its various functions in different cancers; the effects of anti-tumor treatment; and potential therapeutic targets. Research in this area is expected to advance understanding of circadian locomotor output cycles kaput (CLOCK) and brain and muscle ARNT-like protein 1 (BMAL1) in tumor diseases, and contribute to the development of new anti-tumor treatment strategies.

Effect of a hyaluronic acid-based mesotherapeutic injectable on the gene expression of CLOCK and Klotho proteins, and environmentally induced oxidative stress in human skin cells

OBJECTIVE

Normal circadian rhythms are essential to the repair mechanisms of oxidative stress implicated in skin aging. Given reports that hyaluronic acid (HA) homeostasis exhibits a different profile in chronological skin aging, as compared to environmental or extrinsic aging, an improved understanding of the way HA interacts with its surroundings, and the impact of HA injectables in replacing lost HA and encouraging rejuvenation, is of key benefit to skin aging treatments. The objectives of these current studies were twofold. Firstly, to demonstrate the in vitro effects of two lightweight hyaluronic-based injectables on the expression of CLOCK protein in human skin fibroblasts, and their effects on Klotho protein expression as a marker for circadian rhythms in a combined human keratinocyte and Merkel cell model. Secondly, to ascertain whether these findings could be correlated with in vitro effects on various environmental oxidative stress aging markers (blue light, UVA/UVB, Urban Dust, and IR exposures).

METHODS

Oxidative stress studies were aimed to highlight possible protective effects through different challenge conditions in two models, ex vivo human skin explants and in vitro monolayer cultures of normal human dermal fibroblasts (NHDF). The protective effects of the test products were evaluated against an increase of cyclobutene pyrimidine dimers (CPDs) abundance within epidermal section of ex vivo skin explants after UVA/UVB radiation; effects of blue light on gene expression from NHDFs fibroblasts; effects of pollutants (Urban dust, UbD) on gene expression in NHDFs fibroblasts; and an increase of reactive oxygen species (ROS) production by NHDFs fibroblasts after infrared-A radiation. Gene expression was assayed and analyzed utilizing microfluidic TaqMan qPCR arrays. CLOCK expression was measured in young and senescing NHDFs by immunostaining, and Klotho and melatonin expression by immunostaining in Merkel cell-enriched normal adult human epidermal cell cultures.

RESULTS

In an aging culture of mixed keratinocyte and Merkel skin cells, activation of Klotho expression was induced by the application of both HA test products. Moreover, the HA products increase Klotho protein expression in both Merkel cells and keratinocytes. The observed positive effect of the tested products on melatonin receptors 1A and 1B expression in aging Merkel cell culture and keratinocytes is also interesting. HA-Y (developed for patients 25+ years old) stimulated melatonin receptors type 1B expression in aging cell cultures more strongly than HA-S (developed for patients 35-65 years old). In age (stressed) cells, a lower expression of Klotho protein and melatonin receptors 1A and 1B is apparent. The addition of HA-Y and HA-S stimulates their expression thus providing a "protective" effect. The blue light irradiation at 40 J/cm² performed in NHDF fibroblast cultures led to a modification of the expression of several genes, all involved in mechanisms known to be modulated in case of solar radiation stress.

CONCLUSIONS

Although these are preliminary findings, they are the first we know of that demonstrate HA facial injectables having a benefit and possibilities beyond the "physical filling" of the skin. As regards the beneficial effects against blue light-induced oxidative stress, and a return to cellular homeostasis, there is a need to conduct further and more precise investigations into HA-S. Furthermore, the benefit of these HA injectables (Novacutan®) in the modulation of oxidative stressed circadian rhythms widens their potential benefit.

Gene Signatures Associated with Temporal Rhythm as Diagnostic Markers of Major Depressive Disorder and Their Role in Immune Infiltration

Temporal rhythm (TR) is involved in the pathophysiology and treatment response of major depressive disorder (MDD). However, there have been few systematic studies on the relationship between TR-related genes (TRRGs) and MDD. This study aimed to develop a novel prognostic gene signature based on the TRRGs in MDD. We extracted expression information from the Gene Expression Omnibus (GEO) database and retrieved TRRGs from GeneCards. Expressed genes (TRRDEGs) were identified differentially, and their potential biological functions were analyzed. Subsequently, association analysis and receiver operating characteristic (ROC) curves were adopted for the TRRDEGs. Further, upstream transcription factor (TF)/miRNA and potential drugs targeting MDD were predicted. Finally, the CIBERSORT algorithm was used to estimate the proportions of immune cell subsets. We identified six TRRDEGs that were primarily involved in malaria, cardiac muscle contraction, and the calcium-signaling pathway. Four genes (CHGA, CCDC47, ACKR1, and FKBP11) with an AUC of >0.70 were considered TRRDEGs hub genes for ROC curve analysis. Outcomes showed that there were a higher ratio of T cells, gamma-delta T cells, monocytes, and neutrophils, and lower degrees of CD8+ T cells, and memory resting CD4+ T cells in TRRDEGs. Four new TRRDEG signatures with excellent diagnostic performance and a relationship with the immune microenvironment were identified.

Cell adhesion molecule BVES functions as a suppressor of tumor cells extrusion in hepatocellular carcinoma metastasis

Background

Tumor cells detachment from primary lesions is an early event for hepatocellular carcinoma (HCC) metastasis, in which cell adhesion molecules play an important role. The role of mechanical crowding has attracted increasing attention. Previous studies have found that overcrowding can induce live cells extrusion to maintain epithelial cell homeostasis, and normally, live extruded cells eventually die through a process termed anoikis, suggesting the potential of tumor cells resistant to anoikis might initiate metastasis from primary tumors by cell extrusion. We have demonstrated transmembrane adhesion molecule blood vessel epicardial substance (BVES) suppression as an early event in HCC metastasis. However, whether its suppression is involved in HCC cell extrusion, especially in HCC metastasis, remains unknown. This study aims to investigate the role of BVES in tumor cells extrusion in HCC metastasis, as well as the underlying mechanisms.

Methods

Cells extrusion was observed by silicone chamber, petri dish inversion, and three-dimensional cell culture model. Polymerase chain reaction, western blotting, immunohistochemistry, immunofluorescence, co-immunoprecipitation, and RhoA activity assays were used to explore the underlying mechanisms of cell extrusion regulated by BVES. An orthotopic xenograft model was established to investigate the effects of BVES and cell extrusion in HCC metastasis in vivo.

Results

Tumor cell extrusion was observed in HCC cells and tissues. BVES expression was decreased both in HCC and extruded tumor cells. BVES overexpression led to the decrease in HCC cells extrusion in vitro and in vivo. Moreover, our data showed that BVES co-localized with ZO-1 and GEFT, regulating ZO-1 expression and localization, and GEFT distribution, thus modulating RhoA activity.

Conclusion

The present study revealed that BVES downregulation in HCC enhanced tumor cells extrusion, thus promoting HCC metastasis, which contributed to a more comprehensive understanding of tumor metastasis, and provided clues for developing novel HCC therapy strategies.

Circuit formation in the adult brain

Neurons in the mammalian central nervous system display an enormous capacity for circuit formation during development but not later in life. In principle, new circuits could be also formed in adult brain, but the absence of the developmental milieu and the presence of growth inhibition and hundreds of working circuits are generally viewed as unsupportive for such a process. Here, we bring together evidence from different areas of neuroscience—such as neurological disorders, adult‐brain neurogenesis, innate behaviours, cell grafting, and in vivo cell reprogramming—which demonstrates robust circuit formation in adult brain. In some cases, adult‐brain rewiring is ongoing and required for certain types of behaviour and memory, while other cases show significant promise for brain repair in disease models. Together, these examples highlight that the adult brain has higher capacity for structural plasticity than previously recognized. Understanding the underlying mechanisms behind this retained plasticity has the potential to advance basic knowledge regarding the molecular organization of synaptic circuits and could herald a new era of neural circuit engineering for therapeutic repair.

Ultrasound-responsive nutlin-loaded nanoparticles for combined chemotherapy and piezoelectric treatment of glioblastoma cells

Glioblastoma multiforme (GBM), also known as grade IV astrocytoma, represents the most aggressive primary brain tumor. The complex genetic heterogeneity, the acquired drug resistance, and the presence of the blood-brain barrier (BBB) limit the efficacy of the current therapies, with effectiveness demonstrated only in a small subset of patients. To overcome these issues, here we propose an anticancer approach based on ultrasound-responsive drug-loaded organic piezoelectric nanoparticles. This anticancer nanoplatform consists of nutlin-3a-loaded ApoE-functionalized P(VDF-TrFE) nanoparticles, that can be remotely activated with ultrasound-based mechanical stimulations to induce drug release and to locally deliver anticancer electric cues. The combination of chemotherapy treatment with chronic piezoelectric stimulation resulted in activation of cell apoptosis and anti-proliferation pathways, induction of cell necrosis, inhibition of cancer migration, and reduction of cell invasiveness in drug-resistant GBM cells. Obtained results pave the way for the use of innovative multifunctional nanomaterials in less invasive and more focused anticancer treatments, able to reduce drug resistance in GBM.

Advances in the Study of Circadian Genes in Non-Small Cell Lung Cancer

Circadian genes regulate several physiological functions such as circadian rhythm and metabolism and participate in the cytogenesis and progression of various malignancies. The abnormal expression of these genes in non-small cell lung cancer (NSCLC) is closely related to the clinicopathological features of NSCLC and may promote or inhibit NSCLC progression. Circadian rhythm disorders and clock gene abnormalities may increase the risk of lung cancer in some populations. We collected 15 circadian genes in NSCLC, namely PER1, PER2, PER3, TIMELESS, Cry1, Cry2, CLOCK, BMAL1/ARNTL-1, ARNTL2, NPAS2, NR1D1(REV-ERB), DEC1, DEC2, RORα, and RORγ, and determined their relationships with the clinicopathological features of patients and the potential mechanisms promoting or inhibiting NSCLC progression. We also summarized the studies on circadian rhythm disorders and circadian genes associated with lung cancer risk. The present study aimed to provide theoretical support for the future exploration of new therapeutic targets and for the primary prevention of NSCLC from the perspective of circadian genes. Interpretation of circadian rhythms in lung cancer could guide further lung cancer mechanism research and drug development that could lead to more effective treatments and improve patient outcomes.

Sanggenon C Ameliorates Cerebral Ischemia-Reperfusion Injury by Inhibiting Inflammation and Oxidative Stress through Regulating RhoA-ROCK Signaling

Sanggenon C (SC), a natural flavonoid extracted from Cortex Mori (Sang Bai Pi), is reported to possess anti-inflammatory and antioxidant properties in hypoxia. The present study aimed to investigate the therapeutic potential and the underlying mechanisms of SC in cerebral ischemia-reperfusion (I/R) injury. A rat model of reversible middle cerebral artery occlusion (MCAO) was used to induce cerebral I/R injury in vivo, and SC was administrated intragastrically. Brain injuries were evaluated using Bederson scores, brain water content, and 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. The levels of inflammatory factors and oxidative stress were examined using corresponding kits. Cell apoptosis was evaluated by TUNEL. Moreover, the expressions of apoptosis-related and RhoA/ROCK signaling-related proteins were detected through western blotting. In vitro, RhoA was overexpressed in oxygen-glucose deprivation and reperfusion (OGD/R)-induced PC12 cells to confirm the contribution of RhoA-ROCK signaling inhibition by SC to the neuroprotective effects post OGD/R. Pretreatment with SC significantly ameliorated the neurologic impairment, brain edema, and cerebral infarction post MCAO-reperfusion, associated with reductions of inflammation, oxidative stress, and cell apoptosis in the brain. Furthermore, SC remarkably downregulated the expression of RhoA/ROCK signaling-related proteins post MCAO-reperfusion in rats, while overexpression of RhoA reversed the beneficial effects of SC on protecting against inflammation and oxidative stress in OGD/R-induced PC12 cells. Taken together, these findings demonstrated that SC exerts neuroprotective effects after cerebral I/R injury via inhibiting inflammation and oxidative stress through regulating RhoA-ROCK signaling, suggesting a therapeutic potential of SC in cerebral I/R injury.

Translating around the clock: Multi-level regulation of post-transcriptional processes by the circadian clock

The endogenous circadian clock functions to maintain optimal physiological health through the tissue specific coordination of gene expression and synchronization between tissues of metabolic processes throughout the 24 hour day. Individuals face numerous challenges to circadian function on a daily basis resulting in significant incidences of circadian disorders in the United States and worldwide. Dysfunction of the circadian clock has been implicated in numerous diseases including cancer, diabetes, obesity, cardiovascular and hepatic abnormalities, mood disorders and neurodegenerative diseases. The circadian clock regulates molecular, metabolic and physiological processes through rhythmic gene expression via transcriptional and post-transcriptional processes. Mounting evidence indicates that post-transcriptional regulation by the circadian clock plays a crucial role in maintaining tissue specific biological rhythms. Circadian regulation affecting RNA stability and localization through RNA processing, mRNA degradation, and RNA availability for translation can result in rhythmic protein synthesis, even when the mRNA transcripts themselves do not exhibit rhythms in abundance. The circadian clock also targets the initiation and elongation steps of translation through multiple pathways. In this review, the influence of the circadian clock across the levels of post-transcriptional, translation, and post-translational modifications are examined using examples from humans to cyanobacteria demonstrating the phylogenetic conservation of circadian regulation. Lastly, we briefly discuss chronotherapies and pharmacological treatments that target circadian function. Understanding the complexity and levels through which the circadian clock regulates molecular and physiological processes is important for future advancement of therapeutic outcomes.

Time to fight: targeting the circadian clock molecular machinery in cancer therapy

The circadian clock regulates a wide range of molecular pathways and biological processes. The expression of clock genes is often altered in cancer, fostering tumor initiation and progression. Inhibition and activation of core circadian clock genes, as well as treatments that restore circadian rhythmicity, have been successful in counteracting tumor growth in different experimental models. Here, we provide an up-to-date overview of studies that show the therapeutic effects of targeting the clock molecular machinery in cancer, both genetically and pharmacologically. We also highlight future areas for progress that offer a promising path towards innovative anticancer strategies. Substantial limitations in the current understanding of the complex interplay between the circadian clock and cancer in vivo need to be addressed in order to allow clock-targeting therapies in cancer.

Hesperidin modulates the rhythmic proteomic profiling in Drosophila melanogaster under oxidative stress

The circadian clock regulates vital aspects of physiology including protein synthesis and oxidative stress response. In this investigation, we performed a proteome-wide scrutiny of rhythmic protein accrual in Drosophila melanogaster on exposure to rotenone, rotenone + hesperidin and hesperidin in D. melanogaster. Total protein from fly samples collected at 6 h intervals over the 24 h period was subjected to two-dimensional gel electrophoresis and mass spectrometry. Bioinformatics tool, Protein ANalysis THrough Evolutionary Relationships classification system was used to the determine the biological processes of the proteins of altered abundance. Conspicuous variations in the proteome (151 proteins) of the flies exposed to oxidative stress (by rotenone treatment) and after alleviating oxidative stress (by hesperidin treatment) were observed during the 24 h cycle. Significantly altered levels of abundance of a wide variety of proteins under oxidative stress (rotenone treatment) and under alleviation of oxidative stress (rotenone + hesperidin treatment) and hesperidin (alone) treatment were observed. These proteins are involved in metabolism, muscle activity, heat shock response, redox homeostasis, protein synthesis/folding/degradation, development, ion-channel/cellular transport, and gustatory and olfactory function of the flies. Our data indicates that numerous cellular processes are involved in the temporal regulation of proteins and widespread modulations happen under rotenone treatment and, action of hesperidin could also be seen on these categories of proteins.

Upregulated neuregulin-1 protects against optic nerve injury by regulating the RhoA/cofilin/F-actin axis

OBJECTIVE

In recent years, the roles of Neuregulin-1 (NRG-1) in optic nerve injury and retinal cells have been investigated. However, the molecular mechanism by which NRG-1 affects optic nerve injury remains elusive and merits deeper exploration. Hence, this study examined the specific function of NRG-1 in the RhoA/cofilin/F-actin axis in optic nerve injury.

METHODS

Retinal cells were isolated and identified for subsequent experimental uses. Reverse transcription quantitative polymerase chain reaction and Western blot assays were performed to measure NRG-1 expression in retinal cells which were cultured under elevated pressure. TUNEL staining was used to detect the cell apoptosis rate, and Western blot assay was performed to detect the expression of related genes. The axon growth was examined by immunofluorescence. The effects of NRG-1 on RhoA activity, cofilin phosphorylation, and F-actin were detected by Western blot assay. In other studies we established a rat model of acute optic nerve injury, and tested for beneficial effects of NRG-1 in vivo.

RESULTS

High expression of NRG-1 was evident in the retinal tissues of rats with optic nerve injury. Overexpressing NRG-1 successfully inhibited RhoA activity and the phosphorylation of cofilin and promoted F-actin expression. In cell experiments, overexpressed NRG-1 suppressed the apoptosis of retinal cells and promoted axon growth through the RhoA/cofilin/F-actin axis. In animal experiments, overexpressed NRG-1 relieved retinal injury.

CONCLUSION

Our results strongly suggest that overexpressed NRG-1 is highly effective in the protection of normal optic nerve function by suppressing RhoA activity and the phosphorylation of cofilin and rescuing F-actin function.

ROCK (RhoA/Rho Kinase) in Cardiovascular-Renal Pathophysiology: A Review of New Advancements

Rho-associated, coiled-coil containing kinases (ROCK) were originally identified as effectors of the RhoA small GTPase and found to belong to the AGC family of serine/threonine kinases. They were shown to be downstream effectors of RhoA and RhoC activation. They signal via phosphorylation of proteins such as MYPT-1, thereby regulating many key cellular functions including proliferation, motility and viability and the RhoA/ROCK signaling has been shown to be deeply involved in arterial hypertension, cardiovascular–renal remodeling, hypertensive nephropathy and posttransplant hypertension. Given the deep involvement of ROCK in cardiovascular–renal pathophysiology and the interaction of ROCK signaling with other signaling pathways, the reports of trials on the clinical beneficial effects of ROCK’s pharmacologic targeting are growing. In this current review, we provide a brief survey of the current understanding of ROCK-signaling pathways, also integrating with the more novel data that overall support a relevant role of ROCK for the cardiovascular–renal physiology and pathophysiology.

The role of circadian clock gene BMAL1 in vascular proliferation

Brain and muscle Arnt-like protein-1 (BMAL1), a component of the molecular clock, is implicated in the development of cardiovascular diseases, including atherosclerosis and abdominal aortic aneurysms. However, the role of BMAL1 in vascular proliferation associated with vascular remodeling is unknown. In the present study, we investigated the mechanisms underlying BMAL1 expression in vascular smooth muscle cells (VSMCs) and the role of BMAL1 in VSMC proliferation. BMAL1 expression significantly increased in injured carotid arteries in C57BL/6J mice and platelet-derived growth factor (PDGF)-BB-stimulated VSMC cultures. Pretreatment with diphenyleneiodonium (an NADPH oxidase inhibitor) and U0126 or PD98059 (MEK Inhibitors) inhibited PDGF-BB-induced BMAL1 expression in a dose-dependent manner in VSMCs. In addition, the knockdown of early growth factor protein-1 (Egr-1) significantly inhibited PDGF-BB-induced BMAL1 mRNA or protein expression in VSMCs, and the knockdown of BMAL1 significantly decreased PDGF-BB-induced cell proliferation and extracellular signal-regulated kinase (ERK) phosphorylation but not Akt phosphorylation in VSMCs. The results demonstrate that PDGF-BB up-regulates BMAL1 expression through reactive oxygen species/ERK/Egr-1 pathways and that BMAL1 is involved in PDGF-BB-induced cell proliferation partially through ERK in VSMCs. Thus, BMAL1 may be a novel therapeutic target for the treatment of atherosclerosis including vascular remodeling.

Aging Disrupts the Circadian Patterns of Protein Expression in the Murine Hippocampus

Aging is associated with cognitive decline and dysregulation of the circadian system, which modulates hippocampal-dependent memory as well as biological processes underlying hippocampal function. While circadian dysfunction and memory impairment are common features of aging and several neurodegenerative brain disorders, how aging impacts the circadian expression patterns of proteins involved in processes that underlie hippocampal-dependent memory is not well understood. In this study, we profiled the hippocampal proteomes of young and middle-aged mice across two circadian cycles using quantitative mass spectrometry in order to explore aging-associated changes in the temporal orchestration of biological pathways. Of the ∼1,420 proteins that were accurately quantified, 15% (214 proteins) displayed circadian rhythms in abundance in the hippocampus of young mice, while only 1.6% (23 proteins) were rhythmic in middle-aged mice. Remarkably, aging disrupted the circadian regulation of proteins involved in cellular functions critical for hippocampal function and memory, including dozens of proteins participating in pathways of energy metabolism, neurotransmission, and synaptic plasticity. These included processes such as glycolysis, the tricarboxylic acid cycle, synaptic vesicle cycling, long-term potentiation, and cytoskeletal organization. Moreover, aging altered the daily expression rhythms of proteins implicated in hallmarks of aging and the pathogenesis of several age-related neurodegenerative brain disorders affecting the hippocampus. Notably, we identified age-related alterations in the rhythmicity of proteins involved in mitochondrial dysfunction and loss of proteostasis, as well as proteins involved in the pathogenesis of disorders such as Alzheimer’s disease and Parkinson’s disease. These insights into aging-induced changes in the hippocampal proteome provide a framework for understanding how the age-dependent circadian decline may contribute to cognitive impairment and the development of neurodegenerative diseases during aging.

Bmal1-deficiency affects glial synaptic coverage of the hippocampal mossy fiber synapse and the actin cytoskeleton in astrocytes

Bmal1 is an essential component of the molecular clockwork, which drives circadian rhythms in cell function. In Bmal1-deficient (Bmal1-/-) mice, chronodisruption is associated with cognitive deficits and progressive brain pathology including astrocytosis indicated by increased expression of glial fibrillary acidic protein (GFAP). However, relatively little is known about the impact of Bmal1-deficiency on astrocyte morphology prior to astrocytosis. Therefore, in this study we analysed astrocyte morphology in young (6-8 weeks old) adult Bmal1-/- mice. At this age, overall GFAP immunoreactivity was not increased in Bmal1-deficient mice. At the ultrastructural level, we found a decrease in the volume fraction of the fine astrocytic processes that cover the hippocampal mossy fiber synapse, suggesting an impairment of perisynaptic processes and their contribution to neurotransmission. For further analyses of actin cytoskeleton, which is essential for distal process formation, we used cultured Bmal1-/- astrocytes. Bmal1-/- astrocytes showed an impaired formation of actin stress fibers. Moreover, Bmal1-/- astrocytes showed reduced levels of the actin-binding protein cortactin (CTTN). Cttn promoter region contains an E-Box like element and chromatin immunoprecipitation revealed that Cttn is a potential Bmal1 target gene. In addition, the level of GTP-bound (active) Rho-GTPase (Rho-GTP) was reduced in Bmal1-/- astrocytes. In summary, our data demonstrate that Bmal1-deficiency affects morphology of the fine astrocyte processes prior to strong upregulation of GFAP, presumably because of impaired Cttn expression and reduced Rho-GTP activation. These morphological changes might result in altered synaptic function and, thereby, relate to cognitive deficits in chronodisruption.

Regulation of circadian rhythms by NEAT1 mediated TMAO-induced endothelial proliferation: A protective role of asparagus extract

Trimethylamine N-oxide (TMAO) promotes atherosclerosis in association with the functions of endothelial cells. Clock and Bmal1, as two main components of molecular circadian clock, play important regulatory roles during progression of atherogenesis. However, whether Clock and Bmal1 are involved in the regulation of endothelial proliferation disturbed by TMAO are unclear. We observed that cell proliferation of human umbilical vein endothelial cells (HUVECs) was inhibited after exposed to TMAO for 24 h. Besides, TMAO caused increased expression of lncRNA-NEAT1, Clock and Bmal1, and inhibited MAPK pathways. While MAPK pathways were blocked, the expression of Clock and Bmal1 was elevated. NEAT1 showed a circadian rhythmic expression in HUVECs, and its overexpression reduced cell proliferation. Knockdown or overexpression of NEAT1 might decrease or increase the expression of Clock and Bmal1 respectively, while raised or suppressed the expression of MAPK pathways correspondingly. Asparagus extract (AE) was found to improve the TMAO-reduced HUVECs proliferation. Moreover, it ameliorated the disorders of NEAT1, Clock, Bmal1, and MAPK signaling pathways induced by TMAO. Therefore, our findings indicated that NEAT1 regulating Clock-Bmal1 via MAPK pathways was involved in TMAO-repressed HUVECs proliferation, and AE improved endothelial proliferation by TMAO, proposing a novel mechanism for cardiovascular disease prevention.

Circadian protein BMAL1 promotes breast cancer cell invasion and metastasis by up-regulating matrix metalloproteinase9 expression

Background

Metastasis is an important factor in the poor prognosis of breast cancer. As an important core clock protein, brain and muscle arnt-like 1 (BMAL1) is closely related to tumorigenesis. However, the molecular mechanisms that mediate the role of BMAL1 in invasion and metastasis remain largely unknown. In this study, we investigated the BMAL1 may take a crucial effect in the progression of breast cancer cells.

Methods

BMAL1 and MMP9 expression was measured in breast cell lines. Transwell and scratch wound-healing assays were used to detect the movement of cells and MTT assays and clonal formation assays were used to assess cells’ proliferation. The effects of BMAL1 on the MMP9/NF-κB pathway were examined by western blotting, co-immunoprecipitation and mammalian two-hybrid.

Results

In our study, it showed that cell migration and invasion were significantly enhanced when overexpressed BMAL1. Functionally, overexpression BMAL1 significantly increased the mRNA and protein level of matrix metalloproteinase9 (MMP9) and improved the activity of MMP9. Moreover, BMAL1 activated the NF-κB signaling pathway by increasing the phosphorylation of IκB and promoted human MMP9 promoter activity by interacting with NF-kB p65, leading to increased expression of MMP9. When overexpressed BMAL1, CBP (CREB binding protein) was recruited to enhance the activity of p65 and further activate the NF-κB signaling pathway to regulate the expression of its downstream target genes, including MMP9, TNFα, uPA and IL8, and then promote the invasion and metastasis of breast cancer cells.

Conclusions

This study confirmed a new mechanism by which BMAL1 up-regulated MMP9 expression to increase breast cancer metastasis, to provide research support for the prevention and treatment of breast cancer.

Sirt1 inhibits HG-induced endothelial injury: Role of Mff-based mitochondrial fission and F‑actin homeostasis-mediated cellular migration

Although sirtuin 1 (Sirt1) has been found to be involved in diabetic vasculopathy and high glucose (HG)-mediated endothelial injury, the underlying mechanisms remain to be fully elucidated. The aim of the present study was to investigate the role of Sirt1 in HG-induced endothelial injury and its potential mechanism. In the present study, it was demonstrated that HG triggers the downregulation of Sirt1 by activating microRNA-195 in human umbilical vein endothelial cells (HUVECs), as determined by western blot analysis in vivo and in vitro. Furthermore, a lower expression of Sirt1 was correlated with glucose metabolic abnormalities, aortic endothelial dysfunction and endothelial apoptosis as evidenced by western blot analysis and ELISA in mice. By contrast, the loss of Sirt1 evoked mitochondrial fission factor (Mff)-mediated mitochondrial fission through the c-Jun N-terminal kinase (JNK) pathway, which contributes to the apoptosis of HUVECs. In addition, Sirt1 deficiency downregulated the migration of HUVECs through F-actin dyshomeostasis. Collectively, the results identify Sirt1 as a protective factor, which inhibits the JNK/Mff/mitochondrial fission pathway and sustains F-actin homeostasis, and has potential implications for novel approaches to diabetic vasculopathy.