Zinc as a Mediator Through the ROCK1 Pathway of Cognitive Impairment in Aluminum-Exposed Workers: A Clinical and Animal Study

Aluminum (Al) exposure was implicated in neurodegenerative diseases and cognitive impairment, yet the involvement of zinc (Zn) and its mechanism in Al-induced mild cognitive impairment (MCI) remains poorly understood. The objective is to explore the role of Zn in Al-induced cognitive impairment and its potential mechanisms. Montreal cognitive assessment (MoCA) test scores and serum Al, Zn from Al industry workers were collected. A mediation analysis was performed to evaluate the role of serum Zn among serum Al and MoCA test scores. Subsequently, an Al-exposure study was conducted on a rat model categorized into control, low-, medium-, and high-dose groups. After a Morris Water Maze test and detection of Al, Zn content in the hippocampus, integrated transcriptomic and proteomic analyses between the control group and the high-dose group were performed to identify the differentially expressed genes (DEPs), proteins (DEPs), and pathways. To corroborate these findings, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB) were selected to identify the gene and protein results. Zn overall mediates the relationship between serum Al and cognitive function (mediation effect 17.82%, effect value =  - 0.0351). In the Al-exposed rat model, 734 DEGs, 18 miRNAs, 35 lncRNAs, 64 circRNAs, and 113 DEPs were identified between the high-dose group and the control group. Among them, ROCK1, DMD, and other four DEPs were identified as related to zinc finger proteins (ZNF). Co-enrichment analyses of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) linked these changes to the RHOA/ROCK1 signaling axis. ZNF-related proteins Rock1, DMD, and DHX57 in the high-dose group were downregulated (p = 0.006, 0.003, 0.04), and the expression of Myl9, Rhoa, miR431, and miR182 was also downregulated (p = 0.003, 0.032, 0.032, and 0.046). These findings also show correlations between Al, Zn levels in the hippocampus, water maze performance, and expressions of Myl9, Rhoa, miR431, miR182, DMD, ROCK1, and DHX57, with both negative and positive associations. Based on the results, we determined that Zn was involved in Al-induced MCI in Al workers and Al-exposed rat models. Al exposure and interaction with Zn could trigger the downregulation of ZNF of ROCK1, DMD, and DHX57. miR431, miR182 regulate RHOA/ROCK1 was one of the Zn-involved pathways in Al-induced cognitive impairment.

Proteomic and Phosphoproteomic Reprogramming in Epithelial Ovarian Cancer Metastasis

Epithelial ovarian cancer (EOC) is a high-risk cancer presenting with heterogeneous tumors. The high incidence of EOC metastasis from primary tumors to nearby tissues and organs is a major driver of EOC lethality. We used cellular models of spheroid formation and readherence to investigate cellular signaling dynamics in each step toward EOC metastasis. In our system, adherent cells model primary tumors, spheroid formation represents the initiation of metastatic spread, and readherent spheroid cells represent secondary tumors. Proteomic and phosphoproteomic analyses show that spheroid cells are hypoxic and show markers for cell cycle arrest. Aurora kinase B abundance and downstream substrate phosphorylation are significantly reduced in spheroids and readherent cells, explaining their cell cycle arrest phenotype. The proteome of readherent cells is most similar to spheroids, yet greater changes in the phosphoproteome show that spheroid cells stimulate Rho-associated kinase 1 (ROCK1)-mediated signaling, which controls cytoskeletal organization. In spheroids, we found significant phosphorylation of ROCK1 substrates that were reduced in both adherent and readherent cells. Application of the ROCK1-specific inhibitor Y-27632 to spheroids increased the rate of readherence and altered spheroid density. The data suggest ROCK1 inhibition increases EOC metastatic potential. We identified novel pathways controlled by Aurora kinase B and ROCK1 as major drivers of metastatic behavior in EOC cells. Our data show that phosphoproteomic reprogramming precedes proteomic changes that characterize spheroid readherence in EOC metastasis.

Silencing of the circ-Arhgap5 RNA protects neuronal PC12 cells against injury and depends on the miR-29a-3p/Rock1 axis

Circular RNAs (circRNAs) are abundantly expressed in human central nervous system. Here, we explored the role of circ_Arhgap5 in cerebral ischemia/reperfusion (I/R)-induced nerve injury in PC12 cells and its associated mechanism. Cell proliferation ability was assessed by 5-Ethynyl-2'-deoxyuridine (Edu) assay and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry (FCM) was applied to assess cell apoptotic rate. Cell death was analyzed by lactate dehydrogenase (LDH) assay. Oxygen-glucose deprivation and reoxygenation (OGD/R) up-regulates the expression of circRNA Rho GTPase activating protein 5 (circ_Arhgap5; mmu_circ_0000377) in PC12 cells. OGD/R exposure inhibited the proliferation and induced the apoptosis of PC12 cells, and the silence of circ_Arhgap5 attenuated OGD/R-induced injury in PC12 cells. miR-29a-3p was identified as a target of circ_Arhgap5 in PC12 cells. Circ_Arhgap5 knockdown-mediated protective effects in OGD/R-induced PC12 cells were reversed by the interference of miR-29a-3p. miR-29a-3p interacted with the 3' untranslated region (3'UTR) of Rho-associated coiled-coil-containing protein kinase 1 (Rock1), and circ_Arhgap5 can positively regulate Rock1 expression by sponging miR-29a-3p in PC12 cells. miR-29a-3p overexpression protected PC12 cells against OGD/R-induced damage by down-regulating Rock1. In conclusion, circ_Arhgap5 silencing protected PC12 cells from OGD/R-induced injury through mediating miR-29a-3p/Rock1 axis.

Rock1 is a novel host dependency factor of human enterovirus A71: Implication as a drug target

Human enterovirus A71 (EV-A71) is the major causative agent of hand-foot-and-mouth disease (HFMD) commonly associated with severe neurological diseases, particularly in children under 5 years of age. Several investigational therapeutic agents and vaccine candidates are being developed. However, no approved drug against EV-A71 infection is available, and no proven drug target has been identified. Since host kinases are key regulators of multiple signaling pathways in response to viral infections, here we screened a kinase inhibitor library and identified potent inhibitors against EV-A71 infection. Among the hits, GSK269962A, a Rho Associated Coiled-Coil Containing Protein Kinase (Rock) inhibitor with potent antiviral activity, was selected for further analysis. We found that this Rock inhibitor not only efficiently suppressed the replication of EV-A71 in RD cells, but also in human intestinal organoids, in a dose-dependent manner. Interestingly, small interfering RNA depletion of Rock1, but not Rock2, significantly restricted viral replication in RD cells, indicating that Rock1 is a novel host dependency factor for EV-A71 replication and can serve as a target for the development of anti-EV-A71 therapeutics.

The Long Non-coding RNA lnc-31 Interacts with Rock1 mRNA and Mediates Its YB-1-Dependent Translation

Cytoplasmic long non-coding RNAs have been shown to act at many different levels to control post-transcriptional gene expression, although their role in translational control is poorly understood. Here, we show that lnc-31, a non-coding RNA required for myoblast proliferation, promotes ROCK1 protein synthesis by stabilizing its translational activator, YB-1. We find that lnc-31 binds to the Rock1 mRNA as well as to the YB-1 protein and that translational activation requires physical interaction between the two RNA species. These results suggest a localized effect of YB-1 stabilization on the Rock1 mRNA. ROCK1 upregulation by lnc-31, in proliferative conditions, correlates well with the differentiation-repressing activity of ROCK1. We also show that, upon induction of differentiation, the downregulation of lnc-31, in conjunction with miR-152 targeting of Rock1, establishes a regulatory loop that reinforces ROCK1 repression and promotes myogenesis.

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lnc-31 sustains myoblast proliferation, counteracting differentiation

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lnc-31 binds to Rock1 mRNA and YB-1 protein

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Rock-1 translation is favored through its interaction with lnc-31 and YB-1 protein

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lnc-31 counteracts YB-1 protein degradation, thus promoting Rock1 translation

Cellular senescence is associated with reorganization of the microtubule cytoskeleton

Senescent cells undergo structural and functional changes that affect essentially every aspect of cell physiology. To date, the impact of senescence on the cytoskeleton is poorly understood. This study evaluated the cytoskeleton in two independent cellular models of kidney epithelium senescence. Our work identified multiple senescence-related alterations that impact microtubules and filamentous actin during interphase. Both filamentous systems reorganized profoundly when cells became senescent. As such, microtubule stability increased during senescence, making these filaments more resistant to disassembly in the cold or by nocodazole. Microtubule stabilization was accompanied by enhanced α-tubulin acetylation on lysine 40 and the depletion of HDAC6, the major deacetylase for α-tubulin lysine 40. Rho-associated kinase Rock1 is an upstream regulator that modulates key properties of the cytoplasmic cytoskeleton. Our research shows that Rock1 concentrations were reduced significantly in senescent cells, and we revealed a mechanistic link between microtubule stabilization and Rock1 depletion. Thus, Rock1 overexpression partially restored the cold sensitivity of microtubules in cells undergoing senescence. Additional components relevant to microtubules were affected by senescence. Specifically, we uncovered the senescence-related loss of the microtubule nucleating protein γ-tubulin and aberrant formation of γ-tubulin foci. Concomitant with the alterations of microtubule and actin filaments, senescent cells displayed functional changes. In particular, cell migration was impaired significantly in senescent cells. Taken together, our study identified new senescence-associated deficiencies of the microtubule and actin cytoskeleton, provided insights into the underlying molecular mechanisms and demonstrated functional consequences that are important to the physiology and function of renal epithelial cells.

Withdrawal from repeated morphine administration augments expression of the RhoA network in the nucleus accumbens to control synaptic structure

The nucleus accumbens (NAc) is a critical brain reward region that mediates the rewarding effects of drugs of abuse, including those of morphine and other opiates. Drugs of abuse induce widespread alterations in gene transcription and dendritic spine morphology in medium spiny neurons (MSNs) of the NAc that ultimately influence NAc excitability and hence reward-related behavioral responses. Growing evidence indicates that within the NAc small GTPases are common intracellular targets of drugs of abuse where these molecules regulate drug-mediated transcriptional and spine morphogenic effects. The RhoA small GTPase is among the most well-characterized members of the Ras superfamily of small GTPases, and recent work highlights an important role for hippocampal RhoA in morphine-facilitated reward behavior. Despite this, it remains unclear how RhoA pathway signaling in the NAc is affected by withdrawal from morphine. To investigate this question, using subcellular fractionation and subsequent protein profiling we examined the expression of key components of the RhoA pathway in NAc nuclear, cytoplasmic, and synaptosomal compartments during multiple withdrawal periods from repeated morphine administration. Furthermore, using in vivo viral-mediated gene transfer, we determined the consequences of revealed RhoA pathway alterations on NAc MSN dendritic spine morphology. Our findings reveal an important role for RhoA signaling cascades in mediating the effects of long-term morphine withdrawal on NAc MSN dendritic spine elimination.

OPEN PRACTICES

Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/.

MicroRNA-335 and its target Rock1 synergistically influence tumor progression and prognosis in osteosarcoma

MicroRNA (miR)-335 and Rho-associated serine-threonine protein kinase 1 (Rock1) is ectopically expressed in multiple malignant tumors including osteosarcoma. The present study aimed to clarify whether the combined ectopically expressed miR-335 and Rock1 was correlated with clinicopathological features and prognosis in patients with osteosarcoma. The expression of miR-335 and Rock1 in 91 osteosarcoma tissue samples and 47 noncancerous bone tissues were determined respectively by in situ hybridization and immunohistochemistry. The association between miR-335 and Rock1 expression with the clinicopathological features of osteosarcoma was calculated using the Pearson's χ² test. Spearman's correlation analysis was used to study the association between the miR-335 and Rock1 expression. Survival curves were drawn using the Kaplan-Meier method. Univariate and multivariate analysis was performed using the Cox's proportional hazard regression model to allow the prognostic values to be assessed. Expression levels of miR-335 were significantly reduced in osteosarcoma tissues (P<0.001), compared with that in noncancerous bone tissues, while Rock1 expression was significantly increased in osteosarcoma tissues (P<0.001). A strong correlation between miR-335 and Rock1 expression was also shown (P<0.001). Decreased miR-335 expression was identified to be positively associated with higher clinical stage (P=0.004) and distant metastasis (P=0.016), while elevated expression levels of Rock1 was positively associated with a larger tumor size (P=0.013), higher clinical stage (P=0.027) and distant metastasis (P=0.022). The combined high expression of Rock1 and low expression of miR-335 was clearly associated with distant metastasis (P=0.010) and a higher clinical stage (P=0.010). Patients with elevated Rock1 or decreased miR-335 expression exhibited a worse overall survival (OS) and disease-free survival (DFS) compared with patients with decreased Rock1 or increased miR-335 (P<0.001 for the two). In addition, patients with decreased miR-335 and increased Rock1 had the worst OS and DFS (P<0.001 for the two). In multivariate survival analysis, clinical stage (P=0.002 for DFS, P=0.015 for OS), distant metastasis (P=0.024 for DFS, P=0.002 for OS), low expression of miR-335 (P<0.001 for DFS, P=0.002 for OS) and combined depressed miR-335 and elevated Rock1 (P=0.021 for DFS, P=0.050 for OS) expression remained as the independent prognostic factors for DFS and OS. The present findings suggest that there may be an association between the combined downregulation of miR-335 and upregulation of Rock1 with tumor progression and adverse prognosis in patients with osteosarcoma.

Expression and significance of Rac1, Pak1 and Rock1 in gastric carcinoma

AIMS

Rac1, Pak1 and Rock1 are indicators related to gastric cancer invasion and metastasis, but few reports discuss all three kinds of protein in research on gastric cancer invasion and metastasis. The aim of this study was to investigate the expression and clinical significance of Rac1, Pak1 and Rock1 in gastric carcinoma.

METHODS

Rac1, Pak1 and Rock1 expression in 158 cases of gastric carcinoma were investigated via immunohistochemical staining and clinical analysis.

RESULTS

The positive expression rates of Rac1, Pak1 and Rock1 in normal tissue, intraepithelial neoplastic tissues and gastric carcinoma showed an increasing trend (P < 0.05). Their expression in lymph node metastasis was significantly higher than in patients with lymph-node metastasis than in those without lymph nodes metastasis (P < 0.05). Their expression in tumor (TNM stages III and IV) were significantly higher than that in stages I and II (P < 0.05). Rac1, Pak1 and Rock1 expression did not differ significantly with patients' sex (P > 0.05).

CONCLUSION

Positive rates of Rac1, Pak1 and Rock1 expression in normal tissue, dysplasia and gastric carcinoma show an increasing trend and are correlated with tumor lymph node metastasis and TNM stage. Rac1, Pak1 and Rock1 may be important biomarkers of gastric carcinoma invasion and metastasis.

Yolk syncytial layer formation is a failure of cytokinesis mediated by Rock1 function in the early zebrafish embryo

The yolk syncytial layer (YSL) performs multiple critical roles during zebrafish development. However, little is known about the cellular and molecular mechanisms that underlie the formation of this important extraembryonic structure. Here, we demonstrate by timelapse confocal microscopy of a transgenic line expressing membrane-targeted GFP that the YSL forms as a result of the absence of cytokinesis between daughter nuclei at the tenth mitotic division and the regression of pre-existing marginal cell membranes, thus converting the former margin of the blastoderm into a syncytium. We show that disruption of components of the cytoskeleton induces the formation of an expanded YSL, and identify Rock1 as the regulator of cytoskeletal dynamics that lead to YSL formation. Our results suggest that the YSL forms as a result of controlled cytokinesis failure in the marginal blastomeres, and Rock1 function is necessary for this process to occur. Uncovering the cellular and molecular mechanisms underlying zebrafish YSL formation offers significant insight into syncytial development in other tissues as well as in pathological conditions.