[COL4A5 genotypes and clinical characteristics of children with Alport syndrome]. / 儿童Alport综合征COL4A5åŸºå› åž‹åŠä¸´åºŠç‰¹ç‚¹åˆ†æž.

OBJECTIVES: To investigate the genotypes of the pathogenic gene COL4A5 and the characteristics of clinical phenotypes in children with Alport syndrome (AS). METHODS: A retrospective analysis was performed for the genetic testing results and clinical data of 19 AS children with COL4A5 gene mutations. RESULTS: Among the 19 children with AS caused by COL4A5 gene mutations, 1 (5%) carried a new mutation of the COL4A5 gene, i.e., c.3372A>G(p.P1124=) and presented with AS coexisting with IgA vasculitis nephritis; 3 children (16%) had large fragment deletion of the COL4A5 gene, among whom 2 children (case 7 had a new mutation site of loss51-53) had gross hematuria and albuminuria at the onset, and 1 child (case 13 had a new mutation site of loss3-53) only had microscopic hematuria, while the other 15 children (79%) had common clinical phenotypes of AS, among whom 7 carried new mutations of the COL4A5 gene. Among all 19 children, 3 children (16%) who carried COL4A5 gene mutations also had COL4A4 gene mutations, and 1 child (5%) had COL4A3 gene mutations. Among these children with double gene mutations, 2 had gross hematuria and proteinuria at the onset. CONCLUSIONS: This study expands the genotype and phenotype spectrums of the pathogenic gene COL4A5 for AS. Children with large fragment deletion of the COL4A5 gene or double gene mutations of COL4A5 with COL4A3 or COL4A4 tend to have more serious clinical manifestations.

Metabolic Adaptation of a Globally Important Diatom following 700 Generations of Selection under a Warmer Temperature.

Diatoms, accounting for 40% of the marine primary production and 20% of global carbon dioxide fixation, are threatened by the ongoing ocean warming (OW). However, whether and how these ecologically important phytoplankton adapt to OW remains poorly unknown. Here, we experimentally examined the metabolic adaptation of a globally important diatom species Skeletonema dohrnii (S. dohrnii) to OW at two elevated temperatures (24 and 28 °C compared with 20 °C) under short-term (∼300 generations) and long-term (∼700 generations) selection. Both warming levels significantly increased the cell growth rate but decreased the chlorophyll a content. The contents of particulate organic carbon (POC) and particulate organic nitrogen (PON) decreased significantly initially (i.e., until 300 generations) at two temperature treatments but completely recovered after 700 generations of selection, suggesting that S. dohrnii ultimately developed thermal adaptation. Proteomic analysis demonstrated that elevated temperatures upregulated energy metabolism via glycolysis, tricarboxylic acid cycle, and fatty acid oxidation as well as nitrogen acquisition and utilization, which in turn reduced substance storage because of trade-off in the 300th generation, thus decreasing POC and PON. Interestingly, populations at both elevated temperatures exhibited significant proteome plasticity in the 700th generation, as primarily demonstrated by the increased lipid catabolism and glucose accumulation, accounting for the recovery of POC and PON. Changes occurring in cells at the 300th and 700th generations demonstrate that S. dohrnii can adapt to the projected OW, and readjusting the energy metabolism is an important adaptive strategy.

The mechanism and effects of remdesivir-induced developmental toxicity in zebrafish: Blood flow dysfunction and behavioral alterations.

The antiviral drug remdesivir has been used to treat the growing number of coronavirus disease 2019 (COVID-19) patients. However, the drug is mainly excreted through urine and feces and introduced into the environment to affect non-target organisms, including fish, which has raised concerns about potential ecotoxicological effects on aquatic organisms. Moreover, studies on the ecological impacts of remdesivir on aquatic environments have not been reported. Here, we aimed to explore the toxicological impacts of microinjection of remdesivir on zebrafish early embryonic development and larvae and the associated mechanism. We found that 100 µM remdesivir delayed epiboly and impaired convergent movement of embryos during gastrulation, and dose-dependent increases in mortality and malformation were observed in remdesivir-treated embryos. Moreover, 10-100 µM remdesivir decreased blood flow and swimming velocity and altered the behavior of larvae. In terms of molecular mechanisms, 80 differentially expressed genes (DEGs) were identified by transcriptome analysis in the remdesivir-treated group. Some of these DEGs, such as manf, kif3a, hnf1ba, rgn, prkcz, egr1, fosab, nr4a1, and ptgs2b, were mainly involved in early embryonic development, neuronal developmental disorders, vascular disease and the blood flow pathway. These data reveal that remdesivir can impair early embryonic development, blood flow and behavior of zebrafish embryos/larvae, probably due to alterations at the transcriptome level. This study suggests that it is important to avoid the discharge of remdesivir to aquatic ecosystems and provides a theoretical foundation to hinder remdesivir-induced ecotoxicity to aquatic environments.

Illuminating Key Microbial Players and Metabolic Processes Involved in the Remineralization of Particulate Organic Carbon in the Ocean's Twilight Zone by Metaproteomics.

The twilight zone (from the base of the euphotic zone to the depth of 1,000 m) is the major area of particulate organic carbon (POC) remineralization in the ocean, and heterotrophic microbes contribute to more than 70% of the estimated remineralization. However, little is known about the microbial community and metabolic activity directly associated with POC remineralization in this chronically understudied realm. Here, we characterized the microbial community proteomes of POC samples collected from the twilight zone of three contrasting sites in the Northwest Pacific Ocean using a metaproteomic approach. The particle-attached bacteria from Alteromonadales, Rhodobacterales, and Enterobacterales were the primary POC remineralizers. Hydrolytic enzymes, including proteases and hydrolases, that degrade proteinaceous components and polysaccharides, the main constituents of POC, were abundant and taxonomically associated with these bacterial groups. Furthermore, identification of diverse species-specific transporters and metabolic enzymes implied niche specialization for nutrient acquisition among these bacterial groups. Temperature was the main environmental factor driving the active bacterial groups and metabolic processes, and Enterobacterales replaced Alteromonadales as the predominant group under low temperature. This study provides insight into the key bacteria and metabolic processes involved in POC remineralization, and niche complementarity and species substitution among bacterial groups are critical for efficient POC remineralization in the twilight zone. IMPORTANCE The ocean's twilight zone is a critical zone where more than 70% of the sinking particulate organic carbon (POC) is remineralized. Therefore, the twilight zone determines the size of biological carbon storage in the ocean and regulates the global climate. Prokaryotes are major players that govern remineralization of POC in this region. However, knowledge of microbial community structure and metabolic activity is still lacking. This study unveiled microbial communities and metabolic activities of POC samples collected from the twilight zone of three contrasting environments in the Northwest Pacific Ocean using a metaproteomic approach. Alteromonadales, Rhodobacterales, and Enterobacterales were the major remineralizers of POC. They excreted diverse species-specific hydrolytic enzymes to split POC into solubilized POC or dissolved organic carbon. Temperature played a crucial role in regulating the community composition and metabolism. Furthermore, niche complementarity or species substitution among bacterial groups guaranteed the efficient remineralization of POC in the twilight zone.

miR-29a attenuates cardiac hypertrophy through inhibition of PPARδ expression.

Although cardiac hypertrophy is widely recognized as a risk factor that leads to cardiac dysfunction and, ultimately, heart failure, the complex mechanisms underlying cardiac hypertrophy remain incompletely characterized. The nuclear receptor peroxisome proliferator-activated receptor δ (PPARδ) is involved in the regulation of cardiac lipid metabolism. Here, we describe a novel PPARδ-dependent molecular cascade involving microRNA-29a (miR-29a) and atrial natriuretic factor (ANF), which is reactivated in cardiac hypertrophy. In addition, we identify a novel role of miR-29a, in which it has a cardioprotective function in isoproterenol hydrochloride-induced cardiac hypertrophy by targeting PPARδ and downregulating ANF. Finally, we provide evidence that miR-29a reduces the isoproterenol hydrochloride-induced cardiac hypertrophy response, thereby underlining the potential clinical relevance of miR-29a in which it may serve as a potent therapeutic target for heart hypertrophy treatment.

Functional Differences in the Blooming Phytoplankton Heterosigma akashiwo and Prorocentrum donghaiense Revealed by Comparative Metaproteomics.

Phytoplankton blooms are natural phenomena in the ocean, which are the results of rapid cell growth of some phytoplankton species in a unique environment. However, little is known about the molecular events occurring during the bloom. Here, we compared metaproteomes of two phytoplankton Heterosigma akashiwo and Prorocentrum donghaiense in the coastal East China Sea. H. akashiwo and P. donghaiense accounted for 7.82% and 4.74% of the phytoplankton community protein abundances in the nonbloom sample, whereas they contributed to 60.13% and 78.09%, respectively, in their individual blooming samples. Compared with P. donghaiense, H. akashiwo possessed a significantly higher abundance of light-harvesting complex proteins, carbonic anhydrasem and RuBisCO. The blooming H. akashiwo cells expressed more proteins related to external nutrient acquisition, such as bicarbonate transporter SLC4, ammonium transporter, nitrite transporter, and alkaline phosphatase, while the blooming P. donghaiense cells highly expressed proteins related to extra- and intracellular organic nutrient utilization, such as amino acid transporter, 5'-nucleotidase, acid phosphatase, and tripeptidyl-peptidase. The strong capabilities of light harvesting, as well as acquisition and assimilation of inorganic carbon, nitrogen, and phosphorus, facilitated the formation of the H. akashiwo bloom under the high turbidity and inorganic nutrient-sufficient condition, whereas the competitive advantages in organic nutrient acquisition and reallocation guaranteed the occurrence of the P. donghaiense bloom under the inorganic nutrient-insufficient condition. This study highlights the power of metaproteomics for revealing the underlying molecular behaviors of different coexisting phytoplankton species and advances our knowledge on the formation of phytoplankton blooms.IMPORTANCE A deep understanding of the mechanisms driving bloom formation is a prerequisite for effective bloom management. Metaproteomics was applied in this study to reveal the adaptive and responsive strategies of two coexisting phytoplankton species, H. akashiwo and P. donghaiense, during their bloom periods. Metabolic features and niche divergence in light harvesting, as well as carbon, nitrogen, and phosphorus acquisition and assimilation likely promoted the bloom occurrence under different environments. The molecular behaviors of coexisting bloom-causing species will give clues for bloom monitoring and management in the oceans.

Discovery of a ferroelastic topological insulator in a two-dimensional tetragonal lattice.

Ferroelasticity and band topology are two intriguing yet distinct quantum states of condensed matter materials. Their coexistence in a single two-dimensional (2D) lattice, however, has never been observed. Here, we found that the 2D tetragonal HfC monolayer allowed simultaneous presence of ferroelastic and topological orders. By using first-principles calculations, we found that it could allow a low switching barrier with reversible strain of 17.4%, indicating that the anisotropic properties are achievable experimentally for a 2D tetragonal lattice. More interestingly, the tuning of topological behaviors with strain led to spin-separated and gapless edge states, that is, the quantum spin Hall effect. These findings from the coupling of two quantum orders offer insights into ferroelastic control over topological edge states for achieving multifunctional properties in next-generation 2D nanodevices.

Metaproteomics of marine viral concentrates reveals key viral populations and abundant periplasmic proteins in the oligotrophic deep chlorophyll maximum of the South China Sea.

Viral concentrates (VCs), containing bioinformative DNA and proteins, have been used to study viral diversity, viral metagenomics and virus-host interactions in natural ecosystems. Besides viruses, VCs also contain many noncellular biological components including diverse functional proteins. Here, we used a shotgun proteomic approach to characterize the proteins of VCs collected from the oligotrophic deep chlorophyll maximum (DCM) of the South China Sea. Proteins of viruses infecting picophytoplankton, that is, cyanobacteria and prasinophytes, and heterotrophic bacterioplankton, such as SAR11 and SAR116, dominated the viral proteome. Almost no proteins from RNA viruses or known gene transfer agents were detected, suggesting that they were not abundant at the sampling site. Remarkably, nonviral proteins made up about two thirds of VC proteins, including overwhelmingly abundant periplasmic transporters for nutrient acquisition and proteins for diverse cellular processes, that is, translation, energy metabolism and one carbon metabolism. Interestingly, three 56 kDa selenium-binding proteins putatively involved in peroxide reduction from gammaproteobacteria were abundant in the VCs, suggesting active removal of peroxide compounds at DCM. Our study demonstrated that metaproteomics provides a valuable avenue to explore the diversity and structure of the viral community and also the pivotal biological functions affiliated with microbes in the natural environment.

Metaproteomics reveals major microbial players and their metabolic activities during the blooming period of a marine dinoflagellate Prorocentrum donghaiense.

Interactions between bacteria and phytoplankton during bloom events are essential for both partners, which impacts their physiology, alters ambient chemistry and shapes ecosystem diversity. Here, we investigated the community structure and metabolic activities of free-living bacterioplankton in different blooming phases of a dinoflagellate Prorocentrum donghaiense using a metaproteomic approach. The Fibrobacteres-Chlorobi-Bacteroidetes group, Rhodobacteraceae, SAR11 and SAR86 clades contributed largely to the bacterial community in the middle-blooming phase while the Pseudoalteromonadaceae exclusively dominated in the late-blooming phase. Transporters and membrane proteins, especially TonB-dependent receptors were highly abundant in both blooming phases. Proteins involved in carbon metabolism, energy metabolism and stress response were frequently detected in the middle-blooming phase while proteins participating in proteolysis and central carbon metabolism were abundant in the late-blooming phase. Beta-glucosidase with putative algicidal capability was identified from the Pseudoalteromonadaceae only in the late-blooming phase, suggesting an active role of this group in lysing P. donghaiense cells. Our results indicated that diverse substrate utilization strategies and different capabilities for environmental adaptation among bacteria shaped their distinct niches in different bloom phases, and certain bacterial species from the Pseudoalteromonadaceae might be crucial for the termination of a dinoflagellate bloom.

Correction: Prediction of topological property in TlPBr2 monolayer with appreciable Rashba effect.

Correction for 'Prediction of topological property in TlPBr2 monolayer with appreciable Rashba effect' by Min Yuan et al., Phys. Chem. Chem. Phys., 2018, 20, 4308-4316.

Prediction of topological property in TlPBr2 monolayer with appreciable Rashba effect.

A quantum spin Hall (QSH) insulator with high stability, large bulk band gap and tunable topological properties is crucial for both fundamental research and practical application due to the presence of dissipationless edge conducting channels. Recently, chemical functionalization has been proposed as an effective route to realize the QSH effect. Based on first-principles calculations, we predict that a two-dimensional TlP monolayer would convert into a topological insulator with the effect of bromination, accompanied by a large bulk band gap of 76.5 meV, which meets the requirement for room-temperature application. The topological nature is verified by the calculation of Z2 topological invariant and helical edge states. Meanwhile, an appreciable Rashba spin splitting of 77.2 meV can be observed. The bulk band gap can be effectively tuned with external strain and electric field, while the Rashba spin splitting shows a parabolic variation trend under an external electric field. We find that the topological property is available for the TlP film when the coverage rate is more than 0.75. BN and SiC are demonstrated as promising substrates to support the topological nature of TlPBr2 film. Our findings suggest that a TlPBr2 monolayer is an appropriate candidate for hosting the nontrivial topological state and controllable Rashba spin splitting, and shows great potential applications in spintronics.

Oridonin synergizes with Nutlin-3 in osteosarcoma cells by modulating the levels of multiple Bcl-2 family proteins.

The small-molecule inhibitors of p53-murine double minute 2 interaction, such as Nutlin-3, are effective against cancers bearing wild-type p53. However, murine double minute 2 inhibitors often are unable to completely eliminate solid tumor cells. To address this issue, we investigated the anticancer effects of Nutlin-3 in combination with Oridonin in osteosarcoma cells. We found that Oridonin at sub-toxic concentrations synergistically enhanced Nutlin-3-mediated cell viability inhibition in wild-type p53 U2OS and SJSA-1, but not in p53-mutant MNNG/HOS and in null-p53 Saos-2 osteosarcoma cell lines. Importantly, in the presence of Oridonin, Nutlin-3 could completely abolish cell viability in the wild-type p53 osteosarcoma cell lines. Western blotting analysis showed that Oridonin treatment rapidly and distinctly increased the levels of all three forms of Bim and also markedly reduced the levels of Bcl-2 and Bcl-xl in osteosarcoma cells. Western blotting analysis further showed that Oridonin considerably enhanced Nutlin-3-triggered activation of caspases-9 and -3 and poly(ADP-ribose) polymerase cleavage. Flow cytometry assay showed that Oridonin significantly enhanced Nutlin-3-mediated apoptosis in wild-type p53 osteosarcoma cells. Overall, our results suggest that the combined treatment of Nutlin-3 plus Oridonin may offer a novel therapeutic strategy for osteosarcoma.

Prediction of topological crystalline insulators and topological phase transitions in two-dimensional PbTe films.

Topological phases, especially topological crystalline insulators (TCIs), have been intensively explored and observed experimentally in three-dimensional (3D) materials. However, two-dimensional (2D) films are explored much less than 3D TCIs, and even 2D topological insulators. Based on ab initio calculations, here we investigate the electronic and topological properties of 2D PbTe(001) few-layer films. The monolayer and trilayer PbTe are both intrinsic 2D TCIs with a large band gap reaching 0.27 eV, indicating a high possibility for room-temperature observation of quantized conductance. The origin of the TCI phase can be attributed to the px,y-pz band inversion, which is determined by the competition of orbital hybridization and the quantum confinement effect. We also observe a semimetal-TCI-normal insulator transition under biaxial strains, whereas a uniaxial strain leads to Z2 nontrivial states. In particular, the TCI phase of a PbTe monolayer remains when epitaxially grown on a NaI semiconductor substrate. Our findings on the controllable quantum states with sizable band gaps present an ideal platform for realizing future topological quantum devices with ultralow dissipation.

EGF Protects Cells Against Dox-Induced Growth Arrest Through Activating Cyclin D1 Expression.

It has been reported that the antitumor drug doxorubicin (Dox) exerts its toxic effects via GATA-4 depletion and that over-expression of GATA-4 reverses Dox-induced toxicity and apoptosis; however, the precise mechanisms remain unclear. In this study, we observed, for the first time, that EGF protects cells against Dox-mediated growth arrest, G2/M-phase arrest, and apoptosis. Additionally, EGF expression was down-regulated in Dox-treated cells and up-regulated in GATA-4 over-expressing cells. Utilizing real-time PCR and western blotting analysis, we found that the expression of the cell cycle-associated protein cyclin D1 was inhibited in GATA-4-silenced cells and Dox-treated cells and was enhanced in GATA-4 over-expressing cells and EGF-treated cells. Furthermore, EGF treatment reversed the inhibited expression of cyclin D1 that was mediated by GATA-4 RNAi or Dox. Our results indicate that EGF, as a downstream target of Dox, may be involved in Dox-induced toxicity as well as in the protective role of GATA-4 against toxicity induced by Dox via regulating cyclin D1 expression, which elucidates a new molecular mechanism of Dox toxicity with important clinical implications.

Flavonoids from Scutellaria attenuate okadaic acid-induced neuronal damage in rats.

PRIMARY OBJECTIVE: To study the effect of flavonoids isolated from aerial parts of Scutellaria baicalensis Georgi (SSF) on cerebral damage induced by okadaic acid (OA) in rats. METHODS AND PROCEDURES: OA was microinjected into the right lateral ventricle of male rats at a dose of 200 ng kg(-1) twice with a 3-day interval between injections to establish a model of Alzheimer's-disease-like cerebral damage. Neuronal morphology was observed with thionin staining and the expressions of glial fibrillary acidic protein (GFAP) and ß-amyloid peptide 1-40 (Aß1-40) were monitored via immunohistochemistry. The level of malondialdehyde (MDA) and the activities of glutathione peroxidase (GSH-Px) and lactate dehydrogenase (LDH) were measured using spectrophotometry. MAIN OUTCOMES AND RESULTS: The results showed that OA-treated rats exhibited marked neuronal damage accompanied by increased levels of Aß1-40 peptide and MDA accumulation, decreased GFAP protein expression and reduced GSH-Px and LDH activity in the brain. SSF at three doses (25, 50 and 100 mg kg(-1)) dramatically reversed the OA-induced changes in the brains of rats. CONCLUSION: SSF-mediated amelioration of OA-induced neuronal damage in rats provides a rationale for assessing SSF as a means of to reducing tau hyperphosphorylation and Aß expression in the treatment of Alzheimer's disease.

[Efficacy of pegylated-interferon alpha-2a treatment in patients with HBeAg-positive chronic hepatitis B and partial viral response to nucleoside analogue therapy].

OBJECTIVE: To investigate the efficacy and related factors of pegylated-interferon alpha-2a (PEG-IFN-2a) treatment in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) who achieved partial viral response with nucleoside analogue (NA) therapy. METHODS: Patients with HBeAg-positive CHB and partial viral response to NA treatment were administered a PEG-IFN-2a therapy regimen of 180 g subcutaneous injection once weekly for a personlized duration of time. The existing NA therapy was continued in combination with the new PEG-IFN-2a treatment for 12 weeks. Measurements of serum HBV DNA load, hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), HBeAg and hepatitis B e antibody (anti-HBe) were taken at baseline (prior to addition of the PEG-IFN-2a therapy) and every 3 months afterwards.For determining response to treatment, primary efficacy was defined as undetectable HBsAg and seroconversion, and secondary efficacy was defined as HBsAg less than 10 IU/mL and HBeAg seroconversion.Statistical analysis was carried out using SPSS statistical software. RESULTS: A total of 81 consecutive patients with an average of 12.0 months (range: 6.0-24.0 months) of NA therapy were included in the study and received an average of 19.6 months (range: 15.5-33.3 months) of PEG-IFN-2a treatment. At the end of PEG-IFN-2a therapy, 7 (8.6%) of the patients achieved undetectable HBsAg and seroconversion, and 14 (17.3%) showed HBsAg less than 10IU/mL. In addition, 40.7% achieved undetectable HBeAg and seroconversion, a rate that was slightly higher than that (38.3%) seen in treatment-naive patients who received PEG-IFN-2a. Statistical analyses suggest that baseline level of HBsAg at less than 1500 IU/mL may predict end of PEG-IFN-2a treatment response for HBsAg less than 10 IU/mL, as evidenced by the area under the curve measure of 0.747, sensitivity measure of 87.3%, specificity measure of 33.3%, positive predictive value of 82.1% and negative predictive value of 42.8%. CONCLUSION: Patients with HBeAg-positive CHB and partial viral response to NA therapy can achieve undetectable HBsAg and HBeAg seroconversion after switching to PEG-IFN-2a treatment. Baseline HBsAg level may be predictive of response to this therapeutic strategy.

Insulin induces C2C12 cell proliferation and apoptosis through regulation of cyclin D1 and BAD expression.

Insulin is a secreted peptide hormone identified in human pancreas to promote glucose utilization. Insulin has been observed to induce cell proliferation and myogenesis in C2C12 cells. The precise mechanisms underlying the proliferation of C2C12 cells induced by insulin remain unclear. In this study, we observed for the first time that 10 nM insulin treatment promotes C2C12 cell proliferation. Additionally, 50 and 100 nM insulin treatment induces C2C12 cell apoptosis. By utilizing real-time PCR and Western blotting analysis, we found that the mRNA levels of cyclinD1 and BAD are induced upon 10 and 50 nM/100 nM insulin treatment, respectively. The similar results were observed in C2C12 cells expressing GATA-6 or PPARα. Our results identify for the first time the downstream targets of insulin, cyclin D1, and BAD, elucidate a new molecular mechanism of insulin in promoting cell proliferation and apoptosis.

Insulin induces proliferation and cardiac differentiation of P19CL6 cells in a dose-dependent manner.

Insulin is a peptide hormone produced by beta cells of the pancreas. The roles of insulin in energy metabolism have been well studied, with most of the attention focused on glucose utilization, but the roles of insulin in cell proliferation and differentiation remain unclear. In this study, we observed for the first time that 10 nmol/L insulin treatment induces cell proliferation and cardiac differentiation of P19CL6 cells, whereas 50 and 100 nmol/L insulin treatment induces P19CL6 cell apoptosis and blocks cardiac differentiation of P19CL6 cells. By using real-time polymerase chain reaction (PCR) and Western blotting analysis, we found that the mRNA levels of cyclin D1 and α myosin heavy chain (α-MHC) are induced upon 10 nmol/L insulin stimulation and inhibited upon 50/100 nmol/L insulin treatment, whereas the mRNA levels of BCL-2-antagonist of cell death (BAD) exists a reverse trend. The similar results were observed in P19CL6 cells expressing GATA-6 or peroxisome proliferator-activated receptor α (PPARα). Our results identified the downstream targets of insulin, cyclin D1, BAD, α-MHC, and GATA-4, elucidate a novel molecular mechanism of insulin in promoting cell proliferation and differentiation.

miR-200b targets GATA-4 during cell growth and differentiation.

GATA-4 is an important transcription factor involved in several developmental processes of the heart, such as cardiac myocyte proliferation, differentiation and survival. The precise mechanisms underlying the regulation of GATA-4 remain unclear, this is especially true for the mechanisms that mediate the post-transcriptional regulation of GATA-4. Here, we demonstrate that miR-200b, a member of the miR-200 family, is a critical regulator of GATA-4. Overexpression of miR-200b leads to the downregulation of GATA-4 mRNA and a decrease in GATA-4 protein levels. Moreover, miR-200b not only inhibits cell growth and differentiation but also reverses the growth response mediated by GATA-4, whereas depletion of miR-200b leads to a slight reversal of the anti-growth response achieved by knocking down endogenous GATA-4. More importantly, the cell cycle-associated gene cyclin D1, which is a downstream target of GATA-4, is also regulated by miR-200b. Thus, miR-200b targets GATA-4 to downregulate the expression of cyclin D1 and myosin heavy chain (MHC), thereby regulating cell growth and differentiation.

miRNA326-5p Targets DKC1 Gene to Regulate Apoptosis-Related Proteins and Intervene in the Development of Neuroblastoma.

Objective: To study the effect of congenital dyskeratosis 1 (DKC1) on neuroblastoma and its regulation mechanism. Methods: The expression of DKC1 in neuroblastoma was analyzed by TCGA database and molecular assay. NB cells were transfected with siDKC1 to observe the effects of DKC1 on proliferation, cloning, metastasis, and invasion, and apoptosis and apoptosis-related proteins. The tumor-bearing mouse model was constructed, shDKC1 was transfected to observe the tumor growth and tumor tissue changes, and the expression of DKC1 and Ki-67 was detected. Screening and identification of miRNA326-5p targeting DKC1. NB cells were treated with miRNA326-5p mimic or inhibitors to detect the expression of DKC1. NB cells were transfected with miRNA326-5p and DKC1 mimics to detect cell proliferation, apoptosis, and apoptotic protein expression. Results: DKC1 was highly expressed in NB cells and tissues. The activity, proliferation, invasion, and migration of NB cells were significantly decreased by DKC1 gene knockout, while apoptosis was significantly increased. The expression level of B-cell lymphoma-2 in shDKC1 group was significantly lower than that of the control group, while the expression level of BAK, BAX, and caspase-3 was significantly higher than that of the control group. The results of experiments on tumor-bearing mice were consistent with the above results. The results of miRNA assay showed that miRNA326-5p could bind DKC1 mRNA to inhibit the protein expression, thereby inhibiting the proliferation of NB cells, promoting their apoptosis, and regulating the expression of apoptotic proteins. Conclusion: miRNA326-5p targeting DKC1 mRNA regulates apoptosis-related proteins to inhibit neuroblastoma proliferation and promote the apoptotic process.