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Autophagy mediates the degradation of intracellular macromolecules and organelles within lysosomes. There are three types of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy. Heat shock protein 70.1 (Hsp70.1) exhibits dual functions as a chaperone protein and a lysosomal membrane stabilizer. Since chaperone-mediated autophagy participates in the recycling of ∼30% cytosolic proteins, its disorder causes cell susceptibility to stress conditions. Cargo proteins destined for degradation such as amyloid precursor protein and tau protein are trafficked by Hsp70.1 from the cytosol into lysosomes. Hsp70.1 is composed of an N-terminal nucleotide-binding domain (NBD) and a C-terminal domain that binds to cargo proteins, termed the substrate-binding domain (SBD). The NBD and SBD are connected by the interdomain linker LL1, which modulates the allosteric structure of Hsp70.1 in response to ADP/ATP binding. After the passage of the Hsp70.1–cargo complex through the lysosomal limiting membrane, high-affinity binding of the positive-charged SBD with negative-charged bis(monoacylglycero)phosphate (BMP) at the internal vesicular membranes activates acid sphingomyelinase to generate ceramide for stabilizing lysosomal membranes. As the integrity of the lysosomal limiting membrane is critical to ensure cargo protein degradation within the acidic lumen, the disintegration of the lysosomal limiting membrane is lethal to cells. After the intake of high-fat diets, however, β-oxidation of fatty acids in the mitochondria generates reactive oxygen species, which enhance the oxidation of membrane linoleic acids to produce 4-hydroxy-2-nonenal (4-HNE). In addition, 4-HNE is produced during the heating of linoleic acid-rich vegetable oils and incorporated into the body via deep-fried foods. This endogenous and exogenous 4-HNE synergically causes an increase in its serum and organ levels to induce carbonylation of Hsp70.1 at Arg469, which facilitates its conformational change and access of activated μ-calpain to LL1. Therefore, the cleavage of Hsp70.1 occurs prior to its influx into the lysosomal lumen, which leads to lysosomal membrane permeabilization/rupture. The resultant leakage of cathepsins is responsible for lysosomal cell death, which would be one of the causative factors of lifestyle-related diseases.

Aldehyde dehydrogenase 2 (ALDH2) is an enzyme found in the mitochondrial matrix that plays a central role in alcohol and aldehyde metabolism. A common ALDH2 polymorphism in East Asians descent (called ALDH2*2 or E504K missense variant, SNP ID: rs671), present in approximately 8% of the world’s population, has been associated with a variety of diseases. Recent meta-analyses support the relationship between this ALDH2 polymorphism and Alzheimer’s disease (AD). And AD-like pathology observed in ALDH2–/– null mice and ALDH2*2 overexpressing transgenic mice indicate that ALDH2 deficiency plays an important role in the pathogenesis of AD. Recently, the worldwide increase in alcohol consumption has drawn attention to the relationship between heavy alcohol consumption and AD. Of potential clinical significance, chronic administration of alcohol in ALDH2*2/*2 knock-in mice exacerbates the pathogenesis of AD-like symptoms. Therefore, ALDH2 polymorphism and alcohol consumption likely play an important role in the onset and progression of AD. Here, we review the data on the relationship between ALDH2 polymorphism, alcohol, and AD, and summarize what is currently known about the role of the common ALDH2 inactivating mutation, ALDH2*2, and alcohol in the onset and progression of AD.

Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that reduces cell injuries via detoxification of lipid-peroxidation product, 4-hydroxy-2-nonenal (hydroxynonenal). It is generated exogenously via deep-frying of linoleic acid-rich cooking oils and/or endogenously via oxidation of fatty acids involved in biomembranes. Although its toxicity for human health is widely accepted, the underlying mechanism long remained unknown. In 1998, Yamashima et al. have formulated the “calpain–cathepsin hypothesis” as a molecular mechanism of ischemic neuronal death. Subsequently, they found that calpain cleaves Hsp70.1 which became vulnerable after the hydroxynonenal-induced carbonylation at the key site Arg469. Since it is the pivotal aberration that induces lysosomal membrane rupture, they suggested that neuronal death in Alzheimer’s disease similarly occurs by chronic ischemia via the calpain–cathepsin cascade triggered by hydroxynonenal. For nearly three decades, amyloid β (Aβ) peptide was thought to be a root substance of Alzheimer’s disease. However, because of both the insignificant correlations between Aβ depositions and occurrence of neuronal death or dementia, and the negative results of anti-Aβ medicines tested so far in the patients with Alzheimer’s disease, the strength of the “amyloid cascade hypothesis” has been weakened. Recent works have suggested that hydroxynonenal is a mediator of programmed cell death not only in the brain, but also in the liver, pancreas, heart, etc. Increment of hydroxynonenal was considered an early event in the development of Alzheimer’s disease. This review aims at suggesting ways out of the tunnel, focusing on the implication of hydroxynonenal in this disease. Herein, the mechanism of Alzheimer neuronal death is discussed by focusing on Hsp70.1 with a dual function as chaperone protein and lysosomal stabilizer. We suggest that Aβ is not a culprit of Alzheimer’s disease, but merely a byproduct of autophagy/lysosomal failure resulting from hydroxynonenal-induced Hsp70.1 disorder. Enhancing ALDH2 activity to detoxify hydroxynonenal emerges as a promising strategy for preventing and treating Alzheimer’s disease.

Alzheimer’s disease, type 2 diabetes, and non-alcoholic steatohepatitis (NASH) constitute increasingly prevalent disorders. Individuals with type 2 diabetes are well-known to be susceptible to Alzheimer’s disease. Although the pathogenesis of each disorder is multifactorial and the causal relation remains poorly understood, reactive oxygen species (ROS)-induced lipid and protein oxidation conceivably plays a common role. Lipid peroxidation product was recently reported to be a key factor also for non-alcoholic steatohepatitis, because of inducing hepatocyte degeneration/death. Here, we focus on implication of the representative lipid-peroxidation product ‘hydroxynonenal’ for the cell degeneration/death of brain, pancreas, and liver. Since Hsp70.1 has dual roles as a chaperone and lysosomal membrane stabilizer, hydroxynonenal-mediated oxidative injury (carbonylation) of Hsp70.1 was highlighted. After intake of high-fat diets, oxidation of free fatty acids in mitochondria generates ROS which enhance oxidation of ω-6 polyunsaturated fatty acids (PUFA) involved within biomembranes and generate hydroxynonenal. In addition, hydroxynonenal is generated during cooking deep-fried foods with vegetable oils especially containing linoleic acids. These intrinsic and exogenous hydroxynonenal synergically causes an increase in its serum and organ levels to induce Hsp70.1 oxidation. As it is amphiphilic; being water-soluble but displays strong lipophilic characteristics, hydroxynonenal can diffuse within the cells and react with targets like senile and/or atheromatous plaques outside the cells. Hydroxynonenal can deepen and expand lysosomal injuries by facilitating ‘calpain-mediated cleavage of the carbonylated Hsp70.1’. Despite the unique anatomical, physiological, and biochemical characteristics of each organ for its specific disease, there should be a common cascade of the cell degeneration/death which is caused by hydroxynonenal. This review aims to implicate hydroxynonenal-mediated Hsp70.1 carbonylation for lysosomal membrane permeabilization/rupture and the resultant cathepsin leakage for inducing cell degeneration/death. Given the tremendous number of worldwide people suffering various lifestyle-related diseases, it is valuable to consider how ω-6 PUFA-rich vegetable oils is implicated for the organ disorder.

The modest consumption of alcohol has been reported to decrease the incidence of fatty liver or prevalence of steatohepatitis. In this study, we investigated the effect of light alcohol consumption on liver function and gene expression in patients with non-alcoholic fatty liver disease (NAFLD).The study group was formed of 178 patients diagnosed with non-alcoholic fatty liver disease, subclassified into two groups for analysis based on the daily alcohol consumption: non-alcohol group and light alcohol consumer group (≤20 g of ethanol/day). Clinical characteristics, liver histological features, gene expression, comprehensively analyzed using microarrays (BRB-Array tools), and molecular network were evaluated and compared between the two groups.No significant differences in steatosis or inflammation score were noted among the groups. However, the ballooning and fibrosis scores were significantly lower in the light alcohol consumer group than in the non-alcohol group. Gene expression analysis revealed a marked inhibition of the pathways involved in the immune response in the light alcohol group compared to that in the non-alcohol group.Light alcohol consumption might suppress activity of non-alcoholic steatohepatitis by reducing gene expression levels involved in the immune response. This inhibition in gene expression was associated with a lowering of liver fibrosis and hepatocellular injury.

Background Cutaneous malignant melanoma has a poor prognosis. The detrimental effect of incisional biopsies on the outcome of malignant melanoma has been debated. The aim of this study was to determine the effect of the presence and type of biopsy on the prognosis of malignant melanoma. Methods The medical records of 109 malignant melanoma patients treated at Tokushima University Hospital from 1983 to 2007 were reviewed. After excluding 28 cases with stage 0 disease or incomplete data, 81 cases were analyzed in detail with respect to patient sex, age, tumor site, clinical stage at diagnosis, presence of ulceration or lymph node metastasis, and prognosis. The five-year survival and five-year disease-free survival rates of patients who underwent incisional or excisional biopsies were compared with those who did not undergo a biopsy. Results The male-to-female ratio was 1:1.19. The mean age was 61.3 years (range, 19-93 years). The most common site was a lower extremity, and the most common clinical stage was stage II. No significant differences in clinicopathological features, five-year survival rates, and five-year disease-free survival rates were observed among the three groups. Conclusions The presence and type of biopsy neither affected the metastatic rate nor the prognosis of malignant melanoma. The use of incisional biopsies is not encouraged because tumor thickness cannot be measured accurately. However, they may be helpful for confirming the diagnosis if an excisional biopsy cannot be performed.

Background and study aims It is important to examine the pharynx during upper gastrointestinal endoscopy. Pharyngeal anesthesia using topical lidocaine is generally used as pretreatment. In Japan, lidocaine viscous solution is the anesthetic of choice, but lidocaine spray is applied when the former is considered insufficient. However, the relationship between the extent of pharyngeal anesthesia and accuracy of observation is unclear. We compared the performance of lidocaine spray alone versus lidocaine spray combined with lidocaine viscous solution for pharyngeal observation during transoral endoscopy. Patients and methods In this prospective, double-blinded, randomized clinical trial conducted between January and March 2015, 327 patients were randomly assigned to lidocaine spray alone (spray group, n = 157) or a combination of spray and viscous solution (combination group, n = 170). We compared the number of pharyngeal observable sites (non-inferiority test), pain by visual analogue scale, observation time, and the number of gag reflexes between the two groups. Results The mean number of images of suitable quality taken at the observable pharyngeal sites in the spray group was 8.33 (95 % confidence interval [CI]: 7.94 – 8.72) per patient, and 8.77 (95 % CI: 8.49 – 9.05) per patient in the combination group. The difference in the number of observable pharyngeal sites was – 0.44 (95 % CI: – 0.84 to – 0.03, P = 0.01). There were no differences in pain, observation time, or number of gag reflexes between the 2 groups. Subgroup analysis of the presence of sedation revealed no differences between the two groups for the number of pharyngeal observation sites and the number of gag reflexes. However, the number of gag reflexes was higher in the spray group compared to the combination group in a subgroup analysis that looked at the absence of sedation. Conclusions Lidocaine spray for pharyngeal anesthesia was not inferior to lidocaine spray and viscous solution in terms of pharyngeal observation. It was considered that lidocaine viscous solution was unnecessary for pharyngeal observation. UMIN000016073

Background: Recurrence and complication rates of pressure sores are highest in the ischial region, and other donor sites are needed for recurrent pressure sores. The potential of a new freestyle pedicle flap for ischial lesions, an internal pudendal artery perforator (iPap) thigh flap, was examined through anatomical and theoretical analyses and a case series using computed tomography angiography. Methods: The skin flap was designed in the thigh region based on an iPap. The skin perforators were marked with a Doppler probe. One patient underwent computed tomography angiography with fistulography to identify the damage to or effects on the pedicle vessels of the flap. Debridement of ischial lesions and flap elevation were performed in the jackknife position. Results: The iPap thigh flaps were performed in 5 patients, 4 with ischial pressure sores and 1 with calcinosis cutis of the ischial region. The width and length of the flaps ranged from 5 to 8 cm (mean, 6.6 cm) and 10 to 17 cm (mean, 12.6 cm), respectively. Three patients underwent partial osteotomy of the ischial bone. No complications, including flap necrosis or wound dehiscence of the donor and reconstructed sites, were observed. Conclusions: The perforator vessels of the internal pudendal artery are very close to the ischial tuberosity. Blood flow to the flap is reliable when careful debridement of the pressure sore is performed. The iPap thigh flap is a new option for soft-tissue defects in the ischial region, including ischial pressure sores.

Background: When a tumor in the lateral eyebrow region is resected, reconstruction of the eyebrow and upper eyelid defects is necessary. We perform simultaneous reconstruction of such defects; sideburn hair is included on an extended lateral orbital flap. We describe our method and results of a retrospective evaluation. Methods: We treated 6 patients with partial eyebrow and upper eyelid defects. An extended lateral orbital flap was designed on the lateral region of the lateral canthus including sideburn hair and was elevated with a pedicle of the orbicularis oculi muscle. Flap size, surgical outcomes, and reconstructed eyebrow morphology were evaluated. Results: Mean flap size was 2.7 × 4.1 cm, with a maximum width and length of 3.5 and 5.1 cm, respectively. The mean hair-bearing region was 1.4 × 0.9 cm, with a maximum width and length of 1.8 and 1.3 cm, respectively. Total flap survival and hair growth were confirmed in all patients. The reconstructed eyebrow and eyelid were aesthetically satisfactory. The new eyebrow hair grew long and was directed upward but considered acceptable. No additional surgery was performed for any patient. The donor site scar was acceptable because it followed the wrinkles of the lateral eyelid. No paralysis of the temporal branch of the facial nerve resulted. Conclusions: The procedure for raising an extended hair-bearing lateral orbital flap is relatively easy, although attention must be paid to the temporal facial nerve. This flap is useful for simultaneously reconstructing defects of the upper eyelid and lateral eyebrow.