Loss of the centrosomal protein Cenpj leads to dysfunction of the hypothalamus and obesity in mice

Cenpj is a centrosomal protein located at the centrosomes and the base of cilia,it plays essential roles in regulating neurogenesis and cerebral cortex development.Although centrosomal and cilium dysfunction are one of the causes of obesity,insulin resistance,and type 2 diabetes,the role that Cenpj plays in the regulation of body weight remains unclear.Here,we deleted Cenpj by crossing Cenpjflox/flox mice with Nkx2.1-Cre mice.Loss of the centrosomal protein Cenpj in Nkx2.1-expressing cells causes morbid obesity in mice at approximately 4 months of age with expended brain ventricles but no change of brain size.We found that hypothalamic cells exhibited reduced proliferation and increased apoptosis upon Cenpj depletion at the embryonic stages,resulting in a dramatic decrease in the number of Proopiomelanocortin(POMC)neurons and electrophysiological dysfunction of NPY neurons in the arcuate nucleus(ARC)in adults.Furthermore,depletion of Cenpj also reduced the neuronal projection from the ARC to the paraventricular nucleus(PVN),with decreased melanocortin-4 receptors(MC4R)expression in PVN neurons.The study defines the roles that Cenpj plays in regulating hypothalamus development and body weight,providing a foundation for further understanding of the pathological mechanisms of related diseases.

CNKSR2 interactome analysis indicates its association with the centrosome/microtubule system

The protein connector enhancer of kinase suppressor of Ras 2(CNKSR2),present in both the postsynaptic density and cytoplasm of neurons,is a scaffolding protein with several protein-binding domains.Variants of the CNKSR2 gene have been implicated in neurodevelopmental disorders,particularly intellectual disability,although the precise mechanism involved has not yet been fully understood.Research has demonstrated that CNKSR2 plays a role in facilitating the localization of postsynaptic density protein complexes to the membrane,thereby influencing synaptic signaling and the morphogenesis of dendritic spines.However,the function of CNKSR2 in the cytoplasm remains to be elucidated.In this study,we used immunoprecipitation and high-resolution liquid chromatography-mass spectrometry to identify the interactors of CNKSR2.Through a combination of bioinformatic analysis and cytological experiments,we found that the CNKSR2 interactors were significantly enriched in the proteome of the centrosome.We also showed that CNKSR2 interacted with the microtubule protein DYNC1H1 and with the centrosome marker CEP290.Subsequent colocalization analysis confirmed the centrosomal localization of CNKSR2.When we downregulated CNKSR2 expression in mouse neuroblastoma cells(Neuro 2A),we observed significant changes in the expression of numerous centrosomal genes.This manipulation also affected centrosome-related functions,including cell size and shape,cell proliferation,and motility.Furthermore,we found that CNKSR2 interactors were highly enriched in de novo variants associated with intellectual disability and autism spectrum disorder.Our findings establish a connection between CNKSR2 and the centrosome,and offer new insights into the underlying mechanisms of neurodevelopmental disorders.

Four centrosome-related genes to predict the prognosis and drug sensitivity of patients with colon cancer

BACKGROUND As the primary microtubule organizing center in animal cells,centrosome abnormalities are involved in human colon cancer.AIM To explore the role of centrosome-related genes(CRGs)in colon cancer.METHODS CRGs were collected from public databases.Consensus clustering analysis was performed to separate the Cancer Genome Atlas cohort.Univariate Cox and least absolute shrinkage selection operator regression analyses were performed to identify candidate prognostic CRGs and construct a centrosome-related signature(CRS)to score colon cancer patients.A nomogram was developed to evaluate the CRS risk in colon cancer patients.An integrated bioinformatics analysis was conducted to explore the correlation between the CRS and tumor immune microenvironment and response to immunotherapy,chemotherapy,and targeted therapy.Single-cell transcriptome analysis was conducted to examine the immune cell landscape of core prognostic genes.RESULTS A total of 726 CRGs were collected from public databases.A CRS was constructed,which consisted of the following four genes:TSC1,AXIN2,COPS7A,and MTUS1.Colon cancer patients with a high-risk signature had poor survival.Patients with a high-risk signature exhibited decreased levels of plasma cells and activated memory CD4+T cells.Regarding treatment response,patients with a high-risk signature were resistant to immunotherapy,chemotherapy,and targeted therapy.COPS7A expression was relatively high in endothelial cells and fibroblasts.MTUS1 expression was high in endothelial cells,fibroblasts,and malignant cells.CONCLUSION We constructed a centrosome-related prognostic signature that can accurately predict the prognosis of colon cancer patients,contributing to the development of individualized treatment for colon cancer.

The Immuno-fluorescence Quantity Analysis of α-Tubulin and γ-Tubulin Protein in Precancerous Lesion and Carcinoma of the Breast and Its Significance

OBJECTIVE To investigate the changes and values of the expression of α-tubulin and γ-tubulin in atypical ductal hyperplasia （ADH）, ductal carcinoma in situ （DCIS） and invasive ductal carcinoma （IDC） of the breast. The relationship between centrosome abnormalities and breast tumor development was further discussed. METHODS There were three groups including ADH, DCIS and IDC with 30 cases in each group. They were analyzed by immuno-fiuorescence quantity analysis. The expression levels of α-tubulin and γ-tubulin protein in these tissues were detected by flow cytometry immuno-fiuorescence analysis and compared with the results from normal tissues. Immunohistochemistry was also performed in this research. RESULTS The results showed significant differences of the average of the positive （FITC labeled） cells （P=0.000） among the four groups. The level of the IDC group was the highest, while normal breast tissue showed the lowest level. The results suggested that the expression levels of α-tubulin and γ-tubulin both increased as the grade of cellular proliferation and differentiation increased. The expressions showed significant differences among all the groups, except between the ADH and DCIS. There were no significant differences between α-tubulin and γ-tubulin expression in each group （P〈0.05）, as there was agreement in the immuno-fluorescence and immunohistochemical analysis for protein expression. CONCLUSION There is abnormal expression of centrosome tubulin as an early event in the development of breast tumor. Furthermore these aberrations may play a key role during oncogenesis and promote cellular transformation to malignancy. The immuno-fiuorescence quantitive analysis and immunohistochemistry can complement each other.

CORRELATION ANALYSIS BETWEEN STK15 GENE AND LARYNGEAL CARCINOMA

To explore the relationship between STK15 gene abnormal expression and laryngeal carcinoma. Methods: Tumor tissues and matched normal tissues were taken from 55 LSCC patients. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect STK15 expression in 110 specimens. Results: In 38 of the 55 cases (69.1%), the STK15 expression at the mRNA levels was higher than that of the paired normal tissue. The ratio of ADV (average density value) of STK15 gene to ADV of b-actin gene was 1.220.49 in the cancer tissue, and 0.990.54 in the paired normal tissue with a significant difference (t=4.539, P<0.01). Conclusion: There was obvious association between the STK15 overexpression and laryngeal carcinoma. It may serve as an alternative mechanism of activating the pathogenesis of human laryngeal squamous cell carcinoma.

The more the messier：centrosome amplification as a novel biomarker for personalized treatment of colorectal cancers

Colon cancer is currently the third most common cancer and second most fatal cancer in the United States,resulting in approximately 600,000 deaths annually.Though colorectal cancer death rates are decreasing by about 3%every year,disease outcomes could be substantially improved with more research into the drivers of colon carcinogenesis,the determinants of aggressiveness in colorectal cancer and the identification of biomarkers that could enable choice of more optimal treatments.Colon carcinogenesis is notably a slow process that can take decades.Known factors that contribute to the development of colon cancer are mutational,epigenetic and environmental,and risk factors include age,history of polyps and family history of colon cancer.Colorectal cancers exhibit heterogeneity in their features and are often characterized by the presence of chromosomal instability,microscopic satellite instability,or CpG island methylator phenotype.In this review,we propose that centrosome amplification may be a widespread occurrence in colorectal cancers and could potently influence tumor biology.Moreover,the quantitation of this cancer-specific anomaly could offer valuable prognostic information and pave the way for further customization of treatment based on the organellar profile of patients.Patient stratification models that take into account centrosomal status could thus potentially reduce adverse side effects and result in improved outcomes for colorectal cancer patients.

Genomic Instability in Cancer II: 4N-Skewed (90°) Reductive Division via Fragile Sites to Fitness Increase for Solid and Hematological Cancer Beginnings

The objective herein was to connect the ontogeny process of diplochromosomal, amitotic, 4n-skewed division-system, to cytogenetic deficiency lesions in satellite, repetitive DNAs, especially in the chromosomal fragile sites, some 100 distributed over the genome. These latter studies had shown that chemical induced replication-stress led to un-replicated lesions in these fragile sites, which from inaccurate repair processes caused genomic instability. In the chain of events of the ontogeny process to the special tetraploidy, it was proposed that primary damaged human cells could undergo replication stress from repair-process present during cell replication, a suggestion verified by X-ray damaged cells producing the unstable fragile sites (see text). The cancer-importance for therapy is recognition of cell cycle change for the 4n derivative fitness-gained, diploid progeny cells. An open question is whether RB controlling G1 to S-period is mutated at this suggested tumorigenesis initiating phase, and if so, with what consequences for therapy. The fragile site studies further showed that repair of repetitive DNAs could produce two types of genomic changes: single gene mutations and CNVs, which were here shown to be chromosomally located on “borders” to repairing satellite lesions. This genomic placement was found to correspond to mutations identified in tumor sequencing (p53, Rb, MYC), favoring a bad luck location for their cancer “mutational nature”. The CNVs in cancers, are here seen as molecular expressions of long-known cytogenetic HSRs and DMs also with demonstrated origin from amplifications of single genes. Over-expression of oncogenes was hinted of being from duplications, but Drosophila genetics demonstrated the opposite, gene inactivation. The reduced eye-size from dominant, BAR-Ultra-Bar-eye phenotypes, was caused by duplications, inactivating the genetic system for eye-size. The finding of CNVs showing “evasion” of the immune system suggests, inactivation of immune-determining genetics. Since mutated genes on borders to satellite DNAs are a fact in hematological cancers, the 4n-skewed division-system is suggested to replace debated leukemogenesis with fitness-gain from molecular mutations. For these cancers the question is how normal bone marrow cells attain genomic damage for special tetraploidy, which was referred to studies of cells moving in artificial marrow-like substrate, needing serious attention.

The effect of epigenetic sperm abnormalities on early embryogenesis

Sperm are a highly specialized cell type derived to deliver the paternal haploid genome to the oocyte. The epigenetic, or gene regulatory, properties and mechanisms of the sperm assist in preparation of the paternal genome to contribute to embryogenesis and the genome of the zygote. Many recent studies have addressed the issue of altered epigenetic processes in the sperm. This review evaluates the current understanding of DNA damage, chromosome aneuploidy, reduced telomere length, malformations of the centrosome, genomic imprinting errors, altered mRNA profiles, and abnormal nuclear packaging in the sperm prior to fertilization and the observed effects on embryogenesis. Attention has also been given to understanding the underlying etiology of sperm with altered epigenetic mechanisms in humans. （Asian J Androl 2006 Mar; 8： 131-142）

KIFC1 overexpression promotes prostate cancer cell survival and proliferation in vitro by clustering of amplified centrosomes via interaction with Centrin 2

Mitotic kinesin KIFC1 plays critical roles in mitosis by regulating the spindle length,pole formation,and known for clustering extra centrosomes in cancer cells.Centrosome clustering is associated with the survival of cancer cells,but this phenomenon remains obscure in prostate cancer(PCa).The present study demonstrated that PCa cells showed centrosome amplification and clustering during interphase and mitosis,respectively.KIFC1 is highly expressed in PCa cells and tumor tissues of prostatic adenocarcinoma(PAC)patients.Up-regulation of KIFC1 facilitated the PCa cell survival in vitro by ensuring bipolar mitosis through clustering the multiple centrosomes,suggesting centrosome clustering could be a leading cause of prostate carcinogenesis.Conversely,the silencing of KIFC1 resulted in normal centrosome number or multipolar mitosis by inhibiting the clustering of amplified centrosomes in PCa cells.Besides,knockdown of KIFC1 by RNAi in PCa cells reduced cancer cell survival,and proliferation.KIFC1 interacted with centrosome structural protein Centrin 2 in clustering of amplified centrosomes in PCa cells to ensure the bipolar mitotic spindle formation.Knockdown of Centrin 2 in PCa cells inhibited the centrosome amplification and clustering.Moreover,up-regulated KIFC1 promotes PCa cell proliferation via progression of cell cycle possibly through aberrant activation of cyclin dependent kinase 1(Cdk1).Therefore,KIFC1 can be a prognostic marker and therapeutic target of PCa for inhibiting the cancer cell proliferation.

Stem cells' centrosomes: How can organelles identified 130 years ago contribute to the future of regenerative medicine?

At the core of regenerative medicine lies the expectation of repair or replacementof damaged tissues or whole organs. Donor scarcity and transplant rejection aremajor obstacles, and exactly the obstacles that stem cell􀀀based therapy promisesto overcome. These therapies demand a comprehensive understanding of theasymmetric division of stem cells, i.e. their ability to produce cells with identicalpotency or differentiated cells. It is believed that with better understanding,researchers will be able to direct stem cell differentiation. Here, we describeextraordinary advances in manipulating stem cell fate that show that we need tofocus on the centrosome and the centrosome-derived primary cilium. This beliefcomes from the fact that this organelle is the vehicle that coordinates theasymmetric division of stem cells. This is supported by studies that report thesignificant role of the centrosome/cilium in orchestrating signaling pathways thatdictate stem cell fate. We anticipate that there is sufficient evidence to place thisorganelle at the center of efforts that will shape the future of regenerativemedicine.

Significance of β-tubulin Expression in Breast Premalignant Lesions and Carcinomas

OBJECTIVE To explore the expression of β-tubulin in premalignant lesions and carcinomas of the breast, and to observe the relationship of its expression with breast cancer pathological features. METHODS The expression of β-tubulin was detected immunohistochemically in 50 specimens of premalignant lesions of the breast （ADH and Peri-PM with ADH）, 50 specimens of breast in situ ductal carcinomas （DCIS）, and 50 specimens of invasive ductal carcinomas （IDC）. Thirty specimens of normal breast tissues served as a control group. RESULTS Immunohistochemical analysis showed that： the differences among the 4 groups （normal breast tissues, breast premalignant lesions, DCIS and IDC, P 〈 0.05） were significant, and there were also statistically significant differences between any 2 groups （P 〈 0.05） except for the β-tubulin positive expression comparing DCIS versus IDC （P 〉 0.05）. In addition, β-tubulin was expressed at a higher level in Peri-PM with ADH compared to ADH （P 〈 0.05）. Following the degree of breast epithelial hyperplasia involved, and its development into carcinoma, the β-tubulin positive expression displayed an elevating tendency. We also found a significant positive relationship of β-tubulin expression with lymph node metastasis （P 〈 0.05）, but no significant correlation with histological grading and nuclear grade. CONCLUSION Centrosome defects may be an early event in the development of breast cancer and they can also promote tumor progression. Studies of aberrations of centrosomal proteins provide a new way to tumorigenesis. explore the mechanism of breast tumorigenesis.

Centrosome Functions as a Molecular Dynamo in the Living Cell

Recent development in the field of quantum biology highlights that the intracellular electromagnetic field (EMF) of microtubules plays an important role in many fundamental cellular processes such as mitosis. Here I propose an intriguing hypothesis that centrosome functions as molecular dynamo to generate electric flow over the microtubules, leading to the electric excitation of microtubule EMF that is required for spindle body microtubule self-assembly. With the help of motors proteins within the centrosome, centrosome transforms the energy from ATP into intracellular EMF in the living cell that shapes the functions of microtubules. There will be a general impact for the cell biology field to understand the mechanistic function of centrosome for the first time in correlation with its structural features. This hypothesis can be tested with technics such as super resolution live cell microscope.

A New Exposition on Cell Division

This paper provides summary description of the procedures by which human and animal cells (eucaryotic cells) divide into two identical parts. The focus is on the nucleus, with particular attention given to the centrosome and the chromosome. Within the centrosome is a pair of organelle known as centriole. When the cell is about to divide, the centrioles duplicate themselves. At the same time, the DNA within the chromosome duplicates itself. The centriole pair, now two pairs, then separate with one pair migrating about the nucleus to the diametrically opposite side. The original and migrated centriole then emit long strands known as microtubules across the nucleus. Similarly, the chromosome emits long strands known as kinetochores. The microtubules and the kinetochores are perpendicular to each other and they cover the nucleus with a checkered appearance. The diametrically opposed centriole then forms centrosomes which pull the nucleus apart. The two nuclear parts then separate with each part taking with its half of the remainder of the cell (the cytoplasm) and thus two virtually identical cells are attained. The significance of this paper is that it provides the reader with a condensed summary of the life-dependent process known as cell division.

Chromosomes and Centrosomes—Team Players in Cell Division

This paper provides a mid-level description of cell division and duplication. The focus is on the roles by the chromosomes, centrosomes, microtubules and the kinetochores. The emphasis is on the mechanical activity and the resulting physical developments. The paper also provides, in its discussion, the harmful effects occurring when duplication procedures go awry. This often leads to unwanted duplication and possibly cancer.

Centrosome and vascular microenvironmental homeostasis

The homeostasis of vascular microenvironment is essential to maintain the normal vascular structure and function,while its disorder leads to vascular dysfunction,and cardiovascular and cerebrovascular diseases.Centrosome is an important organelle existing in mammalian cells as well as the microtubule organizing center,playing an important role in maintaining vascular structure and homeostasis.This study reviewed the role of centrosome in the regulation of vascular microenvironmental homeostasis.Centrosomal proteins intricately regulate microtubule dynamics and stabilization,and diverse microtubule-relatived cellular activities,including the division,polarization and directional migration of vascular endothelial cells,smooth muscle cells and other types of cells.In addition,primary cilia formed by centrosome are essential in vascular microenvironment.Tumor endothelial cells usually acquire excess centrosomes,and excess centrosomes are regulated by several angiogenic factors.Therefore,uncovering the detailed molecular mechanisms underlying centrosome affecting vascular microenvironmental homeostasis are needed for the treatment of cardiovascular and cerebrovascular diseases.

Cortical development and asymmetric cell divisions

The development of the mammalian neocortex involves rounds of symmetric and asymmetric cell division of neural progenitors to fulfill needs of both self-renewal of progenitors and production of differentiated progenies such as neurons and glia. The machinery for asymmetric cell division is evolutionarily conserved and extensively used in organogeuesis and homeostasis of adult tissues. Here we summarize recent progress regarding cellular characteristics of different types of neural progenitors in mammals, highlighting how asymmetric cell division is utilized during cortical development.

Multifaceted roles of centrosomes in development,health,and disease

The centrosome is a membrane-less organelle consisting of a pair of barrel-shaped centrioles and pericentriolar material and functions as the major microtubule-organizing center and signaling hub in animal cells.The past decades have witnessed the functional complexity and importance of centrosomes in various cellular processes such as cell shaping,division,and migration.In addition,centrosome abnormalities are linked to a wide range of human diseases and pathological states,such as cancer,reproductive disorder,brain disease,and ciliopathies.Herein,we discuss various functions of centrosomes in development and health,with an emphasis on their roles in germ cells,stem cells,and immune responses.We also discuss how centrosome dysfunctions are involved in diseases.A better understanding of the mechanisms regulating centrosome functions may lead the way to potential therapeutic targeting of this organelle in disease treatment.

Abnormal expression of cen-trosome protein (centrin) in spermatozoa of male human infertility

To study the relations between male infertility and centrosome protein (centrin) and the functions of centrin in spermatogenesis, the matured spermatozoa of 10 normal male people and 18 male infertility patients were stained by immunofluorescence labeling antibody against centrin. The results showed that two fluorescence signal dots appeared in the normal male spermatozoa and were located at the base of flagellum. They are proximal centriole and distal centriole. However, in some spermatozoa of the male infertility, centrin protein was located abnormally at the base of flagellum and its staining signals were spread, the normal proximal and distal centrioles were confused and could not be recognized separately. These results suggest that abnormality of centrosome protein may be related to male infertility. This discovery may be used as a marker of abnormal sperm and male infertility.

The cloning and expression characterization of the centrosome protein genes family (centrin genes) in rat testis

Centrins are members of the centrosome protein family, which is highly conserved during revolution. The homologous genes of centrin in many organisms had been cloned, but the sequences of the rat centrin genes were not reported yet in GenBank. We cloned the cDNA fragments of centrin-1, -2 and -3 from the rat testis by RT-PCR, and analyzed the homology of the deduced amino acid sequences. The expression characterization of centrin genes in rat spermatogenesis was carried out by semi-quantitative RT-PCR. The results show that the homology of the corresponding centrin proteins in human, mouse and rat is high. The expression of centrin-1 is testis-specific, spermatogenic cell-specific and developmental stage-related. Centrin-1 begins to be transcribed when the meiosis occurs, and its mRNA level reaches the peak in round spermatids. Centrin-2 and centrin-3 are highly expressed in spermatogonia and their mRNA level decreases markedly when meiosis occurs. These results suggest that centrin-1 may play roles in meiosis and spermiogenesis, and centrin-2 and centrin-3 may be related to mitosis.

Centrosome aberrations and chromosome instability contribute to tumorigenesis and intratumor heterogeneity

Centrosomes serve as the major microtubule organizing centers in cells and thereby contribute to cell shape,polarity,and motility.Also,centrosomes ensure equal chromosome segregation during mitosis.Centrosome aberrations arise when the centrosome cycle is deregulated,or as a result of cytokinesis failure.A long-standing postulate is that centrosome aberrations are involved in the initiation and progression of cancer.However,this notion has been a subject of controversy because until recently the relationship has been correlative.Recently,it was shown that numerical or structural centrosome aberrations can initiate tumors in certain tissues in mice,as well as invasion.Particularly,we will focus on centrosome amplification and chromosome instability as drivers of intra-tumor heterogeneity and their consequences in cancer.We will also discuss briefly the controversies surrounding this theory to highlight the fact that the role of both centrosome amplification and chromosome instability in cancer is highly context-dependent.Further,we will discuss single-cell sequencing as a novel technique to understand intra-tumor heterogeneity and some therapeutic approaches to target chromosome instability.