Understanding Risk in the Oldest Old: Frailty and the Metabolic Syndrome in a Chinese Community Sample Aged 90+ Years

OBJECTIVES

To investigate the relationship between frailty and the metabolic syndrome and to evaluate how these contribute to mortality in very old people.

DESIGN

Secondary analysis of data from the Project of Longevity and Aging in Dujiangyan.

SETTING

Community sample from Sichuan Province, China.

PARTICIPANTS

People aged 90+ years (n=767; baseline age=93.7±3.4 years; 68.0% women.

MEASUREMENTS

After a baseline health assessment, participants were followed for four years (54.0% died). A frailty index (FI) was calculated as the sum of deficits present, divided by the 35 health-related deficits considered. Relationships between the FI and the metabolic syndrome were tested; their effect on death was examined.

RESULTS

The mean FI was 0.26 ±0.11. Higher FI scores were associated with a greater risk of death, adjusted for age, sex, education, and metabolic syndrome items. The hazard ratio was 1.03 (95% confidence interval 1.02, 1.04) for each 1% percent increase of the FI. The mortality risk did not change with the metabolic syndrome (odds ratio=0.99; 0.71-1.36).

CONCLUSIONS

In the oldest old, frailty was a significant risk for near-term death, regardless of the metabolic syndrome. Even using age-adjusted models, the epidemiology of late life illness may need to account for frailty routinely.

Cell-based therapy for traumatic brain injury

Traumatic brain injury is a major economic burden to hospitals in terms of emergency department visits, hospitalizations, and utilization of intensive care units. Current guidelines for the management of severe traumatic brain injuries are primarily supportive, with an emphasis on surveillance (i.e. intracranial pressure) and preventive measures to reduce morbidity and mortality. There are no direct effective therapies available. Over the last fifteen years, pre-clinical studies in regenerative medicine utilizing cell-based therapy have generated enthusiasm as a possible treatment option for traumatic brain injury. In these studies, stem cells and progenitor cells were shown to migrate into the injured brain and proliferate, exerting protective effects through possible cell replacement, gene and protein transfer, and release of anti-inflammatory and growth factors. In this work, we reviewed the pathophysiological mechanisms of traumatic brain injury, the biological rationale for using stem cells and progenitor cells, and the results of clinical trials using cell-based therapy for traumatic brain injury. Although the benefits of cell-based therapy have been clearly demonstrated in pre-clinical studies, some questions remain regarding the biological mechanisms of repair and safety, dose, route and timing of cell delivery, which ultimately will determine its optimal clinical use.

USP4 inhibits p53 and NF-κB through deubiquitinating and stabilizing HDAC2

Histone deacetylases (HDACs) are major epigenetic modulators involved in a broad spectrum of human diseases including cancers. As HDACs are promising targets of cancer therapy, it is important to understand the mechanisms of HDAC regulation. In this study, we show that ubiquitin-specific peptidase 4 (USP4) interacts directly with and deubiquitinates HDAC2, leading to the stabilization of HDAC2. Accumulation of HDAC2 in USP4-overexpression cells leads to compromised p53 acetylation as well as crippled p53 transcriptional activation, accumulation and apoptotic response upon DNA damage. Moreover, USP4 targets HDAC2 to downregulate tumor necrosis factor TNFα-induced nuclear factor (NF)-κB activation. Taken together, our study provides a novel insight into the ubiquitination and stability of HDAC2 and uncovers a previously unknown function of USP4 in cancers.

Polypharmacy among nonagenarians/centenarians in rural China

BACKGROUND

Little is known about the prevalence and relevant factors of polypharmacy in nonagenarian and centenarians.

AIM

The aim of this study is to examine the prevalence and associated factors of polypharmacy in a sample of nonagenarians and centenarians living in a rural area of China.

METHODS

The data were from the 'Project of Longevity and Aging in Dujiangyan' study. Medication use and relevant covariates were obtained by face-to-face interviews. Minor polypharmacy was defined as the concomitant use of two to four medications, whereas major polypharmacy referred to the concomitant use of five or more medications.

RESULTS

We included 859 participants with mean age of 93.7 ± 3.3 years. The number of chronic diseases was 1.4 ± 1.2 per subject, whereas the number of drugs was 0.8 ± 1.4 per subject. The prevalence of minor polypharmacy and major polypharmacy was 16.5% and 3.7% respectively. Illiteracy (odds ratio (OR) 2.93, 95% confidence interval (CI) 1.52 to 5.66), cognitive impairment (OR 3.15, 95% CI 1.44 to 6.88), hypertension (OR 2.88, 95% CI 1.46 to 5.67), respiratory disease (OR 2.22, 95% CI 1.08 to 4.58), osteoarthritis (OR 1.24, 95% CI 1.01 to 1.51), and cancer (OR 10.70, 95% CI 1.90 to 126.80) were positively associated with minor polypharmacy. Illiteracy (OR 4.24, 95% CI 1.53 to 11.81), hypertension (OR 3.40, 95% CI 1.22 to 9.49) and cancer (OR 3.40, 95% CI 1.14 to 10.12) were also positively associated with major polypharmacy.

CONCLUSIONS

Although most subjects suffer from some chronic diseases, minor polypharmacy and major polypharmacy are not common among nonagenarians/centenarians in rural China.

Microvesicles Derived From Human Mesenchymal Stem Cells Restore Alveolar Fluid Clearance in Human Lungs Rejected for Transplantation

The need to increase the donor pool for lung transplantation is a major public health issue. We previously found that administration of mesenchymal stem cells "rehabilitated" marginal donor lungs rejected for transplantation using ex vivo lung perfusion. However, the use of stem cells has some inherent limitation such as the potential for tumor formation. In the current study, we hypothesized that microvesicles, small anuclear membrane fragments constitutively released from mesenchymal stem cells, may be a good alternative to using stem cells. Using our well established ex vivo lung perfusion model, microvesicles derived from human mesenchymal stem cells increased alveolar fluid clearance (i.e. ability to absorb pulmonary edema fluid) in a dose-dependent manner, decreased lung weight gain following perfusion and ventilation, and improved airway and hemodynamic parameters compared to perfusion alone. Microvesicles derived from normal human lung fibroblasts as a control had no effect. Co-administration of microvesicles with anti-CD44 antibody attenuated these effects, suggesting a key role of the CD44 receptor in the internalization of the microvesicles into the injured host cell and its effect. In summary, microvesicles derived from human mesenchymal stem cells were as effective as the parent mesenchymal stem cells in rehabilitating marginal donor human lungs.

Recombinant adenovirus-mediated overexpression of PTEN and KRT10 improves cisplatin resistance of ovarian cancer in vitro and in vivo

Drug resistance is a major cause of treatment failure in ovarian cancer patients, and novel therapeutic strategies are urgently needed. Overexpression of phosphatase and tensin homolog (PTEN) has been shown to preserve the cisplatin-resistance of ovarian cancer cells, while cisplatin-induced keratin 10 (KRT10) overexpression mediates the resistance-reversing effect of PTEN. However, whether overexpression of PTEN or KRT10 can improve the cisplatin resistance of ovarian cancer in vivo has not been investigated. Therefore, we investigated the effects of adenovirus-mediated PTEN or KRT10 overexpression on the cisplatin resistance of ovarian cancer in vivo. Recombinant adenoviruses carrying the gene for PTEN or KRT10 were constructed. The effects of overexpression of PTEN and KRT10 on cisplatin resistance of ovarian cancer cells were examined using the 3(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide (MTT) and TdT-mediated dUTP nick-end labeling (TUNEL) assays in vitro. Subcutaneously transplanted nude mice, as a model of human ovarian cancer, were used to test the effects of PTEN and KRT10 on cisplatin resistance of ovarian cancer in vivo. The MTT assay showed that recombinant adenovirus-mediated overexpression of KRT10 and PTEN enhanced the proliferation inhibition effect of cisplatin on C13K cells. Recombinant adenovirus-mediated overexpression of KRT10 and PTEN also increased the cisplatin-induced apoptosis rate of C13K cells. Furthermore, recombinant adenovirus-mediated overexpression of KRT10 and PTEN enhanced the inhibitory effect of cisplatin on C13K xenograft tumor growth. Thus, recombinant adenovirus-mediated overexpression of KRT10 and PTEN may improve the cisplatin resistance of ovarian cancer in vitro and in vivo.

Serum high mobility group box protein 1 as a clinical marker for ovarian cancer

The aim of the study was to evaluate the clinical value of serum high mobility group box chromosomal protein 1 (HMGB1) in ovarian cancer and analyze the correlation between HMGB1 and ovarian cancer clinicopathologic outcomes.A total of 105 patients with diagnosed epithelial ovarian cancer, 46 patients with ovarian benign disease and 33 healthy volunteers were enrolled from January 2011 through January 2013. Serum HMGB1 levels were analyzed by enzyme-linked immunosorbent assay.The mean value of serum HMGB1 levels in ovarian cancer patients (78.18±54.87ng/ml) was significantly higher than those in benign patients (33.98±9.97ng/ml) and healthy control (26.71±7.99ng/ml, p < 0.0001), respectively. The serum HMGB1 levels were 40.33±6.50ng/ml, 61.16±20.15ng/ml, 81.81±51.15ng/ml and 119.48±84.28ng/ml in patients with TNM stage I, II, III, and IV, respectively (p < 0.0001). There were 81 of the 105 ovarian cancer patients obtained complete remission, the serum HMGB1 levels before treatment(71.99±42.49ng/ml) were much higher than that at remission stage(42.10±15.48ng/ml) (p < 0.0001). During our investigating period, 28 ovarian cancer patients underwent recurrence, the serum HMGB1 levels were 75.54±39.50ng/ml in these recurrent ovarian cancer patients compared to 42.04±10.68ng/ml in non-recurrent ovarian cancer (p < 0.0001). None of the remission or recurrent patients came from benign ovarian tumor group.Our study suggests that HMGB1 may be a useful clinical marker for evaluating progression and predicting prognosis of ovarian carcinoma. Targeting HMGB1 production or release might have potential approaches for ovarian carcinoma treatment.

Ribosomal proteins L11 and L5 activate TAp73 by overcoming MDM2 inhibition

Over the past decade, a number of ribosomal proteins (RPs) have been found to have a role in activating the tumor suppressor p53 by directly binding to MDM2 and impeding its activity toward p53. Herein, we report that RPL5 and RPL11 can also enhance the transcriptional activity of a p53 homolog TAp73, but through a distinct mechanism. Interestingly, even though RPL5 and RPL11 were not shown to bind to p53, they were able to directly associate with the transactivation domain of TAp73 independently of MDM2 in response to RS. This association led to perturbation of the MDM2-TAp73 interaction, consequently preventing MDM2 from its association with TAp73 target gene promoters. Furthermore, ectopic expression of RPL5 or RPL11 markedly induced TAp73 transcriptional activity by antagonizing MDM2 suppression. Conversely, ablation of either of the RPs compromised TAp73 transcriptional activity, as evident by the reduction of p21 and Puma expression, in response to 5-fluorouracil (5-FU). Consistently, overexpression of RPL5 or RPL11 enhanced, but knockdown of either of them hampered, TAp73-mediated apoptosis. Intriguingly, simultaneous knockdown of TAp73 and either of the RPs was required for rescuing the 5-FU-triggered S-phase arrest of p53-null tumor cells. These results demonstrate a novel mechanism underlying the inhibition of tumor cell proliferation and growth by these two RPs via TAp73 activation.

Developments in selective small molecule ATP-targeting the serine/threonine kinase Akt/PKB

The serine/threonine kinase Akt, also known as protein kinase B (PKB), plays a key role in cell survival and proliferation through a number of downstream effectors. Recent studies indicate that unregulated activation of the Phosphatidylinositol 3-kinase (PI3K)/Akt pathway is a prominent feature of many human cancers and Akt is overexpressed or activated in all major cancers. For these reasons, Akt is considered as an attractive target for cancer therapy. In the past few years, several series of compounds with diverse structural features have been reported as Akt inhibitors, such as, ATP-competitive inhibitors, Phosphatidylinositol (PI) analogs, and allosteric inhibitors. Although most of the inhibitors exhibited potent inhibitory activities at nanomolar concentrations against Akt, some of them have shown unfavorable selectivity against other protein kinases especially PKA and PKC. This review will focus on the recent advances in the development and biological evaluation of selective ATP-competitive inhibitors for Akt. We will summarize the novel approaches toward the developments of selective ATP-competitive inhibitors, expecting to give information to design new ATP-competitive inhibitors with high selectivity, bioavailability, and potency.

NAT2 polymorphisms and susceptibility to anti-tuberculosis drug-induced liver injury: a meta-analysis

BACKGROUND AND OBJECTIVE

Although a series of studies have evaluated the potential association between N-acetyltransferase 2 (NAT2) polymorphisms and the risk of anti-tuberculosis drug-induced liver injury (ATLI), the results have generally been controversial and inadequate, mainly due to limited power. The present meta-analysis sought to resolve this problem.

DESIGN

PubMed, Embase and Web of Science were searched using the following key words: 'N-acetyltransferase 2' or 'NAT2' and 'polymorphism' and 'tuberculosis' or 'TB' and 'hepatotoxicity' or 'liver injury'. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were summarised in forest plots and set out in a table.

RESULTS

A total of 14 studies, comprising 474 cases and 1446 controls, were included in the meta-analysis. A significant association was observed between NAT2 slow acetylators and the risk of ATLI. The OR for NAT2 slow acetylators compared with rapid acetylators was 4.697 (95%CI 3.291-6.705, P < 0.001). Subgroup analyses indicate that both Asian and non-Asian cases with slow acetylators develop ATLI more frequently, which is similar to patients with slow acetylators receiving first-line combination treatment. On comparing NAT2 intermediate acetylators with rapid acetylators, the OR for ATLI was 1.261 (95%CI 0.928-1.712, P = 0.138).

CONCLUSIONS

This meta-analysis showed that tuberculosis patients with slow acetylators had a higher risk of ATLI than other acetylators. Screening of patients for the NAT2 genetic polymorphisms will be useful for the clinical prediction and prevention of ATLI.

Ribosomal protein S14 unties the MDM2-p53 loop upon ribosomal stress

The MDM2-p53 feedback loop is crucially important for restricting p53 level and activity during normal cell growth and proliferation, and is thus subjected to dynamic regulation in order for cells to activate p53 upon various stress signals. Several ribosomal proteins, such as RPL11, RPL5, RPL23, RPL26 or RPS7, have been shown to have a role in regulation of this feedback loop in response to ribosomal stress. Here, we identify another ribosomal protein S14, which is highly associated with 5q-syndrome, as a novel activator of p53 by inhibiting MDM2 activity. We found that RPS14, but not RPS19, binds to the central acidic domain of MDM2, similar to RPL5 and RPL23, and inhibits its E3 ubiquitin ligase activity toward p53. This RPS14-MDM2 binding was induced upon ribosomal stress caused by actinomycin D or mycophenolic acid. Overexpression of RPS14, but not RPS19, elevated p53 level and activity, leading to G1 or G2 arrest. Conversely, knockdown of RPS14 alleviated p53 induction by these two reagents. Interestingly, knockdown of either RPS14 or RPS19 caused a ribosomal stress that led to p53 activation, which was impaired by further knocking down the level of RPL11 or RPL5. Together, our results demonstrate that RPS14 and RPS19 have distinct roles in regulating the MDM2-p53 feedback loop in response to ribosomal stress.

A randomized, controlled trial of fingolimod (FTY720) in Japanese patients with multiple sclerosis

BACKGROUND

Fingolimod (FTY720) has previously shown clinical efficacy in phase II/III studies of predominantly Caucasian populations with multiple sclerosis (MS).

OBJECTIVES

To report six-month efficacy and safety outcomes in Japanese patients with relapsing MS treated with fingolimod.

METHODS

In this double-blind, parallel-group, phase II study, 171 Japanese patients with relapsing MS were randomized to receive once-daily fingolimod 0.5 mg or 1.25 mg, or matching placebo for six months. The primary and secondary endpoints were the percentages of patients free from gadolinium (Gd)-enhanced lesions at months 3 and 6, and relapses over six months, respectively; safety outcomes were also assessed.

RESULTS

147 patients completed the study. Higher proportions of patients were free from Gd-enhanced lesions at months 3 and 6 with fingolimod (0.5 mg: 70%, p = 0.004; 1.25 mg: 86%, p < 0.001) than with placebo (40%). Odds ratios for the proportions of relapse-free patients over six months favoured fingolimod versus placebo but were not significant. Adverse events related to fingolimod included transient bradycardia and atrioventricular block at treatment initiation, and elevated liver enzyme levels.

CONCLUSIONS

This study demonstrated the clinical efficacy of fingolimod for the first time in Japanese patients with MS, consistent with the established effects of fingolimod in Caucasian patients.

Presence of baseline prehypertension and risk of incident stroke: a meta-analysis

OBJECTIVE

To qualitatively and quantitatively assess the association of prehypertension with incident stroke through a meta-analysis of prospective cohort studies.

METHODS

We searched Medline, Embase, the Cochrane Library, and bibliographies of retrieved articles. Prospective cohort studies were included if they reported multivariate-adjusted relative risks (RRs) and corresponding 95%confidence intervals (CI) of stroke with respect to baseline prehypertension.

RESULTS

Twelve studies with 518,520 participants were included. Prehypertension was associated with risk of stroke (RR 1.55, 95% CI 1.35-1.79; p < 0.001). Seven studies further distinguished a low prehypertensive population (systolic blood pressure [SBP] 120-129 mm Hg or diastolic blood pressure [DBP] 80-84 mm Hg) and a high prehypertensive population (SBP 130-139 mm Hg or DBP 85-89 mm Hg). Among persons with lower-range prehypertension, stroke risk was not significantly increased (RR 1.22, 0.95-1.57). However, for persons with higher values within the prehypertensive range, stroke risk was substantially increased (RR 1.79, 95% CI 1.49-2.16).

CONCLUSIONS

Prehypertension is associated with a higher risk of incident stroke. This risk is largely driven by higher values within the prehypertensive range and is especially relevant in nonelderly persons. Randomized trials to evaluate the efficacy of blood pressure reduction in persons with this designation are warranted.

The emergence of cold-induced brown adipocytes in mouse white fat depots is determined predominantly by white to brown adipocyte transdifferentiation

The origin of brown adipocytes arising in white adipose tissue (WAT) after cold acclimatization is unclear. Here, we demonstrate that several UCP1-immunoreactive brown adipocytes occurring in WAT after cold acclimatization have a mixed morphology (paucilocular adipocytes). These cells also had a mixed mitochondrioma with classic "brown" and "white" mitochondria, suggesting intermediate steps in the process of direct transformation of white into brown adipocytes (transdifferentiation). Quantitative electron microscopy disclosed that cold exposure (6 degrees C for 10 days) did not induce an increase in WAT preadipocytes. beta(3)-adrenoceptor-knockout mice had a blunted brown adipocyte occurrence upon cold acclimatization. Administration of the beta(3)-adrenoceptor agonist CL316,243 induced the occurrence of brown adipocytes, with the typical morphological features found after cold acclimatization. In contrast, administration of the beta(1)-adrenoceptor agonist xamoterol increased only the number of preadipocytes. These findings indicate that transdifferentiation depends on beta(3)-adrenoceptor activation, whereas preadipocyte recruitment is mediated by beta(1)-adrenoceptor. RT-qPCR experiments disclosed that cold exposure induced enhanced expression of the thermogenic genes and of genes expressed selectively in brown adipose tissue (iBAT) and in both interscapular BAT and WAT. beta(3)-adrenoceptor suppression blunted their expression only in WAT. Furthermore, cold acclimatization induced an increased WAT expression of the gene coding for C/EBPalpha (an antimitotic protein), whereas Ccna1 expression (related to cell proliferation) was unchanged. Overall, our data strongly suggest that the cold-induced emergence of brown adipocytes in WAT predominantly reflects beta(3)-adrenoceptor-mediated transdifferentiation.