mmu-miR-185 regulates osteoclasts differentiation and migration by targeting Btk.

BACKGROUND: Bones undergo a constant remodeling, a process involving osteoclast-mediated bone resorption and osteoblast-mediated bone formation, crucial for maintaining healthy bone mass. We previously observed that miR-185 depletion may promote bone formation by regulating Bgn expression and the BMP/Smad signaling pathway. However, the effects of miR-185-5p on the osteoclasts and bone remodeling have not been elucidated, warranting further exploration. METHODS: Tartrate-resistant acid phosphatase staining was utilized to assess the differentiation ability of bone marrow mononuclear macrophages (BMMs) from mmu-miR-185 gene knockout (KO) mice and wild-type (WT) mice. A reverse transcriptase-quantitative PCR was conducted to compare differences in miR-185-5p and osteoclast marker molecules, including Trap, Dcstamp, Ctsk and Nfatc1, between the KO group and WT group BMMs. Western blot analysis was employed to observe the expression of osteoclast marker molecules. A cell-counting kit-8 was used to analyze cell proliferation ability. Transwell experiments were conducted to detect cell migration. Dual-luciferase reporter assays were employed to confirm whether Btk is a downstream target gene of miR-185-5p. RESULTS: miR-185 depletion promoted osteoclast differentiation in bone marrow-derived monocytes/macrophages. Overexpression of miR-185-5p in RAW264.7 cells inhibited differentiation and migration of osteoclasts. Furthermore, Btk was identified as a downstream target gene of miR-185-5p, suggesting that miR-185-5p may inhibit osteoclast differentiation and migration by targeting Btk. CONCLUSIONS: miR-185 regulates osteoclasts differentiation, with overexpression of miR-185-5p inhibiting osteoclast differentiation and migration in vitro. Additionally, miR-185-5p may modulate osteoclastic differentiation and migration by regulating Btk expression.

Secondary Phase Precipitation in Fe-22Mn-9Al-0.6C Low-Density Steel during Continuous Cooling Process.

Secondary phase precipitation in Fe-22Mn-9Al-0.6C low-density steel was investigated during a continuous cooling process with different cooling rates through a DIL805A thermal expansion dilatometer, and the changes in microstructures and hardness by different cooling rates were discussed. The results showed that the matrix of the Fe-22Mn-9Al-0.6C was composed of austenite and δ-ferrite; moreover, the secondary phases included κ-carbide, ß-Mn and DO3 at room temperature. The precipitation temperatures of 858 °C, 709 °C and 495 °C corresponded to the secondary phases B2, κ-carbide and ß-Mn, respectively, which were obtained from the thermal expansion curve by the tangent method. When the cooling rate was slow, it had enough time to accommodate C-poor and Al-rich regions in the austenite due to amplitude modulation decomposition. Furthermore, the Al enrichment promoted δ-ferrite formation. Meanwhile, the subsequent formation of κ-carbide and ß-Mn occurred through the continuous diffusion of C and Mn into austenite. In addition, the hardness of austenite was high at 0.03 °C/s due to the κ-carbide and ß-Mn production and C enrichment, and it was inversely proportional to the cooling rate. It can be concluded that the presence of κ-carbide, DO3 and ß-Mn produced at the austenitic/ferrite interface when the cooling rate was below 0.1 °C/s resulted in κ-carbide and ß-Mn precipitating hardly at cooling rates exceeding 0.1 °C/s, which provides a guideline for the industrial production of Fe-Mn-Al-C low-density steel in the design of the hot working process.

Dissolution Behavior of Eutectic Carbides in Medium-Alloy Steels for Heavy Forgings.

In this study, we investigate the dissolution behavior of eutectic carbides in heavy forgings. High-temperature diffusion treatment was conducted on 35Cr3Ni3MoVW2 (MoVW2) and 35Cr2Ni3MoV (MoV) steels at 1230 °C for a duration ranging from 0 to 100 h. The dissolution of eutectic carbides and its effects on the microstructure and hardness of the steels were characterized and analyzed via SEM+EBSD, ImageJ, and Thermo-Calc. The results show that the coarse eutectic carbides in both steels gradually dissolved. The distribution and morphology tend to be uniform and spherical, respectively. For holding 50 h, the hardness of both steels significantly exhibited an increasing trend, and it was attributed to the combined effects of solid solution strengthening. Thermodynamic calculations indicated that the higher W content in MoVW2 steel promoted the precipitation of M6C eutectic carbides. Moreover, both MoVW2 and MoV steels exhibited the precipitation of M7C3 eutectic carbides in the final stage of solidification, facilitated by the enrichment of C and Cr in the liquid steels.

Regulation Law of Tempering Cooling Rate on Toughness of Medium-Carbon Medium-Alloy Steel.

Temper embrittlement is a major challenge encountered during the heat treatment of high-performance steels for large forgings. This study investigates the microstructural evolution and mechanical properties of Cr-Ni-Mo-V thick-walled steel, designed for large forgings with a tensile strength of 1500 MPa, under different tempering cooling rates. Optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) were employed to analyze the microstructural features. The results demonstrate that the embrittlement occurring during air cooling after tempering is attributed to the concentration of impurities near Fe3C at the grain boundaries. The low-temperature impact toughness at -40 °C after water quenching reaches 29 J due to the accelerated cooling rate during tempering, which slows down the diffusion of impurity elements towards the grain boundaries, resulting in a reduced concentration and dislocation density and an increased stability of the grain boundaries, thereby enhancing toughness. The bainite content decreases and the interface between martensite and bainite undergoes changes after water quenching during tempering. These alterations influence the crack propagation direction within the two-phase microstructure, further modifying the toughness. These findings contribute to the understanding of temper embrittlement and provide valuable guidance for optimizing heat treatment processes to enhance the performance of high-performance steels in large forgings.

Clinical study of recurrent mild encephalitis/encephalopathy with a reversible splenial lesion in two cases.

BACKGROUND: Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) has been reported worldwidely. However, the data about recurrent cases is limited. We aimed to analyze the clinical and radiographic features of recurrent MERS, and its possible mechanisms. CASE PRESENTATION: Two patients with clinically recurrent MERS were reported here, exhibiting neurological symptoms such as limbs weakness and numbness, stand/walk unsteadily, slurred speech and irritability, and typical lesions in the corpus callosum and white matter. One of them experienced another four episodes with a similar clinical course and magnetic resonance imaging findings over a period of 10 years. The Na levels in the present two patients were normal. DISCUSSION AND CONCLUSION: Combined with the patients reported previously, recurrence could be seen in both MERS type 1 and type 2 patients, from two to multiple times, with the latter possibly more common. It suggested that some genetic factors might be involved in MERS, especially for MERS type 2 or familial MERS.

Research on Blind Super-Resolution Technology for Infrared Images of Power Equipment Based on Compressed Sensing Theory.

Infrared images of power equipment play an important role in power equipment status monitoring and fault identification. Aiming to resolve the problems of low resolution and insufficient clarity in the application of infrared images, we propose a blind super-resolution algorithm based on the theory of compressed sensing. It includes an improved blur kernel estimation method combined with compressed sensing theory and an improved infrared image super-resolution reconstruction algorithm based on block compressed sensing theory. In the blur kernel estimation method, we propose a blur kernel estimation algorithm under the compressed sensing framework to realize the estimation of the blur kernel from low-resolution images. In the estimation process, we define a new Lw norm to constrain the gradient image in the iterative process by analyzing the significant edge intensity changes before and after the image is blurred. With the Lw norm, the salient edges can be selected and enhanced, the intermediate latent image generated by the iteration can move closer to the clear image, and the accuracy of the blur kernel estimation can be improved. For the super-resolution reconstruction algorithm, we introduce a blur matrix and a regular total variation term into the traditional compressed sensing model and design a two-step total variation sparse iteration (TwTVSI) algorithm. Therefore, while ensuring the computational efficiency, the boundary effect caused by the block processing inside the image is removed. In addition, the design of the TwTVSI algorithm can effectively process the super-resolution model of compressed sensing with a sparse dictionary, thereby breaking through the reconstruction performance limitation of the traditional regularized super-resolution method of compressed sensing due to the lack of sparseness in the signal transform domain. The final experimental results also verify the effectiveness of our blind super-resolution algorithm.

Blur Kernel Estimation and Non-Blind Super-Resolution for Power Equipment Infrared Images by Compressed Sensing and Adaptive Regularization.

Infrared sensing technology is more and more widely used in the construction of power Internet of Things. However, due to cost constraints, it is difficult to achieve the large-scale installation of high-precision infrared sensors. Therefore, we propose a blind super-resolution method for infrared images of power equipment to improve the imaging quality of low-cost infrared sensors. If the blur kernel estimation and non-blind super-resolution are performed at the same time, it is easy to produce sub-optimal results, so we chose to divide the blind super-resolution into two parts. First, we propose a blur kernel estimation method based on compressed sensing theory, which accurately estimates the blur kernel through low-resolution images. After estimating the blur kernel, we propose an adaptive regularization non-blind super-resolution method to achieve the high-quality reconstruction of high-resolution infrared images. According to the final experimental demonstration, the blind super-resolution method we proposed can effectively reconstruct low-resolution infrared images of power equipment. The reconstructed image has richer details and better visual effects, which can provide better conditions for the infrared diagnosis of the power system.

Improving Neural Network Detection Accuracy of Electric Power Bushings in Infrared Images by Hough Transform.

To improve the neural network detection accuracy of the electric power bushings in infrared images, a modified algorithm based on the You Only Look Once version 2 (YOLOv2) network is proposed to achieve better recognition results. Specifically, YOLOv2 corresponds to a convolutional neural network (CNN), although its rotation invariance is poor, and some bounding boxes (BBs) exhibit certain deviations. To solve this problem, the standard Hough transform and image rotation are utilized to determine the optimal recognition angle for target detection, such that an optimal recognition effect of YOLOv2 on inclined objects (for example, bushing) is achieved. With respect to the problem that the BB is biased, the shape feature of the bushing is extracted by the Gap statistic algorithm, based on K-means clustering; thereafter, the sliding window (SW) is utilized to determine the optimal recognition area. Experimental verification indicates that the proposed rotating image method can improve the recognition effect, and the SW can further modify the BB. The accuracy of target detection increases to 97.33%, and the recall increases to 95%.

TRAF3IP3 at the trans-Golgi network regulates NKT2 maturation via the MEK/ERK signaling pathway.

Thymic natural killer T (NKT)2 cells are a subset of invariant NKT cells with PLZFhiGATA3hiIL-4+. The differentiation of NKT2 cells is not fully understood. In the present study, we report an important role of TRAF3-interacting protein 3 (TRAF3IP3) in the functional maturation and expansion of committed NKT2s in thymic medulla. Mice with T-cell-specific deletion of TRAF3IP3 had decreased thymic NKT2 cells, decreased IL-4-producing peripheral iNKTs, and defects in response to α-galactosylceramide. Positive selection and high PLZF expression in CD24+CD44- and CCR7+CD44- immature iNKTs were not affected. Only CD44hiNK1.1- iNKTs in Traf3ip3-/- mice showed reduced expression of Egr2, PLZF, and IL-17RB, decreased proliferation, and reduced IL-4 production upon stimulation. This Egr2 and IL-4 expression was augmented by MEK1/ERK activation in iNKTs, and TRAF3IP3 at the trans-Golgi network recruited MEK1 and facilitated ERK phosphorylation and nuclear translocation. LTßR-regulated bone marrow-derived nonlymphoid cells in the medullary thymic microenvironment were required for MEK/ERK activation and NKT2 maturation. These data demonstrate an important functional maturation process in NKT2 differentiation that is regulated by MEK/ERK signaling at the trans-Golgi network.

Homeobox B8 Targets Sterile Alpha Motif Domain-Containing Protein 9 and Drives Glioma Progression.

Gliomas are the most commonly occurring tumors of the central nervous system. Glioblastoma multiforme (GBM) is the most malignant and aggressive brain cancer in adults. Further understanding of the mechanisms underlying the aggressive nature of GBM is urgently needed. Here we identified homeobox B8 (HOXB8), a member of the homeobox family, as a crucial contributor to the aggressiveness of GBM. Data mining of publicly accessible RNA sequence datasets and our patient cohorts confirmed a higher expression of HOXB8 in the tumor tissue of GBM patients, and a strong positive correlation between the expression level and pathological grading of tumors and a negative correlation between the expression level and the overall survival rate. We next showed that HOXB8 promotes the proliferation and migration of glioblastoma cells and is crucial for the activation of the PI3K/AKT pathway and expression of epithelial-mesenchymal transition-related genes, possibly through direct binding to the promoter of SAMD9 (Sterile Alpha Motif Domain-Containing Protein 9) and activating its transcription. Collectively, we identified HOXB8 as a critical contributor to the aggressiveness of GBM, which provides insights into a potential therapeutic target for GBM and opens new avenues for improving its treatment outcome.

MARVELD1 attenuates arsenic trioxide-induced apoptosis in liver cancer cells by inhibiting reactive oxygen species production.

BACKGROUND: Arsenic trioxide (As2O3) is widely used for the treatment of acute promyelocytic leukemia (APL), and more recently, has also been applied to solid tumors. However, there are a fraction of patients with solid tumors, such as liver cancer, who respond to As2O3 treatment poorly. The underlying mechanisms for this remain unclear. METHODS: We determined the suitable concentration of drugs by IC50. Cell Counting Kit-8 (CCK-8) and flow cytometry were used to analyze the apoptosis. Morphological changes of the cells were observed by laser scanning confocal microscopy. Furthermore, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected by flow cytometry. Quantitative polymerase chain reaction (qPCR) and Western blot tests were conducted to detect the mRNA and protein levels in different groups. Finally, a xenograft tumor assay and histopathological analysis were performed to evaluate the MARVELD1 function in cell proliferation and apoptosis. RESULTS: Here, we show that MARVELD1 enhances the therapeutic effects of epirubicin, while inducing the strong resistance of liver cancer cells to As2O3 treatment. We further demonstrate that the As2O3-induced apoptosis was inhibited by MARVELD1 overexpression (24 h Vector vs. MARVELD1 =30.58% vs. 17.41%, P<0.01; 48 h Vector vs. MARVELD1 =46.50% vs. 21.02%, P<0.01), possibly through inhibiting ROS production by enhancing TRXR1 expression. In vivo, we found a significantly increased size (Vector vs. MARVELD1 =203.90±21.92 vs. 675.70±37.84 mm3, P<0.001) and weight (Vector vs. MARVELD1 =0.19±0.02 vs. 0.58±0.05 g, P<0.001) of tumors with high expression of MARVELD1 after As2O3 treatment. Consistently, a higher expression of MARVELD1 predicted a poor prognosis for liver cancer patients. CONCLUSIONS: Our data identified a unique role of MARVELD1 in As2O3-induced apoptosis and As2O3 cancer therapy resistance.

Mmu-miR-185 depletion promotes osteogenic differentiation and suppresses bone loss in osteoporosis through the Bgn-mediated BMP/Smad pathway.

MicroRNAs (miRs) play an essential role in the regulation of bone formation and homeostasis. miR-185 has been reported to negatively regulate osteogenesis in vitro. However, whether it has an impact on in vivo bone homeostasis remains unknown. Here, we demonstrated that primary osteoblasts and mesenchymal stem cells derived from miR-185-knockout (KO) mice exhibited enhanced osteogenesis. Further, we constructed an ovariectomized mouse model to investigate the role of miR-185 during osteoporosis. Micro-computed tomography revealed an increased bone volume in KO compared to wild-type mice 6 weeks after surgery, indicating redundant bone formation after miR-185 depletion. Dual-luciferase reporter assays identified biglycan (Bgn), which promotes bone formation through the BMP/Smad pathway, as the direct target of miR-185. Taken together, these findings indicate that blocking miR-185 expression increases bone formation during osteoporosis, which may partly occur through the regulation of Bgn expression and BMP/Smad signaling.

GXYLT2 accelerates cell growth and migration by regulating the Notch pathway in human cancer cells.

Glucoside xylosyltransferase2 (GXYLT2), a member of the human α-1,3-D-xylosyltransferases, functions to modify the first xylose to the O-Glucose residue on epidermal growth factor (EGF) repeats of Notch receptors. It is well-established that the Notch signaling pathway plays a critical role in proper development and homeostasis. However, the regulatory role of EGF xylosylation in Notch signaling and different cell activities in human cells remains unknown. In this study, we showed that knockdown of GXYLT2 suppressed human cell proliferation and induced G1/S phase cell cycle arrest. GXYLT2 downregulation also inhibited cell migration and invasion, whereas the overexpression of GXYLT2 had the opposite effects. Additionally, GXYLT2 activated Notch signaling and promoted the phosphorylation of MAPKs but not PI3K and Akt. Taken together, our findings indicated that GXYLT2 plays an important role in cell activities via regulation of the Notch signaling.

Nop-7-associated 2 (NSA2) is required for ribosome biogenesis and protein synthesis.

Ribosome biogenesis is a fundamental cellular process and occurs mainly in the nucleolus in eukaryotes. The process is exceptionally complex and highly regulated by numerous ribosomal and non-ribosomal factors. A recent discovery strengthened the link between ribosome biogenesis and malignant transformation. Here, we determined that Nop-7-associated 2 (NSA2) is a nucleolar protein required for ribosome biogenesis. NSA2 knockdown reduced the rate of rRNA synthesis, diminishing the 60S ribosomal subunit. Moreover, we demonstrated that depletion of NSA2 suppressed protein synthesis. To investigate the signaling pathway affected by NSA2, NSA2 was depleted, which triggered the inactivation of the mTOR signaling pathway. Taken together, our findings reveal a novel function of NSA2 and provide insight into the regulation of ribosome biogenesis by NSA2.

mmu-miR-1963 negatively regulates the ameloblast differentiation of LS8 cell line by directly targeting Smoc2 3'UTR.

RUNX2 is a key regulator of osteogenic differentiation and odontoblastic differentiation. RUNX2 mutations could cause Cleidocranial dysplasia (CCD; OMIM119600), which is featured by abnormal development of bone and teeth. By using microRNA array, we identified a large number of microRNAs that showed different expression between wild-type Runx2 group and mutant groups. The aim of this study is to find out the effect of mmu-miR-1963, which was downregulated in all mutant Runx2 groups, on the ameloblast differentiation of LS8 cells. qPCR and Western Blot results showed the suppressive effect of mmu-miR-1963 on ameloblast differentiation of LS8 cell line. We further confirmed Smoc2 as one direct target of mmu-miR-1963. For the first time, we showed that mmu-miR-1963 could regulate the ameloblast differentiation of LS8 by targeting Smoc2. This study suggests the suppressive role of mmu-miR-1963 on ameloblast differentiation of LS8 via directly targeting the 3'UTR of Smoc2. We also demonstrated that Smoc2 itself could promote the ameloblast differentiation of LS8 for the first time. Our results indicate a novel explanation to the enamel hypoplasia phenotype in part of CCD patients.

Mutant Runx2 regulates amelogenesis and osteogenesis through a miR-185-5p-Dlx2 axis.

Regulation of microRNAs (miRNA) has been extensively investigated in diseases; however, little is known about the roles of miRNAs in cleidocranial dysplasia (CCD). The aim of the present study was to investigate the potential involvement of miRNAs in CCD. In vitro site-directed mutagenesis was performed to construct three mutant Runx2 expression vectors, which were then transfected into LS8 cells and MC3T3-E1 cells, to determine the impact on amelogenesis and osteogenesis, respectively. miRCURY LNA miRNA microarray identify miR-185-5p as a miRNA target commonly induced by all three Runx2 mutants. Real-time quantitative PCR was applied to determine the expression of miR-185-5p and Dlx2 in samples. Dual-luciferase reporter assays were conducted to confirm Dlx2 as a legitimate target of miR-185-5p. The suppressive effect of miR-185-5p on amelogenesis and osteogenesis of miR-185-5p was evaluated by RT-PCR and western blot examination of Amelx, Enam, Klk4, and Mmp20 gene and protein expression, and by Alizarin Red stain. We found that mutant Runx2 suppressed amelogenesis and osteogenesis. miR-185-5p, induced by Runx2, suppressed amelogenesis and osteogenesis. Furthermore, we identified Dlx2 as direct target of miR-185-5p. Consistently, Dlx2 expression was inversely correlated with miR-185-5p levels. This study highlights the molecular etiology and significance of miR-185-5p in CCD, and suggests that targeting miR-185-5p may represent a new therapeutic strategy in prevention or intervention of CCD.

Identification of four novel XPC mutations in two xeroderma pigmentosum complementation group C patients and functional study of XPC Q320X mutant.

Xeroderma pigmentosum (XP) is a rare, recessive hereditary disease characterized by sunlight hypersensitivity and high incidence of skin cancer with clinical and genetic heterogeneity. We collected two unrelated Chinese patients showing typical symptoms of XPC without neurologic symptoms. Direct sequencing of XPC gene revealed that patient 1 carried IVS1+1G>A and c.958 C>T mutations, and patient 2 carried c.545_546delTA and c.2257_2258insC mutations. All these four mutations introduced premature terminal codons (PTCs) in XPC gene. The nonsense mutation c.958 C>T yielded truncated mutant Q320X, and we studied its function for global genome repair kinetics. Overexpressed Q320X mutant can localize to site of DNA damage, but it is defective in CPD and 6-4PP repair. Readthrough of PTCs is a new approach to treatment of genetic diseases. We found that aminoglycosides could significantly increase the full length protein expression of Q320X mutant, but NER defects were not rescued in vitro.

Novel mutations in the lipase H gene lead to secretion defects of LIPH in Chinese patients with autosomal recessive woolly hair/hypotrichosis (ARWH/HT).

Autosomal recessive woolly hair/hypotrichosis (ARWH/HT: OMIM #278150/604379) is a rare hereditary hair disease characterized by tightly curled hair at birth which can lead to sparse hair later in life. The mutations in both LIPH and LPAR6/P2RY5 are responsible for autosomal recessive woolly hair with or without hypotrichosis (ARWH/HT). To conduct clinical and genetic investigations in four patients from three unrelated Chinese Han families with ARWH/HT, we performed mutation screening of LIPH and LPAR6/P2RY5 gene and identified four mutations in LIPH: c.454G>A, c.614A>G, c.736T>A, c.742C>A. c.736T>A and c.742C>A mutations were reported in previous studies, and c.454G>A, c.614A>G were identified for the first time. We carried out functional studies of the two mutants with c.454G>A (p.Gly152Arg, G152R) or c.614A>G (p.His205Arg, H205R). Interestingly, both of them lead to secretion defects of LIPH, which are involved in the pathogenesis of ARWH/HT.

Functional Study of Ectodysplasin-A Mutations Causing Non-Syndromic Tooth Agenesis.

Recent studies have demonstrated that ectodysplasin-A (EDA) mutations are associated with non-syndromic tooth agenesis. Indeed, we were the first to report three novel EDA mutations (A259E, R289C and R334H) in sporadic non-syndromic tooth agenesis. We studied the mechanism linking EDA mutations and non-syndromic tooth agenesis in human embryonic kidney 293T cells and mouse ameloblast-derived LS8 cells transfected with mutant isoforms of EDA. The receptor binding capability of the mutant EDA1 protein was impaired in comparison to wild-type EDA1. Although the non-syndromic tooth agenesis-causing EDA1 mutants possessed residual binding capability, the transcriptional activation of the receptor's downstream target, nuclear factor κB (NF-κB), was compromised. We also analyzed the changes of selected genes in other signaling pathways, such as WNT and BMP, after EDA mutation. We found that non-syndromic tooth agenesis-causing EDA1 mutant proteins upregulate BMP4 (bone morphogenetic protein 4) mRNA expression and downregulate WNT10A and WNT10B (wingless-type MMTV integration site family member 10A and 10B) mRNA expression. Our results indicated that non-syndromic tooth agenesis causing EDA mutations (A259E, R289C and R334H) were loss-of-function, and suggested that EDA may regulate the expression of WNT10A, WNT10B and BMP4 via NF-κB during tooth development. The results from our study may help to understand the molecular mechanism linking specific EDA mutations with non-syndromic tooth agenesis.

Two Novel Heterozygous Mutations in ERCC8 Cause Cockayne Syndrome in a Chinese Patient.

BACKGROUND: Cockayne syndrome (MIM #133540, Cockayne syndrome B; 216400, Cockayne syndrome A) is a rare autosomal recessive inherited disease in which the characteristic symptoms are premature aging, cachectic dwarfism, lack of subcutaneous fat, neurological alterations, light sensitivity, and failure to thrive. The mutated gene responsible for this syndrome has been identified as usually either CSA (CKN1, ERCC8) or CSB (ERCC6). In this study, we describe the case of a 7-year-old Chinese boy with characteristic symptoms of Cockayne syndrome A and the conduction of mutation screening of the CSA gene. METHODS: The patient was diagnosed with Cockayne syndrome in the pediatrics clinic for growth failure and developmental delay. We collected peripheral blood samples of the patient and his parents and then extracted the genomic DNA. DNA samples from control subjects and the patient were subjected to polymerase chain reaction amplification. All exons and the flanking intron-exon boundaries of CSA were amplified; then, the polymerase chain reaction products were directly sequenced for mutation screening. RESULTS: Two novel heterozygous CSA mutations, c.551-2A>C and c.394_398delTTACA, were identified in the patient. The c.551-2A>C mutation originates from his father and changed the splice acceptor site AG to CG, thus possibly causing alternative splicing. The c.394_398delTTACA from his mother caused a frameshift after the amino acid at position 132, thus introducing a premature stop codon in the gene sequence. CONCLUSIONS: These mutations extend the mutation spectrum of Cockayne syndrome in the context of Chinese race and provide possibilities of prenatal diagnosis for future offsprings in this family.