Overexpression of glial cell line-derived neurotrophic factor in the CNS rescues motoneurons from programmed cell death and promotes their long-term survival following axotomy

To study the role of one of the most potent motoneuron (MN) survival factors, glial cell line-derived neurotrophic factor (GDNF) derived from the CNS, we generated transgenic animals overexpressing GDNF under the control of an astrocyte-specific GFAP promoter. In situ hybridization revealed that GDNF was expressed at high levels in astrocytes throughout the brain and spinal cord. We analyzed the effects of CNS-derived GDNF on MN survival during the period of programmed cell death (PCD) and after nerve axotomy. In GFAP-GDNF mice at E15, E18, and P1, the survival of brachial MNs was increased on average by 30%, lumbar MNs by 20%, and thoracic MNs at P1 by 33%. GDNF also prevented MN PCD in several cranial motor nuclei. We demonstrated for the first time that the number of MNs in the mouse abducens nucleus was also increased by 40%, thus extending known MN populations that are responsive to GDNF. Next, we tested if GDNF could support complete and relatively long-term survival of MNs following neonatal facial nerve axotomy. We found that virtually all MNs (91%) in GFAP-GDNF mice survived for up to 18 weeks post-axotomy. This is the longest GDNF-mediated survival of neonatal MNs reported following axotomy. Most of surviving MNs were not atrophic, and MN-specific ChAT and neurofilament immunoreactivity (IR) were preserved. Furthermore, GDNF attenuated axotomy-induced astroglial activation. These data demonstrate that overexpression of GDNF in the CNS has very profound effects on MN survival both during the PCD period and after neuronal injury. GFAP-GDNF mice will be valuable to study the effects of CNS-derived GDNF in mouse models of MN degenerative diseases and axonal regeneration in vivo.     

Independent study: 10-year programme review

The Ohio State University College of Medicine has offered an independent study curricular option since 1970. This study reports our experience covering 10 entering classes and compares the independent study programme (ISP) students to the students who entered the traditional lecture-discussion programme (LDP). It looks at (a) entering demographic and personality characteristics, (b) academic, clinical and research performance during school and at graduation and (c) practice and career outcomes. The major findings are that, as groups, students from the two curricular programmes are far more alike than different but that the flexibility of an independent study programme provides special options without loss of academic achievement. Individual talents and interests were enhanced and research opportunities have aided recruitment and development of particular students. Independent study students pursued more research during medical school and hold more full-time academic positions in practice. A comparative cost study showed that, once the two programmes are operational, per student operational costs are equivalent. Results of this study indicate, that at Ohio State, the benefits of a two-track system outweigh the additional costs.     

Rheumatic immune-related adverse events in patients on anti-PD-1 inhibitors: Fasciitis with myositis syndrome as a new complication of immunotherapy

Objective

To evaluate the prevalence and type of rheumatic immune-related adverse events (IRAEs) in patients receiving programmed cell death protein-1 (PD-1) inhibitors.

中国汉族群体中PDCD1基因多态性与结直肠癌的相关性CSCD

目的探讨程序性细胞死亡受体1（ programmed cell death 1,PDCD1）基因多态性与结直肠癌的发生发展的关联性。方法应用聚合酶链反应-限制性片段长度多态性（PCR-restriction fragment length polymorphism, PCR-RFLP）方法对426例结直肠癌患者及500名正常个体的rs36084323、rs11568821、rs2227981、rs2227982和rs10204525位点进行多态性分析。结果rs36084323位点G等位基因在显性遗传模型下与TNM分期进展期结直肠癌的发生正关联（OR＝1.59,95%CI：1.02～2.48）。rs36084323、rs11568821、rs2227981、rs2227982和rs10204525位点组成的单倍型G-G-C-T-A和A-G-C-C-G与结直肠癌的发生负关联。结论PDCD1基因rs36084323位点AG和GG基因型与TNM分期进展期的结直肠癌存在正关联。而G-G-C-T-A和A-G-C-C-G单倍型与结直肠癌的发生负关联。     

Combined immune checkpoint inhibitors of CTLA4 and PD-1 for hepatic melanoma of unknown primary origin: A case report

BACKGROUNDMelanoma is uncommonly found in lymph nodes, subcutaneous tissue, or visceral organs without a primary lesion, where it is identified as metastatic melanoma with unknown primary (MUP). Hepatic MUP is extremely rare and has a poor prognosis. There is limited information on its pathogenesis, clinical and imaging features, and pathological findings. There are no guidelines for the use of immune checkpoint inhibitors (ICIs) in hepatic MUP, and the treatment outcome has rarely been reported.CASE SUMMARYA 42-year-old woman presented to our hospital with hepatic tumors found incidentally during a routine check-up. Contrast-enhanced abdominal com-puterized tomography showed multiple mass lesions in the liver. Pathological results revealed melanoma, which was confirmed by immunohistochemical staining for HMB-45(+), Melan-A(+), S-100(+), and SOX10(+). There was no evidence of primary cutaneous, ocular, gastrointestinal, or anal lesion on a comprehensive examination. The patient was diagnosed with hepatic MUP. She received combined antibodies against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4, ipilimumab) and programmed death protein-1 (PD-1, nivolumab). She died of hepatic failure 9 mo after hepatic MUP was diagnosed. This the first case of hepatic MUP treated with combined ipilimumab and nivolumab, who showed better outcome than previous cases.CONCLUSIONCombined ICIs of PD-1 and CTLA-4 may be considered as the first-line therapy for patients with hepatic MUP.     

副凋亡在肿瘤中的研究进展

<正>肿瘤是严重危害人类健康的疾病之一,流行病学数据显示,2018年全球约有1 810万肿瘤新发病例以及960万肿瘤死亡病例;肿瘤的发病率和死亡率在全球范围内迅速增长,其难治性及危害性使得肿瘤成为全球最重要的生命科学领域之一^[1]。细胞死亡方式的研究对于肿瘤有重要意义,如细胞凋亡的发现对肿瘤细胞的清除及肿瘤治疗学产生了巨大影响,但单一方式的治疗常常伴随耐药性的产生^[2-4];与此同时,诱导肿瘤细胞其它死亡形式在临床抗肿瘤治疗中也发挥重要的作用^[5]。     

IL-17A/F enable cholangiocytes to restrict T cell-driven experimental cholangitis by upregulating PD-L1 expression

1. Download : Download high-res image (246KB)
2. Download : Download full-size image

     

Anti-PD-1 synergizes with cyclophosphamide to induce potent anti-tumor vaccine effects through novel mechanisms

Programmed death-1 receptor (PD-1) is expressed on T cells following TCR activation. Binding of this receptor to its cognate ligands, programmed death ligand (PDL)-1 and PDL-2, down-regulates signals by the TCR, promoting T-cell anergy and apoptosis, thus leading to immune suppression. Here, we find that using an anti-PD-1 antibody (CT-011) with Treg-cell depletion by low-dose cyclophosphamide (CPM), combined with a tumor vaccine, induces synergistic antigen-specific immune responses and reveals novel activities of each agent in this combination. This strategy led to complete regression of established tumors in a significant percentage of treated animals, with survival prolongation. We show for the first time that combining CT-011 and CPM significantly increases the number of vaccine-induced tumor-infiltrating CD8(+) T cells, with simultaneous decrease in infiltrating Treg cells. Interestingly, we find that CT-011 prolongs Treg-cell inhibition induced by CPM, leading to a sustainable significant synergistic decrease of splenic and tumor-infiltrated Treg cells. Surprisingly, we find that the anti-tumor effect elicited by the combination of CT-011 and CPM is dependent on both CD8(+) and CD4(+) T-cell responses, although the antigen we used is a class I MHC-restricted peptide. Thus, we describe a novel and effective therapeutic approach by combining multiple strategies to target several tumor-mediated immune inhibitory mechanisms.     

Kainic acid dose affects delayed cell death mechanism after status epilepticus

Kainic acid (KA)-induced status epilepticus (SE) produces hippocampal neuronal death, which varies from necrosis to apoptosis or programmed cell death (PCD). We examined whether the type of neuronal death was dependent on KA dose. Adult rats were induced SE by intraperitoneal injection of KA at 9 mg/kg (K9) or 12 mg/kg (K12). Hippocampal neuronal death was assessed by TUNEL staining, electron microscopy, and Western blotting of caspase-3 on days 1, 3 and 7 after SE induction. K12 rats showed higher a mortality rate and shorter latency to the onset of SE when compared with K9 rats. In both groups, acidophilic and pyknotic neurons were evident in CA1 at 24h after SE and neuronal loss developed from day 3. The degenerated neurons became TUNEL-positive on days 3 and 7 in K9 rats but not in K12 rats. Caspase-3 activation was detected on days 3 and 7 in K9 rats but was undetectable in K12 rats. Ultrastructural study revealed shrunken neurons exhibiting pyknotic nuclei containing small and dispersed chromatin clumps 24h after SE in CA1. No cells exhibited apoptosis. On days 3 and 7, the degenerated neurons were necrotic with high electron density and small chromatin clumps. There were no ultrastructural differences between the K9 and K12 groups. These results revealed that differences in KA dose affected the delayed cell death (3 and 7 days after SE); however, no effect was seen on the early cell death (24h after SE). Moderate-dose KA induced necrosis, while low-dose KA induced PCD.