Responsiveness of sphingosine phosphate lyase insufficiency syndrome to vitamin B6 cofactor supplementation

Sphingosine-1-phosphate (S1P) lyase is a vitamin B6-dependent enzyme that degrades sphingosine-1-phosphate in the final step of sphingolipid metabolism. In 2017, a new inherited disorder was described caused by mutations in SGPL1, which encodes sphingosine phosphate lyase (SPL). This condition is referred to as SPL insufficiency syndrome (SPLIS) or alternatively as nephrotic syndrome type 14 (NPHS14). Patients with SPLIS exhibit lymphopenia, nephrosis, adrenal insufficiency, and/or neurological defects. No targeted therapy for SPLIS has been reported. Vitamin B6 supplementation has therapeutic activity in some genetic diseases involving B6-dependent enzymes, a finding ascribed largely to the vitamin's chaperone function. We investigated whether B6 supplementation might have activity in SPLIS patients. We retrospectively monitored responses of disease biomarkers in patients supplemented with B6 and measured SPL activity and sphingolipids in B6-treated patient-derived fibroblasts. In two patients, disease biomarkers responded to B6 supplementation. S1P abundance and activity levels increased and sphingolipids decreased in response to B6. One responsive patient is homozygous for an SPL R222Q variant present in almost 30% of SPLIS patients. Molecular modeling suggests the variant distorts the dimer interface which could be overcome by cofactor supplementation. We demonstrate the first potential targeted therapy for SPLIS and suggest that 30% of SPLIS patients might respond to cofactor supplementation.

Metabolic Biomarkers of Aging and Aging-related Diseases in Chinese Middle-Aged and Elderly Men

BACKGROUND

Aging is an acknowledged risk factor for most chronic diseases and functional impairments. The practicability of potential biomarkers of aging remains unsure. Moreover, biomarkers related to certain geriatric diseases, such as carotid atherosclerosis and multiple co-morbidities are less understood. The purpose of this study was to investigate the definite relationship between metabolic biomarkers and aging-related diseases.

METHODS

Eighty-five male adults aged fifty years or older from the general population were enrolled. Plasma metabolic biomarkers, including fourteen amino acids and thirty-six acylcarnitines, were measured by liquid chromatography mass spectrometry. Bivariate correlation analysis was employed to estimate the correlations between variables and age, and also to evaluate the relationship between metabolic biomarkers and aging-related diseases. Receiver operating characteristic (ROC) curve was conducted to judge the diagnostic efficiency of potential metabolic biomarkers for co-morbidities.

RESULTS

Certain metabolic biomarkers were strongly positively correlated with age, such as tetradecenoylcarnitine (C14:1), microalbumin-urine creatinine ratio (UACR), dodecenoylcarnitine (C12:1) and citrulline (p < 0.001). Carotid atherosclerosis and co-morbidities were positively correlated with aging (p < 0.001). After adjustment for age, hydroxytetradecanoylcarnitine (C14OH) remained positively correlated with carotid plague area. Besides, citrulline had diagnostic power for co-morbidities.

CONCLUSIONS

Citrulline may be a promising metabolic biomarker in the middle-aged and elderly men. Larger-scale and long-term studies are needed to confirm our findings.

RKIp inhibits the migration and invasion of human prostate cancer PC-3M cells through regulation of extracellular matrix

Raf kinase inhibitor protein (RKIP) plays a pivotal role in several intracellular signaling cascades and has been implicated as a metastasis suppressor in multiple cancer cells including prostate cancer cells, but the mechanism is not very clear. In this study, we investigated the effect of RKIP on cell proliferation, migration and invasion using human prostate cancer PC-3M cells as a model system. Our results indicate that RKIP does not effect cell proliferation in PC-3M cells, but inhibits both cell migration and cell invasion. In association with this inhibitory effect, RKIP down-regulates matrix metalloproteinases (MMP-2 and MMP-9), cathepsin B and urinary plasminogen activator (uPA). Also RKIP has the ability to regulate the expression of E-cadherin. But ectopic expression of RKIP does not affect the level of the Snail protein. As it has been indicated here, RKIP inhibits the migration and invasion ability of human prostate cancer cells through regulation of the extracellular matrix. These findings provide new mechanistic insight how RKIP suppresses metastasis in vitro.

Adjuvant chemotherapy in completely resected stage III-N2 non-small cell lung cancer

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Background: We evaluate effect of postoperative adjuvant chemotherapy on overall survival after complete resection of stage III-N2 non-small-cell lung cancer. Methods: From Jan.1999 to Dec. 2003, a total of 150 stage III-N2 non-small cell lung cancer patients randomly received four cycles of chemotherapy (NVB25mg/m2, D1,D5 or paclitaxel 175mg/m2, D1 / carboplatin AUC=5, D1) or observation after operation. Results: The median survival for the 150 patients was 879 days, with a 1-year survival rate of 81%, 3-year survival rate of 43%, and 5-year survival rate of 28%.There was significant difference in median survival between chemotherapy and control group (897 days vs 821 days p=0.04), and also there was significant difference in 5-year survival rate (30% vs 24% p<0.05). The most common site of recurrence was brain. 26% (39/150) of patients recurred in the brain as their first site, 22% (18/79) for chemotherapy group, 29% (21/71) for control group. The median survival time for brain metastasis patients between chemotherapy and control group is no difference (812 days vs 512 days, p=0.122), but there was significant difference in 2-year survival rate (66.71% vs 37.6% p<0.05). Conclusions: Postoperative adjuvant chemotherapy dose significantly improves median survival among completely resected stage III-N2 non-small-cell lung cancer patients, and significantly improves 5-year survival rate. It dose not decrease incidence of brain metastasis but postpone the time of brain metastasis in chemotherapy group.

No significant financial relationships to disclose.

Differential responses of antioxidative system to chilling and drought in four rice cultivars differing in sensitivity

Responses of antioxidative defense systems to chilling and drought stresses were comparatively studied in four cultivars of rice (Oryza sativa L.) differing in sensitivity, two of them (Xiangnuo no. 1 and Zimanuo) are tolerant to chilling but sensitive to drought and the other two (Xiangzhongxian no. 2 and IR50) are tolerant to drought but sensitive to chilling. The seedlings of rice were transferred into growth chamber for 5 d at 8 degrees C as chilling treatment, or at 28 degrees C as control, or at 28 degrees C but cultured in 23% PEG-6000 solution as drought stress treatment. Under drought stress the elevated levels of electrolyte leakage, contents of H(2)O(2) and total thiobarbituric acid-reacting substances (TBARS) in Xiangzhongxian no. 2 and IR50 are lower than those in Xiangnuo no. 1 and Zimanuo. On the contrary, Xiangnuo no. 1 and Zimanuo have much lower level of electrolyte leakage, H(2)O(2) and TBARS than Xiangzhongxian no. 2 and IR50 under chilling stress. Activities of antioxidant enzymes (superoxide dismutase (SOD), catalase, and ascorbate-peroxidase (APX)) and contents of antioxidants (ascorbaic acid and reduced glutathione) were measured during the stress treatments. All of them were enhanced greatly until 3 d after drought stress in the two drought-tolerant cultivars, or after chilling stress in the two chilling-tolerant cultivars. They all were decreased at 5 d after stress treatments. On the other hand, activities of antioxidant enzymes and contents of antioxidants were decreased greatly in the drought-sensitive cultivars after drought stress, or in the chilling-sensitive cultivars after chilling stress. The results indicated that tolerance to drought or chilling in rice is well associated with the enhanced capacity of antioxidative system under drought or chilling condition, and that the sensitivity of rice to drought or chilling is linear correlated to the decreased capacity of antioxidative system.

Gastrointestinal stromal tumours overexpress fatty acid synthase

Fatty acid synthase (FASN), a key enzyme for de novo lipogenesis, is overexpressed in many malignant tumours and is associated with aggressive biological behaviour. FASN expression and its possible relationship with more aggressive behaviour in gastrointestinal stromal tumours (GISTs) have not been addressed to date. Here, FASN expression was assessed by immunohistochemistry in 60 primary GISTs (28 low/intermediate risk and 32 high risk) and seven metastatic GISTs. Sixteen smooth muscle gastrointestinal tumours were used as controls. FASN was overexpressed in 36 of 60 GISTs (60%): in 12 of 28 (42%) low/intermediate-risk GISTs and in 24 of 32 (75%) high-risk GISTs (p<0.05). Two primary and seven metastatic GISTs and five GIST cell lines (GIST882, GIST430, GIST522, GIST62, and GIST48), analysed by western blot, showed variable FASN expression. Most metastatic samples expressed high levels of FASN protein. Additionally, seven of 60 GISTs showed a proliferation rate higher than 10% by Ki67 and all of them expressed FASN (p<0.04). Finally, proliferation and apoptosis were investigated after FASN silencing in GIST882 cells, which displayed the highest FASN expression. siRNA-mediated FASN knock-down inhibited expression of the proliferation marker cyclin A, whereas no changes in p27 and cleaved PARP expression were seen. It is concluded that FASN is preferentially overexpressed in high-risk and metastatic GISTs, and that its overexpression likely contributes to cell proliferation.

dsRNA enhances eotaxin-3 production through interleukin-4 receptor upregulation in airway epithelial cells

The exacerbation of asthma during viral infections is mainly explained by neutrophils infiltrating into the airways. However, enhanced functions of eosinophils are also observed. The aim of this study was to reveal the mechanism of how eosinophils are activated during and after viral infection of the airways, using a model of viral infection. A synthetic double-stranded RNA, poly inosinic-cytidyric acid (poly(IC)), was transfected to a human airway epithelial cell line (BEAS-2B) and the primary bronchial epithelial cells, to mimic a viral infection. The production of chemokines from the cells was investigated. The transfection of poly(IC), alone, marginally affected the eotaxin-3 production of the cells. However, the transfection of poly(IC) prior to interleukin (IL)-4 stimulation enhanced eotaxin-3 production. Poly(IC) transfection increased mRNA and protein expressions of IL-4 receptor (R)alpha and IL-2Rgamma, components of the IL-4R. In BEAS-2B cells, IL-4-mediated phosphorylation of signal transducer and activator of transcription six was enhanced in poly(IC) transfected cells. This was reversed by the addition of anti-IL-4Ralpha antibody, suggesting the role of an increased number of IL-4 receptors in enhanced IL-4-induced eotaxin-3 production. Poly(IC)-induced upregulation of IL-4Ralpha was inhibited by treatment with cycloheximide or dexamethasone. In conclusion, these results suggest that viral airway infection may enhance interleukin-4-induced eotaxin-3 production through upregulation of the interleukin-4 receptor in airway epithelial cells.

A comparative study of quantitative structure-activity relationship methods based on gallic acid derivatives

By using hologram quantitative structure-activity relationship (HQSAR) and comparative molecular field analysis (CoMFA) methods, the relationships between the structures of 49 gallic acid derivatives and their analgesic activity have been investigated to yield statistically reliable models with considerable predictive power. The best HQSAR model was generated using atoms, bond and connectivity as fragment distinction parameters and fragment size 5-7 from a hologram length of 307 with 3 components. High conventional r2 (r2 = 0.825) and cross-validation r2 (r2(cv) = 0.726) values were obtained. CoMFA analyses varying lattice size and location, grid spacing, probe charges and using, Tripos standard and Indicator force field were performed. The best model was developed with 4 components using sp3-hybridized carbon atom with +1.0 charge as probe, grid spacing (2 A), lattice offset (1.0, 3.0, -2.5). The CoMFA model showed a conventional correlation coefficient r2 of 0.889 and across-validation r2(cv) equals to 0.633. The robustness and predictive ability of the HQSAR and CoMFA models have been validated by means of an external test set. The results indicate that both models possess high statistical quality in the prediction of analgesic potency of novel gallic acid analogs.

[Skip metastasis to the mediastinal lymph nodes in non-small cell lung cancer]

OBJECTIVE

To ascertain if any difference exists in clinical characteristics between resected non-small cell lung cancer (NSCLC) with either skip or ordinary mediastinal lymph node metastases.

METHODS

Among 176 patients with stage IIIAN2 disease between 1982-1994 treated in our hospital, 53 had no metastasis at the hilar lymph nodes [skip(+) group] while 123 had [skip(-) group]. To investigate the extent of nodal involvement, the mediastinal lymph nodes were divided into three regions.

RESULTS

In the skip(+) group, mediastinal node metastasis was found in only one region in 49 of the 53 patients(92.4%), whereas 45 of the 123 patients(36.6%) from the skip (-) group revealed medinastinal metastasis at two or three regions The overall survival rate at 5 years after operation was 29.3% in the skip(+) group and 12.2% in the skip (-) group (P = 0.038). Furthermore, regarding patients with mediactint node metantion in one region, the skip(+) group had a better prognosis than the skip (-) group (32.1% vs 15.3%, P = 0.042).

CONCLUSION

These results suggest that patients with skip mediastinal lymph node metastases represent a unique subgroup of N2 disease.

[Survival and prognosis after pneumonectomy for non-small cell lung cancer (NSCLC) in the elderly]

BACKGROUND

To study the probability and prognosis after pneumonectomy for NSCLC in the elderly.

METHODS

From 1985 to 1995 , pneumonectomy was performed in 122 patients with non-small cell lung cancer. Of the 122 patients , 23 cases were 65 years old or older ( study group) and the other 99 cases were less than 65 years old. Five-year survival , operative complications and mortality , and change of lung functions before and after operation were compared between the two groups. Kaplan-meier method was used to analyzed the survival.

RESULTS

The 5-year survival for the study group was similar to that for the control group (27. 56 % vs 30. 51 % , P > 0. 05) , but the mortality in the study group was significantly higher than that in the control group (13. 04 % vs 2. 02 % , P < 0. 05) . There was no significant difference between the pre-operative and post-operative lung function for both groups.

CONCLUSIONS

Pneumonectomy in elderly patients with NSCLC appears to be applicable. However , it shoud be performed only in carefully selected patients because of the increased operative risk and death.

Changes of callus diameter during axial loading and after fixator removal in leg lengthening

We retrospectively reviewed nine tibial lengthenings in seven achondroplastic patients. The callotasis method was used, and a unilateral type lengthener, either the Dynamic Axial Fixator (Orthofix, Italy; eight legs) or the High Functional Fixator (Matsumoto Co., Japan; one leg), was applied. The distracted length averaged 14.6 (range 10-18) cm. The minimum diameter of the callus was measured using a ruler on anteroposterior and lateral radiographs. The callus diameter ratio (%) was calculated as the callus diameter divided by the original diaphysis diameter. For periods during axial loading and after removal of the fixator in each patient, a single regression line was drawn on the callus diameter ratio data using the least squares method, and the diameter change rate (%/day) was evaluated by inclination of this line. The diameter change rates during axial loading were negative in six legs, but those after fixator removal were positive in all legs, and the latter were significantly greater than the former. The diameter change rates after fixator removal on the anteroposterior radiographs were negatively correlated with the callus diameter ratio at the time of fixator removal (r = 0.84, P = 0.0008). Simple axial loading may not be a sufficient mechanial environment for restoration of the physiological shape, and it is important to be aware that we cannot expect the callus diameter to increase by this means alone.

The diameter of callus in leg lengthening: 28 tibial lengthenings in 14 patients with achondroplasia

We investigated the relation between callus diameter during bone distraction and the occurrence of late fracture and deformity. We retrospectively reviewed 28 tibial lengthenings in 14 patients with achondroplasia. The minimal diameter of the lengthened zone was measured on radiographs, when the sliding mechanism of the lengthening device was released, and the callus diameter ratio in two planes (CDR; diameter of the callus/diameter of the tibia at the level of the osteotomy end) was calculated. The CDR correlated negatively with the distracted length. Late fracture or late angular deformity occurred in 6 of the 28 lengthenings. When the CDR was 85% or more in both planes, these complications did not occur, but when the CDR was 80% or less in either plane, they occurred in 6 of 20 bones. Careful attention should therefore be given not only to the continuity of the callus but also to its diameter.

Influence of femoral lengthening on hip joint space in posttraumatic femoral shortening

We performed femoral lengthening for post-traumatic femoral shortening in 14 patients (10 men). The mean age was 26 (17-33) years. The callotasis method was employed using an Orthofix or Hifixator monolateral external fixator. The average length gained was 6 (3-13) cm, equal to 16 (7-36)%. The mean narrowing ratio of the hip joint space during lengthening was 9 (0-26)% and the narrowing persisted at the final follow-up. Cases with narrowing greater than 5% had a longer time between the development of the shortening and the lengthening than the others (p = 0.03). Our findings indicate that femoral lengthening for posttraumatic femoral shortening should be done as early as possible to prevent the development of joint space narrowing during the lengthening procedure.

Callus formation in femur and tibia during leg lengthening: 7 patients examined with DXA

We examined the callus formation during leg lengthening in 7 achondroplastic patients who underwent 3 bilateral femoral and 4 bilateral tibial lengthenings. Bone mineral content and bone mineral density (BMD) in the lengthened callus space were evaluated every 1 or 2 weeks for 10 weeks after the start of distraction using dual energy X-ray absorptiometry. The mean rate of callus mineralization in femurs (0.64 g/wk) was higher than in tibias (0.22 g/wk). The mean BMD at 10 weeks after the start was 0.35 g/cm2 in the femur and 0.14 g/cm2 in the tibia. Different rates of callus formation in different kinds of long tubular bones have not been reported previously.

Prevention of equinus deformity during tibial lengthening. Comparison of passive stretching with an orthosis

We have reviewed 28 tibial lengthenings in 14 patients with achondroplasia at an average age of 15 years, and compared the effectiveness of physiotherapy and an orthosis in preventing an equinus deformity. Physiotherapy of 15 min a day was ineffective even when the patients were able to walk. An orthosis worn for 16 h a day prevented equinus deformity up to at least 50% of lengthening, and the difference from physiotherapy was significant at more than 30% of lengthening.

Effects of model extension peptides containing glycine, proline and serine residues on the import of mitochondrial enzyme precursors into mitochondria

We found previously that Ac-(Leu-Leu-Ala-Arg-Leu)3-NHCH3 (5(3)), a model of the extension peptide of cytochrome P-450(SCC) precursor, strongly inhibited the import of the precursor into mitochondria. Unexpectedly, however, 5(3) showed the break of respiratory control of mitochondria. In the present study, desAc- [Pro7, Ser10] 5(3) (1), [Pro7, Ser10] 5(3) (2), desAc- [Gly5, Pro7, Ser10] 5(3) (3) and [Gly5, Pro7, Ser10] 5(3) (4) were synthesized in order to investigate the influence of the Gly, Pro and Ser residues, which are present in the extension peptide, on the import and respiration. CD measurement indicated that all the peptides had an alpha-helical conformation in the presence of DPPC-DPPG (3:1) liposomes. The order of the content of alpha-helical conformation was 5(3) greater than 1, 2 greater than 3, 4, while SEP1-15 (N-terminal 1-15 fragment of the extension peptide of cytochrome P-450(SCC) precursor) showed no alpha-helical structure. The measurements of dye-leakage from liposomes, import-inhibition of P-450(SCC) and adrenodoxin precursors and respiratory inhibition of mitochondria indicated that 3 and 4, rather than 1 and 2, are similar to SEP1-15, and that the glycine residue in the extension peptide is of considerable importance for the import of the precursors.

Inhibition of cytochrome c oxidase and hemolysis caused by lysosphingolipids

Galactosylsphingosine, glucosylsphingosine and sphingosine all inhibited cytochrome c oxidase activity in mitochondria from rat liver; more than 50% inhibition was caused by 5 microM lipid (0.1 mumol/mg mitochondrial protein). However, these lysosphingolipids did not suppress the activity of purified cytochrome c oxidase. When the enzyme was "reconstituted" with phosphatidylcholine, the lysosphingolipids clearly inhibited the activity. On the other hand, galactosylsphingosine, glucosylsphingosine and sphingosine all hemolyzed erythrocytes, indicating that lysosphingolipids can disrupt the membrane. Thus, it appears that the inhibition of cytochrome c oxidase, a membrane-bound enzyme in mitochondria, is due to perturbation of the environment of the enzyme and that the primary attacking site of the lysosphingolipids is the membrane. Because the potency to inhibit cytochrome c oxidase and to hemolyze erythrocytes did not differ among these lysosphingolipids and because galactosylceramide caused neither inhibition of cytochrome c oxidase nor hemolysis, the free amino group in the lysosphingolipids seems to be essential to give the effects. In addition, both inhibition of cytochrome c oxidase and hemolysis caused by lysosphingolipids were completely abolished by albumin, suggesting that toxic effects of lysosphingolipids may not be apparent in blood.

Effects of synthetic model peptides resembling the extension peptides of mitochondrial enzyme precursors on import of the precursors into mitochondria

One common and characteristic feature of the extension peptides of mitochondrial enzyme precursors is the presence of repeating short stretches of uncharged amino acids linked by basic amino acids. We synthesized several model peptides having this particular feature of the extension peptides. The peptides contained arginine or lysine as a basic amino acid residue linking sequences of two to four residues of leucine and alanine. We examined the effects of the peptides on the import of the precursors of two mitochondrial enzymes, cytochrome P-450(SCC) and adrenodoxin, and found that the peptides were generally inhibitory to the import of the precursors into mitochondria. The effective concentrations of some of the inhibitory peptides were as low as a few microM. The peptides containing lysine instead of arginine had an essentially similar inhibitory effect on the import. The peptides did not inhibit the binding of pre-P450(SCC) to the surface of mitochondria. The synthetic model peptides uncoupled oxidative phosphorylation of mitochondria prepared from either rat liver or bovine adrenal cortex, and induced leakage of enzymes from the inner compartments of mitochondria. However, the synthetic model peptides did not solubilize membrane-bound enzymes from mitochondria, suggesting that their effect on the membranes is different from that of detergents. The synthetic model peptides seem to bind to the membranes causing significant perturbation in the membrane structure, which is possibly related to the functions of the particular common sequence found in the extension peptides of mitochondrial enzyme precursors.

T cell growth factor: parameters of production and a quantitative microassay for activity

Several soluble factors have recently been associated with the proliferation and differentiation of thymus-derived lymphocytes. One of these factors present in medium conditioned by T cell mitogen-stimulated lymphocytes has the ability to promote the long-term culture of normal and antigen-specific cytotoxic T cells. We report a method to test for this proliferative stimulus in the form of a sensitive microassay based upon the tritiated-thymidine incorporation of continuous murine tumor-specific cytotoxic T cell lines (CTLL). The microassay requires microliter quantitites of sample fluid and is amenable to quantitative analysis. This highly reproducible, quantitative assay for T cell growth factor (TCGF) has allowed investigation as to the kinetics of TCGF generation and has revealed that T lymphocytes are required for its production. Further investigation has supported the notion that this nonspecies-specific factor is actively removed from tissue culture medium by the proliferation of either T cell mitogen-activated lymphocytes or CTLL.