Long Noncoding RNA PVT1 Promotes Stemness and Temozolomide Resistance through miR-365/ELF4/SOX2 Axis in Glioma

Long non-coding RNA (lncRNA) are a class of non-coding RNAs demonstrated to play pivotal roles in regulating tumor progression. Therefore, deciphering the regulatory role of lncRNA in the development of glioma may offer a promising therapeutic target for treatment of glioma. We performed RT-qPCR analysis on the expression of lncRNA plasmacytoma variant translocation 1 (PVT1) and miR-365 in glioma tissues and cell lines. Cell proliferation and viability was assessed with CCK8 assay. Cell migration was assessed by wound healing assay. Transwell assay was used to assess cell invasion capacity. Expression of CD133+ cells was detected by flow cytometry. Western blot assay was used to detection the expression of ELF4 and stemness-related protein SOX2, Oct4 and Nanog. Bioinformatics and dual-luciferase assay were used to predict and validate the interaction between PVT1 and miR-365. Elevated PVT1 expression was observed in glioma tissues and cells. Knockdown of PVT1 and overexpression of miR-365 inhibited proliferation, migration, invasion and promoted stemness and Temozolomide (TMZ) resistance of glioma cells. PVT1 regulated ELF4 expression by competitively binds to miR-365. PVT1 regulated the stemness and sensitivity of TMZ of glioma cells through miR-365/ELF4/ SOX2 axis. This study identified that PVT1 promoted glioma stemness through miR-365/ELF4/SOX2 axis.

Long Noncoding RNA PVT1 Promotes Stemness and Temozolomide Resistance through miR-365/ELF4/SOX2 Axis in Glioma

Long non-coding RNA (lncRNA) are a class of non-coding RNAs demonstrated to play pivotal roles in regulating tumor progression. Therefore, deciphering the regulatory role of lncRNA in the development of glioma may offer a promising therapeutic target for treatment of glioma. We performed RT-qPCR analysis on the expression of lncRNA plasmacytoma variant translocation 1 (PVT1) and miR-365 in glioma tissues and cell lines. Cell proliferation and viability was assessed with CCK8 assay. Cell migration was assessed by wound healing assay. Transwell assay was used to assess cell invasion capacity. Expression of CD133+ cells was detected by flow cytometry. Western blot assay was used to detection the expression of ELF4 and stemness-related protein SOX2, Oct4 and Nanog. Bioinformatics and dual-luciferase assay were used to predict and validate the interaction between PVT1 and miR-365. Elevated PVT1 expression was observed in glioma tissues and cells. Knockdown of PVT1 and overexpression of miR-365 inhibited proliferation, migration, invasion and promoted stemness and Temozolomide (TMZ) resistance of glioma cells. PVT1 regulated ELF4 expression by competitively binds to miR-365. PVT1 regulated the stemness and sensitivity of TMZ of glioma cells through miR-365/ELF4/ SOX2 axis. This study identified that PVT1 promoted glioma stemness through miR-365/ELF4/SOX2 axis.

Genetic Prion Disease: Insight from the Features and Experience of China National Surveillance for Creutzfeldt-Jakob Disease / 神经科学通报·英文版

Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50–59 year group. Gerstmann–Sträussler–Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt–Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.

Genetic Prion Disease: Insight from the Features and Experience of China National Surveillance for Creutzfeldt-Jakob Disease / 神经科学通报·英文版

Human genetic prion diseases (gPrDs) are directly associated with mutations and insertions in the PRNP (Prion Protein) gene. We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020. Nineteen different subtypes were identified and gPrDs accounted for 10.9% of all diagnosed PrDs within the same period. Some subtypes of gPrDs showed a degree of geographic association. The age at onset of Chinese gPrDs peaked in the 50-59 year group. Gerstmann-Sträussler-Scheinker syndrome (GSS) and fatal familial insomnia (FFI) cases usually displayed clinical symptoms earlier than genetic Creutzfeldt-Jakob disease (gCJD) patients with point mutations. A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients. None of the E196A gCJD patients reported a family history. The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD (sCJD). EEG examination was not sensitive for gPrDs. sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients. CSF 14-3-3 positivity was frequently detected in gCJD patients. Increased CSF tau was found in more than half of FFI and T188K gCJD cases, and an even higher proportion of E196A and E200K gCJD patients. 63.6% of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC. GSS and FFI cases had longer durations than most subtypes of gCJD. This is one of the largest studies of gPrDs in East Asians, and the illness profile of Chinese gPrDs is clearly distinct. Extremely high proportions of T188K and E196A occur among Chinese gPrDs; these mutations are rarely reported in Caucasians and Japanese.

Role of adiponectin in diabetes myocardial ischemia-reperfusion injury and ischemic postconditioning

Abstract Purpose Patients with diabetes are vulnerable to myocardial I/R (ischaemia/reperfusion) injury, but are not responsive to IPO (ischaemic post-conditioning). We hypothesized that decreased cardiac Adiponectin (APN) is responsible for the loss of diabetic heart sensitivity to IPO cardioprotecton. Methods Diabetic rats were subjected to I/R injury (30 min of LAD occlusion followed by 120 min of reperfusion). Myocardial infarct area was determined by TTC staining. Cardiac function was monitored by a microcatheter. ANP, 15-F2t-isoprostane, nitrotyrosine and MDA were measured by assay kits. Levels of p-Akt, total-Akt and GAPDH were determined by Western Blot. Results Diabetic rats subjected to myocardial IR exhibited severe myocardial infarction and oxidative stress injury, lower APN in the plasma and cardiac p-Akt expression ( P <0.05). IPO significantly attenuated myocardial injury and up-regulated plasma APN content and cardiac p-Akt expression in non-diabetic rats but not in diabetic rats. Linear correlation analysis showed that the expression of adiponectin was positively correlated with p-Akt and negatively correlated with myocardial infarction area ( P <0.01). Conclusion Protective effect of IPO was tightly correlated with the expression of adiponectin, exacerbation of I/R injury and ineffectiveness of IPO was partially due to the decline of adiponectin and inactivation of Akt in diabetes mellitus.

Neurotrophin-3 modified hyaluronan-methylcellulose hydrogel promotes neurological function in rats with spinal cord injury / 中国组织工程研究

BACKGROUND: Hyaluronan-methylcellulose hydrogel cannot only be conjugated with short peptide sequences and growth factors to achieve sustained release, but also has a role in blocking dural defects and reducing inflammation. It is an ideal biomaterial for the treatment of spinal cord injury. OBJECTIVE: To investigate the effect of neurotrophin-3 modified hyaluronan-methylcellulose (HAMC-NT-3) hydrogel on the recovery of neurological function in rats with spinal cord injury. METHODS: Fifty-four female Sprague-Dawley rats (provided by the Experimental Animal Center of the Academy of Military Medical Sciences in China) were randomly divided into three groups (n=18 per group) . The sham group only underwent T10 laminectomy. In the model group and the experimental group, an aneurysm clip was used to establish spinal cord injury models after T10 laminectomy. The experimental group was locally injected with HAMC-NT-3 hydrogel. The Basso Beattie Bresnahan function scoring was performed at 1 day, 1, 2, 3, 4, 5, 6, 7, and 8 weeks after surgery. The inclined plane test was performed at 4, 6 and 8 weeks after surgery to evaluate the recovery of hindlimb motor function. ELISA was used to detect the concentrations of inflammatory factors in the spinal cord at 1 week after surgery. Immunohistochemical staining was used to observe the area of syringomyelia, glial fibrillary acidic protein expression and nerve regeneration at 8 weeks after surgery. RESULTS AND CONCLUSION: (1) The Basso Beattie Bresnahan scores of the model group and the experimental group were lower than those of the sham group at various time points after surgery (P < 0.05) . The Basso Beattie Bresnahan scores of the experimental group were higher than those of the model group at 4-8 weeks after surgery (P < 0.05) . (2) In the inclined plane test, the maximum inclined angles of the model group and the experimental group at each time point after surgery were lower than that of the sham group (P < 0.05) . The maximum inclined angles of the experimental group at 6 and 8 weeks after surgery were higher than those of the sham group (P < 0.05) . (3) The concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-6 and interleukin-10 in the experimental group and the model group were higher than those in the sham group (P < 0.05) . The concentrations of tumor necrosis factor-α, interleukin-1β and interleukin-6 in the experimental group were lower than those in the model group (P < 0.05) . The concentration of interleukin-10 in the experimental group was higher than that in the model group (P < 0.05) . (4) Immunohistochemical staining showed that the expression levels of glial fibrillary acidic protein in the experimental group and the model group were higher than those in the sham group, while the expression of glial fibrillary acidic protein in the experimental group was lower than that in the model group. The area of syringomyelia in the experimental group was smaller than that in the model group (P < 0.05) . These results indicate that local injection of HAMC-NT-3 hydrogel can effectively inhibit inflammation as well as astrocyte activation and proliferation, reduce fibrous scar formation, and promote the protection of nerve tissue and the recovery of hindlimb motor function after spinal cord injury.

Alterations of CaM pathway in the brains of scrapie infected mice / 中华实验和临床病毒学杂志

Objective@#To analysis the alterations of CaM and its downstream factors in the brains of scrapie infected mice.@*Methods@#Using the methods of Western blot and immunohistochemistry assay to detect the levels and distributions of CaM, as well as the expressing alterations of the downstream substrates of CaM in the brains of mice infected with scrapie.@*Results@#Compared with the normal controls, the levels of CaM are significantly increased in the brains of scrapie-infected mice and particularly distributing in the regions of cortex, thamalus and cerebellum. Remarkable high levels of CaMKII, p-CaMKII and p-CaMKIV are observed in the brain homogenates of scrapie-infected mice. The regulatory protein of cAMP response element binding protein (CREB) and p-CERB are also increased, while the levels of BDNF which is regulated by p-CREB are obeviously downregulated.@*Conclusions@#The synthesis of BDNF may be influenced by the prion replication in neuron and further attenuates its neuronal protective features.

Histopathological features of middle cerebral artery and superficial temporal artery from patients with moyamoya disease and enlightenments on clinical treatment / 华中科技大学学报（医学）（英德文版）

The histopathological features of the middle cerebral artery (MCA) and superficial temporal artery (STA) from moyamoya disease (MMD) and their relationships with gender, age, angiography stage were explored. The causes and the clinical significance of vasculopathy of STA were also discussed. The clinical data and specimens of MCA and STA from 30 MMD patients were collected. Twelve samples of MCA and STA from non-MMD patients served as control group. Histopathological examination was then performed by measuring the thickness of intima and media, and statistical analysis was conducted. The MCA and STA specimens from MMD group had apparently thicker intima and thinner media than those from the control group. There was no significant pathological difference between the hemorrhage group and non-hemorrhage group, and between the males and females in MMD patients. Neither the age nor the digital subtraction angiography (DSA) stage was correlated with the thickness of intima in MCA and STA. MMD is a systemic vascular disease involving both intracranial and extracranial vessels. Preoperative external carotid arteriography, especially super-selective arteriography of the STA, benefits the selection of donor vessel.

Significance of cyclooxygenase-2 elevation in middle cerebral artery for patients with hemorrhagic moyamoya disease / 华中科技大学学报（医学）（英德文版）

The etiology and pathogenesis of moyamoya disease (MMD) remain elusive. Some inflammatory proteins, such as cyclooxygenase (COX)-2, are believed to be implicated in the development of MMD. So far, the relationship between COX-2 and MMD is poorly understood and reports on the intracranial vessels of MMD patients are scanty. In this study, tiny pieces of middle cerebral artery (MCA) and superficial temporal artery (STA) from 13 MMD patients were surgically harvested. The MCA and STA samples from 5 control patients were also collected by using the same technique. The expression of COX-2 was immunohistochemically detected and the average absorbance (A) of positively-stained areas was measured. High-level COX-2 expression was found in all layers of the MCA samples from all 5 hemorrhagic MMD patients, while positive but weak expression of COX-2 was observed only in the endothelial layer of the MCA samples from most ischemic MMD patients (6/8, 75%). The average A values of COX-2 in the hemorrhagic MMD patients were substantially higher than those in their ischemic counterparts (t=4.632, P=0.001). There was no significant difference in the COX-2 expression among the "gender" groups, or "radiographic grade" groups, or "lesion location" groups (P>0.05 for all). The COX-2 expression was detected neither in the MCA samples from the controls nor in all STA specimens. Our results suggested that COX-2 was up-regulated in the MCA of MMD patients, especially in hemorrhagic MMD patients. We are led to speculate that COX-2 may be involved in the pathogenesis of MMD and even contribute to the hemorrhagic stroke of MMD patients.

Significance of cyclooxygenase-2 elevation in middle cerebral artery for patients with hemorrhagic moyamoya disease / 华中科技大学学报（医学）（英德文版）

The etiology and pathogenesis of moyamoya disease (MMD) remain elusive. Some inflammatory proteins, such as cyclooxygenase (COX)-2, are believed to be implicated in the development of MMD. So far, the relationship between COX-2 and MMD is poorly understood and reports on the intracranial vessels of MMD patients are scanty. In this study, tiny pieces of middle cerebral artery (MCA) and superficial temporal artery (STA) from 13 MMD patients were surgically harvested. The MCA and STA samples from 5 control patients were also collected by using the same technique. The expression of COX-2 was immunohistochemically detected and the average absorbance (A) of positively-stained areas was measured. High-level COX-2 expression was found in all layers of the MCA samples from all 5 hemorrhagic MMD patients, while positive but weak expression of COX-2 was observed only in the endothelial layer of the MCA samples from most ischemic MMD patients (6/8, 75%). The average A values of COX-2 in the hemorrhagic MMD patients were substantially higher than those in their ischemic counterparts (t=4.632, P=0.001). There was no significant difference in the COX-2 expression among the "gender" groups, or "radiographic grade" groups, or "lesion location" groups (P>0.05 for all). The COX-2 expression was detected neither in the MCA samples from the controls nor in all STA specimens. Our results suggested that COX-2 was up-regulated in the MCA of MMD patients, especially in hemorrhagic MMD patients. We are led to speculate that COX-2 may be involved in the pathogenesis of MMD and even contribute to the hemorrhagic stroke of MMD patients.

Treatment strategies for huge central neurocytomas / 华中科技大学学报（医学）（英德文版）

Central neurocytomas (CNs), initially asymptomatic, sometimes become huge before detection. We described and analyzed the clinical, radiological, operational and outcome data of 13 cases of huge intraventricular CNs, and discussed the treatment strategies in this study. All huge CNs (n=13) in our study were located in bilateral lateral ventricle with diameter ≥5.0 cm and had a broad-based attachment to at least one side of the ventricle wall. All patients received craniotomy to remove the tumor through transcallosal or transcortical approach and CNs were of typical histologic and immunohistochemical features. Adjuvant therapies including conventional radiation therapy (RT) or gamma knife radiosurgery (GKRS) were also performed postoperatively. Transcallosal and transcortical approaches were used in 8 and 5 patients, respectively. Two patients died within one month after operation and 3 patients with gross total resection (GTR) were additionally given a decompressive craniectomy (DC) and/or ventriculoperitoneal shunt (VPS) as the salvage therapy. Six patients received GTR(+RT) and 7 patients received subtotal resection (STR)(+GKRS). Eight patients suffered serious complications such as hydrocephalus, paralysis and seizure after operation, and patients who underwent GTR showed worse functional outcome [less Karnofsky performance scale (KPS) scores] than those having STR(+GKRS) during the follow-up period. The clinical outcome of huge CNs seemed not to be favorable as that described in previous reports. Surgical resection for huge CNs should be meticulously considered to guarantee the maximum safety. Better results were achieved in STR(+GKRS) compared with GTR(+RT) for huge CNs, suggesting that STR(+GKRS) may be a better treatment choice. The recurrent or residual tumor can be treated with GKRS effectively.

Treatment strategies for huge central neurocytomas / 华中科技大学学报（医学）（英德文版）

Central neurocytomas (CNs), initially asymptomatic, sometimes become huge before detection. We described and analyzed the clinical, radiological, operational and outcome data of 13 cases of huge intraventricular CNs, and discussed the treatment strategies in this study. All huge CNs (n=13) in our study were located in bilateral lateral ventricle with diameter ≥5.0 cm and had a broad-based attachment to at least one side of the ventricle wall. All patients received craniotomy to remove the tumor through transcallosal or transcortical approach and CNs were of typical histologic and immunohistochemical features. Adjuvant therapies including conventional radiation therapy (RT) or gamma knife radiosurgery (GKRS) were also performed postoperatively. Transcallosal and transcortical approaches were used in 8 and 5 patients, respectively. Two patients died within one month after operation and 3 patients with gross total resection (GTR) were additionally given a decompressive craniectomy (DC) and/or ventriculoperitoneal shunt (VPS) as the salvage therapy. Six patients received GTR(+RT) and 7 patients received subtotal resection (STR)(+GKRS). Eight patients suffered serious complications such as hydrocephalus, paralysis and seizure after operation, and patients who underwent GTR showed worse functional outcome [less Karnofsky performance scale (KPS) scores] than those having STR(+GKRS) during the follow-up period. The clinical outcome of huge CNs seemed not to be favorable as that described in previous reports. Surgical resection for huge CNs should be meticulously considered to guarantee the maximum safety. Better results were achieved in STR(+GKRS) compared with GTR(+RT) for huge CNs, suggesting that STR(+GKRS) may be a better treatment choice. The recurrent or residual tumor can be treated with GKRS effectively.

Analysis of the human papillomavirus in laryngeal squamous cell carcinoma patients / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To analyze the infection of human papillomavirus in laryngeal squamous cell carcinoma patients.</p><p><b>METHODS</b>The pathological samples of 64 clinical diagnosed laryngeal squamous cell carcinoma patients were collected. Lunimex and PCR techniques were used to detect the HPV gene infection and immunohistochemistry method was used to analyze the HPV protein expression in the samples.</p><p><b>RESULTS</b>In the 64 cases, 7 were positive for HPV infection by Luminex and PCR tests. 18 were positive for HPV16/18 E6 protein expression. The total positive rate was about 39. 1%.</p><p><b>CONCLUSION</b>The high HPV infection rate in laryngeal squamous cell carcinoma patients in the study indicated indirectly that the importance of the HPV infection in pathogenesis of the laryngeal squamous cell carcinoma.</p>

The analysis of human papillomavirus infection in lip squamous cell carcinoma patients / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To analyze the infection of human papillomavirus in lip squamous cell carcinoma patients.</p><p><b>METHODS</b>The pathological samples of 9 clinical diagnosed lip cancer patients were collected. Lunimex and PCR techniques were used to detect the HPV gene infection and immunohistochemistry method was used to analyze the HPV protein expression in the samples.</p><p><b>RESULTS</b>In the 9 cases, 1 was positive for HPV16 gene and 7 were positive for HPV16/18 E6 protein expression. The total positive rate was about 8/9.</p><p><b>CONCLUSION</b>The high HPV infection rate in lip cancer patients in the study indicated indirectly that the importance of the direct contact to the infection of HPV what was the basis for pathogenesis of the lip squamous cell carcinoma.</p>

Mutant D178N prion protein converts spontaneously in RT-QuIC assay / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the conversion of mutant D178N prion protein in RT-QuIC assay.</p><p><b>METHODS</b>The D178N mutant prion PRNP was generated by the method of single site mutation. The mutant PRNP gene was inserted into plasmids of pET24. The full and N-truncated recombinant human prion proteins were expressed and purified. The fibril formations of these proteins were real-time monitored by the method of RT-QuIC. The ability to resist proteinase K (PK) of these fibrils was analyzed.</p><p><b>RESULTS</b>We succeed to construct human PrP-D178N plamids. The N-truncated human prion protein with D178N (PrP90-231-D178N) can convert spontaneously in RT-QuIC, while full length of human prion D178N protein (PrP23-231-D178N) fails to convert spontaneously. The spontaneously generated fibril has been domenstrated it is partily PK-resistant.</p><p><b>CONCLUSION</b>The N-terminal of prion protein (23-90) plays an important role for the D178N mutant protein spontaneously conversion, which provide the clues for study the pathogenesis of genetic CJD.</p>

Clinical and familial characteristics of ten chinese patients with fatal family insomnia / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Fatal familial insomnia (FFI) is an autosomal dominant prion disease characterized clinically by inattention, sleep loss, dysautonomia, and motor signs. This study is aimed to investigate clinical and familial characteristics of ten Chinese Patients with FFI.</p><p><b>METHODS</b>We identified ten FFI cases from the surveillance network for Creutafeldt-Jakob disease (CJD) in China. Final diagnosis of FFI cases was made in accordance with the WHO criteria for CJD. The main clinical features and family histories of these ten FFI cases were analyzed.</p><p><b>RESULTS</b>The median age of ten cases at onset was 38 years (from 19 to 55). The foremost symptoms seemed to be various, including sleep disturbances, vision disorder, dizziness and anorexia. Sleep disturbances appeared in all cases and lasted in the whole clinical courses. Progressive sympathetic symptoms, memory loss, movement disturbances, myoclonus and hypertension were also frequently observed. The median duration of the disease was 9.5 months. EEG and MRI did not figure out special abnormality. 14-3-3 protein in CSF was positive in five out of eight tested patients. Clear family histories were identified in 8 patients.</p><p><b>CONCLUSION</b>The data from our study confirm that the Chinese FFI cases have similar clinical characteristics as that of the Caucasian cases. Compared with other genetic CJD associated mutations, the genetic frequencies of D178N in PRNP are apparently high among the Chinese cases.</p>

A redox process of ethanethiol group increases formation of beta-sheet structure and amyloid fibrils of wild type human prion protein / 病毒学报

In order to explore the potential influences of the disulfide bridge on the physical and chemical properties of PrP protein, the expressed recombinant human wild-type PrP protein was purified for using in an established redox process for the reduction and oxidation of the ethanethiol group within PrP. Sedimentation tests illustrated that redox process remarkably promoted the aggregation of recombinant PrP. Thioflavin T binding assay revealed an enhanced fibrillization of the recombinant human PrP after redox process. Far-UV circular dichroism demonstrated that the PrP treated with redox process showed a significant p-sheet rich structure. Furthermore, PrP-specific Western blot identified that the recombinant PrP after redox possessed stronger proteinase K-resistance. Those data indicates that the formation of the disulfide bridge induces the alteration of the secondary structure and enhances the progresses of aggregation and fibrillization of PrP protein.

Immune responses in wild-type mice against prion proteins induced using a DNA prime-protein boost strategy / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To break immune tolerance to prion (PrP) proteins using DNA vaccines.</p><p><b>METHODS</b>Four different human prion DNA vaccine candidates were constructed based on the pcDNA3.1 vector: PrP-WT expressing wild-type PrP, Ubiq-PrP expressing PrP fused to ubiquitin, PrP-LII expressing PrP fused to the lysosomal integral membrane protein type II lysosome-targeting signal, and PrP-ER expressing PrP locating the ER. Using a prime-boost strategy, three-doses of DNA vaccine were injected intramuscularly into Balb/c mice, followed by two doses of PrP protein. Two weeks after the last immunization, sera and spleens were collected and PrP-specific humoral and cellular immune responses evaluated by ELISA and ELISPOT tests.</p><p><b>RESULTS</b>Higher levels of serum PrP antibodies were detected in mice vaccinated using the strategy of DNA priming followed by protein boosting. Of these, WT-PrP, Ubiq-PrP, and PrP-LII induced significantly higher humoral responses. ELISPOT tests showed markedly increased numbers of IFN-γ-secreting T cells in mice vaccinated using the strategy of DNA priming followed by protein boosting after stimulation with recombinant PrP23-90 and PrP23-231. PrP-ER induced the strongest T-cell response.</p><p><b>CONCLUSION</b>Prion vaccines can break tolerance to PrP proteins and induce PrP-specific humoral and cellular immune responses.</p>

Alternations of tau protein and its phosphorylated profiles in the experimental hamsters infected by scrapie agents 263K and 139A / 病毒学报

In human prion diseases, phosphorylated-tau deposition has been described in a rare genetic form, Gerstmann-Straussler-Scheinker disease, but is not considered part of the neuropathological picture of Creutzfeldt-Jakob disease. To investigate the possible changes of tau and phosphorylated tau (Ser396/Ser404) in transmissible spongiform encephalopathies (TSEs), the expressions and transcriptions of above biological factors in the brain tissues of 263K- and 139A-infected hamsters were evaluated by Western blots and Real Time PCR, respectively, followed by quantitative analyses of immunoblot images and relative transcriptional levels compared with normal animals. The contents of total tau increased, but phosphorylated tau at Ser396 and Ser404 decreased, regardless of the types of scrapie agents and clinical incubations. Transcriptions of two tau isoforms were also markedly increased. These findings suggested that dephosphorylation of tau at Ser396/Ser404 was a illness-correlative phenomenon in TSEs. Alterations of tau and phosphorylated tau (Ser396/Ser404) were either intermediate or consequent events in TSE pathogenesis and proposed the potential linkage of these bioactive proteins with the pathogenesis of prion diseases.

Molecular interaction between PrP protein and the signal protein 14-3-3 beta / 病毒学报

The molecular interaction between PrP and 14-3-3 beta and the possible interactional domain between two proteins were studied by co-immunoprecipitation, pull down and FRET assays. The results showed that PrP protein could interact with 14-3-3 beta in vitro and in vivo. The domain which responded for the interaction was located at C-terminal of PrP (amino acid residues 106 to 126). This study of the interaction between PrP and 14-3-3 protein further provided the insight into the potential role of 14-3-3 in the biological function of PrP and the pathogenesis of prion disease.