Granulysin: A Novel Host Defense Molecule

Granulysin is a novel cationic molecule present in the granules of cytotoxic T lymphocytes and natural killer cells. Cytotoxic T lymphocytes have long been associated with graft destruction in transplant rejection. Recent studies implicate granulysin in cell-mediated cytotoxicity, chemoattraction, immune activation and as a potential diagnostic biomarker for transplant rejection.     

Comparison of anatomical location of squamous cell carcinoma within the oral cavity and oropharynx with the incidence of in vitro hyperdiploidy

The anatomical location of the squamous cell carcinoma (SCCA) within the oral cavity and oropharynx influenced the association of SCCA with the biomarker in vitro hyperdiploidy in human dermal fibroblast cultures (IVH). There was a strong association of IVH with the occurrence of SCCA in the anterior 2/3 of the tongue, floor of the mouth and lower alveolar ridge of the oral cavity and in the base of the tongue and pharyngeal wall of the oropharynx. There was a lower association of SCCA with IVH in the tonsillar region of the oropharynx. IVH showed no association with SCCA located in other anatomical parts of the oral region. The patient group whose diagnosis of SCCA in the anterior 2/3 of the tongue occurred prior to the age of 50 years were invariably IVH-, whereas those diagnosed after the age of 50 years were IVH+, providing evidence for heterogeneity. There was no such correlation of biomarker subgrouping with age of diagnosis demonstrated for SCCA at any other anatomical location within the oral cavity or oropharynx.     

Quantitation of aberrant interlocus T-cell receptor rearrangements in mouse thymocytes and the effect of the herbicide 2,4-dichlorophenoxyacetic acid

Small studies in human populations have suggested a correlation between the frequency of errors in antigen receptor gene assembly and lymphoid malignancy risk. In particular, agricultural workers exposed to pesticides have both an increased risk for lymphoma and an increased frequency of errors in antigen receptor gene assembly. In order to further investigate the potential of such errors to serve as a mechanistically based biomarker of lymphoid cancer risk, we have developed a sensitive PCR assay for quantifying errors of V(D)J recombination in the thymocytes of mice. This assay measures interlocus rearrangements between two T-cell receptor loci, V-gamma and J-beta, located on chromosomes 13 and 6, respectively. The baseline frequency in four strains of mice was determined at several ages (2-8 weeks of age) and was found to be stable at approximately 1.5 x 10(-5) per thymocyte. Strain AKR, which has a high susceptibility to T-cell lymphomas, did not show an elevated frequency of aberrant V(D)J events. We used this assay to examine the effects of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the frequency of these events. Female B6C3F1 mice, 27 days of age, were exposed to 2,4-D by gavage at doses of 0, 3, 10, 30, and 100 mg/kg/day for 4 successive days and sacrificed on day 5. Thymus DNA was isolated and examined for illegitimate V(D)J recombination-mediated gene rearrangements. In addition, pregnant mice were exposed to 2,4-D and thymocytes from the offspring examined at 2 weeks of age. No significant increase in aberrant V(D)J rearrangements was found, indicating that under these conditions 2,4-D does not appear to effect this important mechanism of carcinogenesis.     

Vegan Diet and Bone Health—Results from the Cross-Sectional RBVD Study

Scientific evidence suggests that a vegan diet might be associated with impaired bone health. Therefore, a cross-sectional study (n = 36 vegans, n = 36 omnivores) was used to investigate the associations of veganism with calcaneal quantitative ultrasound (QUS) measurements, along with the investigation of differences in the concentrations of nutrition- and bone-related biomarkers between vegans and omnivores. This study revealed lower levels in the QUS parameters in vegans compared to omnivores, e.g., broadband ultrasound attenuation (vegans: 111.8 ± 10.7 dB/MHz, omnivores: 118.0 ± 10.8 dB/MHz, p = 0.02). Vegans had lower levels of vitamin A, B2, lysine, zinc, selenoprotein P, n-3 fatty acids, urinary iodine, and calcium levels, while the concentrations of vitamin K1, folate, and glutamine were higher in vegans compared to omnivores. Applying a reduced rank regression, 12 out of the 28 biomarkers were identified to contribute most to bone health, i.e., lysine, urinary iodine, thyroid-stimulating hormone, selenoprotein P, vitamin A, leucine, α-klotho, n-3 fatty acids, urinary calcium/magnesium, vitamin B6, and FGF23. All QUS parameters increased across the tertiles of the pattern score. The study provides evidence of lower bone health in vegans compared to omnivores, additionally revealing a combination of nutrition-related biomarkers, which may contribute to bone health. Further studies are needed to confirm these findings.     

创伤性脊髓损伤患者血清和尿液的代谢组学分析

背景:创伤性脊髓损伤在临床上主要依赖于量表评估与影像学检查,但对于损伤程度的预后评估具有一定局限性,利用代谢组学技术进行生物标志物筛选,对于估计病变范围、损伤与恢复程度以及开发新疗法具有重要意义。目的:使用代谢组学技术来表征创伤性脊髓损伤患者的代谢特征,探寻潜在的生物标志物及失调的代谢途径。方法:收集20例创伤性脊髓损伤患者(观察组)和10例健康受试者(对照组)的血清和尿液样本,进行代谢物分析,然后利用多元变量统计分析进行数据处理,筛选差异代谢物。通过MetaboAnalyst软件进行代谢通路富集,应用logistic回归构建生物标志物组合模型,并分析其与美国脊髓损伤协会(ASIA)分级的关系。结果与结论:两组受试者的血清和尿液中分别检测出160种和73种具有显著差异的代谢物。通路富集分析显示,创伤性脊髓损伤后脂质代谢出现明显的紊乱,包括鞘脂类、亚油酸、α-亚麻酸和花生四烯酸代谢以及糖基磷脂酰肌醇生物合成。识别出他索沙坦和葫芦素糖苷这组生物标志物,并且二者构成的代谢物组合在血清和尿液中的水平与ASIA分级存在相关性。由此可见,代谢组学技术为进一步理解创伤性脊髓损伤病理机制、筛选治疗靶点提供帮助。识别出的代谢生物标志物组合可能为评估创伤性脊髓损伤的严重程度提供参考。     

Discovery and Validation of a Urinary Exosome mRNA Signature for the Diagnosis of Human Kidney Transplant Rejection

BackgroundDeveloping a noninvasive clinical test to accurately diagnose kidney allograft rejection is critical to improve allograft outcomes. Urinary exosomes, tiny vesicles released into the urine that carry parent cells’ proteins and nucleic acids, reflect the biologic function of the parent cells within the kidney, including immune cells. Their stability in urine makes them a potentially powerful tool for liquid biopsy and a noninvasive diagnostic biomarker for kidney-transplant rejection.MethodsUsing 192 of 220 urine samples with matched biopsy samples from 175 patients who underwent a clinically indicated kidney-transplant biopsy, we isolated urinary exosomal mRNAs and developed rejection signatures on the basis of differential gene expression. We used crossvalidation to assess the performance of the signatures on multiple data subsets.ResultsAn exosomal mRNA signature discriminated between biopsy samples from patients with all-cause rejection and those with no rejection, yielding an area under the curve (AUC) of 0.93 (95% CI, 0.87 to 0.98), which is significantly better than the current standard of care (increase in eGFR AUC of 0.57; 95% CI, 0.49 to 0.65). The exosome-based signature’s negative predictive value was 93.3% and its positive predictive value was 86.2%. Using the same approach, we identified an additional gene signature that discriminated patients with T cell–mediated rejection from those with antibody-mediated rejection (with an AUC of 0.87; 95% CI, 0.76 to 0.97). This signature’s negative predictive value was 90.6% and its positive predictive value was 77.8%.ConclusionsOur findings show that mRNA signatures derived from urinary exosomes represent a powerful and noninvasive tool to screen for kidney allograft rejection. This finding has the potential to assist clinicians in therapeutic decision making.