Phosphorylated TDP-43 in Alzheimer’s disease and dementia with Lewy bodies

Phosphorylated and proteolytically cleaved TDP-43 is a major component of the ubiquitin-positive inclusions in the most common pathological subtype of frontotemporal lobar degeneration (FTLD-U). Intracellular accumulation of TDP-43 is observed in a subpopulation of patients with other dementia disorders, including Alzheimer’s disease (AD) and dementia with Lewy bodies (DLB). However, the pathological significance of TDP-43 pathology in these disorders is unknown, since biochemical features of the TDP-43 accumulated in AD and DLB brains, especially its phosphorylation sites and pattern of fragmentation, are still unclear. To address these issues, we performed immunohistochemical and biochemical analyses of AD and DLB cases, using phosphorylation-dependent anti-TDP-43 antibodies. We found a higher frequency of pathological TDP-43 in AD (36–56%) and in DLB (53–60%) than previously reported. Of the TDP-43-positive cases, about 20–30% showed neocortical TDP-43 pathology resembling the FTLD-U subtype associated with progranulin gene (PGRN) mutations. Immunoblot analyses of the sarkosyl-insoluble fraction from cases with neocortical TDP-43 pathology showed intense staining of several low-molecular-weight bands, corresponding to C-terminal fragments of TDP-43. Interestingly, the band pattern of these C-terminal fragments in AD and DLB also corresponds to that previously observed in the FTLD-U subtype associated with PGRN mutations. These results suggest that the morphological and biochemical features of TDP-43 pathology are common between AD or DLB and a specific subtype of FTLD-U. There may be genetic factors, such as mutations or genetic variants of PGRN underlying the co-occurrence of abnormal deposition of TDP-43, tau and α-synuclein.     

No association of PGRN 3′UTR rs5848 in frontotemporal lobar degeneration

Frontotemporal lobar degeneration (FTLD) is a highly familial neurodegenerative disease. It has been claimed that homozygosity of the SNP rs5848 located in the 3′UTR of progranulin increases risk for FTLD. We have attempted to replicate the association of rs5848 in three independent FTLD cohorts. No association of rs5848 with FTLD was observed in any individual cohort nor was any observed when the data was combined. These data argue that rs5848 is not a risk factor for FTLD.     

Potential value of serum progranulin as an activity biomarker in rheumatoid arthritis patients: Relation to musculoskeletal ultrasonographic evaluation

Aim of the work

To determine the serum progranulin levels in rheumatoid arthritis (RA) patients and to study its relation with disease activity assessed clinically and by ultrasound (US).

Progranulin does not affect motor neuron degeneration in mutant SOD1 mice and rats

Motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is familial in 10% of patients, with mutations in SOD1 and C9orf72 being the most frequent cause. There is convincing evidence for overlap between ALS and frontotemporal lobar degeneration at the genetic, pathological, and clinical level. Null mutations in progranulin (PGRN) are a frequent cause of familial frontotemporal lobar degeneration. PGRN exerts neurotrophic properties on motor neurons in vitro and in vivo. We therefore examined whether PGRN could affect disease progression in mutant SOD1 mice and rats, both established models for ALS. Overexpression of PGRN in mice and intracerebroventricular delivery of PGRN in rats did not affect onset or progression of motor neuron degeneration.     

Mini review – The role of Glucocerebrosidase and Progranulin as possible targets in the treatment of Parkinson's disease

As per recent reports, there is an association between glucocerebrosidase (Gcase) enzyme and Parkinson's disease (PD). In addition, certain mutations in the Gcase gene (GBA) and the progranulin (PGRN) gene are found to be linked with the imbalance in the levels of Gcase enzyme. This imbalance or decrease or impairment in Gcase activity can lead to Gaucher disease, frontotemporal lobar degeneration (FTLD), dementia, etc. Recent evidences suggest that the drugs used to treat these diseases can be used for PD. The present review has focused on the therapeutic approaches used for diseases linked with Gcase enzyme, which can be used for PD. The review also considered possible target specific novel strategies, which may help to meet the unmet needs in the treatment of PD.     

Genetic studies of GRN and IFT74 in amyotrophic lateral sclerosis

There is increasing evidence of a clinical, neuropathological and genetic overlap between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). We conducted a case–control study using a UK dataset to test the hypothesis that polymorphisms in two FTD-related genes (GRN and FT74) are associated with increased susceptibility to ALS. We evaluated the majority of known genetic variability in IFT74 and GRN. The results revealed that the common variations in IFT74 and GRN neither constitute strong ALS risk factors nor modify the age-at-onset. However, the possibility of a modest risk effect remains to be assessed in large datasets.     

颗粒蛋白前体在神经系统疾病中的研究进展

颗粒蛋白前体（progranulin,PGRN）是一种多功能的分泌型糖蛋白。其表达水平及相关基因 的异常改变与神经系统炎性病变、退行性病变、变性疾病、脑中溶酶体的稳态及血脑屏障完整性密 切相关,参与到多种神经系统疾病的病理过程。本文对PGRN的生物学作用及其与相关神经系统疾病 的研究进展进行综述,以期为相关患者的干预及相关疾病的研究提供思路及理论依据。     

颗粒蛋白前体在高脂饮食诱导的肥胖PCOS大鼠卵巢中的表达

目的研究颗粒蛋白前体(PGRN)在肥胖PCOS大鼠卵巢中的表达情况,初步探讨PGRN在PCOS发病中的作用。方法选择SPF级23日龄SD雌性大鼠38只,使用随机数字表随机分为3组:正常对照组(n=8)、PCOS组(DHEA组,n=15)及肥胖PCOS组(DHEA+HFD组,n=15)。采用脱氢表雄酮联合高脂饲料(DHEA+HFD)诱导肥胖PCOS大鼠。HE染色光镜下观察PCOS大鼠卵巢的病理结构改变。酶联免疫吸附法测定血清睾酮(T)、雌二醇(E2)及空腹血糖(FBG)、空腹胰岛素(FINS)含量等,比较各组间的水平差异。采用免疫组织化学法检测各组卵巢PGRN的表达水平及分布情况。结果造模结束时,DHEA+HFD组体重显著高于对照组(P<0.01)及DHEA组(P<0.05)。DHEA组及DHEA+HFD组的FINS、稳态模型评估的胰岛素抵抗指数(HOMA-IR)均显著高于对照组(P<0.05)。DHEA组及DHEA+HFD组的睾酮(T)、FSH水平均显著升高(P<0.01)。DHEA组及DHEA+HFD组卵巢组织光镜下均表现出典型的多囊样改变。免疫组化结果显示各组大鼠卵巢中均可见PGRN蛋白表达,主要分布于卵泡的颗粒细胞层及黄体;DHEA组PGRN表达水平显著高于对照组(P<0.01),DHEA+HFD组PGRN表达水平显著高于DHEA组及对照组(P<0.01)。结论 PGRN在卵巢颗粒细胞层有表达。其在PCOS大鼠和肥胖PCOS大鼠卵巢组织中的差异性表达,提示PGRN可能通过作用于局部卵泡微环境,参与PCOS肥胖及慢性代谢性炎症的发生。