Downregulation of ABLIM3 confers to the metastasis of neuroblastoma via regulating the cell adhesion molecules pathway

Neuroblastoma (NB) is the most prevalent extracranial solid tumor in pediatric patients, and its treatment failure often associated with metastasis. In this study, LASSO, SVM-RFE, and random forest tree algorithms, was used to identify the pivotal gene involved in NB metastasis. NB cell lines (SK-N-AS and SK-N-BE2), in conjunction with NB tissue were used for further study. ABLIM3 was identified as the hub gene and can be an independent prognostic factor for patients with NB. The immunohistochemical analysis revealed that ABLIM3 is negatively correlated with the metastasis of NB. Patients with low expression of ABLIM3 had a poor prognosis. High ABLIM3 expression correlated with APC co-stimulation and Type1 IFN response, and TIDE analysis indicated that patients with low ABLIM3 expression exhibited enhanced responses to immunotherapy. Downregulation of ABLIM3 by shRNA transfection increased the migration and invasion ability of NB cells. Gene Set Enrichment Analysis (GSEA) revealed that genes associated with ABLIM3 were primarily enriched in the cell adhesion molecules (CAMs) pathway. RT-qPCR and western blot analyses demonstrated that downregulation of ABLIM3 led to decreased expression of ITGA3, ITGA8, and KRT19, the key components of CAMs. This study indicated that ABLIM3 can be an independent prognostic factor for NB patients, and CAMs may mediate the effect of ABLIM3 on the metastasis of NB, suggesting that ABLIM3 is a potential therapeutic target for NB metastasis, which provides a novel strategy for future research and treatment strategies for NB patients.

Eosinophilic Solid and Cystic Renal Cell Carcinoma: Morphologic and Immunohistochemical Study of 18 Cases and Review of the Literature

CONTEXT.—

Eosinophilic solid and cystic renal cell carcinoma is now defined in the 5th edition of the 2022 World Health Organization classification of urogenital tumors.

OBJECTIVE.—

To perform morphologic, immunohistochemical, and preliminary genetic studies about this new entity in China for the purpose of understanding it better.

DESIGN.—

The study includes 18 patients from a regional tertiary oncology center in northern China (Tianjin, China). We investigated the clinical and immunohistochemical features of these cases.

RESULTS.—

The mean age of patients was 49.6 years and the male to female ratio was 11:7. Macroscopically, 1 case had the classic cystic and solid appearance whereas the others appeared purely solid. Microscopically, all 18 tumors shared similar solid and focal macrocystic or microcystic growth pattern, and the cells were characterized by voluminous and eosinophilic cytoplasm, along with coarse amphophilic stippling. Immunohistochemically, most of the tumors had a predominant cytokeratin (CK) 20-positive feature, ranging from focal cytoplasmic staining to diffuse membranous accentuation. Initially, we separated these cases into different immunohistochemical phenotypes. Group 1 (7 of 18; 38.5%) was characterized by positive phospho-4EBP1 and phospho-S6, which can imply hyperactive mechanistic target of rapamycin complex 1 (mTORC1) signaling. Group 2 (4 of 18; 23%) was negative for NF2, probably implying a germline mutation of NF2. Group 3 (7 of 18; 38.5%) consisted of the remaining cases. One case had metastatic spread and exhibited an aggressive clinical course, and we detected cyclin-dependent kinase inhibitor 2A (CDKN2A) mutation in this case; other patients were alive and without disease progression.

CONCLUSIONS.—

Our research proposes that eosinophilic solid and cystic renal cell carcinoma exhibits prototypical pathologic features with CK20 positivity and has aggressive potential.

ISG15 targets glycosylated PD-L1 and promotes its degradation to enhance antitumor immune effects in lung adenocarcinoma

BACKGROUND

Immunocheckpoint inhibitors (ICIs) have been widely used in the clinical treatment of lung cancer. Although clinical studies and trials have shown that patients can benefit significantly after PD-1/PD-L1 blocking therapy, less than 20% of patients can benefit from ICIs therapy due to tumor heterogeneity and the complexity of immune microenvironment. Several recent studies have explored the immunosuppression of PD-L1 expression and activity by post-translational regulation. Our published articles demonstrate that ISG15 inhibits lung adenocarcinoma progression. Whether ISG15 can enhance the efficacy of ICIs by modulating PD-L1 remains unknown.

METHODS

The relationship between ISG15 and lymphocyte infiltration was identified by IHC. The effects of ISG15 on tumor cells and T lymphocytes were assessed using RT-qPCR and Western Blot and in vivo experiments. The underlying mechanism of PD-L1 post-translational modification by ISG15 was revealed by Western blot, RT-qPCR, flow cytometry, and Co-IP. Finally, we performed validation in C57 mice as well as in lung adenocarcinoma tissues.

RESULTS

ISG15 promotes the infiltration of CD4⁺ T lymphocytes. In vivo and in vitro experiments demonstrated that ISG15 induces CD4⁺ T cell proliferation and invalidity and immune responses against tumors. Mechanistically, we demonstrated that the ubiquitination-like modifying effect of ISG15 on PD-L1 increased the modification of K48-linked ubiquitin chains thus increasing the degradation rate of glycosylated PD-L1 targeting proteasomal pathway. The expression of ISG15 and PD-L1 was negatively correlated in NSCLC tissues. In addition, reduced accumulation of PD-L1 by ISG15 in mice also increased splenic lymphocyte infiltration as well as promoted cytotoxic T cell infiltration in the tumor microenvironment, thereby enhancing anti-tumor immunity.

CONCLUSIONS

The ubiquitination modification of PD-L1 by ISG15 increases K48-linked ubiquitin chain modification, thereby increasing the degradation rate of glycosylated PD-L1-targeted proteasome pathway. More importantly, ISG15 enhanced the sensitivity to immunosuppressive therapy. Our study shows that ISG15, as a post-translational modifier of PD-L1, reduces the stability of PD-L1 and may be a potential therapeutic target for cancer immunotherapy.

[Clinical characteristics of digestive system cancers metastatic to the heart]

Objective: To investigate the clinical features of patients with cardiac metastases from digestive system tumors. Methods: This retrospective study collected and analyzed the medical records of patients with cardiac metastases from digestive system tumors who received treatments in the Cancer Hospital, Chinese Academy of Medical Sciences between January 1999 and January 2021. Kaplan-Meier method was used for survival analysis. Results: A total of 19 patients were identified. The primary tumors were esophageal squamous cell carcinoma (n=7), gastric or gastroesophageal junction adenocarcinoma (n=6), hepatobiliary cancers (n=3) and colorectal cancers (n=3). 16 patients had pericardial metastases, 2 patients had right atrium metastases, and 1 patient had left ventricle metastasis. The most common symptom was dyspnea, which was present in 8 cases. 7 patients received locoregional treatment, while 11 patients underwent systemic therapies. The median overall survival from diagnosis of primary cancer was 31.4 months, and the median overall survival time from diagnosis of cardiac metastasis was 4.7 months. Conclusion: Cardiac metastasis from digestive system tumors is associated with low incidence and a poor prognosis. Systemic treatment remains the cornerstone of management, while novel anti-tumor drugs may improve therapeutic efficacy.

Untargeted lipidomics analysis in women with intrahepatic cholestasis of pregnancy: a cross-sectional study

OBJECTIVE

To compare the plasma lipid profiles in women with normal pregnancies and those with mild or severe intrahepatic cholestasis of pregnancy (ICP). Our goal was to reveal lipidome-wide alterations in ICP and delve into the pathogenesis of ICP from a lipid metabolism perspective.

DESIGN

Cross-sectional study, including women with normal pregnancies, women with mild ICP and women with severe ICP.

SETTING

Gansu Provincial Hospital.

POPULATION

Women with ICP were recruited from October 2019 to March 2020 in Gansu, China.

METHODS

Untargeted lipidomics was used to analyse differentially expressed plasma lipids in controls, in women with mild ICP and in women with severe ICP (n = 30 per group). For lipidomics, liquid chromatography and Q-Exactive Plus Orbitrap mass spectrometry were performed.

MAIN OUTCOME MEASURES

Differentially expressed lipids.

RESULTS

Thirty-three lipids were differentially expressed in the severe and mild ICP groups, compared with the control group, and 20 of those were sphingolipids (ceramide, six species; sphingomyelin, 14 species). All differentially expressed sphingolipids in women with mild ICP were also differentially expressed in women with severe ICP; the fold change and significance of the differential expression were positively correlated with disease severity.

CONCLUSIONS

We systematically characterized the lipidome-wide alterations in mild and severe ICP groups. The results indicated a link between ICP and disordered sphingolipid homeostasis.

TWEETABLE ABSTRACT

Abnormal sphingolipid metabolism is involved in the pathogenesis of ICP.

A nomogram-based immune-serum scoring system predicts overall survival in patients with lung adenocarcinoma

OBJECTIVE

The immunoscore, which is used to quantify immune infiltrates, has greater relative prognostic value than tumor, node, and metastasis (TNM) stage and might serve as a new system for classification of colorectal cancer. However, a comparable immunoscore for predicting lung adenocarcinoma (LUAD) prognosis is currently lacking.

METHODS

We analyzed the expression of 18 immune features by immunohistochemistry in 171 specimens. The relationship of immune marker expression and clinicopathologic factors to the overall survival (OS) was analyzed with the Kaplan-Meier method. A nomogram was developed by using the optimal features selected by least absolute shrinkage and selection operator (LASSO) regression in the training cohort (n = 111) and evaluated in the validation cohort (n = 60).

RESULTS

The indicators integrated in the nomogram were TNM stage, neuron-specific enolase, carcino-embryonic antigen, CD8center of tumor (CT), CD8invasive margin (IM), FoxP3CT, and CD45ROCT. The calibration curve showed prominent agreement between the observed 2- and 5-year OS and that predicted by the nomogram. To simplify the nomogram, we developed a new immune-serum scoring system (I-SSS) based on the points awarded for each factor in the nomogram. Our I-SSS was able to stratify same-stage patients into different risk subgroups. The combination of I-SSS and TNM stage had better prognostic value than the TNM stage alone.

CONCLUSIONS

Our new I-SSS can accurately and individually predict LUAD prognosis and may be used to supplement prognostication based on the TNM stage.

Structural exercise-based intervention for health problems in individuals with autism spectrum disorders: a pilot study

OBJECTIVE

Exercise-based intervention promises to be more effective in a structured framework for individuals with autism spectrum disorders (ASD). The aim of this study was to observe changes in behavior of individuals with ASD by investigating their physical status after the structured exercise-based intervention.

PATIENTS AND METHODS

The exercise intervention integrated an 8-week exercise program that included aerobic, resistive, and neuromuscular exercises. Body composition and the Autism Treatment Evaluation Checklist (ATEC) were evaluated to assess changes after the exercise-based intervention.

RESULTS

After the exercise intervention, the fat mass of individuals with ASD were significantly reduced, and their behavior improved markedly.

CONCLUSIONS

This pilot study demonstrated that individuals with ASD require long-term, structured exercise-based intervention, and that such exercise-based intervention is effective for improving their health.

Characterization of a distinct low-grade oncocytic renal tumor (CD117-negative and cytokeratin 7-positive) based on a tertiary oncology center experience: the new evidence from China

To examine the clinicopathologic and immunohistochemical features of a group of newly defined low-grade oncocytic renal tumors (LOT) that have the "CD117 negative/cytokeratin (CK)7 positive" immunoprofile. We have queried our hospital database and found 4456 consecutive renal tumors between 2016 and 2019. Among these renal tumors, eight (8) cases meet the morphologic and immunohistochemical characterization for low-grade oncocytic renal tumor (LOT). The eight (8) patients' mean age is 56.6 years (range 39-70 years old), and the male to female ratio is 1:1. Macroscopically, these LOTs generally present with tan-brown and solid cut surfaces and demonstrate similar solid, compact nested growth pattern microscopically. Tumor cells exhibit oncocytic cytoplasm and uniformly rounded to oval nuclei. There are areas of edematous stroma containing dispersed single or small clustered tumor cells. All tumors are negative for CD117 and positive for CK7. Uniform reactivity is also found for BerEP4, cyclin D1, and SDHB. Besides, CD10, vimentin, and AMACR are either negative or only focally positive. All of the tumors are negative for CA9 and TFE. The Ki-67 index is less than 5% in the seven (7) internal cases. Seven (7) of the eight (8) patients who are available for follow-up are alive and without disease recurrence (mean follow-up period of 21.6 months, ranging from 6 to 43 months). We described a group of low-grade oncocytic renal tumors identified retrospectively in a large tertiary cancer center, which was probably the first report originated from China or even Asia in the English literature so far. These tumors demonstrated eosinophilic cytoplasm and low-grade appearing nuclei with a "CD117 negative/CK7 positive" immunoprofile. The incidence rate was about 3.7% of the oncocytic renal tumors and 0.18% of all the renal tumors that were received in our lab during the four-year period. It is necessary to separate this group of tumors by its characteristic morphologic and immunophenotypic features.

ISG15 induces ESRP1 to inhibit lung adenocarcinoma progression

Our previous work demonstrated that Epithelial Splicing Regulatory Protein 1 (ESRP1) could inhibit the progression of lung adenocarcinoma (ADC). When ESRP1 was upregulated, the interferon (IFN) pathway was activated and Interferon-stimulated gene 15 (ISG15) expression increased exponentially in our microarray result. In this study, we aim to explore the function of ISG15 and its interactions with ESRP1 and to provide new insights for ADC treatment. ISG15 expression in lung ADC tissues was determined by immunohistochemistry (IHC) staining. The effect of ISG15 on lung ADC progression was examined by in vitro and in vivo assays. The mechanism of action on ESRP1 regulating ISG15 was investigated using Western blotting, RT-qPCR, immunofluorescence staining, chromatin immunoprecipitation, and a dual luciferase reporter system. The ISGylation between ISG15 and ESRP1 was detected by co-immunoprecipitation. Patients with high ISG15 expression were associated with higher survival rates, especially those with ISG15 expression in the nucleus. In vitro and in vivo experiments showed that upregulation of ISG15 inhibited EMT in lung ADC. ESRP1 upregulated the expression of ISG15 through CREB with enriched ISG15 in the nucleus. Importantly, ISG15 promoted ISGylation of ESRP1 and slowed the degradation of ESRP1, which demonstrated that ESRP1 and ISG15 formed a positive feedback loop and jointly suppressed EMT of lung ADC. In conclusion, ISG15 serves as an independent prognostic marker for long-term survival in lung ADC patients. We have revealed the protective effect of ISG15 against lung ADC progression and the combinatorial benefit of ISG15 and ESRP1 on inhibiting EMT. These findings suggest that reconstituting ISG15 and ESRP1 may have the potential for treating lung ADC.

A combination of tumor and molecular markers predicts a poor prognosis in lung adenocarcinoma

PURPOSE

Whether patients with stage IA-IIA lung adenocarcinoma require conventional chemotherapy is still a controversy. An ideal metastasis risk prediction model in lung adenocarcinoma is valuable for determining the prognosis and giving timely, individualized treatment.

RESULTS

Analyzing the clinical cases of 153 lung adenocarcinoma patients using an χ² test, Kaplan-Meier survival curves, and a multivariate logistic regression analysis, we selected the most valuable factors for determining metastasis and constructed metastasis prediction models. We confirmed the importance of the tumor markers (CEA, NSE) and a molecular marker (CAMKII) as independent prognostic factors in lung adenocarcinoma. The result of a five-year survival status was significantly associated with CAMKII and CEA (P < 0.05). A nomogram was created using CEA, NSE, CYFRA 21-1, and CAMKII to estimate the metastasis probability for individuals, specifically, 78 stage I lung adenocarcinoma patients were used to verify the effectiveness of the nomogram. Using machine learning, LASSO selected the subset of variables that minimized the predictive error of the outcome, including CEA, NSE, CYFRA 21-1, CAMKII, tumor size, histologic type, lymph node status, smoking, and age. A ten-fold cross-validation showed the average accuracy of this model was 86.208%, with an area under the curve of 0.857, a sensitivity value of 0.840, and a specificity value of 0.873.

CONCLUSION

Using both complementary methods, the predictive models illustrated that the combination of tumor markers and a key molecule to predict the prognosis of lung adenocarcinoma patients in early stages is valuable. The postoperative transfer rate of stage I patients can be effectively predicted by these complementary methods.

Multidisciplinary team for the diagnosis and treatment of 2 cases of primary intestinal yolk sac tumor

Extragonadal primary yolk sac tumor of the intestinal tract origin is exceedingly rare. Through a multiple disciplinary team, the diagnosis and treatment of primary intestinal yolk sac tumor were further defined. We report 2 such cases with detailed histologic and immunohistochemical analysis. The two patients were a 7-year-old girl and a 29-year-old woman. Both of them preoperatively had an elevated serum alpha fetoprotein (AFP) level (≥ 1,210 ng/mL). The tumors are located in the intestine and imaging examination indicated the rectum as the primary site. Grossly the mass was grey-white and crisp texture. Microscopic examination featured reticular, microcystic, macrocystic, papillary, solid, and some glandular patterns. Immunohistochemically, tumor cells of both cases were positive for SALL4, AFP, pan-cytokeratin (AE1/AE3), and glypican-3. Simultaneously, a stain for EMA, OCT4, CD30, HCG, vimentin and CK20 were negative in all 2 neoplasms. The features of morphology, immunohistochemistry, laboratory examinations and imaging studies consist of the diagnosis of primary yolk sac tumor of the intestine.

Epidemiology and molecular characterization of Porcine teschovirus in Hunan, China

Porcine teschoviruses (PTVs) have been shown to be widely distributed in pig populations. In this study, 261 faecal and 91 intestinal content samples collected from pigs at 29 farms in Hunan, China, were tested for the presence of PTV by reverse transcription-polymerase chain reaction (RT-PCR). An overall PTV-positivity rate of 19.03% was detected by RT-PCR, and a high PTV infection rate was circulating in asymptomatic fattening and nursery pigs. In total, 40 PTV isolates (PTV-HuNs) were obtained. Alignment of their coding sequences with those of other known PTVs revealed that the genomic sequence of the polyprotein contains 6,606-6,621 nucleotides, encoding a 2,202-2,207-amino acid sequence. Phylogenetic analyses based on the VP1 gene and capsid protein gene exhibited 13 main lineages corresponding to PTV serotypes 1-13, and seven PTV serotypes (PTV 2-6, 9, and 11) were identified in the isolates obtained in our study; this is the first report of PTV 5, 9 and 11 in China. Recombination analysis among the PTV-HuNs indicated that nine recombination events have occurred, including both inter- and intraserotype events. In addition, results demonstrated that only limited positive selection is acting on the global population of PTV isolates, and purifying selection is predominant. In conclusion, this study revealed a high infection rate of PTVs circulating in asymptomatic fattening and nursery pigs. The 40 PTV-HuNs showed high genetic diversity, and genetic analysis of all available PTV sequences revealed that strong purifying selection and recombination play important roles in the genetic diversity and evolution of the virus.

Phase-Lock Requirements in a Serial Array of Spin Transfer Nano-Oscillators

The most promising approach to attain a narrow linewidth and a large output power simultaneously in spin torque oscillators is self-phase-locking of an array of oscillators. Two long range coupling mechanisms, magnetostatic interaction and self-induced current, are explored. Synchronization occurs with MR ratio ~14% and volume ~2.1 × 10⁻⁵ μm³ at room temperature for an experimental frequency dispersion, when only the self-induced microwave current is present. The dipole interaction decreases the MR ratio requirement when the elements are properly spaced.

Targeted cell reprogramming produces analgesic chromaffin-like cells from human mesenchymal stem cells

Transplantation of allogeneic adrenal chromaffin cells demonstrated the promise of favorable outcomes for pain relief in patients. However, there is a very limited availability of suitable human adrenal gland tissues, genetically well-matched donors in particular, to serve as grafts. Xenogeneic materials, such as porcine and bovine adrenal chromaffin cells, present problems; for instance, immune rejection and possible pathogenic contamination are potential issues. To overcome these challenges, we have tested the novel approach of cell reprogramming to reprogram human bone marrow (BM)-derived mesenchymal stem cells (hMSCs) using cellular extracts of porcine chromaffin cells. We produced a new type of cell, chromaffin-like cells, generated from the reprogrammed hMSCs, which displayed a significant increase in expression of human preproenkephalin (hPPE), a precursor for enkephalin opioid peptides, compared to the inherent expression of hPPE in naive hMSCs. The resultant chromaffin-like cells not only expressed the key molecular markers of adrenal chromaffin cells, such as tyrosine hydroxylase (TH) and methionine enkephalin (Met-enkephalin), but also secreted opioid peptide Met-enkephalin in culture. In addition, intrathecal injection of chromaffin-like cells in rats produced significant analgesic effects without using immunosuppressants. These results suggest that analgesic chromaffin-like cells can be produced from an individual's own tissue-derived stem cells by targeted cell reprogramming and also that these chromaffin-like cells may serve as potential autografts for chronic pain management.

Generation of neural stem cell-like cells from bone marrow-derived human mesenchymal stem cells

Under appropriate culture conditions, bone marrow (BM)-derived mesenchymal stem cells are capable of differentiating into diverse cell types unrelated to their phenotypical embryonic origin, including neural cells. Here, we report the successful generation of neural stem cell (NSC)-like cells from BM-derived human mesenchymal stem cells (hMSCs). Initially, hMSCs were cultivated in a conditioned medium of human neural stem cells. In this culture system, hMSCs were induced to become NSC-like cells, which proliferate in neurosphere-like structures and express early NSC markers. Like central nervous system-derived NSCs, these BM-derived NSC-like cells were able to differentiate into cells expressing neural markers for neurons, astrocytes, and oligodendrocytes. Whole-cell patch clamp recording revealed that neuron-like cells, differentiated from NSC-like cells, exhibited electrophysiological properties of neurons, including action potentials. Transplantation of NSC-like cells into mouse brain confirmed that these NSC-like cells retained their capability to differentiate into neuronal and glial cells in vivo. Our data show that multipotent NSC-like cells can be efficiently produced from BM-derived hMSCs in culture and that these cells may serve as a useful alternative to human neural stem cells for potential clinical applications such as autologous neuroreplacement therapies.

LPS induces IL-8 expression through TLR4, MyD88, NF-kappaB and MAPK pathways in human dental pulp stem cells

AIM

To evaluate the effects of lipopolysaccharide (LPS) on interleukin-8 (IL-8) and related intracellular signalling pathways in human dental pulp stem cells (hDPSCs).

METHODOLOGY

Human pulp tissues were isolated from human impacted third molars, and the hDPSCs were cultured and characterized. The effects of LPS on IL-8 and Toll-like receptor 4 (TLR4) gene expression in hDPSCs were investigated using real-time quantitative RT-PCR and ELISA. Whether TLR4/MyD88/NF-кB was involved in the LPS-induced up-regulation of IL-8 in hDPSCs was determined using transient transfection, luciferase assay and ELISA. The involvement of MAPKs in the LPS-induced up-regulation of IL-8 in hDPSCs was investigated via transient transfection, luciferase assay, ELISA and western blot. The data were statistically analysed using Student's t-test or one-way anova followed by the Student-Neumann-Keuls test.

RESULTS

Cells exposed to LPS not only displayed an enhanced expression of TLR4 but also showed an elevated IL-8 gene expression; exposure to LPS also resulted in the induction of IL-8 gene transcription via promoter activation. The LPS-induced IL-8 promoter activation was inhibited through dominant-negative mutations in TLR4 and MyD88, but not in TLR2. The LPS-induced IL-8 protein release was attenuated through the administration of TLR4-neutralizing antibody or MyD88 inhibitory peptide and a dominant-negative mutation in IκBα. In contrast, IL-8 protein release was enhanced through the expression of NF-κB p65. Treatment with PDTC, TPCK or Bay117082 effectively antagonized LPS-induced IL-8 protein release. Moreover, both the promoter activity and the LPS-induced release of IL-8 were diminished upon the administration of U0126 and SB203580, but not SP600125. Moreover, the exposure to LPS activated ERK1/2 and p38 MAPK phosphorylation in cells.

CONCLUSIONS

This study reports the LPS-mediated transcriptional and post-translational up-regulation of IL-8, which is a process that also involves TLR4, MyD88, NF-κB and MAPK.

Amyloid precursor protein regulates differentiation of human neural stem cells

Although amyloid beta (Abeta) deposition has been a hallmark of Alzheimer's disease (AD), the absence of a phenotype in the beta amyloid precursor protein (APP) knockout mouse, tends to detract our attention away from the physiological functions of APP. Although much attention has been focused on the neurotoxicity of Abeta, many studies suggest the involvement of APP in neuroplasticity. We found that secreted amyloid precursor protein (sAPP) increased the differentiation of human neural stem cells (hNSCs) in vitro, while an antibody-recognizing APP dose-dependently inhibited these activities. With a high dose of sAPP treatment or wild-type APP gene transfection, hNSCs were differentiated into astrocytes rather than neurons. In vivo, hNSCs transplanted into APP-transgenic mouse brain exhibited glial differentiation rather than neural differentiation. Our results suggest that APP regulates neural stem cell biology in the adult brain, and that altered APP metabolism in Down syndrome or AD may have implications for the pathophysiology of these diseases.

Familial atrophia maculosa varioliformis cutis: case report and pedigree analysis

Atrophia maculosa varioliformis cutis (AVMC) was first described in 1918, as a rarely reported form of idiopathic macular atrophy on the cheeks. Nineteen patients have been reported in the past 86 years. Recently we diagnosed a 25-year-old woman as AMVC and investigated her family history. We collected the clinical data of the pedigree and presumed that AVMV is in a autosomal dominant inheritance.

Differentiation of human neural stem cells into retinal cells

We have previously reported that transplanted human neural stem cells (HNSCs) display extensive migration and positional incorporation into the aged rat brain, which is associated with an improvement in cognitive function. In the current study, to investigate whether HNSCs are capable of differentiating into retinal cells, we treated HNSCs with human transforming growth factor-beta3 (TGF-beta3) under a serum-free differentiation condition. After 5 days of differentiation in vitro we detected opsin-immunopositive cells in the culture treated with TGF-beta3. We also transplanted TGF-beta3-treated HNSCs into the rat vitreous cavity. The donor cells migrated and differentiated into opsin-positive cells in the host retinal cell layer. Here we show for the first time that TGF-beta3-treated HNSCs differentiate into retinal cells.

Reelin function in neural stem cell biology

In the adult brain, neural stem cells (NSC) must migrate to express their neuroplastic potential. The addition of recombinant reelin to human NSC (HNSC) cultures facilitates neuronal retraction in the neurospheroid. Because we detected reelin, alpha3-integrin receptor subunits, and disabled-1 immunoreactivity in HNSC cultures, it is possible that integrin-mediated reelin signal transduction is operative in these cultures. To investigate whether reelin is important in the regulation of NSC migration, we injected HNSCs into the lateral ventricle of null reeler and wild-type mice. Four weeks after transplantation, we detected symmetrical migration and extensive neuronal and glial differentiation of transplanted HNSCs in wild-type, but not in reeler mice. In reeler mice, most of the injected HNSCs failed to migrate or to display the typical differentiation pattern. However, a subpopulation of transplanted HNSCs expressing reelin did show a pattern of chain migration in the reeler mouse cortex. We also analyzed the endogenous NSC population in the reeler mouse using bromodeoxyuridine injections. In reeler mice, the endogenous NSC population in the hippocampus and olfactory bulb was significantly reduced compared with wild-type mice; in contrast, endogenous NSCs expressed in the subventricular zonewere preserved. Hence, it seems likely that the lack of endogenous reelin may have disrupted the migration of the NSCs that had proliferated in the SVZ. We suggest that a possible inhibition of NSC migration in psychiatric patients with a reelin deficit may be a potential problem in successful NSC transplantation in these patients.

A comparison in monkeys of (99m)Tc labeled to a peptide by 4 methods

Although a number of different strategies for labeling peptides with (99m)Tc have been developed, only a few studies have compared the in vivo properties of (99m)Tc when attached to different chelators. Furthermore, these comparisons are usually in mice, whereas results obtained in nonhuman primates may be expected to be more relevant to the clinical situation.

METHODS

We evaluated the influence of 4 common chelators on the biodistribution in monkeys of (99m)Tc-labeled HNE-2, a 6.7-kDa peptide being investigated as an inflammation/infection imaging agent. The peptide was conjugated with the N-hydroxysuccinimide ester of mercaptoacetyltriglycine (MAG3), mercaptoacetyltriserine (MAS3), hydrazinonicotinamide (HYNIC), and the cyclic anhydride of diethylenetriaminepentaacetic acid (DTPA). After radiolabeling, each peptide was administered intravenously to rhesus monkeys with a Staphylococcus aureus-induced focal inflammation/infection.

RESULTS

Quantification of radioactivity accumulation by regions of interest over 3 h after administration in monkeys showed important differences among labeling methods: For example, at 3 h, kidney accumulation varied in percentage injected dose per organ (%ID per organ) from 31 %ID per organ (HYNIC) to 18 %ID per organ (MAG3), whereas liver varied from 7.8 %ID per organ (MAG3) to 2.8 %ID per organ (MAS3). Radioactivity accumulation in the lesion was independent of labeling method. These organ accumulations were compared with that obtained earlier in mice by sacrifice and dissection also at 3 h and at the same administered dosage. In the rodent, kidney levels varied from 45 %ID per organ (HYNIC) to 12 %ID per organ (MAS3) and liver levels varied from 6.5 %ID per organ (DTPA) to 2.0 %ID per organ (MAS3).

CONCLUSION

In agreement with previous work from this laboratory and elsewhere, the method of radiolabeling had an important effect on the biodistribution of (99m)Tc. Furthermore, although biodistribution results in mice should be used with caution to predict biodistributions in primates, in major organs, these results in mice and monkeys were similar.

Survival and plasticity of basal forebrain cholinergic systems in mice transgenic for presenilin-1 and amyloid precursor protein mutant genes

The basalo-cortical cholinergic system was characterized in mice expressing mutant human genes for presenilin-1 (PS1), amyloid precursor protein (APP), and combined PS/APP. Dual immunocytochemistry for ChAT and A beta revealed swollen cholinergic processes within cortical plaques in both APP and PS/APP brains by 12 months, suggesting aberrant sprouting or redistribution of cholinergic processes in response to amyloid deposition. At 8 months, cortical and subcortical ChAT activity was normal (PS/APP) or elevated (PS, APP frontal cortex), while cholinergic cell counts (nBM/SI) and receptor binding were unchanged. ChAT mRNA was up-regulated in the nBM/SI of all three transgenic lines at 8 months. The data indicate that the basal forebrain cholinergic system does not degenerate in mice expressing AD-related transgenes, even in mice with extreme amyloid load. The

Human neural stem cells improve cognitive function of aged brain

The capability for in vitro expansion of human neural stem cells (HNSCs) provides a well characterized and unlimited source alternative to using primary fetal tissue for neuronal replacement therapies. The HNSCs, injected into the lateral ventricle of 24-month-old rats after in vitro expansion, displayed extensive and positional incorporation into the aged host brain with improvement of cognitive score assessed by the Morris water maze after 4 weeks of the transplantation. Our results demonstrate that the aged brain is capable of providing the necessary environment for HNSCs to retain their pluripotent status and suggest the potential for neuroreplacement therapies in age-associated neurodegenerative disease.

Different chelators and different peptides together influence the in vitro and mouse in vivo properties of 99Tcm

Relatively few studies comparing different methods of labelling peptides with 99Tcm have been reported. In this investigation, we evaluated the influence of three chelators on the in vitro and in vivo properties of two small, similar peptides (HNE2 and HNE4) labelled with 99Tcm. Both peptides were labelled with hydrazinonicotinamide (HYNIC) (tricine) at pH 5-6 and with diethylenetriaminepentaacetic acid (DTPA) and mercaptoacetyltriglycine (MAG3) at both pH 5-6 and 7-8. All ten preparations were brought to pH 7.2 immediately after labelling. Each preparation labelled well and control labelling showed each label to be attached specifically at chelation sites. Analysis of 37 degrees C human serum incubates showed little evidence of label instability but high protein binding in several cases. The stability of 99Tcm to cysteine challenge for labelled DTPA- and MAG3-peptides was similar but lower than that for the HYNIC-peptides. Reverse phase HPLC of the DTPA-peptides, but not the MAG3-peptides, showed different 99Tcm species depending on labelling pH. The 3 h biodistributions in normal mice were generally independent of labelling pH for both MAG3-peptides but were heavily influenced by labelling pH for both DTPA-peptides. While significant differences in biodistribution for the same labelling method were evident between peptides, as expected, far larger differences in the case of both peptides resulted from changing chelators and, in the case of DTPA, changing the labelling method. In summary, the chelators and labelling methods influenced the biodistribution of 99Tcm in a characteristic fashion common to both peptides. Differences in biodistribution due to the different peptides were relatively small and generally lost in the much larger differences due to chelator and labelling method. In conclusion, it may be important to compare chelators and labelling methods before selecting a 99Tcm labelling method for any particular peptide.

5-Lipoxygenase and cyclooxygenase mRNA expression in rat hippocampus:early response to glutamate receptor activation by kainate

Recent research has identified in central nervous system neurons the expression of two enzymes from the inflammatory pathway of the metabolism of arachidonic acid, the 5-lipoxygenase (5LOX) and the cyclooxygenase-2 (COX2). Expression of both enzymes appears to be upregulated during aging; upregulated 5LOX/COX2 expression in neurons may be responsible for the increased neuronal vulnerability to degeneration. Involvement of the excitatory neurotransmitter glutamate in aging-associated neurodegeneration has also been suggested. Stimulation of glutamate receptors by kainic acid (kainate) has been shown independently to affect the brain expression of 5LOX or COX2. Using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay to measure the contents of mRNAs we found 3h after kainate injection (intraperitoneally; 10 mg/kg) increased mRNA levels of 5LOX and COX2, but not that of COX1 in the hippocampus of rats. Pretreatment with the COX2 inhibitor NS-398 (9 mg/kg, 1h prior to kainate) inhibited the kainate-stimulated increase of 5LOX and COX2 mRNA levels. Our results indicate that hippocampal expression of both 5LOX and COX2 increases rather promptly when glutamate receptors are stimulated by kainate. The mechanism of how NS-398 inhibits this action of kainate should be further investigated.

Biodistribution and metabolism of a mixed backbone oligonucleotide (GEM 231) following single and multiple dose administration in mice

Biodistribution and metabolism of a mixed backbone oligonucleotide (MBO), GEM 231, targeted to the RIalpha subunit of protein kinase A has been studied in normal and tumor xenografted mice. The study has been carried out using [35S]-labeled MBO following single and multiple administrations of doses varying from 2 to 50 mg/kg. MBO showed wide tissue distribution following intravenous and subcutaneous administration. The highest concentration of MBO was in the kidney and liver. The general disposition of MBO was followed by digitized autoradiographic pictures of tumored mice and further confirmed wide tissue disposition and also showed defined intratumor uptake of MBO. Multiple dose administration showed increased disposition in the majority of the tissues/organs, with the exception of the kidneys. Analysis of the extracted MBO by polyacrylamide gel electrophoresis (PAGE) showed the presence of primarily intact MBO along with its degraded forms. Based on our radioactivity levels, the primary route of excretion was in urine, analysis of which showed mainly degraded forms of MBO.

Inflammatory 5-LOX mRNA and protein are increased in brain of aging rats

5-Lipoxygenase (5-LOX) is the key enzyme in the synthesis of leukotrienes, inflammatory mediators of arachidonic acid. 5-LOX is also expressed in neurons (in particular in the hippocampus and the cerebellum), and it seems to be capable of promoting neurodegeneration. Recently, we observed greater 5-LOX mRNA content in the hippocampus of older (24 months) than younger (2 months) rats. In this study, we measured in the hippocampus and the cerebellum of younger and older male F344 rats the contents of: 5-LOX mRNA, FLAP (5-LOX activating protein) mRNA, and 5-LOX protein. By using a quantitative reverse transcription/polymerase chain reaction (PCR) (RT-PCR) with internal standards we found that 5-LOX but not FLAP mRNA content is greater (both in hippocampus and cerebellum) of older than younger rats. By using quantitative Western immunoblotting, we found a greater content of 5-LOX protein in the hippocampus and the cerebellum of older rats; we also established that the membrane/cytosol 5-LOX content ratio is larger in the brains of older than younger rats (statistically significant in the cerebellum). The latter can be considered an indication of 5-LOX translocation/activation during aging. Together these results suggest that aging increases both neuronal 5-LOX expression and protein translocation, and indicate that the 5-LOX system might play a significant role in the pathobiology of aging-associated neurodegenerative diseases.

Putative role of neuronal 5-lipoxygenase in an aging brain

Aging is associated with increased incidence and/or severity of neurodegenerative pathologies. Oxygen-mediated events are being considered as possible mechanisms responsible for the increasing neuronal vulnerability. Lipoxygenases are enzymes that, as cyclooxygenases (COX), can insert oxygen into the molecule of arachidonic acid and thereby synthesize inflammatory eicosanoids: leukotrienes [due to 5-lipoxygenase (5-LOX) activity] and prostaglandins (via COX activity). It appears that 5-LOX is expressed in central nervous system neurons and may participate in neurodegeneration. 5-LOX-triggered cell death may be initiated by the enzymatic activity of 5-LOX but could also occur via the nonenzymatic actions of the 5-LOX protein; new data point to the possibility that 5-LOX protein exerts actions such as interaction with tyrosine kinase receptors, cytoskeletal proteins, and the nucleus. The expression of neuronal 5-LOX is susceptible to hormonal regulation, presumably due to the presence of hormone-responsive elements in the structure of the 5-LOX gene promoter. The expression of the 5-LOX gene and the activity of the 5-LOX pathway are increased in elderly subjects. One possible mechanism of such 5-LOX up-regulation implies the contribution of aging-associated hormonal changes: relative melatonin deficiency and/or hyperglucocorticoidemia. Thus, the 5-LOX pathway could become a promising target of neuroprotective therapies for the aging brain.

Inflammation and infection imaging with a 99mTc-neutrophil elastase inhibitor in monkeys

A radiolabeled human neutrophil elastase inhibitor (EPI-HNE-2) may represent an improved nuclear medicine imaging agent for inflammation and infection. This peptide displays rapid pharmacokinetics due to its low molecular weight and localizes specifically on neutrophil elastase released in inflammatory sites by activated neutrophils.

METHODS

In this investigation, the peptide was radiolabeled with 99mTc using N-hydroxysuccinimidyl S-acetylmercaptoacetyltriglycline (NHS-MAG3) as a bifunctional chelator and was administered on 18 occasions to 5 rhesus monkeys with inflammation/infection.

RESULTS

Plasma clearance was rapid, with liver and kidneys representing the major organs of accumulation. No evidence of toxicity, dosage effects, or circulating antiMAG3-EPI-HNE-2 antibodies was observed. Specificity of localization was established using radiolabeled bovine pancreatic trypsin inhibitor (a non-hNE-binding peptide of similar size) as a nonspecific negative control peptide and by predosing with unlabeled EPI-HNE-2 to block receptor sites before the administration of radiolabeled EPI-HNE-2. The ability of radiolabeled EPI-HNE-2 to image inflammation/infection was evaluated in 12 studies in monkeys receiving only radiolabeled EPI-HNE-2 and with lesions in the arm, shoulder, or lower back. Positive images were obtained in all studies, uptake was apparent almost immediately, and images were still positive 24 h later. As a positive control, animals also received nonspecific IgG antibody radiolabeled with 99mTc either directly or by NHS-MAG3. Compared with labeled antibody, plasma clearance of 99mTc was faster with labeled EPI-HNE-2 and accumulation in liver and heart was lower. Uptake of radioactivity in the inflammation was higher during the first hour with EPI-HNE-2 versus antibody but lower thereafter.

CONCLUSION

When radiolabeled with 99mTc, EPI-HNE-2 localized specifically in inflammations in a monkey model and provided early images of diagnostic quality.

Technetium-99m labeled peptides--an investigation of multiple HPLC peaks

This laboratory, and others, have reported multiple radioactive peaks in the size exclusion high performance liquid chromatographic (HPLC) analysis of 99mTc-labeled peptides. In the case of one 99mTc-MAG3-labeled peptide studied in this laboratory, human neutrophil elastase inhibitor, all five radioactive peaks were shown to be due to active peptide rather than radiocontaminants. By a variety of experiments, the nature of these peaks have now been examined. A high molecular weight UV peak could be generated by heating the MAG3 coupled, but not the native, peptide. Furthermore, this UV peak did not appear upon heating the peptide if the sulfur within the MAG3 chelator was replaced with oxygen. This peak may therefore be due to polymers resulting from intermolecular disulfide bond formation between sulfurs in the MAG3 chelate and the peptide. Several peaks with apparent lower molecular weights were absent on analysis with a different size exclusion column with superior resolution in their molecular weight range. More importantly, they were also absent on analysis by SDS polyacrylamide gel electrophoresis. These "low" molecular weight radioactive peaks may therefore be due to interactions between the 99mTc-MAG3 chelate and the peptide which produce multiple molecular configurations of identical molecular weight but differing in shape, charge, isomerism or lipophilicity such that they are resolved under the conditions of certain analyses. In support of this possibility, lengthening the linker between MAG3 and the peptide reduced the number of radioactive peaks, while encouraging the interaction by replacing MAG3 with the shorter MAG2 seemed to increase the number of radioactive peaks. Finally, that the three "low" molecular weight radioactive peaks reappeared when a single peak fraction was reanalyzed suggests that the species responsible are in rapid equilibrium. One conclusion from this investigation is that the appearance of a single peak by any HPLC analysis offers no assurance that multiple peaks would not appear on alternative HPLC analyses. Evidence that each species is due to radiolabeled active peptide and not to radiocontaminants is therefore potentially more important than evidence of a single peak.

NHS-MAS3: a bifunctional chelator alternative to NHS-MAG3

This laboratory uses an N-hydroxysuccinimide derivative of S-acetylmercaptoacetyltriglycine (NHS-MAG3) to conjugate amines for subsequent labeling with 99mTc. However, the synthesis from triglycerine is general and not restricted to this tripeptide. We had earlier selected a small number of alternative tripeptides and synthesized the corresponding NHS derivatives. Each was then evaluated in a search for bifunctional chelators with properties superior to NHS-MAG3, such as lower serum protein binding or improved stability to cysteine challenge. Based on these preliminary results, NHS-S-acetylmercaptoacetyltriserine (NHS-MAS3) was selected for further investigation. We have now conjugated this bifunctional chelator to an biocytin and to an amine-derivatized peptide nucleic acid (PNA). Both carriers were also conjugated with NHS-MAG3 under identical conditions and all were labeled with 99mTc at neutral pH and at boiling temperature while the conjugated PNAs were radiolabelled at neutral pH and at room temperature. Regardless of the chelator, reverse phase HPLC radiochromatograms of the labeled biotins and PNAs after purification showed a single peak. However, by size exclusion HPLC, the radiochromatograms always showed several peaks even after purification, but the MAS3 radiochromatograms were less complicated. For biotin and PNA both, radiolabeling via MAS3 showed improved 99mTc stability in 37 degrees C serum and in cysteine solution. The four preparations were administered to mice implanted in one thigh with avidin beads (biotins) or complementary PNA beads (PNAs). At 5 h post-administration, no significant differences were observed in the targeting of PNA beads between the two chelators, however the target thigh/normal thigh ratio was significantly higher for MAS3-biotin compared to MAG3-biotin. We conclude that labeling biocytin and amine-derivatized PNA with NHS-MAS3 compared to NHS-MAG3 provides simpler radiochromatographic profiles, improved stability of the label in serum and cysteine solution and can improve in vivo targeting.

Early upregulation of hippocampal 5-lipoxygenase following systemic administration of kainate to rats

5-Lipoxygenase (5-LO; arachidonate:oxygen 5-oxidoreductase, EC 1.13.11.34) is the enzyme responsible for the first step in the formation of inflammatory leukotrienes from arachidonic acid. 5-LO is expressed in hippocampal neurons. Increased formation of leukotrienes was found in the hippocampus of rats in which seizures were induced by a glutamate receptor agonist, kainate. Expression of the 5-LO gene can be stimulated by vitamin D3 and suppressed by the pineal hormone melatonin. Here we hypothesize that kainate also stimulates 5-LO expression in the hippocampus. Kainate was injected intraperitoneally (10 mg/kg). Rats were sacrificed 3 hr later and their hippocampi were dissected and total RNA was extracted and processed for quantitative reverse transcription/polymerase chain reaction (RT-PCR) assay of 5-LO and cyclophilin (cyc) mRNAs. Mutated primers were used as internal standards to assay attomol quantities of these two specific mRNAs per microgram of total RNA. Fixed hippocampal slices were processed for 5-LO immunostaining and Nissl staining (assay of cell damage). Kainate induced about a 2.5-fold increase in 5-LO mRNA and triggered a redistribution of 5-LO like immunoreactivity from the pyramidal cell bodies into the dendrites of these neurons, particularly in the CA3 area. The results suggest that glutamate receptor-mediated signaling may modify the expression of neuronal 5-LO and that this enzyme might be involved in glutamate receptor-mediated neuronal plasticity and/or degeneration.

Labeling peptides with technetium-99m using a bifunctional chelator of a N-hydroxysuccinimide ester of mercaptoacetyltriglycine

A modified mercaptoacetyltriglycine (MAG3) chelator, which has acetyl S-protection and which is derivitized with N-hydroxysuccinimide (NHS) ester for conjugation, has been used to radiolabel four small (approximately 6- to 7-kDa) peptides, bovine pancreatic trypsin inhibitor, epidermal growth factor, human neutrophil elastase inhibitor and plasmin inhibitor, with 99mTc.

METHODS

Each peptide was specifically labeled at the MAG3 chelation sites at ambient temperature and neutral pH. Specific activities of 100-150 mCi/mg were achieved at labeling efficiencies of about 50%, but specific activities of 3500 mCi/micromol could be attained.

RESULTS

By a variety of assays, protein activity was unimpaired by the conjugation and labeling for two of the four peptides. The activities for plasmin of the plasmin inhibitor and bovine pancreatic trypsin inhibitor were reduced by conjugation, presumably because of a sensitive lysine residue in the structure of each of these two peptides. Multiple peaks were present in the high-performance liquid chromatography radiochromatograms, especially of human neutrophil elastase inhibitor; however, most peaks could be shown to be labeled active peptide. Stability during cysteine challenge at modest cysteine-to-peptide molar ratios and during incubation in serum was observed in each case. Large differences among the labeled peptides were apparent in the 3-hr biodistributions of 99mTc in normal mice.

CONCLUSION

The use of NHS-S-acetyl-MAG3 may be a convenient method of radiolabeling peptides with 99mTc.