Effects of interleukin-15 on autophagy regulation in the skeletal muscle of mice

This study aimed to evaluate the role of skeletal muscle-derived interleukin (IL)-15 in the regulation of skeletal muscle autophagy using IL-15 knockout (KO) and transgenic (TG) mice. Male C57BL/6 wild-type (WT), IL-15 KO, and IL-15 TG mice were used in this study. Changes in muscle mass, forelimb grip strength, succinate dehydrogenase (SDH) activity, gene and protein expression levels of major regulators and indicators of autophagy, comprehensive gene expression, and DNA methylation in the gastrocnemius muscle were analyzed. Enrichment pathway analyses revealed that the pathology of IL-15 gene deficiency was related to the autophagosome pathway. Moreover, although IL-15 KO mice maintained gastrocnemius muscle mass, they exhibited a decrease in autophagy induction. IL-15 TG mice exhibited a decrease in gastrocnemius muscle mass and an increase in forelimb grip strength and SDH activity in skeletal muscle. In the gastrocnemius muscle, the ratio of phosphorylated adenosine monophosphate-activated protein kinase α (AMPKα) to total AMPKα and unc-51-like autophagy activating kinase 1 and Beclin1 protein expression were higher in the IL-15 TG group than in the WT group. IL-15 gene deficiency induces a decrease in autophagy induction. In contrast, IL-15 overexpression could improve muscle quality by activating autophagy induction while decreasing muscle mass. The regulation of IL-15 in autophagy in skeletal muscles may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.NEW & NOTEWORTHY IL-15 gene deficiency can decrease autophagy induction. However, although IL-15 overexpression induced a decrease in muscle mass, it led to an improvement in muscle quality. Based on these results, understanding the role of IL-15 in regulating autophagy pathways within skeletal muscle may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.

Knee Extensor Weakness Potently Predicts Postoperative Outcomes in Older Gastrointestinal Cancer Patients

OBJECTIVES

Muscle weakness, assessed by grip strength, has been shown to predict postoperative mortality in older patients with cancer. Because lower extremity muscle strength well reflects physical performance, we examined whether lower knee extension muscle strength predicts postoperative mortality better than grip strength in older patients with gastrointestinal cancer.

DESIGN

Prospective, observational study in a single institution.

SETTING AND PARTICIPANTS

A total of 813 patients (79.0 ± 4.2 years, 66.5% male) aged 65 years or older with gastrointestinal cancer who underwent preoperative evaluation of grip strength and isometric knee extension muscle strength between April 2012 and April 2019 were included.

METHODS

The study participants were prospectively followed up for postoperative mortality. Muscle weakness was defined as the lowest quartile of grip strength or knee extension strength (GS-muscle weakness and KS-muscle weakness, respectively).

RESULTS

Among the study participants, 176 patients died during a median follow-up of 716 days. In the Kaplan-Meier analysis, we found that patients with both GS-muscle weakness and KS-muscle weakness had a lower survival rate than those without muscle weakness. As expected, higher clinical stages and abdominal and thoracic surgeries compared with endoscopic surgery were associated with increased all-cause mortality. In addition, we found that KS-muscle weakness, but not GS-muscle weakness, was an independent prognostic factor after adjusting for sex, body mass index, cancer stage, surgical technique, and surgical site in the Cox proportional hazard model.

CONCLUSIONS AND IMPLICATIONS

In older patients with gastrointestinal cancer, muscle weakness based on knee extension muscle strength can be a better predictor of postoperative prognosis than muscle weakness based on grip strength.

Effects of luseogliflozin treatment on hyperglycemia-induced muscle atrophy in rats

Diabetes mellitus is recognized as a risk factor for sarcopenia. Luseogliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, reduces inflammation and oxidative stress by improving hyperglycemia, subsequently improving hepatosteatosis or kidney dysfunction. However, the effects of SGLT2 inhibitor on the regulation of skeletal muscle mass or function in hyperglycemia are still unknown. In this study, we investigated the effects of luseogliflozin-mediated attenuation of hyperglycemia on the prevention of muscle atrophy. Twenty-four male Sprague-Dawley rats were randomly divided into four groups: control, control with SGLT2 inhibitor treatment, hyperglycemia, and hyperglycemia with SGLT2 inhibitor treatment. The hyperglycemic rodent model was established using a single injection of streptozotocin, a compound with preferential toxicity toward pancreatic beta cells. Muscle atrophy in streptozotocin-induced hyperglycemic model rats was inhibited by the suppression of hyperglycemia using luseogliflozin, which consequently suppressed hyperglycemia-mediated increase in the levels of advanced glycation end products (AGEs) and activated the protein degradation pathway in muscle cells. Treatment with luseogliflozin can restore the hyperglycemia-induced loss in the muscle mass to some degree partly through the inhibition of AGEs-induced or homeostatic disruption of mitochondria-induced activation of muscle degradation.

Effects of nicotinamide mononucleotide on older patients with diabetes and impaired physical performance: A prospective, placebo-controlled, double-blind study

OBJECTIVE

Nicotinamide adenine dinucleotide regulates various biological processes. Nicotinamide mononucleotide (NMN) increases its intracellular levels and counteracts age-associated changes in animal models. We investigated the safety and efficacy of oral nicotinamide mononucleotide supplementation in older patients with diabetes and impaired physical performance.

METHOD

We carried out a 24-week placebo-controlled, double-blinded study of male patients with diabetes aged ≥65 years with reduced grip strength (<26 kg) or walking speed (<1.0 m/s). The primary end-points were to determine the safety of NMN oral administration (250 mg/day), and changes in grip strength and walking speed. The secondary end-points were to determine the changes in various exploratory indicators.

RESULTS

We studied 14 participants aged 81.1 ± 6.4 years. NMN was tolerable without any severe adverse events. The changes in grip strength and walking speed showed no difference between the two groups: 1.25 kg (95% confidence interval -2.31 to 4.81) and 0.033 m/s (-0.021 to 0.087) in the NMN group, and -0.44 kg (-4.15 to 3.26) and 0.014 m/s (-0.16 to -0.13) in the placebo group, respectively. There were no significant differences in any exploratory indicators between the two groups. However, improved prevalence of frailty in the NMN group (P = 0.066) and different changes in central retinal thickness between the two groups (P = 0.051) was observed.

CONCLUSION

In older male patients with diabetes and impaired physical performance, NMN supplementation for 24 weeks was safe, but did not improve grip strength and walking speed. Geriatr Gerontol Int 2023; 23: 38-43.

Phase I Study to Assess the Safety and Immunogenicity of an Intradermal COVID-19 DNA Vaccine Administered Using a Pyro-Drive Jet Injector in Healthy Adults

We conducted a nonrandomized, open-label phase I study to assess the safety and immunogenicity of an intradermal coronavirus disease 2019 (COVID-19) DNA vaccine (AG0302-COVID-19) administered using a pyro-drive jet injector at Osaka University Hospital between Yanagida November 2020 and December 2021. Twenty healthy volunteers, male or female, were enrolled in the low-dose (0.2 mg) or high-dose (0.4 mg) groups and administered AG0302-COVID19 twice at a 2-week interval. There were no adverse events that led to discontinuation of the study drug vaccination schedule. A serious adverse event (disc protrusion) was reported in one patient in the high-dose group, but the individual recovered, and the adverse event was not causally related to the study drug. In the analysis of the humoral immune response, the geometric mean titer (GMT) of serum anti-SARS-CoV-2 spike glycoprotein-specific antibody was low in both the low-dose and high-dose groups (246.2 (95% CI 176.2 to 344.1, 348.2 (95% CI 181.3 to 668.9)) at the 8 weeks after first vaccination. Regarding the analysis of the cellular immune, the number of IFN-γ-producing cells responsive to the SARS-CoV-2 spike glycoprotein increased with individual differences after the first dose and was sustained for several months. Overall, no notable safety issues were observed with the intradermal inoculations of AG0302-COVID19. Regarding immunogenicity, a cellular immune response was observed in some subjects after AG0302-COVID19 intradermal inoculation, but no significant antibody production was observed.

IL-15RA regulates IL-15 localization and protein expression in skeletal muscle cells

NEW FINDINGS

What is the central question of this study? How are the dynamics of IL-15 and its receptors altered during the differentiation of myoblasts into myotubes, and how is IL-15 regulated? What is the main finding and its importance?

ABSTRACT

Interleukin-15 (IL-15) is a myokine in the Interleukin-2 (IL-2) family that is generated in the skeletal muscle during exercise. The functional effect of IL-15 involves muscle regeneration and metabolic regulation in skeletal muscle. Reports have indicated that the mechanism of Interleukin-15 receptor subunit alpha (IL-15RA) regulates IL-15 localization in immune cells. However, the dynamic of IL-15 and its receptors, which regulate the IL-15 pathway in skeletal muscle differentiation, have not yet been clarified. This study investigated the mechanism of IL-15 regulation using a mouse skeletal muscle cell line, C2C12 cells. We found that the mRNA expression of IL-15, Interleukin 2 Receptor Subunit Beta (IL-2RB) (CD122), and Interleukin 2 Receptor Subunit Gamma (IL-2RG) (CD132) increased, but that IL-15RA exhibits different kinetics as differentiation progresses. We also found that IL-15, mainly localized in the cytosol, preassembled with IL-15RA in the cytosol and fused to the plasma membrane. Moreover, IL-15RA increased IL-15 protein levels. Our findings suggest that genes comprising the IL-15 signaling complex are enhanced with the differentiation of myotubes and that IL-15RA regulates the protein kinetics of IL-15 signaling in skeletal muscle. This article is protected by copyright. All rights reserved.

Effects of combined treatment with blood flow restriction and low-current electrical stimulation on capillary regression in the soleus muscle of diabetic rats

To clarify the preventive effects of low-current electrical stimulation (ES) under blood flow restriction (Bfr) on diabetes-associated capillary regression in skeletal muscles, we assessed the changes in three-dimensional capillary architecture and angiogenic factors. Twenty-four Goto-Kakizaki rats were randomly divided into four groups: the sedentary diabetes mellitus (DM), Bfr (DM + Bfr), electrical stimulation (DM + ES), and Bfr plus ES (DM + Bfr + ES) groups. Six healthy Wistar rats were used as age-matched controls. Bfr was performed using pressure cuffs (80 mmHg) around the thighs of the rats, and low-current ES was applied to the calf muscles of the rats. The current intensity was set at 30% of the maximal isometric contraction (24-30 mA). The treatments were delivered three times a week for 8 wk. In the DM group, the capillary diameter and volume of the soleus muscle decreased, and, the antiangiogenic factor level increased. Furthermore, DM caused an increase in the hypoxia-inducible factor. Individually, Bfr or ES treatments failed to inhibit the DM-associated capillary regression and increase in antiangiogenic factor. However, combined treatment with Bfr and ES prevented DM-associated capillary regression via inhibition of the increased antiangiogenic factor and enhancement of interleukin-15 expression, mitochondrial biogenesis factors, and a proangiogenic factor. Therefore, DM-associated capillary regression inhibited by the combined treatment may prevent the effects of the increased antiangiogenic factor and enhance the proangiogenic factor.NEW & NOTEWORTHY The combined treatment of blood flow restriction and low intensity electrical stimulation attenuated type 2 diabetes (T2D)-associated capillary regression in the skeletal muscles. The treatment inhibits the T2D-associated increase in antiangiogenic factors via inhibition of intramuscular chronic hypoxia; it can inhibit intramuscular chronic hypoxia by enhancing proangiogenic factors. These results suggest that the combined treatment may be an effective therapeutic intervention for the prevention of T2D-associated capillary regression in the skeletal muscles.

Double Deletion of Angiotensin II Type 2 and Mas Receptors Accelerates Aging-Related Muscle Weakness in Male Mice

Background The activation of AT2 (angiotensin II type 2 receptor ) and Mas receptor by angiotensin II and angiotensin-(1-7), respectively, is the primary process that counteracts activation of the canonical renin-angiotensin system (RAS). Although inhibition of canonical RAS could delay the progression of physiological aging, we recently reported that deletion of Mas had no impact on the aging process in mice. Here, we used male mice with a deletion of only AT2 or a double deletion of AT2 and Mas to clarify whether these receptors contribute to the aging process in a complementary manner, primarily by focusing on aging-related muscle weakness. Methods and Results Serial changes in grip strength of these mice up to 24 months of age showed that AT2/Mas knockout mice, but not AT2 knockout mice, had significantly weaker grip strength than wild-type mice from the age of 18 months. AT2/Mas knockout mice exhibited larger sizes, but smaller numbers and increased frequency of central nucleation (a marker of aged muscle) of single skeletal muscle fibers than AT2 knockout mice. Canonical RAS-associated genes, inflammation-associated genes, and senescence-associated genes were highly expressed in skeletal muscles of AT2/Mas knockout mice. Muscle angiotensin II content increased in AT2/Mas knockout mice. Conclusions Double deletion of AT2 and Mas in mice exaggerated aging-associated muscle weakness, accompanied by signatures of activated RAS, inflammation, and aging in skeletal muscles. Because aging-associated phenotypes were absent in single deletions of the receptors, AT2 and Mas could complement each other in preventing local activation of RAS during aging.

RAGE ligands stimulate angiotensin II type I receptor (AT1) via RAGE/AT1 complex on the cell membrane

The receptor for advanced glycation end-products (RAGE) and the G protein-coupled angiotensin II (AngII) type I receptor (AT1) play a central role in cardiovascular diseases. It was recently reported that RAGE modifies AngII-mediated AT1 activation via the membrane oligomeric complex of the two receptors. In this study, we investigated the presence of the different directional crosstalk in this phenomenon, that is, the RAGE/AT1 complex plays a role in the signal transduction pathway of RAGE ligands. We generated Chinese hamster ovary (CHO) cells stably expressing RAGE and AT1, mutated AT1, or AT2 receptor. The activation of two types of G protein α-subunit, Gq and Gi, was estimated through the accumulation of inositol monophosphate and the inhibition of forskolin-induced cAMP production, respectively. Rat kidney epithelial cells were used to assess RAGE ligand-induced cellular responses. We determined that RAGE ligands activated Gi, but not Gq, only in cells expressing RAGE and wildtype AT1. The activation was inhibited by an AT1 blocker (ARB) as well as a RAGE inhibitor. ARBs inhibited RAGE ligand-induced ERK phosphorylation, NF-κB activation, and epithelial-mesenchymal transition of rat renal epithelial cells. Our findings suggest that the activation of AT1 plays a central role in RAGE-mediated cellular responses and elucidate the role of a novel molecular mechanism in the development of cardiovascular diseases.

The endocytosis of oxidized LDL via the activation of the angiotensin II type 1 receptor

Arrestin-dependent activation of a G-protein-coupled receptor (GPCR) triggers endocytotic internalization of the receptor complex. We analyzed the interaction between the pattern recognition receptor (PRR) lectin-like oxidized low-density lipoprotein (oxLDL) receptor (LOX-1) and the GPCR angiotensin II type 1 receptor (AT1) to report a hitherto unidentified mechanism whereby internalization of the GPCR mediates cellular endocytosis of the PRR ligand. Using genetically modified Chinese hamster ovary cells, we found that oxLDL activates Gαi but not the Gαq pathway of AT1 in the presence of LOX-1. Endocytosis of the oxLDL-LOX-1 complex through the AT1-β-arrestin pathway was demonstrated by real-time imaging of the membrane dynamics of LOX-1 and visualization of endocytosis of oxLDL. Finally, this endocytotic pathway involving GPCR kinases (GRKs), β-arrestin, and clathrin is relevant in accumulating oxLDL in human vascular endothelial cells. Together, our findings indicate that oxLDL activates selective G proteins and β-arrestin-dependent internalization of AT1, whereby the oxLDL-LOX-1 complex undergoes endocytosis.

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The binding of oxidized LDL (oxLDL) to LOX-1 induces selective activation of AT1

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oxLDL and angiotensin II additively or competitively activate AT1 in different cells

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oxLDL promotes β-arrestin-dependent internalization of oxLDL-LOX-1-AT1 complex

A pressor dose of angiotensin II has no influence on the angiotensin-converting enzyme 2 and other molecules associated with SARS-CoV-2 infection in mice

In the early phase of the Coronavirus disease 2019 (COVID‐19) pandemic, it was postulated that the renin‐angiotensin‐system inhibitors (RASi) increase the infection risk. This was primarily based on numerous reports, which stated that the RASi could increase the organ Angiotensin‐converting enzyme 2 (ACE2), the receptor of Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), in rodents. RASi can theoretically antagonize the potential influence of angiotensin II (Ang II) on ACE2. However, while Ang II decreases the ACE2 levels in cultured cells, there is little evidence that supports this phenomenon in living animals. In this study, we tested whether Ang II or Ang II combined with its antagonist would alter the ACE2 and other molecules associated with the infection of SARS‐CoV‐2. Male C57BL6/J mice were administered vehicle, Ang II (400 ng/kg/min), or Ang II with losartan (10 mg/kg/min) for 2 weeks. ACE2 knockout mice were used as a negative control for the ACE2 assay. We found that both Ang II, which elevated blood pressure by 30 mm Hg, and Ang II with losartan, had no effect on the expression or protein activity of ACE2 in the lung, left ventricle, kidney, and ileum. Likewise, these interventions had no effect on the expression of Transmembrane Protease Serine 2 (TMPRSS2) and Furin, proteases that facilitate the virus‐cell fusion, and the expression or activity of Tumor Necrosis Factor α‐Convertase (TACE) that cleaves cell‐surface ACE2. Collectively, physiological concentrations of Ang II do not modulate the molecules associated with SARS‐CoV‐2 infection. These results support the recent observational studies suggesting that the use of RASi is not a risk factor for COVID‐19.

Differential effects of pre-exercise on cancer cachexia-induced muscle atrophy in fast- and slow-twitch muscles

We hypothesized that pre-exercise may effectively prevent cancer cachexia-induced muscle atrophy in both fast- and slow-twitch muscle types. Additionally, the fast-twitch muscle may be more affected by cancer cachexia than slow-twitch muscle. This study aimed to evaluate the effects of pre-exercise on cancer cachexia-induced atrophy and on atrophy in fast- and slow-twitch muscles. Twelve male Wistar rats were randomly divided into sedentary and exercise groups, and another 24 rats were randomly divided into control, pre-exercise, cancer cachexia induced by intraperitoneal injections of ascites hepatoma AH130 cells, and pre-exercise plus cancer cachexia groups. We analyzed changes in muscle mass and in gene and protein expression levels of major regulators and indicators of muscle protein degradation and synthesis pathways, angiogenic factors, and mitochondrial function in both the plantaris and soleus muscles. Pre-exercise inhibited muscle mass loss, rescued protein synthesis, prevented capillary regression, and suppressed hypoxia in the plantaris and soleus muscles. Pre-exercise inhibited mitochondrial dysfunction differently in fast- and slow-twitch muscles. These results suggested that pre-exercise has the potential to inhibit cancer-cachexia-induced muscle atrophy in both fast- and slow-twitch muscles. Furthermore, the different progressions of cancer-cachexia-induced muscle atrophy in fast- and slow-twitch muscles are related to differences in mitochondrial function.

Investigator-initiated clinical study of a functional peptide, SR-0379, for limb ulcers of patients with Werner syndrome as a pilot study

AIM

An investigator-initiated clinical study was carried out to evaluate the therapeutic potency of SR-0379 for the treatment of leg ulcers in patients with Werner syndrome.

METHODS

A multicenter, open-label study was carried out from September 2017 to February 2018. The inclusion criteria for leg ulcers were: (i) leg ulcers in patients with Werner syndrome, diabetes or critical limb ischemia/venous stasis; and (ii) a wound size of >1 cm and <6 cm in diameter. Four individuals with Werner syndrome and diabetic ulcers, respectively, were enrolled. SR-0379 (0.1%) was sprayed on skin ulcers once per day for 4 weeks. Efficacy was evaluated by determining the rate of wound size reduction as a primary end-point at 4 weeks after the first treatment compared with the pretreatment wound size. As secondary end-points, the DESIGN-R score index, the 50% wound size reduction ratio, time to wound closure and quantification of wound bacteria were also evaluated. The safety of SR-0379 was evaluated during the study period.

RESULTS

The reduction rate of ulcer size treated with 0.1% SR-0379 was 22.90% (mean) in the Werner syndrome ulcers group (n = 4) and 35.70% (mean) in the diabetic ulcers group (n = 4), respectively. The DESIGN-R score decreased by 4.0 points in the Werner syndrome ulcers group and 4.3 points in the diabetic ulcers group. Two mild adverse events were reported in two patients, and causal relationships were denied in any events.

CONCLUSION

Treatment with SR-0379 was safe, well-tolerated, and effective for leg ulcers of both Werner syndrome and diabetes patients. Geriatr Gerontol Int 2019; 19: 1118-1123.

1,6-α-L-Fucosidases from Bifidobacterium longum subsp. infantis ATCC 15697 Involved in the Degradation of Core-fucosylated N -Glycan

Bifidobacterium longum subsp. infantis ATCC 15697 possesses five α-L-fucosidases, which have been previously characterized toward fucosylated human milk oligosaccharides containing α1,2/3/4-linked fucose [Sela et al.: Appl. Environ. Microbiol., 78, 795-803 (2012)]. In this study, two glycoside hydrolase family 29 α-L-fucosidases out of five (Blon_0426 and Blon_0248) were found to be 1,6-α-L-fucosidases acting on core α1,6-fucose on the N-glycan of glycoproteins. These enzymes readily hydrolyzed p-nitrophenyl-α-L-fucoside and Fucα1-6GlcNAc, but hardly hydrolyzed Fucα1-6(GlcNAcβ1-4)GlcNAc, suggesting that they de-fucosylate Fucα1-6GlcNAcβ1-Asn-peptides/proteins generated by the action of endo-β- N-acetylglucosaminidase. We demonstrated that Blon_0426 can de-fucosylate Fucα1-6GlcNAc-IgG prepared from Rituximab using Endo-CoM from Cordyceps militaris. To generate homogenous non-fucosylated N-glycan-containing IgG with high antibody-dependent cellular cytotoxicity (ADCC) activity, the resulting GlcNAc-IgG has a potential to be a good acceptor substrate for the glycosynthase mutant of Endo-M from Mucor hiemalis. Collectively, our results strongly suggest that Blon_0426 and Blon_0248 are useful for glycoprotein glycan remodeling.

Serum albumin/globulin ratio is associated with cognitive function in community-dwelling older people: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study

AIM

The objective of this study was to clarify the relationship between cognitive function and the serum albumin/globulin ratio (A/G ratio) in community-dwelling Japanese older adults.

METHODS

Randomly extracted residents in both urban and rural parts of Japan were enrolled in this study. A total of 1827 participants with a mean age of 70 or 80 years were recruited. A venue survey method was carried out with comprehensive studies, including interviews, blood collection, physical examination and cognitive function tests.

RESULTS

Univariate analysis showed a significant positive correlation between the total Japanese version of the Montreal Cognitive Assessment score and the serum A/G ratio at the age of 70 and 80 years, in which better cognitive function was associated with a high serum A/G ratio. Multiple regression analysis with the total Japanese version of the Montreal Cognitive Assessment score as the dependent variable showed that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and sex were related to the Japanese version of the Montreal Cognitive Assessment total score at the age of 70 years, and that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and stroke were related at the age of 80 years. The serum A/G ratio showed a better correlation than the serum globulin levels at the age of 70 and 80 years (70 years: β = 0.131 vs -0.111, 80 years: β = 0.108 vs -0.071).

CONCLUSIONS

We found a correlation between cognitive function and the serum A/G ratio in community-dwelling older people, suggesting that nutritional status and chronic inflammation might influence cognitive function. Geriatr Gerontol Int 2019; 19: 967-971.

Preventive effects of low-intensity exercise on cancer cachexia-induced muscle atrophy

We hypothesized that low-intensity endurance exercise might be more effective in preventing cancer cachexia-induced muscle atrophy through both an increase in protein synthesis and a decrease in protein degradation. The purpose of present study was to evaluate the effects and to clarify the mechanism of low-intensity endurance exercise on cancer cachexia-induced muscle atrophy. Twenty-four male Wistar rats were randomly divided into 4 groups: control (Cont), Cont plus exercise (Ex), AH130-induced cancer cachexia (AH130), and AH130 plus Ex. Cancer cachexia was induced by intraperitoneal injections with AH130 Yoshida ascites hepatoma cells; we analyzed the changes in muscle mass and the gene and protein expression levels of major regulators or indicators of skeletal muscle protein degradation and synthesis pathway in the soleus muscles. Low-intensity exercise inhibited the muscle mass loss through a suppression of the ubiquitin-proteasome pathway, increased hypoxia-inducible factor- 1α and phosphorylated AMPK, and inhibited the deactivation of mammalian target of rapamycin pathway in the soleus muscle, which contributed to the prevention of cancer cachexia-induced muscle atrophy. These results suggest that low-intensity exercise has the potential to become an effective therapeutic intervention for the prevention of cancer cachexia-induced muscle atrophy.-Tanaka, M., Sugimoto, K., Fujimoto, T., Xie, K., Takahashi, T., Akasaka, H., Kurinami, H., Yasunobe, Y., Matsumoto, T., Fujino, H., Rakugi, H. Preventive effects of low-intensity exercise on cancer cachexia-induced muscle atrophy.

Angiotensin-converting enzyme 2 deficiency accelerates and angiotensin 1-7 restores age-related muscle weakness in mice

BACKGROUND

A pharmacologic strategy for age-related muscle weakness is desired to improve mortality and disability in the elderly. Angiotensin-converting enzyme 2 (ACE2) cleaves angiotensin II into angiotensin 1-7, a peptide known to protect against acute and chronic skeletal muscle injury in rodents. Since physiological aging induces muscle weakness via mechanisms distinct from other muscle disorders, the role of ACE2-angiotensin 1-7 in age-related muscle weakness remains undetermined. Here, we investigated whether deletion of ACE2 alters the development of muscle weakness by aging and whether angiotensin 1-7 reverses muscle weakness in older mice.

METHODS

After periodic measurement of grip strength and running distance in male ACE2KO and wild-type mice until 24 months of age, we infused angiotensin 1-7 or vehicle for 4 weeks, and measured grip strength, and excised tissues. Tissues were also excised from younger (3-month-old) and middle-aged (15-month-old) mice. Microarray analysis of RNA was performed using tibialis anterior (TA) muscles from middle-aged mice, and some genes were further tested using RT-PCR.

RESULTS

Grip strength of ACE2KO mice was reduced at 6 months and was persistently lower than that of wild-type mice (p < 0.01 at 6, 12, 18, and 24-month-old). Running distance of ACE2KO mice was shorter than that of wild-type mice only at 24 months of age [371 ± 26 vs. 479 ± 24 (m), p < 0.01]. Angiotensin 1-7 improved grip strength in both types of older mice, with larger effects observed in ACE2KO mice (% increase, 3.8 ± 1.5 and 13.3 ± 3.1 in wild type and ACE2KO mice, respectively). Older, but not middle-aged ACE2KO mice had higher oxygen consumption assessed by a metabolic cage than age-matched wild-type mice. Angiotensin 1-7 infusion modestly increased oxygen consumption in older mice. There was no difference in a wheel-running activity or glucose tolerance between ACE2KO and wild-type mice and between mice with vehicle and angiotensin 1-7 infusion. Analysis of TA muscles revealed that p16INK4a, a senescence-associated gene, and central nuclei of myofibers increased in middle-aged, but not younger ACE2KO mice. p16INK4a and central nuclei increased in TA muscles of older wild-type mice, but the differences between ACE2KO and wild-type mice remained significant (p < 0.01). Angiotensin 1-7 did not alter the expression of p16INK4a or central nuclei in TA muscles of both types of mice. Muscle ACE2 expression of wild-type mice was the lowest at middle age (2.6 times lower than younger age, p < 0.05).

CONCLUSIONS

Deletion of ACE2 induced the early manifestation of muscle weakness with signatures of muscle senescence. Angiotensin 1-7 improved muscle function in older mice, supporting future application of the peptide or its analogues in the treatment of muscle weakness in the elderly population.

Design Improvement of the Jellyfish Valve for Long-term Use in Artificial Hearts

In a previous communication, we reported a leaflet fracture in a Jellyfish valve that was incorporated into a blood pump, after a 312-day animal implant duration. Subsequent finite element analysis revealed that the fracture location was consistent with an area of maximum strain concentration. Therefore, the aim of this study was to improve the durability in the light of these findings. Based on the engineering analysis results, a new valve seat having a concentric ring of 0.5mm width, located at a radius of 7.0 mm, was designed and fabricated. Accelerated fatigue tests, conducted under the conditions recommended by ISO 5840, demonstrated that the durability of this new prototype was extended by a factor of 10, as compared to the original valve. Moreover, further finite element analysis indicated that the maximum equivalent elastic strain of the proposed new valve was reduced by 52.3% as compared to the original valve. Accordingly, it has been confirmed that the modified Jellyfish valve is suitable for use in long-term artificial hearts.

High plasma adiponectin levels are associated with frailty in a general old-old population: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study

AIM

The objective of the present study was to investigate the association between frailty and plasma adiponectin levels in a general population of Japanese older adults.

METHODS

The volunteer older adults, aged approximately 83 years, were recruited randomly from a general population in the Japanese Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study. We used the modified Cardiovascular Health Study criteria to assess the frailty status of the study participants. The study participants were classified as non-frail, pre-frail and frail according to their physical activities. We compared plasma adiponectin levels among these three groups and applied a multivariate logistic regression analysis including plasma adiponectin levels to clarify the factors associated with frailty status in the cross-sectional design.

RESULTS

The mean age of the participants was 83.1 ± 0.9 years, and 51.8% were men. The frailty index was available to assess 353 participants, of whom 24.6% were classified as non-frail, 62.3% as prefrail and 13.0% as frail. The log-transformed plasma adiponectin levels increased stepwise in the following order: non-frail, pre-frail and frail. A multivariate logistic regression analysis showed that higher plasma adiponectin levels, a higher estimated glomerular filtration rate and lower hemoglobin levels were independent determinants for pre-frail/frail status compared with non-frail status.

CONCLUSIONS

The present study showed that higher plasma adiponectin levels were associated with frailty status in older Japanese adults in the general population. Further longitudinal study is essential to clarify the role of plasma adiponectin in the progression of frailty. Geriatr Gerontol Int 2018; 18: 839-846.

Generation of interspecies limited chimeric nephrons using a conditional nephron progenitor cell replacement system

Animal fetuses and embryos may have applications in the generation of human organs. Progenitor cells may be an appropriate cell source for regenerative organs because of their safety and availability. However, regenerative organs derived from exogenous lineage progenitors in developing animal fetuses have not yet been obtained. Here, we established a combination system through which donor cells could be precisely injected into the nephrogenic zone and native nephron progenitor cells (NPCs) could be eliminated in a time- and tissue-specific manner. We successfully achieved removal of Six2+ NPCs within the nephrogenic niche and complete replacement of transplanted NPCs with donor cells. These NPCs developed into mature glomeruli and renal tubules, and blood flow was observed following transplantation in vivo. Furthermore, this artificial nephron could be obtained using NPCs from different species. Thus, this technique enables in vivo differentiation from progenitor cells into nephrons, providing insights into nephrogenesis and organ regeneration.

The transplantation of tissue-specific progenitor cells may be an approach in organ regeneration. Here the authors show that the nephron progenitor population of a developing mouse kidney, when ablated, can be replaced by exogenously supplied rat nephron progenitors, generating interspecies nephrons.

Discovery of Novel Seven-Membered Prostacyclin Analogues as Potent and Selective Prostaglandin FP and EP3 Dual Agonists

A novel series of prostaglandin analogues with a seven-membered ring scaffold was designed, synthesized, and evaluated for the functional activation of prostaglandin receptors to identify potent and subtype-selective FP and EP3 dual agonists. Starting from the prostacyclin derivative 5b, a nonselective agonist for prostaglandin receptors, replacement of the core structure with an octahydro-2H-cyclopenta[b]oxepine scaffold led to the discovery of the potent and selective FP and EP3 dual agonist 11b as a lead compound for the development of an antiglaucoma agent.

Discovery of ONO-7300243 from a Novel Class of Lysophosphatidic Acid Receptor 1 Antagonists: From Hit to Lead

Lysophosphatidic acid (LPA) evokes various physiological responses through a series of G protein-coupled receptors known as LPA_1-6. A high throughput screen against LPA₁ gave compound 7a as a hit. The subsequent optimization of 7a led to ONO-7300243 (17a) as a novel, potent LPA₁ antagonist, which showed good efficacy in vivo. The oral dosing of 17a at 30 mg/kg led to reduced intraurethral pressure in rats. Notably, this compound was equal in potency to the α₁ adrenoceptor antagonist tamsulosin, which is used in clinical practice to treat dysuria with benign prostatic hyperplasia (BPH). In contrast to tamsulosin, compound 17a had no impact on the mean blood pressure at this dose. These results suggest that LPA₁ antagonists could be used to treat BPH without affecting the blood pressure. Herein, we report the hit-to-lead optimization of a unique series of LPA₁ antagonists and their in vivo efficacy.

Focal Fatty Masses of the Pancreas

Five patients with solitary fatty mass of the pancreas examined with CT and ultrasound (US) were evaluated. The areas of fat replacement were located in the pancreatic neck, body or tail. The size ranged from 4 to 30 mm in the longest diameter. The shape varied from roundish, to ovoid to semicircular, and the contour was universally well defined. The internal structure was homogeneous in 3 patients, but in one case there were thin septa and, in another, a slightly hyperdense part in the peripheral portion. All the masses except the smallest one were in part contact with pancreatic fat. CT showed fat with the same density as the peripancreatic fat and low HU units. The mass was hypoechoic in 2 cases and hyperechoic in one. The masses in the tail of the pancreas were not detected by US.

Glycolysis of Rigid Polyurethane Foam under Various Reaction Conditions

The dissolution time of rigid polyurethane foam (PUF) under various glycolysis conditions was examined in a detailed investigation of the glycolysis reactivity of PUF. PUF dissolution depended on the molecular weight of glycol. Dipropylene glycol and tetraethylene glycol dissolved PUF in the shortest time among polypropylene glycols and polyethylene glycols, respectively. PUF dissolution time was reduced to one-half for each 10 C rise in the range of 170–200 C. Also PUF dissolution time was inverselyproportional to KOH (catalyst) concentration. Dibutyltindilaurate concentration had less influence on PUF dissolution time than KOH concentration. Smaller PUF particles dissolved in a shorter time. Especially, the initial glycolysis conversion of PUF was proportional to the total surface area of PUF particles.

Abstract P5-12-07: Hormone dynamics, pharmacokinetics, safety and efficacy of leuprorelin acetate 6-month depot formulation and tamoxifen adjuvant endocrine therapy combination in premenopausal patients with hormone receptor-positive breast cancer

Background: Luteinizing hormone-releasing hormone agonist + tamoxifen is standard postoperative adjuvant endocrine therapy for premenopausal patients with hormone receptor-positive breast cancer. Postoperative adjuvant endocrine therapy is now used for a longer period, and the longer-lasting leuprorelin acetate 6-month depot formulation (TAP-144-SR[6M]) is expected to increase patients' quality of life and decrease medical practitioners' burden.

Methods: The hormone dynamics, pharmacokinetics (PK), safety, and efficacy of TAP-144-SR(6M) were compared with those of the 3-month depot formulation (TAP-144-SR[3M]) in a 96-week, phase 3 open-label parallel-group comparison study in premenopausal breast cancer patients after surgery (ClinicalTrial.gov ID: NCT01546649). Inclusion criteria were estrogen receptor (ER) and/or progesterone receptor (PgR) positive; TNM classification of T1-T3, any N, M0; and premenopausal (menstruation confirmed within the previous 12 weeks or both follicle-stimulating hormone [FSH] &lt;40 mIU/mL and estradiol [E2] ≥10 pg/mL at enrollment). Patients were randomized to TAP-144-SR(6M) (6M group [6MG]) or TAP-144-SR(3M) (3M group [3MG]) based on number of axillary lymph node metastases, tumor size, age, ER/PgR status, chemotherapy or not, and study site. The primary endpoint was serum E2 suppression rate based on the menopausal level (≤30 pg/mL) from 4 to 48 weeks after the first administration. Secondary endpoints were serum hormone dynamics, efficacy (disease-free survival [DFS] and distance DFS [DDFS]), PK and safety. The planned number of patients was 164 (82 in each group).

Results: A total of 180 patients were enrolled from Apr 2012 to Feb 2013 and 167 patients were randomized. We compared 83 patients in 6MG (age: mean 44.2; SD 4.90) and 84 patients in 3MG (44.0; 5.18). There were no significant differences in background factors between the groups. 6MG showed non-inferior suppression of serum E2 levels to 3MG (See Table). Serum LH and FSH levels were also decreased. DFSs and DDFSs at 96 weeks after randomization were similar in both groups. A double-peak PK profile and sustainable release of the study drug for 24 weeks were found with 6MG. All-grade adverse events (AEs) occurred in 98.8% and 97.6% and grade 3 or higher AEs in 18.1% and 21.4% with 6MG and 3MG, respectively. There were no significant differences in lumbar spine bone mineral density change rates in both groups.

Table Serum E2 suppression rate based on the menopausal level (≤30 pg/mL) from 4 to 48 weeks after the first administration 6MG (n = 83)3MG (n = 84)Serum E2 suppression rate (%) (95% CI)97.6 (91.565, 99.707)96.4 (89.916, 99.257)6MG − 3MG (95% CI)1.2 (−5.241, 7.806)Note: Noninferiority margin of 10%.

Conclusion: This first clinical study of TAP-144-SR(6M) in premenopausal breast cancer patients showed clinically noninferior serum E2 suppression levels to TAP-144-SR(3M), and no significant safety differences between the groups. TAP-144-SR(6M) was confirmed to have excellent usability in premenopausal breast cancer patients after surgery, and is considered valuable for the appropriate treatment of these patients.

Citation Format: Kurebayashi J, Toyama T, Sumino S, Fujimoto T. Hormone dynamics, pharmacokinetics, safety and efficacy of leuprorelin acetate 6-month depot formulation and tamoxifen adjuvant endocrine therapy combination in premenopausal patients with hormone receptor-positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-12-07.