CARASIL is associated with mutations in the HTRA1 gene. Our findings indicate a link between repressed inhibition of signaling by the TGF-beta family and ischemic cerebral small-vessel disease, alopecia, and spondylosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. Accumulating evidence has shown that 43kDa TAR-DNA-binding protein (TDP-43) is the disease protein in ALS and frontotemporal lobar degeneration. We previously reported a familial ALS with Bumina bodies and TDP-43-positive skein-like inclusions in the lower motor neurons; these findings are indistinguishable from those of sporadic ALS. In three affected individuals in two generations of one family, we found a single base-pair change from A to G at position 1028 in TDP-43, which resulted in a Gln-to-Arg substitution at position 343. Our findings provide a new insight into the molecular pathogenesis of ALS.

Objective:To clarify the genetic, clinicopathologic, and neuroimaging characteristics of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) with the colony stimulating factor 1 receptor (CSF-1R) mutation.Methods:We performed molecular genetic analysis of CSF-1R in patients with HDLS. Detailed clinical and neuroimaging findings were retrospectively investigated. Five patients were examined neuropathologically.Results:We found 6 different CSF-1R mutations in 7 index patients from unrelated Japanese families. The CSF-1R mutations included 3 novel mutations and 1 known missense mutation at evolutionarily conserved amino acids, and 1 novel splice-site mutation. We identified a novel frameshift mutation. Reverse transcription PCR analysis revealed that the frameshift mutation causes nonsense-mediated mRNA decay by generating a premature stop codon, suggesting that haploinsufficiency of CSF-1R is sufficient to cause HDLS. Western blot analysis revealed that the expression level of CSF-1R in the brain from the patients was lower than from control subjects. The characteristic MRI findings were the involvement of the white matter and thinning of the corpus callosum with signal alteration, and sequential analysis revealed that the white matter lesions and cerebral atrophy relentlessly progressed with disease duration. Spotty calcifications in the white matter were frequently observed by CT. Neuropathologic analysis revealed that microglia in the brains of the patients demonstrated distinct morphology and distribution.Conclusions:These findings suggest that patients with HDLS, irrespective of mutation type in CSF-1R, show characteristic clinical and neuroimaging features, and that perturbation of CSF-1R signaling by haploinsufficiency may play a role in microglial dysfunction leading to the pathogenesis of HDLS.

The mutant HTRA1s observed in manifesting heterozygotes might result in an impaired HTRA1 activation cascade of HTRA1 or be unable to form stable trimers.

PurposeCancer cachexia is characterized by decreased body weight (mainly lean body mass [LBM]) and negatively impacts quality of life (QOL) and prognosis. Anamorelin (ONO-7643) is a novel selective ghrelin receptor agonist under development for treating cancer cachexia.MethodsIn this double-blind, exploratory phase 2 trial, we examined the efficacy and safety of anamorelin in Japanese patients (n = 181) with non-small cell lung cancer (NSCLC) and cancer cachexia (≥5 % weight loss within the previous 6 months). The participants were randomized into three groups and were administered 50 or 100 mg anamorelin, or placebo, orally every day for 12 weeks. The co-primary endpoints were the changes from baseline over 12 weeks in LBM and handgrip strength (HGS). Secondary endpoints included body weight, QOL, Karnofsky Performance Scale (KPS), and serum biomarkers.ResultsThe change in LBM over 12 weeks was 0.55 and 1.15 kg in the placebo and 100-mg anamorelin groups, respectively, but the efficacy of anamorelin in HGS was not detected. The changes in body weight were −0.93, 0.54, and 1.77 kg in the placebo, 50-mg anamorelin, and 100-mg anamorelin groups, respectively. Anamorelin (100 mg) significantly improved KPS and QOL-ACD compared with placebo. Administration of anamorelin for 12 weeks was well tolerated.ConclusionsThis phase 2 study showed that 100 mg anamorelin has promising results in improving lean body mass, performance status, and especially, QOL in patients with cancer cachexia.Electronic supplementary materialThe online version of this article (doi:10.1007/s00520-016-3144-z) contains supplementary material, which is available to authorized users.

Cerebral small-vessel disease is a common disorder in elderly populations; however, its molecular basis is not well understood. We recently demonstrated that mutations in the high-temperature requirement A (HTRA) serine peptidase 1 (HTRA1) gene cause a hereditary cerebral small-vessel disease, cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). HTRA1 belongs to the HTRA protein family, whose members have dual activities as chaperones and serine proteases and also repress transforming growth factor-β (TGF-β) family signaling. We demonstrated that CARASIL-associated mutant HTRA1s decrease protease activity and fail to decrease TGF-β family signaling. However, the precise molecular mechanism for decreasing the signaling remains unknown. Here we show that increased expression of ED-A fibronectin is limited to cerebral small arteries and is not observed in coronary, renal arterial or aortic walls in patients with CARASIL. Using a cell-mixing assay, we found that HTRA1 decreases TGF-β1 signaling triggered by proTGF-β1 in the intracellular space. HTRA1 binds and cleaves the pro-domain of proTGF-β1 in the endoplasmic reticulum (ER), and cleaved proTGF-β1 is degraded by ER-associated degradation. Consequently, the amount of mature TGF-β1 is reduced. These results establish a novel mechanism for regulating the amount of TGF-β1, specifically, the intracellular cleavage of proTGF-β1 in the ER.

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disorder. In motor neurons of ALS, TAR DNA binding protein-43 (TDP-43), a nuclear protein encoded by TARDBP, is absent from the nucleus and forms cytoplasmic inclusions. TDP-43 auto-regulates the amount by regulating the TARDBP mRNA, which has three polyadenylation signals (PASs) and three additional alternative introns within the last exon. However, it is still unclear how the autoregulatory mechanism works and how the status of autoregulation in ALS motor neurons without nuclear TDP-43 is. Here we show that TDP-43 inhibits the selection of the most proximal PAS and induces splicing of multiple alternative introns in TARDBP mRNA to decrease the amount of cytoplasmic TARDBP mRNA by nonsense-mediated mRNA decay. When TDP-43 is depleted, the TARDBP mRNA uses the most proximal PAS and is increased in the cytoplasm. Finally, we have demonstrated that in ALS motor neurons—especially neurons with mislocalized TDP-43—the amount of TARDBP mRNA is increased in the cytoplasm. Our observations indicate that nuclear TDP-43 contributes to the autoregulation and suggests that the absence of nuclear TDP-43 induces an abnormal autoregulation and increases the amount of TARDBP mRNA. The vicious cycle might accelerate the disease progression of ALS.

To clarify the molecular pathogenesis of amyotrophic lateral sclerosis (ALS) associated with TAR-DNA binding protein 43 kDd (TDP-43), the quality and quantity of TDP-43 take a crucial role. Regarding to the quality of TDP-43, TDP-43 has been reported as an aggregate-prone protein. Especially the C-terminus of the TDP-43 tends to form aggregate and has prion-like domain. Interestingly the mutations in the genes, which produce proteins with prion-like domain, have been identified in several neurodegenerative disorders. These results suggest the existence of the common property in the causative proteins for neurodegenerative disorders. For the quantity of TDP-43, the adequate amount of TDP-43 is necessary for maintaining cell function and cell survival. The amount of TDP-43 is tightly regulated by TDP-43. However the mechanism for autoregulation has not been fully elucidated. For the function of TDP-43, TDP-43 locates at stress granule, GEM and associates with the large genes and introns. Thus the alteration of TDP-43 may affect the function of stress granule, GEM and RNA metabolism in several genes. Moreover a U12 type spliceosome, which is matured in GEM, is decreased in ALS. The investigation of whether these dysfunctions explain the selective pathology in ALS provides a new therapeutic strategy for ALS.