1D Cu(I)-based chiral organic-inorganic hybrid material with second harmonic generation and circular polarized luminescence

In recent years, organic-inorganic hybrid materials have demonstrated exceptional performance in nonlinear optics, attracting widespread attention. However, there are relatively few examples of coordination compounds synthesized with Cu as the metal center that exhibit excellent nonlinear optical properties. In this study, we successfully synthesized a pair of enantiomers named R/S-Cu2I2 by reacting chiral ligands with CuI. The crystal structure reveals a one-dimensional copper-iodide chain structure built by Cu2I2 clusters, and its ordered arrangement in space provides not only a strong second harmonic generation (SHG) signal (1.24 × KDP) but also a large birefringence (0.15@1064 nm). Under excitation at 395 nm, the crystals exhibit red fluorescence peaked at 675 nm. The CD spectra of R/S-Cu2I2 show a distinct mirror-symmetric Cotton effect, and their CPL signals are corresponding and opposite in the emission range, with a maximum glum of approximately ±2.5 × 10-3. Theoretical calculations using density functional theory were also carried out to enhance our understanding of the correlation between their structures and optical properties.

[Modified gasless trans-subclavian approach endoscopic lateral neck dissection for treatment of papillary thyroid carcinoma: a series of 31 cases]

Objective: To examine the feasibility of the modified gasless trans-subclavian approach endoscopic thyroidectomy for lateral neck dissection (LND) in papillary thyroid carcinoma (PTC). Methods: The clinical data of 31 patients with PTC who underwent modified gasless trans-subclavian approach endoscopic LND in the Department of Head and Neck Surgery, Run Run Shaw Hospital, from January to October 2022 were retrospectively analyzed. There were 2 males and 29 females, aged (32.6±8.3) years (range: 17 to 55 years). The maximum diameter of the primary thyroid lesion (M(IQR)) was 1.06 (1.16) cm (range: 0.53 to 2.44 cm), and the maximum diameter of the metastatic lymph node was (1.04±0.37) cm (range: 0.44 to 1.88 cm). Operation time, postoperative hospital stay, number of lymph nodes dissected, and postoperative complications were recorded. Outpatient follow-up was conducted until November 30, 2022. Results: All operations were successfully completed with the endoscopy approach without conversion to open surgery. The operation time was 160 (20) minutes (range: 100 to 215 minutes), and the postoperative hospital stay was 4 (2) days (range: 2 to 14 days). The number of lymph nodes obtained by dissection in the central and lateral compartment of the neck was 11 (12) (range: 0 to 37) and 34.7±14.8 (range: 15 to 69), respectively. Temporary hypoparathyroidism occurred in 4 cases and all recovered within 1 month after the operation. One case suffered from recurrent laryngeal nerve injury (continuing followed up to assess whether it is a temporary injury). The complication of LND included 1 case of chylous leakage that was recovered with conservative treatment, 1 case of Horner syndrome returned to normal 3 months after surgery. During follow-up, there was no residual tumor or recurrence. Conclusion: The modified gasless trans-subclavian approach endoscopic LND for PTC is feasible, with a thorough dissection and concealed incision.

SRSF3/AMOTL1 splicing axis promotes the tumorigenesis of nasopharyngeal carcinoma through regulating the nucleus translocation of YAP1

Dysregulation of serine/arginine splicing factors (SRSFs) and abnormal alternative splicing (AS) have been widely implicated in various cancers but scarcely investigated in nasopharyngeal carcinoma (NPC). Here we examine the expression of 12 classical SRSFs between 87 NPC and 10 control samples, revealing a significant upregulation of SRSF3 and its association with worse prognosis in NPC. Functional assays demonstrate that SRSF3 exerts an oncogenic function in NPC progression. Transcriptome analysis reveals 1,934 SRSF3-regulated AS events in genes related to cell cycle and mRNA metabolism. Among these events, we verify the generation of a long isoform of AMOTL1 (AMOTL1-L) through a direct bond of the SRSF3 RRM domain with the exon 12 of AMOTL1 to promote exon inclusion. Functional studies also reveal that AMOTL1-L promotes the proliferation and migration of NPC cells, while AMOTL1-S does not. Furthermore, overexpression of AMOTL1-L, but not -S, significantly rescues the inhibitory effects of SRSF3 knockdown. Additionally, compared with AMOTL1-S, AMOTL1-L has a localization preference in the intracellular than the cell membrane, leading to a more robust interaction with YAP1 to promote nucleus translocation. Our findings identify SRSF3/AMOTL1 as a novel alternative splicing axis with pivotal roles in NPC development, which could serve as promising prognostic biomarkers and therapeutic targets for NPC.

Spontaneous urinary bladder regeneration after subtotal cystectomy increases YAP/WWTR1 signaling and downstream BDNF expression: Implications for smooth muscle injury responses

Rodents have the capacity for spontaneous bladder regeneration and bladder smooth muscle cell (BSMC) migration following a subtotal cystectomy (STC). YAP/WWTR1 and BDNF (Brain-derived neurotrophic factor) play crucial roles in development and regeneration. During partial bladder outlet obstruction (PBO), excessive YAP/WWTR1 signaling and BDNF expression increases BSMC hypertrophy and dysfunction. YAP/WWTR1 and expression of BDNF and CYR61 were examined in models of regeneration and wound repair. Live cell microscopy was utilized in an ex vivo model of STC to visualize cell movement and division. In Sprague-Dawley female rats, STC was performed by resection of the bladder dome sparing the trigone, followed by closure of the bladder. Smooth muscle migration and downstream effects on signaling and expression were also examined after scratch wound of BSMC with inhibitors of YAP and BDNF signaling. Sham, PBO and incision (cystotomy) were comparators for the STC model. Scratch wound in vitro increased SMC migration and expression of BDNF, CTGF and CYR61 in a YAP/WWTR1-dependent manner. Inhibition of YAP/WWTR1 and BDNF signaling reduced scratch-induced migration. BDNF and CYR61 expression was elevated during STC and PBO. STC induces discrete genes associated with endogenous de novo cell regeneration downstream of YAP/WWTR1 activation.

Maternal exposure to 4-vinylcyclohexene diepoxide during pregnancy induces subfertility and birth defects of offspring in mice

4-vinylcyclohexene diepoxide (VCD), widely used in industry, is a hazardous compound that can cause premature ovarian failure, but whether maternal VCD exposure affects the health and reproduction of offspring is unknown. Here we focused on the effects of VCD on fertility and physical health of F1 and F2 offspring in mice. The pregnant mice were injected intraperitoneally with different dosages of VCD once every day from 6.5 to 18.5 days post-coitus (dpc). We showed that maternal exposure to VCD during pregnancy significantly reduced the litter size and ovarian reserve, while increasing microtia occurrences of F1 mice. The cytospread staining showed a significant inhibition of meiotic prophase I progression from the zygotene stage to the pachytene stage. Mechanistically, the expression level of DNA damage marker (γ-H2AX) and BAX/BCL2 ratios were significantly increased, and RAD51 and DMC1 were extensively recruited to DNA double strand breaks sites in the oocytes of offspring from VCD-exposed mothers. Overall, our results provide solid evidence showing that maternal exposure to VCD during pregnancy has intergenerational deleterious effects on the offspring.

Viscoelastic Notch Signaling Hydrogel Induces Liver Bile Duct Organoid Growth and Morphogenesis

Cholangiocyte organoids can be used to model liver biliary disease; however, both a defined matrix to emulate cholangiocyte self-assembly and the mechano-transduction pathways involved therein remain elusive. A series of defined viscoelastic hyaluronan hydrogels to culture primary cholangiocytes are designed and it is found that by mimicking the stress relaxation rate of liver tissue, cholangiocyte organoid growth can be induced and expression of Yes-associated protein (YAP) target genes could be significantly increased. Strikingly, inhibition of matrix metalloproteinases (MMPs) does not significantly affect organoid growth in 3D culture, suggesting that mechanical remodeling of the viscoelastic microenvironment-and not MMP-mediated degradation-is the key to cholangiocyte organoid growth. By immobilizing Jagged1 to the hyaluronan, stress relaxing hydrogel, self-assembled bile duct structures form in organoid culture, indicating the synergistic effects of Notch signaling and viscoelasticity. By uncovering critical roles of hydrogel viscoelasticity, YAP signaling, and Notch activation, cholangiocyte organogenesis is controlled, thereby paving the way for their use in disease modeling and/or transplantation.

[Effects and mechanism of hydrogen peroxide pretreatment with low molarity on oxidative stress induced apoptosis of mouse bone marrow mesenchymal stem cells]

Objective: To investigate the effects and mechanism of hydrogen peroxide (HP) pretreatment with low molarity on oxidative stress induced apoptosis of mouse bone marrow mesenchymal stem cells (BMSCs). Methods: The experimental research methods were used. BMSCs were isolated and cultured from two 2-week-old male BALB/c mice by the whole bone marrow culture method. The 3rd-7th passages of cells in logarithmic growth phase were used for the experiments after identification. According to the random number table (the same grouping method below), the cells were divided into 0 μmol/L HP group (without HP, the same below), 25 μmol/L HP group, 50 μmol/L HP group, 100 μmol/L HP group, 150 μmol/L HP group, 200 μmol/L HP group, 250 μmol/L HP group, and 300 μmol/L HP group in which cells were treated by the corresponding final molarity of HP, respectively. The apoptosis rate was detected by flow cytometry (n=4) after 24 hours of culture. The cells were divided into 0 μmol/L HP group, 25 μmol/L HP group, 50 μmol/L HP group, and 100 μmol/L HP group in which cells were treated by the corresponding final molarity of HP, respeclively. After 24 hours of culture, the protein expressions of B-lymphoma-2 (Bcl-2) and Bcl-2-related X protein (Bax) were detected by Western blotting, and the Bcl-2/Bax ratio was calculated (n=3). The cells were divided into 0 μmol/L HP group, 25 μmol/L HP group, 50 μmol/L HP group, 100 μmol/L HP group, 200 μmol/L HP group, and 300 μmol/L HP group in which cells were treated by the corresponding final molarity of HP, respectively. After 24 hours of culture, the protein expressions of glycogen synthase kinase-3β (GSK-3β) and phosphorylated GSK-3β (p-GSK-3β) were detected by Western blotting (n=3). The cells were divided into 0 μmol/L HP group, 50 μmol/L HP group, and 300 μmol/L HP group in which cells were treated by the corresponding final molarity of HP, respeclively, and HP pretreatment group with 50 μmol/L HP being added in advance for 12 h and then 300 μmol/L HP being added. After 24 hours of culture, the morphology and growth of cells were observed by inverted fluorescence microscopy (non-fluorescent condition) and immunofluorescence method, the apoptosis rate was detected by flow cytometry, the protein expressions of Bcl-2, Bax, cysteine aspartic acid specific protease-3 (caspase-3), caspase-9, cleavage caspase-3, cleavage caspase-9, GSK-3β, and p-GSK-3β were detected by Western blotting, and the Bcl-2/Bax ratio was calculated, with all the number of samples being 3. Data were statistically analyzed with one-way analysis of variance and Bonferroni test. Results: After 24 hours of culture, compared with that in 0 μmol/L HP group, the apoptosis rate of cells did not change significantly in 25 μmol/L HP group, 50 μmol/L HP group, or 100 μmol/L HP group (P>0.05) but increased significantly in 150 μmol/L HP group, 200 μmol/L HP group, 250 μmol/L HP group, and 300 μmol/L HP group (P<0.01). After 24 hours of culture, compared with that in 0 μmol/L HP group, the Bcl-2/Bax ratio of cells increased significantly in 25 μmol/L HP group and 50 μmol/L HP group (P<0.05 or P<0.01) but decreased significantly in 100 µmol/L HP group (P<0.05). After 24 hours of culture, compared with those in 0 μmol/L HP group, the protein expression of GSK-3β in cells showed no significant change in 25 μmol/L HP group and 50 μmol/L HP group (P>0.05), the protein expressions of p-GSK-3β in cells significantly increased in 25 μmol/L HP group and 50 μmol/L HP group (P<0.01), the protein expressions of GSK-3β and p-GSK-3β in cells in 100 μmol/L HP group showed no significant change (P>0.05), the protein expressions of GSK-3β in cells in 200 μmol/L HP group and 300 μmol/L HP group were significantly increased (P<0.05). but the protein expression of p-GSK-3β in cells in 200 μmol/L HP group and 300 μmol/L HP group was significantly decreased (P<0.05). After 24 hours of culture, the morphology and growth of cells in 0 μmol/L HP group and 50 μmol/L HP group were similar and normal; in contrast, the cells in 300 µmol/L HP group became smaller and round, with the cell protrusions being shorter or disappeared, the nucleus being cavitated, and the cell abscission being increased significantly; the morphology of most cells in HP pretreatment group was normal, with the shedding of cells being less than that in 300 µmol/L HP group, and the morphology of nucleus being normal. After 24 hours of culture, the protein expression of caspase-9 was similar among the four groups (P>0.05). Compared with that in 0 μmol/L HP group, the apoptosis rate and the protein expressions of cleavage caspase-9, caspase-3, and cleavage caspase-3 of cells in 50 μmol/L HP group showed no significant changes (P>0.05), the Bcl-2/Bax ratio of cells in 50 μmol/L HP group increased significantly (P<0.05), the apoptosis rate and the protein expressions of cleavage caspase-9, caspase-3, and cleavage caspase-3 of cells in 300 μmol/L HP group were significantly increased (P<0.01), while the Bcl-2/Bax ratio of cells in 300 μmol/L HP group was significantly decreased (P<0.05). Compared with those in 300 μmol/L HP group, the apoptosis rate and the protein expressions of cleavage caspase-9, caspase-3, and cleavage caspase-3 of cells were significantly decreased in HP pretreatment group (P<0.05 or P<0.01), while the Bcl-2/Bax ratio of cells was significantly increased in HP pretreatment group (P<0.01). After 24 hours of culture, the protein expressions of GSK-3β and p-GSK-3β of cells in 0 μmol/L HP group, 50 μmol/L HP group, 300 μmol/L HP group, and HP pretreatment group were 1.09±0.14, 0.62±0.17, 1.35±0.21, 0.74±0.34, 0.68±0.03, 0.85±0.08, 0.38±0.10, and 0.54±0.09, respectively. Compared with those in 0 μmol/L HP group, the protein expression of p-GSK-3β of cells was significantly increased in 50 μmol/L HP group (P<0.05) but significantly decreased in 300 μmol/L HP group (P<0.01), while the protein expression of GSK-3β of cells was significantly increased in 300 μmol/L HP group (P<0.05). Compared with those in 300 μmol/L HP group, the protein expression of GSK-3β of cells was significantly decreased in HP pretreatment group (P<0.01), while the protein expression of p-GSK-3β of cells was significantly increased in HP pretreatment group (P<0.01). Conclusions: The molarity of 50 μmol/L may be the optimal molarity of HP to pretreat mouse BMSCs, and 50 μmol/L HP pretreatment can antagonize mitochondrial pathway of oxidative stress induced apoptosis by inhibiting the activity of GSK-3β.

[The value of renal color Doppler ultrasound in evaluating the severity and prognosis of patients with acute organophosphorus pesticide poisoning complicated by acute kidney injury]

Objective: To analyze the value of renal color Doppler ultrasound examination and clinical indicators in evaluating the severity and prognosis of acute organophosphorus pesticide poisoning (AOPP) complicated by acute kidney injury (AKI) . Methods: In November 2019, 86 AOPP patients complicated by AKI who were admitted from May 2018 to May 2019 were selected as the observation group, and they were divided into AKI stage 1 group (n=37) , AKI stage 2 group (n=32) and AKI stage 3 group (n=17) . 40 healthy people were selected as the control group. The differences in power Doppler ultrasound (PDU) score, renal interlobular artery resistance index (RI) value and related clinical indicators of each group were measured and analyzed, and the correlations between the indicators were analyzed. At the same time, binary logistic regression was used to analyze the risk factors of death in AOPP patients complicated by AKI. Results: There were statistically significant differences in Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱscore, mean arterial pressure (MAP) , serum creatinine (SCr) and the length of continuous renal replacement therapy (CRRT) between different groups (P<0.05) . Compared with the control group, the APACHE Ⅱscores and SCr of patients in the AKI stage 2 and resistance index AKI stage 3 groups increased, while the MAP decreased (P<0.05) . Compared with the control group, AKI stage 1 group and AKI stage 2 group, the PDU score of patients in the AKI stage 3 group was significantly decreased, and the renal interlobular artery RI value was significantly increased (P<0.05) . SCr was positively correlated with the RI value of renal interlobular arteries and CRRT days (r=0.435, 0.713, P<0.05) , and was negatively correlated with renal PDU score (r=-0.643, P<0.05) . The renal PDU score was negatively correlated with the RI value of renal interlobular arteries and CRRT days (r=-0.350, -0.556, P<0.01) . Binary logistic regression analysis showed that SCr (OR=1.017, 95%CI: 1.004-1.041) and APACHE Ⅱ score (OR=1.289, 95%CI: 1.019-1.827) were risk factors for death in patients with AOPP complicated by AKI (P<0.05) . Conclusion: Both PDU score and the RI value of renal interlobular artery can reflect the severity and stage of patients with AOPP complicated by AKI to a certain extent, but neither of them is a key factor affecting the death of patients.

Generation of functional ciliated cholangiocytes from human pluripotent stem cells

The derivation of mature functional cholangiocytes from human pluripotent stem cells (hPSCs) provides a model for studying the pathogenesis of cholangiopathies and for developing therapies to treat them. Current differentiation protocols are not efficient and give rise to cholangiocytes that are not fully mature, limiting their therapeutic applications. Here, we generate functional hPSC-derived cholangiocytes that display many characteristics of mature bile duct cells including high levels of cystic fibrosis transmembrane conductance regulator (CFTR) and the presence of primary cilia capable of sensing flow. With this level of maturation, these cholangiocytes are amenable for testing the efficacy of cystic fibrosis drugs and for studying the role of cilia in cholangiocyte development and function. Transplantation studies show that the mature cholangiocytes generate ductal structures in the liver of immunocompromised mice indicating that it may be possible to develop cell-based therapies to restore bile duct function in patients with biliary disease.

Inhibition of DNA methylation during chronic obstructive bladder disease (COBD) improves function, pathology and expression

Partial bladder outlet obstruction due to prostate hyperplasia or posterior urethral valves, is a widespread cause of urinary dysfunction, patient discomfort and also responsible for immense health care costs. Even after removal or relief of obstruction, the functional and pathologic aspects of obstruction remain as a chronic obstructive bladder disease (COBD). Epigenetic changes, such as DNA methylation, contribute to the persistent character of many chronic diseases, and may be altered in COBD. We tested whether candidate genes and pathways and the pathophysiology of COBD were affected by a hypomethylating agent, decitabine (DAC). COBD was created in female Sprague-Dawley rats by surgical ligation of the urethra for 6 weeks, followed by removal of the suture. Sham ligations were performed by passing the suture behind the urethra. After removal of the obstruction or sham removal, animals were randomized to DAC treatment (1 mg/kg/3-times/week intraperitoneally) or vehicle (normal saline). Bladder function was non-invasively tested using metabolic cages, both one day prior to de-obstruction at 6 weeks and prior to sacrifice at 10 weeks. Residual volume and bladder mass were measured for each bladder. Bladders were examined by immunostaining as well as qPCR. The effects of DNA methyltransferase (DNMT)-3A knockout or overexpression on smooth muscle cell (SMC) function and phenotype were also examined in bladder SMC and ex vivo culture. Residual volumes of the DAC treated group were not significantly different from the NS group. Compared to COBD NS, COBD DAC treatment helped preserve micturition volume with a significant recovery of the voiding efficiency (ratio of the maximum voided volume/maximum bladder capacity) by one third (Fig. 1, p > 0.05). Brain-derived neurotrophic factor (BDNF) variants 1 and 5 were upregulated by COBD and significantly reduced by DAC treatment. Deposition of collagen in the COBD bladder was reduced by DAC, but gross hypertrophy remained. In bladder SMC, DNMT3A overexpression led to a loss of contractile function and phenotype. In bladders, persistently altered by COBD, inhibition of DNA-methylation enhances functional recovery, unlike treatment during partial obstruction, which exacerbates obstructive pathology. The underlying mechanisms may relate to the gene expression changes in BDNF and their effects on signaling in the bladder.

[Role of interleukin-6 in human umbilical vein endothelial cell to mesenchymal cell transformation]

Objective: To observe the effect of interleukin-6 (IL-6) on the phenotype and function of human umbilical vein endothelial cells (HUVECs) and explore the role of IL-6 in the process of endothelial-to-mesenchymal transition (EndMT). Methods: The experimental research method was used. Fresh umbilical cord discarded after normal maternal delivery was collected. On the second day of the primary cell isolation and cultivation, the cell morphology was observed under inverted phase contrast microscope. HUVECs of the 4th passage were identified by immunofluorescence method, and 2 batches of HUVECs ofthe 3rd to 5th passages were used for the subsequent experiments. The first batch of cells were divided into 6 groups according to the random number table (the same below): blank control group, 5 ng/mL IL-6 group, 10 ng/mL IL-6 group, 25 ng/mL IL-6 group, 50 ng/mL IL-6 group, and 100 ng/mL IL-6 group. The second batch of cells were divided into 4 groups: blank control group, 10 ng/mL IL-6 group, 25 ng/mL IL-6 group,and 50 ng/mL IL-6 group; the cells in blank control group was cultured with complete culture medium only, while the cells in the other groups were added with IL-6 of the corresponding final mass concentrations.Cells from the 1st batch were cultured for 72 hours after grouping, the morphology of HUVECS in the 6 groups was observed under inverted phase contrast microscope. At 72 h after grouping culture, the positive expressions of coagulation factor Ⅷ and α vascular smooth muscle actin (α-SMA) in HUVECs in the 6 groups were detected by immunofluorescence method, and the ratio of the number of double positive cells to the number of coagulation factor Ⅷ positive cells (the ratio of double positive cells for short) was calculated, with 6 samples per group; mRNA expression levels of vascular endothelial cadherin and α-SMA of HUVECs in 6 groups were detected by reverse transcription-polymerase chain reaction, with 3 samples per group.Cells from the 2nd batch were cultured 72 hours after grouping, the protein expression levels of vascular endothelial cadherin, α-SMA, and type Ⅰ collagen in the 4 groups were detected by Western blotting, with 3 samples per group. Data were statistically analyzed with one-way analysis of variance and Bonferroni correction. Results: On the 2nd day after isolation and cultivation, the primary cells were in short spindle shape or polygon, cells of the 4th passage were identified as HUVECs by immunofluorescence method. At 72 hours of culture after grouping, the cells from the 1st batch in the 6 groups changed to long spindle shape morphologically along with the increase of IL-6 concentration, the intercellular connections decreased or disappeared with the gap between cells becoming larger. At 72 h after grouping culture, compared with that inblank control group, the ratio of double positive cells in 25 ng/mL IL-6 group, 50 ng/mL IL-6 group, and 100 ng/mL IL-6 group were significantly increased (P<0.01); compared with that in 5 ng/mL IL-6 group, the ratio of double positive cells in 25 ng/mL IL-6 group, 50 ng/mL IL-6 group, and 100 ng/mL IL-6 group were significantly increased (P<0.01); compared with that in 10 ng/mL IL-6 group, the ratio of double positive cells in 50 ng/mL IL-6 group and 100 ng/mL IL-6 group were significantly increased (P<0.01); the ratio of double positive cells in 100 ng/mL IL-6 group was significantly increased compared with those in 25 ng/mL IL-6 group and 50 ng/mL IL-6 group (P<0.01). At 72 h after grouping culture, compared with that in blank control group, the mRNA expression levels of vascular endothelial cadherin of cells in 25 ng/mL IL-6 group, 50 ng/mL IL-6 group, and 100 ng/mL IL-6 group were significantly decreased (P<0.01 or P<0.05); compared with that in 5 ng/mL IL-6 group, the mRNA expression levels of vascular endothelial cadherin of cells in 50 ng/mL IL-6 group and 100 ng/mL IL-6 group were significantly decreased (P<0.01); compared with that in 10 ng/mL IL-6 group, the mRNA expression levels of vascular endothelial cadherin of cells in 50 ng/mL IL-6 group and 100 ng/mL IL-6 group were significantly decreased (P<0.01); compared with that in 25 ng/mL IL-6 group, the mRNA expression levels of vascular endothelial cadherin of cells in 50 ng/mL IL-6 group and 100 ng/mL IL-6 group were significantly decreased (P<0.01). At 72 h after grouping culture, compared with that in blank control group, the mRNA expression levels of α-SMA of cells in 5 ng/mL IL-6 group, 10 ng/mL IL-6 group, 25 ng/mL IL-6 group, 50 ng/mL IL-6, group, and 100 ng/mL IL-6 group were significantly increased (P<0.05 or P<0.01). Cells from the 2nd batch were cultured for 72 hours after grouping. Compared with 1.391±0.026 in blank control group, the protein expressions of vascular endothelial cadherin of cells in 10 ng/mL IL-6 group (1.185±0.063), in 25 ng/mL IL-6 group (0.717±0.078), and in 50 ng/mL IL-6 group (0.239±0.064) were significantly decreased (P<0.05); compared with that in 10 ng/mL IL-6 group, the protein expressions of vascular endothelial cadherin of cells in 25 ng/mL IL-6 group and 50 ng/mL IL-6 group were significantly decreased (P<0.01); compared with that in 25 ng/mL IL-6 group, the protein expression of vascular endothelial cadherin of cells in 50 ng/mL IL-6 group was significantly decreased (P<0.01). At 72 h after grouping culture, compared with that in blank control group, the protein expression levels of α-SMA of cells in 10 ng/mL IL-6 group, 25 ng/mL IL-6 group, and 50 ng/mL IL-6 group were significantly increased (P<0.01); compared with that in 10 ng/mL IL-6 group, the protein expression levels of α-SMA of cells in 25 ng/mL IL-6 group and 50 ng/mL IL-6 group were significantly increased (P<0.01). At 72 h after grouping culture, compared with that in blank control group, the protein expressions of type Ⅰ collagen of cells in 25 ng/mL IL-6 group and 50 ng/mL IL-6 group were significantly increased (P<0.05). Conclusions: After IL-6 treatment, the phenotype and function of HUVECS showed the characteristics of mesenchymal cells in a concentration-dependent manner. The inflammatory factor can promote the process of EndMT, and become one of the important factors regulating the mechanism of tissue fibrosis.

One-Step Formation of Protein-Based Tubular Structures for Functional Devices and Tissues

Tubular biological structures consisting of extracellular matrix (ECM) proteins and cells are basic functional units of all organs in animals and humans. ECM protein solutions at low concentrations (5-10 milligrams per milliliter) are abundantly used in 3D cell culture. However, their poor "printability" and minute-long gelation time have made the direct extrusion of tubular structures in bioprinting applications challenging. Here, this limitation is overcome and the continuous, template-free conversion of low-concentration collagen, elastin, and fibrinogen solutions into tubular structures of tailored size and radial, circumferential and axial organization is demonstrated. The approach is enabled by a microfabricated printhead for the consistent circumferential distribution of ECM protein solutions and lends itself to scalable manufacture. The attached confinement accommodates minute-long residence times for pH, temperature, light, ionic and enzymatic gelation. Chip hosted ECM tubular structures are amenable to perfusion with aqueous solutions and air, and cyclic stretching. Predictive collapse and reopening in a crossed-tube configuration promote all-ECM valves and pumps. Tissue level function is demonstrated by factors secreted from cells embedded within the tube wall, as well as endothelial or epithelial barriers lining the lumen. The described approaches are anticipated to find applications in ECM-based organ-on-chip and biohybrid structures, hydraulic actuators, and soft machines.

Estimation of salt intake assessed by 24-h urinary sodium level among adults speaking different dialects from the Chaoshan region of southern China

OBJECTIVE

Dietary salt intake may vary depending on different lifestyles. We aimed to estimate the different salt intakes and evaluate the knowledge and self-awareness about salt among people speaking the Teochew, Teochew-Hakka and Hakka dialects in the Chaoshan region of southern China.

DESIGN

The study followed a cluster sampling of residents in Chaoshan region. General characteristics, lifestyles, health status as well as knowledge and self-awareness related to salt intake were investigated using a questionnaire. Anthropometric variables as well as Na and K excretion in a 24-h urine collection were measured.

SETTING

Chaoshan region of China.

PARTICIPANTS

Four hundred fifteen adults who spoke only one of these three dialects.

RESULTS

The salt intake of adults who spoke the Teochew, Teochew-Hakka and Hakka dialects was 7·19 (interquartile range (IQR) 5·29-10·17), 9·03 (IQR 6·62-11·54) and 10·12 (IQR 7·61-12·82) g/d, respectively, with significant differences between Teochew and Teochew-Hakka speakers and between Teochew and Hakka speakers (both P < 0·05). The Na:K ratio for adults who spoke the three dialects was 3·00 (IQR 2·00-4·11), 3·50 (IQR 2·64-4·82) and 4·52 (IQR 3·35-5·97), respectively, and differed significantly among the groups (all P < 0·05). Multiple linear regression analysis showed increased Na:K ratio associated with hypertension (β = 0·71, P = 0·043) in Hakka speakers. Knowledge and self-awareness about salt intake were poor in this population.

CONCLUSIONS

Salt intake was closely related to lifestyles and was higher than the upper limit (5 g/d) recommended by the WHO in adults of Chaoshan, especially those speaking the Hakka dialect.

NADPH oxidase 4 (Nox4) deletion accelerates liver regeneration in mice

Liver is a unique organ in displaying a reparative and regenerative response after acute/chronic damage or partial hepatectomy, when all the cell types must proliferate to re-establish the liver mass. The NADPH oxidase NOX4 mediates Transforming Growth Factor-beta (TGF-β) actions, including apoptosis in hepatocytes and activation of stellate cells to myofibroblasts. Aim of this work was to analyze the impact of NOX4 in liver regeneration by using two mouse models where Nox4 was deleted: 1) general deletion of Nox4 (NOX4-/-) and 2) hepatocyte-specific deletion of Nox4 (NOX4hepKO). Liver regeneration was analyzed after 2/3 partial hepatectomy (PH). Results indicated an earlier recovery of the liver-to-body weight ratio in both NOX4-/- and NOX4hepKO mice and an increased survival, when compared to corresponding WT mice. The regenerative hepatocellular fat accumulation and the parenchyma organization recovered faster in NOX4 deleted livers. Hepatocyte proliferation, analyzed by Ki67 and phospho-Histone3 immunohistochemistry, was accelerated and increased in NOX4 deleted mice, coincident with an earlier and increased Myc expression. Primary hepatocytes isolated from NOX4 deleted mice showed higher proliferative capacity and increased expression of Myc and different cyclins in response to serum. Transcriptomic analysis through RNA-seq revealed significant changes after PH in NOX4-/- mice and support a relevant role for Myc in a node of regulation of proliferation-related genes. Interestingly, RNA-seq also revealed changes in the expression of genes related to activation of the TGF-β pathway. In fact, levels of active TGF-β1, phosphorylation of Smads and levels of its target p21 were lower at 24 h in NOX4 deleted mice. Nox4 did not appear to be essential for the termination of liver regeneration in vivo, neither for the in vitro hepatocyte response to TGF-β1 in terms of growth inhibition, which suggest its potential as therapeutic target to improve liver regeneration, without adverse effects.

Persistent myopathy despite release of partial obstruction: in vivo reversal of dysfunction and transcriptional responses using rapamycin

Current and potential medical therapy for obstruction-induced myopathic bladder dysfunction (from benign prostatic hyperplasia or posterior urethral valves) focuses on symptoms. The persistent tissue pathology and dysfunction after release of obstruction is often deemed irreversible without any systematic therapeutic approaches. As rapamycin can attenuate bladder smooth muscle hypertrophy and dysfunction during the genesis of partial obstruction in vivo, we tested whether rapamycin could improve persistent function after release of obstruction (de-obstruction or REL). Female Sprague-Dawley rat bladders were partially obstructed (PBO) by suturing around both the urethra and a para-urethral steel rod, then removing the rod. One day prior to release of obstruction (preREL), voiding parameters and residual urine volume of preREL+future rapa, preREL+future veh groups were recorded. Release of obstruction (REL) was performed by suture removal following 6 weeks of PBO. For 4 more weeks after the de-obstruction, REL animals were randomized to rapamycin (REL+rapa) or vehicle (REL+veh). PBO for 6 weeks were used as positive controls. In shams, the urethra was exposed, but no suture tied. Voiding parameters and residual urine volume were measured prior to sacrifice of sham and REL+veh or REL+rapa, and PBO. Rapamycin efficacy was tested by pair-wise comparison of changes in individual voiding data from preREL+future veh or preREL+future rapa versus REL+veh or REL+rapa, respectively, as well as by comparisons of REL+veh to REL+rapa groups. Bladders were weighed and processed for a high-throughput QPCR array, and histopathology. Bladder/body mass ratios with PBO increased significantly and remained higher in the release phase in REL+veh animals. REL+rapa versus REL+veh improved residual volumes and micturition fractions toward sham levels. Three genes encoding extracellular proteins, BMP2, SOD3, and IGFBP7, correlated with functional improvement by Pearson's correlations. The promoters of these genes showed enrichment for several motifs including circadian E-boxes. While obstruction and REL augmented CLOCK and NPAS2 expression above sham levels, rapamycin treatment during release significantly blocked their expression. This experimental design of pharmaco-intervention during the de-obstruction phase revealed a novel pathway dysregulated during the clinically relevant treatment phase of obstructive bladder myopathy.

[Effect of picroside Ⅱ on the expression of mitochondrial VDAC1 after cerebral ischemia/reperfusion in rats]

Objective: To explore the effect of picroside Ⅱ on the expression of mitochondrial voltage-dependent anion channel 1 (VDAC1) in rats after cerebral ischemiareperfusion. Methods: A total of 70 Wistar rats models with middle cerebral artery occlusionreperfusion (MCAO/R) were randomly divided into the sham group, model group, picroside (Picr) group, ruthenium red (RuR) group, RuR+ Picr group, Spermine (Sper) group, Sper+ Picr group (n=10 per group). Modified neurological severity scale (mNSS) was used to evaluated the neurobehavioral function, the expression of reactive oxygen species (ROS) in brain tissues were measured by enzyme-linked immunosorbent assay (ELISA), the morphology of brain tissues was observed by hematoxylin-eosin (HE) staining, the apoptotic cells were counted by terminal deoxynucleotidyl transferase dUTP nick end labeling assay (TUNEL), and the expressions of VDAC1 and endonuclease G (EndoG) were determined by immunohistochemical assay and Western blot. Results: Compared with the shame group, the mNSS scores (9.6±1.9), the expression of ROS[(47.6±2.7)U/ml], the apoptosis of neuron(23.8±2.8), and the expressions of VDAC1(0.94±0.06) and EndoG in cytoplasm (0.76±0.06) and nuclei(0.75±0.06)were enhanced in the model group (all P<0.05). The Picr group had obviously decreased mNSS scores (5.7±0.9), ROS expression[(35.6±2.2)U/ml], number of apoptotic cells (14.5±2.1), VDAC1 (0.63±0.06) and EndoG in cytoplasm (0.34±0.05) and nuclei (0.31±0.06)expressions compared to the model group (P<0.05). Conclusion: Picroside Ⅱ could attenuate cerebral I/R injury by down-regulating the expression of VDAC1 and inhibiting the EndoG release from mitochondria into cytoplasm.

Endometrial carcinoma: diffusion-weighted imaging diagnostic accuracy and correlation with Ki-67 expression

AIM

To evaluate the role of diffusion-weighted imaging (DWI) in the detection of endometrial carcinoma and to correlate the apparent diffusion coefficient (ADC) value with Ki-67 expression.

MATERIALS AND METHODS

Fifty-two patients with invasive cancer who underwent pelvic MRI were prospectively evaluated using DWI with b-values of 0 and 1000 s/mm^2.The ADC values from standard DWI were measured. The expression of Ki-67 in histological specimens was analysed using immunohistochemistry. The ADC values of endometrial carcinoma and normal endometrial parenchyma were compared. Relationships between ADC values and Ki-67 expression were determined using Wilcoxon's signed rank test and the Kruskal-Wallis test.

RESULTS

Endometrial carcinoma was detected at DWI as a hyperintense area in 92.3% (48/52) of patients. There was a significant difference in the mean ADC values between endometrial carcinoma and normal endometrial parenchyma (1.39±0.27×10^-3 versus 0.93±0.21×10^-3 mm²/s, p<0.001). The mean ADC values of grade 1 patients were significantly higher than those of grade 3 patients (1.01±0.16×10^-3 versus 0.83±0.21×10^-3 mm²/s, p<0.05). The mean ADC values of stage IB patients were significantly lower than those of stage IA patients (0.86±0.16×10^-3 versus 1.04±0.21×10^-3 mm²/s, p<0.01). The mean ADC values of high Ki-67 expression patients were significantly lower than those of low Ki-67 expression patients (0.82±0.12×10^-3 versus 1.16±0.12×10^-3 mm²/s, p<0.001). There was a significant negative correlation between the mean ADC value and Ki-67 expression (r=-0.82, p<0.001).

CONCLUSION

The ADC value was a helpful parameter for detecting the tumour grade, stage, and proliferation of endometrial carcinoma, and may further improve patient prognosis and contribute to the development of more effective treatment programmes.

[Role of maternal drug use and environmental exposure during pregnancy and delivery pattern in allergic infants and toddlers]

Objective: To understand correlation between maternal drug use and environmental exposure during pregnancy and delivery pattern and allergy in infants and toddlers, and provide theoretical bases for the early prevention and intervention of infantile allergies. Methods: Case control study based on cross-sectional investigation was conducted. Thirty-three cities were selected in China. Randomly cluster sampling method was used to select a community in each city as the study sample, the women with infants aged 0-24 months were interviewed in the form of face-to-face questionnaire survey. Infants and toddlers were divided into two groups: case group, including 2 113 children who had allergic symptoms and were diagnosed with allergic disease, and control group, including 6 303 children who never had symptoms of allergic disease. Results: Children whose parents had allergic disease histories were more likely to have allergic disease (OR=3.950) compared with the children whose mother or father had allergic disease histories (OR=2.277). Maternal use of antibiotics (OR=1.396), disinfector exposure (OR=1.386), smoking exposure (OR=1.301) during pregnancy and cesarean delivery (OR=1.255) were risk factors for allergic disease in infants and toddlers, the differences were significant (P<0.05). Conclusion: It is essential to conduct primary prevention of infant allergy during pregnancy, and it is necessary to avoid unnecessary cesarean delivery and irrational antibiotic use, disinfector and smoking exposures during pregnancy.

Uropathogenic E. coli (UPEC) Infection Induces Proliferation through Enhancer of Zeste Homologue 2 (EZH2)

Host-pathogen interactions can induce epigenetic changes in the host directly, as well as indirectly through secreted factors. Previously, uropathogenic Escherichia coli (UPEC) was shown to increase DNA methyltransferase activity and expression, which was associated with methylation-dependent alterations in the urothelial expression of CDKN2A. Here, we showed that paracrine factors from infected cells alter expression of another epigenetic writer, EZH2, coordinate with proliferation. Urothelial cells were inoculated with UPEC, UPEC derivatives, or vehicle (mock infection) at low moi, washed, then maintained in media with Gentamycin. Urothelial conditioned media (CM) and extracellular vesicles (EV) were isolated after the inoculations and used to treat naïve urothelial cells. EZH2 increased with UPEC infection, inoculation-induced CM, and inoculation-induced EV vs. parallel stimulation derived from mock-inoculated urothelial cells. We found that infection also increased proliferation at one day post-infection, which was blocked by the EZH2 inhibitor UNC1999. Inhibition of demethylation at H3K27me3 had the opposite effect and augmented proliferation. CONCLUSION: Uropathogen-induced paracrine factors act epigenetically by altering expression of EZH2, which plays a key role in early host cell proliferative responses to infection.

Systematic review and meta-analysis comparing three techniques for pancreatic remnant closure following distal pancreatectomy

BACKGROUND

Established closure techniques for the pancreatic remnant after distal pancreatectomy include stapler, suture and anastomotic closure. However, controversy remains regarding the ideal technique; therefore, the aim of this study was to compare closure techniques and risk of postoperative pancreatic fistula (POPF).

METHODS

A systematic review was carried out according to PRISMA guidelines for studies published before January 2014 that compared at least two closure techniques for the pancreatic remnant in distal pancreatectomy. A random-effects model was constructed using weighted odds ratios (ORs).

RESULTS

Thirty-seven eligible studies matched the inclusion criteria and 5252 patients who underwent distal pancreatectomy were included. The primary outcome measure, the POPF rate, ranged 0 from to 70 per cent. Meta-analysis of the 31 studies comparing stapler versus suture closure showed that the stapler technique had a significantly lower rate of POPF, with a combined OR of 0.77 (95 per cent c.i. 0.61 to 0.98; P = 0.031). Anastomotic closure was associated with a significantly lower POPF rate than suture closure (OR 0.55, 0.31 to 0.98; P = 0.042). Combined stapler and suture closure had significantly lower POPF rates than suture closure alone, but no significant difference compared with stapler closure alone.

CONCLUSION

The use of stapler closure or anastomotic closure for the pancreatic remnant after distal pancreatectomy significantly reduces POPF rates compared with suture closure. The combination of stapler and suture closure shows superiority over suture closure alone.

Connexin43 hemichannels mediate small molecule exchange between chondrocytes and matrix in biomechanically-stimulated temporomandibular joint cartilage

OBJECTIVE

Connexin (Cx) 43 hemichannels play a role in mechanotransduction. This study was undertaken in order to determine if Cx43 hemichannels were activated in rat temporomandibular joint (TMJ) chondrocytes under mechanical stimulation.

METHODS

Sprague-Dawley rats were stimulated dental-mechanically. Cx43 expression in rat TMJ cartilage was determined with immunohistochemistry and real-time PCR, and Cx43 hemichannel opening was evaluated by the extra- and intracellular levels of prostaglandin E2 (PGE2). Both primary rat chondrocytes and ATDC5 cells were treated with fluid flow shear stress (FFSS) to induce hemichannel opening. The Cx43 expression level was then determined by real-time PCR or Western blotting, and the extent of Cx43 hemichannel opening was evaluated by measuring both PGE2 release and cellular dye uptake.

RESULTS

Cx43 expression and intra- and extracellular PGE2 levels were increased in mechanically-stimulated rat TMJ cartilage compared to the unstimulated control. The FFSS treatment increased Cx43 expression and induced Cx43 hemichannel opening in primary rat chondrocytes and ATDC5 cells indicated by enhanced PGE2 release and dye uptake. Furthermore, the Cx43 hemichannel opening could be blocked by the addition of 18β-glycyrrhetinic acid, a Cx channel inhibitor, Cx43-targeting siRNA, or by withdrawal of FFSS stimulation. The migration of cytosolic Cx43 protein to the plasma membrane in ATDC5 cells was still significant after 8 h post 2-h FFSS treatment, and the Cx43 protein level was still high at 48 h, which returned to control levels at 72 h after treatment.

CONCLUSION

Cx43 hemichannels are activated and mediate small molecule exchange between TMJ chondrocytes and matrix under mechanical stimulation.

Differential impact of adenosine nucleotides released by osteocytes on breast cancer growth and bone metastasis

Extracellular ATP has been shown to either inhibit or promote cancer growth and migration; however, the mechanism underlying this discrepancy remained elusive. Here we demonstrate the divergent roles of ATP and adenosine released by bone osteocytes on breast cancers. We showed that conditioned media (CM) collected from osteocytes treated with alendronate (AD), a bisphosphonate drug, inhibited the migration of human breast cancer MDA-MB-231 cells. Removal of the extracellular ATP by apyrase in CM abolished this effect, suggesting the involvement of ATP. ATP exerted its inhibitory effect through the activation of purinergic P2X receptor signaling in breast cancer cells evidenced by the attenuation of the inhibition by an antagonist, oxidized ATP, as well as knocking down P2X7 with small interfering RNA (siRNA), and the inhibition of migration by an agonist, BzATP. Intriguingly, ATP had a biphasic effect on breast cancer cells-lower dosage inhibited but higher dosage promoted its migration. The stimulatory effect on migration was blocked by an adenosine receptor antagonist, MRS1754, ARL67156, an ecto-ATPase inhibitor, and A2A receptor siRNA, suggesting that in contrast to ATP, adenosine, a metabolic product of ATP, promoted migration of breast cancer cells. Consistently, non-hydrolyzable ATP, ATPγS, only inhibited but did not promote cancer cell migration. ATP also had a similar inhibitory effect on the Py8119 mouse mammary carcinoma cells; however, adenosine had no effect owing to the absence of the A2A receptor. Consistently, ATPγS inhibited, whereas adenosine promoted anchorage-independent growth of MDA-MB-231 cells. Our in vivo xenograft study showed a significant delay of tumor growth with the treatment of ATPγS. Moreover, the extent of bone metastasis in a mouse intratibial model was significantly reduced with the treatment of ATPγS. Together, our results suggest the distinct roles of ATP and adenosine released by osteocytes and the activation of corresponding receptors P2X7 and A2A signaling on breast cancer cell growth, migration and bone metastasis.

Transcriptome network-based method to identify genes associated with unruptured intracranial aneurysms

Intracranial aneurysm is a balloon or sac-like dilatation of blood vessels inside the brain. Despite their importance, the biological mechanisms of intracranial aneurysms are not totally understood. We used public genome-wide gene expression profile data to identify potential genes that are involved in intracranial aneurysm in order to construct a regulation network. Some of the transcription factors and target genes that we identified in this network had been identified as related to intracranial aneurysm in previous studies. We found additional transcription factors and target genes that are apparently related to intracranial aneurysm with this method. The confirmation of previously identified genes and transcription factors supports the usefulness of this transcriptome network analysis for the identification of candidate genes involved in intracranial aneurysm.

Phenotypic switching induced by damaged matrix is associated with DNA methyltransferase 3A (DNMT3A) activity and nuclear localization in smooth muscle cells (SMC)

Extracellular matrix changes are often crucial inciting events for fibroproliferative disease. Epigenetic changes, specifically DNA methylation, are critical factors underlying differentiated phenotypes. We examined the dependency of matrix-induced fibroproliferation and SMC phenotype on DNA methyltransferases. The cooperativity of matrix with growth factors, cell density and hypoxia was also examined. Primary rat visceral SMC of early passage (0–2) were plated on native collagen or damaged/heat-denatured collagen. Hypoxia was induced with 3% O₂ (balanced 5% CO₂ and 95% N₂) over 48 hours. Inhibitors were applied 2–3 hours after cells were plated on matrix, or immediately before hypoxia. Cells were fixed and stained for DNMT3A and smooth muscle actin (SMA) or smooth muscle myosin heavy chain. Illumina 450 K array of CpG sites was performed on bisulfite-converted DNA from smooth muscle cells on damaged matrix vs native collagen. Matrix exquisitely regulates DNMT3A localization and expression, and influences differentiation in SMCs exposed to denatured matrix +/− hypoxia. Analysis of DNA methylation signatures showed that Matrix caused significant DNA methylation alterations in a discrete number of CpG sites proximal to genes related to SMC differentiation. Matrix has a profound effect on the regulation of SMC phenotype, which is associated with altered expression, localization of DNMTs and discrete changes DNA methylation.

First Report of Fruit Stem Anthracnose of Kiwifruit Caused by Glomerella septospora in China

Kiwifruit (Actinidia spp.) is a very economically important fruit crop in southern China, namely Fengxin County. In 2011 and 2012, a new anthracnose on the fruit stem of kiwifruit with blight symptoms was observed during the blossom and fruit-set periods. This caused considerable blossom and fruit drop. To isolate the causal pathogen, symptomatic fruit-stem tissue at the junction of diseased and healthy tissue was cut into 30-mm-long segments. The segments were surface-sterilized in 70% ethanol solution for 10 s, followed by 0.1% mercuric chloride solution for 3 min, and a final set of three rinses in sterile distilled water. Segments were plated onto PDA and incubated at 25°C on a 12-h alternating light-dark cycle (1). Colonies emerging from plant tissues were then transferred to new PDA plates to obtain pure cultures. Colonies grew at the rate of 13.75 mm/day, and were initially white, then became dark green. After 25 days incubation, black and subglobose perithecia appeared at the center of the colonies. Through microscopic examination of perithecia at 400× magnification, club-shaped asci, usually containing 8 ascospores, were found. Ascospores were cylindrical to narrowly fusiform, straight or slightly curved, mostly 3-septate, and 54.5 to 107.5 × 5.0 to 7.5 μm in size. Combining cultural and morphological characteristics with reports in the literature (2), the pathogen was preliminarily identified as a Glomerella species. For six isolates, the rDNA internal transcribed spacer (ITS) region was amplified with the primers ITS1 and ITS4, and the sequences were deposited in GenBank (JX885687). A BLASTn search of GenBank showed that the ITS sequence of our Glomeralla isolate (JX885687) had 100% homology with that of an isolate of Glomeralla septospora (GU935911). Twenty representative isolates (G. septospora) obtained from infected fruit stem tissues in the blossom period and the fruit-set period, respectively, were selected for pathogenicity tests on detached young fruit stems of kiwifruit (JinKui). Each isolate was inoculated into three fruit stems, each of which was slightly wounded with a sterile scalpel and inoculated with a 5-mm-diameter colonized potato dextrose agar (PDA) plug. Negative control stems were treated with the sterile PDA plugs. The inoculated stems were incubated in a growth chamber at 25°C and 95% relatively humidity. After 4 days, characteristic symptoms of fruit stem anthracnose were observed on all inoculated stems, whereas the controls remained asymptomatic. Pure cultures of G. septospora were recovered from all inoculated fruit stems, fulfilling Koch's postulates. These results showed G. septospora is the pathogen of fruit stem anthracnose of kiwifruit, and to our knowledge, this is the first report of G. septospora causing fruit stem anthracnose of kiwifruit in Fengxin county, Jiangxi Province of China, as well as in the world. References: (1) J. Y. Lu. Plant Pathogenic Mycology. China Agriculture Press, Beijing, China, 2004. (2) A. Sivanesan and W. H. Hsieh. Mycological Research, 97:1523, 1993.

Rapamycin attenuates bladder hypertrophy during long-term outlet obstruction in vivo: tissue, matrix and mechanistic insights

PURPOSE

Previous molecular studies showed that the mTOR inhibitor rapamycin prevents bladder smooth muscle hypertrophy in vitro. We investigated the effect of rapamycin treatment in vivo on bladder smooth muscle hypertrophy in a rat model of partial bladder outlet obstruction.

MATERIALS AND METHODS

A total of 48 female Sprague-Dawley® rats underwent partial bladder outlet obstruction and received daily subcutaneous injections of rapamycin (1 mg/kg) or vehicle commencing 2 weeks postoperatively. A total of 36 rats underwent sham surgery and received rapamycin or vehicle. Rats were sacrificed 3, 6 and 12 weeks after surgery. Before sacrifice, voiding was observed in a metabolic cage for 24 hours. Bladder-to-body weight in gm bladder weight per kg body weight and post-void residual urine were assessed. We evaluated Col1a1, Col3a1, Eln and Mmp7 mRNA expression and histology. Two-factor ANOVA and the post hoc t test were applied.

RESULTS

Bladder outlet obstruction caused a significant increase in bladder weight in all obstructed groups. Three weeks postoperatively (1 week of treatment) there was no difference in the bladder-to-body weight ratio in the obstructed group. However, at 6 and 12 weeks (4 and 10 weeks of treatment, respectively) the bladder-to-body weight ratio of rats with obstruction plus rapamycin was significantly lower than that of rats with obstruction plus vehicle. Post-void residual urine volume after 6 and 12 weeks of obstruction was lower in obstructed rats with rapamycin compared to that in obstructed rats with vehicle. Rapamycin decreased the obstruction induced expression of Col1a1, Col3a1, Eln and Mmp7.

CONCLUSIONS

Rapamycin prevents mechanically induced hypertrophy in cardiovascular smooth muscle. In vivo mTOR inhibition may attenuate obstruction induced detrusor hypertrophy and help preserve bladder function.

Abstract P3-13-06: Osteocytic Connexin 43 Hemichannels in Prevention of Bone Metastasis

Bone metastases are major, potentially fatal complications in patients with advanced cancers including breast, prostate and lung cancers. The gap junction-forming protein connexin 43 (Cx43) has been known to inhibit primary tumor cell growth. In addition to gap junctions, Cx43 also forms halves of gap junctions known as hemichannels which allow communication between the intracellular and extracellular environments. Cx43 hemichannels in osteocytes have been shown to open when induced by mechanical stimulation as well as by treatment with alendronate (AD), an efficacious and commonly used bisphosphonate drug. The opening of hemichannels is known to release small molecules important for bone formation and remodeling. To confirm the opening of Cx43 hemichannels in the presence of AD, we measured uptake of ethidium bromide (EtBr) in MLO-Y4 cells after the addition of AD. As expected, an increase in Cx43 hemichannels EtBr uptake was observed after AD treatment. To elucidate the effect(s) of osteocyte Cx43 hemichannels on cancer cell growth and migration, we treated MLO-Y4 osteocytes with AD. Conditioned media (CM) was collected after treatment and were used to incubate with metastatic MDA-MB-231 breast cancer cells and PC3 prostate cancer cells. Cell migration was measured using wound healing and transwell migration assays, and cell proliferation was measured using the soft agarose anchorage-independent growth assay. The CM collected from MLO-Y4 osteocytes treated with AD reduced cancer cell migration and proliferation in a dose-dependent manner. However, direct treatment with AD had no effect on the cell migration or proliferation of the MDA-MB-231 cells. These data validated that the decrease in migration and proliferation was not a result of direct action by AD on the cancer cells. In order to elucidate the direct functional involvement of Cx43 hemichannels in cell migration, we treated the MLO-Y4 cells with Cx43 (E2) antibody, a specific antibody which blocks hemichannel activity but not gap junction channels formed by Cx43. The inhibitory effect of the CM on the migration and proliferation of MDA-MB-231 and PC3 cells was diminished. Interestingly, the inhibitory effects of osteocytes on cancer cell migration were not observed when using osteoblasts. Together, these results suggest the functional importance of osteocytic Cx43 hemichannels in attenuating cancer cell migration and growth.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-13-06.

Iron binding capacity of dephytinised soy protein isolate hydrolysate as influenced by the degree of hydrolysis and enzyme type

Soy protein is increasingly used in extended meat products and dairy type products due to the presence of high quality proteins with excellent functional properties. However, it has been shown to inhibit iron bioavailability because of phytic acid present in the protein. This present study investigated the effects of dephytinise from soy protein isolate (SPI) on iron binding capacity and degree of hydrolysis. Also the effects of enzyme type and degree of hydrolysis on iron binding capacity were studied. It was demonstrated that phytase and anion exchange resin could remove effectively the phytate from SPI. The dephytinise would decrease the degree of hydrolysis of SPI. The enzyme type and degree of hydrolysis influenced significantly the iron binding capacity of the hydrolysate. Flavourzyme might be the best choice for producing peptides with iron binding capacity from SPI and middle degree of hydrolysis would be benefitable to this process.

Gap junctions or hemichannel-dependent and independent roles of connexins in cataractogenesis and lens development

In the last decade or so, increasing evidences suggest that the mutations of two connexin genes, GJA3 and GJA8, are directly linked to human congenital cataracts in North and Central America, Europe and Asia. GIA3 and GIA8 genes encode gap junction-forming proteins, connexin (Cx) 46 and Cx50, respectively. These two connexins are predominantly expressed in lens fiber cells. Majority of identified mutations are missense, and the mutated sites are scattered across various domains of connexin molecules. Genetic deletion of either of these two genes leads to the development of cataracts; however, the types of cataracts developed are distinctive. More interestingly, microphthalmia is only developed in Cx50, but not Cx46 deficient mice, suggesting the unique role of Cx50 in lens cell growth and development. Knockin studies with the replacement of Cx46 or Cx50 at their respective gene locus further demonstrate the unique properties of these two connexins. Furthermore, the function of Cx50 in epithelial-fiber differentiation appears to be independent of its conventional role in forming gap junction junction channels. Due to their specific functions in maintaining lens clarity and development, and their malfunctions resulting in lens cataractogenesis and developmental impairment, connexin molecules could be developed as potential drug targets for therapeutic intervention for treatment of cataracts and other eye disorders. Recent advances in basic research of lens connexins and the discoveries of clinical disorders as a result of lens connexin dysfunctions are summarized and discussed here.

Differential expression of connexins during histogenesis of the chick retina

Gap junction (GJ) channels couple adjacent cells, allowing transfer of second messengers, ions, and molecules up to 1 kDa. These channels are composed by a multigene family of integral membrane proteins called connexins (Cx). In the retina, besides being essential circuit element in the visual processing, GJ channels also play important roles during its development. Herein, we analyzed Cx43, Cx45, Cx50, and Cx56 expression during chick retinal histogenesis. Cx exhibited distinct expression profiles during retinal development, except for Cx56, whose expression was not detected. Cx43 immunolabeling was observed at early development, in the transition of ventricular zone and pigmented epithelium. Later, Cx43 was seen in the outer plexiform and ganglion cell layers, and afterwards also in the inner plexiform layer. We observed remarkable changes in the phosphorylation status of this protein, which indicated modifications in functional properties of this Cx during retinal histogenesis. By contrast, Cx45 showed stable gene expression levels throughout development and ubiquitous immunoreactivity in progenitor cells. From later embryonic development, Cx45 was mainly observed in the inner retina, and it was expressed by glial cells and neurons. In turn, Cx50 was virtually absent in the chick retina at initial embryonic phases. Combination of PCR, immunohistochemistry and Western blot indicated that this Cx was present in differentiated cells, arising in parallel with the formation of the visual circuitry. Characterization of Cx expression in the developing chick retina indicated particular roles for these proteins and revealed similarities and differences when compared to other species.

A two year family based behaviour treatment for obese children

BACKGROUND

Childhood obesity has become a nutritional problem in China since the 1990s.

AIMS

A family based behavioural treatment was developed and tested, to see if its use was feasible in China and to evaluate its impact on obese schoolchildren.

METHODS

In a single school in Beijing, 33 obese children were randomly assigned to a treatment group and 35 to a control group. The treatment group participated in a family based behavioural treatment programme for two years. Height and weight were measured every six months for all participants. Blood pressure, cholesterol, and triglyceride levels were measured at baseline and after two years of programme implementation.

RESULTS

Body mass index (BMI, kg/m2) was significantly reduced in the treatment group (from 26.6 (1.7) to 24.0 (0.9), 95% CI 2.06 to 3.18) but not in the control group (from 26.1 (1.5) to 26.0 (1.6)). Total cholesterol decreased 5.5% and triglycerides 9.7% in the treatment group. There was a significant correlation between change in BMI and change in triglycerides. There were no significant changes in plasma lipids in the controls. Blood pressure values also decreased significantly in the treatment, but not the control group.

CONCLUSIONS

A family based behavioural intervention was feasible to use in treating obesity in schoolchildren in Beijing, China. After two years of implementation, it successfully decreased the degree of obesity, reduced levels of blood pressure, and decreased serum lipids in treatment; there were no significant changes among control children.

Delimitation of the rice wide compatibility gene S5 ( n ) to a 40-kb DNA fragment

Wide compatibility varieties (WCVs) are a special class of rice (Oryza sativa L.) germplasm that produces hybrids with normal pollen and spikelet fertility when crossed with both indica and japonica subspecies. The wide compatibility gene S5 ( n ) has been used extensively in inter-subspecific hybrid breeding programs. We previously mapped the S5 locus to a 2.2-cM genomic region between RM253 and R2349 on chromosome 6, using a population of 356 F(1) plants derived from the three-way cross 02428/Nanjing11//Balilla. In this study, a chromosome walking strategy was employed to construct a physical map covering this genomic region using these two closest markers as the starting points. A physical map consisting of six overlapping BAC clones was formed, spanning a genomic region of 540-kb in length. By analyzing recombination events from a population of 8,000 F(1) plants derived from a three-way cross based on near isogenic lines of the S5 locus, the S5 locus was localized to a DNA fragment of 40-kb in length, flanked by two shotgun subclones, 7B1 and 15D2. Sequence analysis of this fragment predicted five open reading frames, encoding xyloglucan fucosyltransferases, dnak-type molecular chaperone BiP, a putative eukaryotic aspartyl protease, and a hypothetical protein. This result will be very useful in molecular cloning of the S5 ( n ) allele and marker-assisted transferring of the wide compatibility gene in rice breeding programs.

Chiral Ligands Derived from Abrine 8. An Experimental and Theoretical Study of Free Ligand Conformational Preferences and the Addition of Diethylzinc to Benzaldehyde

Three structurally similar series of 1,2,3,4-tetrahydro-beta-carboline ligands, 4a-d, 6a-d and 7a-d, and two series of chiral oxazolidines, 8a-d and 9a-g, were synthesized and used as chiral catalysts in the addition of diethylzinc to benzaldehyde. The enantioselectivities of the resulting 1-phenyl-1-propanol were obtained in each case, and these ee values were, in most cases, related to the conformational populations of the free ligand as expressed by the calculated differences in the energies of the ligand conformations formed by inversion at nitrogen. This suggested the possible existence of a linear free energy relationship. The effect on enantioselectivity of the carbon chain length of the R group located (1) on the C-3 substituent of 4a-d, 6a-d, and 7a-d or (2) at C-5 in 8a-d and 9a-g was studied in detail. On the basis of the correlations observed and the ligands' structural characterization, a structure was proposed for the transition state during ethyl group transfer when using ligands 8a-d. Furthermore, the change in enantioselectivity was successfully predicted when diastereomeric ligands 11 and 12 were compared in this chiral addition.

Regulation of lens connexin 45.6 by apoptotic protease, caspase-3

Gap junctions are important in maintaining lens homeostasis. Here we report that connexin 45.6 (Cx45.6) was partially truncated to a 46 kDa fragment during chicken lens development. This specific truncation initiated during embryonic days and the truncated fragment accumulated towards the later developmental stages. When membranes of the embryonic lens were subjected to caspase-3 treatment, the 46 kDa fragment of Cx45.6 was reproduced, suggesting apoptotic protease caspase-3 is a potential protease involved. The COOH-terminus of Cx45.6 in GST-fusion protein was also cleaved by caspase-3, confirming that Cx45.6 is a direct substrate of caspase-3. Induction of apoptosis in lens primary cultures regenerated the 46 kDa fragment and this cleavage was blocked by a caspase-3 inhibitor. Alteration of amino acid residue Asp364 or Glu367 to Ala prevented Cx45.6 from cleavage by caspase-3, suggesting that the cleavage site of Cx45.6 is likely to be between Glu367 and Gly361. Phosphorylation of Ser363, a known substrate for casein kinase II (CKII) in vivo, inhibited the cleavage of Cx45.6 by caspase-3. Thus, this study demonstrates that a lens connexin can be a direct target of caspase-3 and the cleavage by caspase-3 leads to the development-associated truncation of Cx45.6. Finally, caspase-3 mediated truncation can be modulated by the specific connexin phosphorylation.

Mechanical stimulation of gap junctions in bone osteocytes is mediated by prostaglandin E2

Gap junction-mediated intercellular communications are thought to transduce the effects of mechanical strain from osteocytes to cells on the bone surface to initiate remodeling. To determine whether gap junctions may co-ordinate the effects of mechanical loading, osteocyte-like MLO-Y4 cells were exposed to fluid flow-imposed shear stress. After exposure of MLO-Y4 to fluid flow, intercellular coupling increased in direct proportion to shear stress level. Interestingly, this stimulation is further enhanced during the post-stress period, indicating that released factor(s) is likely to be involved. The conditioned medium obtained from the fluid flow treated MLO-Y4 cells induced an increase in the number of functional gap junctions and Cx43 protein when added to non-sheer-stressed cells. Fluid flow was found to induce prostaglandin F2 (PGE2) release and increase cyclooxygenase 2 (COX-2) expression. When PGE2 was depleted from the fluid flow conditioned medium, the stimulatory effect on gap junctions was significantly decreased. Addition of the COX inhibitor indomethacin partially blocked the stimulatory effects of mechanical strain on gap junctions. Together, these studies suggest that the stimulatory effect of fluid flow on gap junctions is mediated in part by de novo synthesis and release of PGE2. Gap junctions may serve as channels for the signals generated by osteocytes in response to mechanical loading.

Maize dwarf mosaic disease in different regions of China is caused by Sugarcane mosaic virus

Sugarcane mosaic virus (SCMV) was detected in all 62 maize samples collected from eight maize-growing provinces in China showing dwarf mosaic symptoms by immunocapture reverse-transcription polymerase chain reaction (RT-PCR). Maize dwarf mosaic virus (MDMV), Sorghum mosaic virus (SrMV) and Johnsongrass mosaic virus (JGMV), however, were not detected in any of the samples by RT-PCR. Eleven cDNA fragments of approximately 0.8 kilobases covering most of the coat protein (CP) gene of SCMV were sequenced and sequence analysis indicates that these eleven isolates share 98.1 to 100 % identity at the amino acid level. Sequence comparison and phylogenetic analysis of the CP genes from the eleven Chinese isolates as well as 21 SCMV subgroup virus isolates indicate that the eleven Chinese virus isolates were closely related to SCMV with 97.0 to 98.1 % sequence identity at the amino acid level, while relatively lower sequence identity was found with MDWV, SrMV or JGMV. The results indicate that the Chinese isolates are members of the SCMV species, and thus, SCMV can be considered as the most common and important potyvirus infecting maize in China.

The development-associated cleavage of lens connexin 45.6 by caspase-3-like protease is regulated by casein kinase II-mediated phosphorylation

Gap junctions are important in maintaining lens transparency and metabolic homeostasis. In this paper, we report that the gap junction-forming protein, connexin (Cx) 45.6, was specifically truncated during lens development and that the majority of the truncated fragments were located in the differentiated lens fibers. When isolated lens membranes were treated by caspase-3, the truncated fragments of Cx45.6 were reproduced, and this truncation occurred at the COOH terminus of Cx45.6. Moreover, when primary lens cells were treated with apoptosis-inducing reagents, Cx45.6 was cleaved similarly as the in vitro treatment by caspase-3, and this cleavage was blocked by a caspase-3 inhibitor. These results suggest that caspase-3 is responsible for the development-associated cleavage of Cx45.6. The cleavage site of Cx45.6 was identified between amino acid residues Glu(367) and Gly(368). We have shown previously that Ser(363) is an in vivo phosphorylated site by casein kinase II, and this specific phosphorylation leads to a rapid turnover of Cx45.6. Interestingly, we found here that when Ser(363) was phosphorylated by casein kinase II, the cleavage of Cx45.6 catalyzed by caspase-3 was inhibited. This study, for the first time, demonstrates that a connexin can be a direct target of an apoptotic protease and that cleavage by caspase-3-like protease leads to the development-associated truncation of a lens connexin. Finally, caspase-3-mediated cleavage can be regulated by casein kinase II-mediated phosphorylation, suggesting that Cx45.6 turnover and specific cleavage by caspase-3-like protease is alternatively modulated.

Cloning a novel mouse Gabarapl2 cDNA and its characterization

AIM

To clone a novel mouse GABAA-receptor-associated protein like 2 (Gabarapl2) gene, and to analysis its primary function.

METHODS

With the aid of computer, the human GABARAPL2 cDNA was used as information probe to search mouse EST database of GenBank for mouse homolog. A series of overlapping EST were found and assembled into an EST contig using Genetics Computer Group (GCG) ASSEMBLY program. The existence of the gene was then identified by experiment. Northern blotting was performed to hybridize [alpha-32P]dATP labeled probe with mRNA of 11 different mouse tissues that had been transferred to the nylon membrane.

RESULTS

The novel gene was deposited in GenBank under Accession No AF190644. Its cDNA contained an intact open reading frame and a canonical polyadenylation signal AATAAA followed by polyA. The deduced protein was completely identical to that of human GABARAPL2, and was termed Gabarapl2 by Mouse Gene Nomenclature Committee. The putative protein of Gabarapl2 has a calculated molecular weight of 13 700 and an isoelectric point of 8.56. It was also predicted to contain two protein kinase C phosphorylation sites and one tyrosine kinase phosphorylation site. Northern hybridization showed that Gabarapl2 was expressed as a single 1.35 kb transcript, with high levels in brain, thymus, lung, heart, kidney, and liver, and low in pancreas, testis, small intestine, colon, and stomach.

CONCLUSION

A novel mouse Gabarapl2 gene was cloned and identified.

PGE(2) is essential for gap junction-mediated intercellular communication between osteocyte-like MLO-Y4 cells in response to mechanical strain

We have observed, in our previous studies, that fluid flow increases gap junction-mediated intercellular coupling and the expression of a gap junction protein, connexin 43, in osteocyte-like MLO-Y4 cells. Interestingly, this stimulation is further enhanced during the poststress period, indicating that a released factor(s) is likely to be involved. Here, we report that the conditioned medium obtained from the fluid flow-treated MLO-Y4 cells increased the number of functional gap junctions and connexin 43 protein. These changes are similar to those observed in MLO-Y4 cells directly exposed to fluid flow. Fluid flow was found to induce PGE(2) release and increase cyclooxygenase 2 expression. Treatment of the cells with PGE(2) had the same effect as fluid flow, suggesting that PGE(2) could be responsible for these autocrine effects. When PGE(2) was depleted from the fluid flow-conditioned medium, the stimulatory effect on gap junctions was partially, but significantly, decreased. Addition of the cyclooxygenase inhibitor, indomethacin, partially blocked the stimulatory effects of mechanical strain on gap junctions. Taken together, these studies suggest that the stimulatory effect of fluid flow on gap junctions is mediated, in part, by the release of PGE(2). Hence, PGE(2) is an essential mediator between mechanical strain and gap junctions in osteocyte-like cells.

Characterization of an N-system amino acid transporter expressed in retina and its involvement in glutamine transport

We report here on the characterization of a mouse N-system amino acid transporter protein, which is involved in the transport of glutamine. This protein of 485 amino acids shares 52% sequence homology with an N-system amino acid transporter, mouse N-system amino acid transporter (mNAT) and its orthologs. Because this protein shares a high degree of sequence homology and functional similarity to mNAT, we named it mNAT2. mNAT2 is predominately expressed in the retina and to a slightly lesser extent in the brain. In the retina, it is located in the axons of ganglion cells in the nerve fiber layer and in the bundles of the optic nerve. Functional analysis of mNAT2 expressed in Xenopus oocytes revealed that the strongest transport activities were specific for l-glutamine. In addition, mNAT2 is a Na(+)- and pH-dependent, high affinity transporter and partially tolerates substitution of Na(+) by Li(+). Additionally, mNAT2 functions as a carrier-mediated transporter that facilitates efflux. The unique expression pattern and selective glutamine transport properties of mNAT2 suggest that it plays a specific role in the uptake of glutamine involved in the generation of the neurotransmitter glutamate in retina.

A novel human amino acid transporter, hNAT3: cDNA cloning, chromosomal mapping, genomic structure, expression, and functional characterization

Amino acid transporters are proteins that transport amino acids across the membrane. We report here the isolation and characterization of a novel human cDNA clone encoding a protein of 547 amino acids. This protein shares approximately 50% amino acid sequence homology with the amino acid transporters mouse mNAT and its orthologs, rat SN1 and human g17, and mouse GlnT/ATA1 and ATA2. Expression of this cRNA in Xenopus oocytes revealed that the strongest transport activities were specific for l-alanine. In addition, hNAT3 is a Na(+)- and pH-dependent, low-affinity transporter and partially tolerates substitution of Na(+) by Li(+). Since this protein has sequence and functional similarities to the previously identified system N amino acid transporters, we named this protein hNAT3. The genomic DNA sequence encoding the transcript of hNAT3 spans over 14 kb with 16 exons and 15 introns. Using fluorescence in situ hybridization, we mapped the hNAT3 gene to human chromosome 12q12-q13. By RT-PCR of embryonic and adult human tissues, hNAT3 was detected to be predominantly expressed in the liver and to a much lesser extent in the muscle, kidney, and pancreas. The data obtained in this study are likely to offer critical clues for identification of amino acid transporter-associated diseases.

Expression of functional gap junctions and regulation by fluid flow in osteocyte-like MLO-Y4 cells

Osteocytes are thought to be mechanosensory cells that respond to mechanical stress by sending signals to other bone cells to initiate bone remodeling. An osteocyte-like cell line MLO-Y4 provides a model system to examine whether gap junctions participate in the regulation of osteocyte function and signaling by mechanical stress. In this study, we show that MLO-Y4 cells are coupled and that gap junction channels mediate this coupling. Biochemical analyses show that connexin 43 (Cx43) is a major gap junction protein expressed in MLO-Y4 cells and approximately 5% of Cx43 protein is phosphorylated. MLO-Y4 cells were exposed to mechanical stress using a parallel plate flow chamber to model bone fluid flow shear stress. Fluid flow increased significantly the length of the dendritic processes, a morphological characteristic of osteocytes. A redistribution of the gap junction protein, Cx43 also was observed from a location circling the nucleus to punctate spots in the cytoplasm and in the dendritic processes. "Scrape-loading" dye transfer analyses showed that fluid flow increased intercellular coupling and increased the number of cells coupled immediately after fluid flow treatment, in direct proportion to shear stress magnitude. Although intercellular coupling continued to increase, stimulation of Cx43 protein expression during the poststress period was found to be biphasic. Cx43 protein was elevated 30 minutes after application of stress but decreased at 24 h poststress. Pulsating fluid flow had a similar stimulatory effect as steady fluid flow on gap junctions. However, this stimulatory effect in osteocyte-like cells was not observed in osteoblast-like 2T3 cells. Together, these results show that fluid flow has stimulatory effects on osteocyte-like MLO-Y4 cells with early effects on cellular morphology, opening of gap junctions, and redistribution of Cx43 protein and delayed effects on Cx43 protein expression. The high expression of Cx43 and its location in the cytoplasm also suggest that Cx43 may have unknown functions in addition to forming gap junctions. These studies indicate that gap junctions may serve as channels for signals generated by osteocytes in response to mechanical loading.