SARC-F and modified versions using arm and calf circumference: Diagnostic performance for sarcopenia screening and the impact of obesity.

AIM: SARC-F is limited by low sensitivity for sarcopenia identification. As surrogates of muscle mass, mid-arm circumference (MAC) and/or calf circumference have been proposed as additions to SARC-F to enhance sarcopenia identification. The aim of this study was to evaluate the diagnostic performance of SARC-F, SARC-CalF, SARC-F + MAC, and SARC-CalF + MAC in sarcopenia detection, and to assess the impact of obesity on their diagnostic performance. METHODS: We studied 230 healthy non-frail community-dwelling older adults age >50 years. We performed receiver operating characteristic curve analysis for SARC-F, SARC-CalF, SARC-F + MAC and SARC-CalF + MAC against sarcopenia diagnosed by the Asian Working Group for Sarcopenia (AWGS) 2019 as the reference standard. Obesity was defined by high waist circumference (men ≥90 cm, women ≥80 cm). We performed subgroup analysis to compare between obese and non-obese groups. RESULTS: The prevalence of sarcopenia was 27.0% by AWGS 2019. SARC-CalF + MAC had the best diagnostic performance (area under the curve [AUC] 0.74, 95% confidence interval [CI] 0.67-0.81; sensitivity 66.1%; specificity 69.1%), followed by SARC-CalF (AUC 0.70, 95% CI 0.62-0.78; sensitivity 21.0%; specificity 95.8%). SARC-F (AUC 0.57, 95% CI 0.49-0.66; sensitivity 0%; specificity 100%) performed significantly worsethan its modified versions (P < 0.05). There was higher accuracy of sarcopenia identification in obese compared with non-obese groups for SARC-F + MAC (AUC 0.75, 95% CI 0.65-0.85 vs. 0.58, 95% CI 0.46-0.70) and SARC-CalF + MAC (AUC 0.75, 95% CI 0.66-0.85 vs. 0.70, 95% CI 0.59-0.81). CONCLUSIONS: The addition of arm circumference to SARC-CalF confers better diagnostic accuracy for sarcopenia identification, especially in the obese group. Thus, MAC may complement SARC-CalF for community screening of sarcopenia amongst healthy community-dwelling older adults by increasing sensitivity for the detection of sarcopenic obesity. Geriatr Gerontol Int 2023; ••: ••-••.

Enhanced glucose homeostasis via Clostridium symbiosum-mediated glucagon-like peptide 1 inhibition of hepatic gluconeogenesis in mid-intestinal bypass surgery.

BACKGROUND: The small intestine is known to play a crucial role in the development and remission of diabetes mellitus (DM). However, the exact mechanism by which mid-small intestinal bypass improves glucose metabolism in diabetic rats is not fully understood. AIM: To elucidate the mechanisms by which mid-small intestinal bypass improves glucose metabolism. METHODS: Streptozotocin (STZ) was used to induce DM in Sprague-Dawley (SD) rats at a dose of 60 mg/kg. The rats were then randomly divided into two groups: The mid-small intestine bypass (MSIB) group and the sham group (underwent switch laparotomy). Following a 6-wk recovery period post-surgery, the rats underwent various assessments, including metabolic parameter testing, analysis of liver glycogen levels, measurement of key gluconeogenic enzyme activity, characterization of the gut microbiota composition, evaluation of hormone levels, determination of bile acid concentrations, and assessment of the expression of the intestinal receptors Takeda G protein-coupled receptor 5 and farnesoid X receptor. RESULTS: The MSIB group of rats demonstrated improved glucose metabolism and lipid metabolism, along with increased hepatic glycogen content. Furthermore, there was a decrease in the expression of the key gluconeogenic enzymes phosphoenolpyruvate carboxykinase 1 and glucose-6-phosphatase. Importantly, the MSIB group exhibited a substantial increase in the abundances of intestinal Lactobacillus, Clostridium symbiosum, Ruminococcus gnavus, and Bilophila. Moreover, higher levels of secondary bile acids, such as intestinal lithocholic acid, were observed in this group. Remarkably, the changes in the gut microbiota showed a significant correlation with the expression of key gluconeogenic enzymes and glucagon-like peptide 1 (GLP-1) at 6 wk postoperatively, highlighting their potential role in glucose regulation. These findings highlight the beneficial effects of mid-small intestine bypass on glucose metabolism and the associated modulation of the gut microbiota. CONCLUSION: The findings of this study demonstrate that the introduction of postoperative intestinal Clostridium symbiosum in the mid-small intestine contributes to the enhancement of glucose metabolism in nonobese diabetic rats. This improvement is attributed to the increased inhibition of hepatic gluconeogenesis mediated by GLP-1, resulting in a favorable modulation of glucose homeostasis.

Differences in metabolic improvement after metabolic surgery are linked to the gut microbiota in non-obese diabetic rats.

BACKGROUND: Different metabolic/bariatric surgery approaches vary in their effect on weight loss and glucose levels, although the underlying mechanism is unclear. Studies have demonstrated that the gut microbiota might be an important mechanism of improved metabolism after metabolic/bariatric surgery. AIM: To investigate the relationship between the improvement in metabolic disturbances and the changes in gut microbiota after gastric or intestinal bypass. METHODS: We performed sleeve gastrectomy (SG), distal small intestine bypass (DSIB) or sham surgery in nonobese rats with diabetes induced by 60 mg/kg streptozotocin (STZ-DM). RESULTS: The group comparisons revealed that both SG and DSIB induced a reduction in body weight and significant improvements in glucose and lipid metabolism in the STZ-DM rats. Furthermore, DSIB exhibited a stronger glucose-lowering and lipid-reducing effect on STZ-DM rats than SG. 16S ribosomal RNA gene sequencing revealed the gut abundance of some Lactobacillus spp. increased in both the SG and DSIB groups after surgery. However, the DSIB group exhibited a more pronounced increase in the gut abundance of Lactobacillus spp. compared to the SG group, with more Lactobacillus spp. types increased in the gut. CONCLUSION: The gut abundance of Lactobacillus was significantly correlated with the improvement in glycolipid metabolism and the change in serum fibroblast growth factor 21 levels.

Activation of the cGAS-STING pathway by a mitochondrial DNA-targeted emissive rhodium(iii) metallointercalator.

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon (STING) pathway is a key mediator of innate immunity involved in cancer development and treatment. The roles of mitochondrial DNA (mtDNA) in cancer immunotherapy have gradually emerged. Herein, we report a highly emissive rhodium(iii) complex (Rh-Mito) as the mtDNA intercalator. Rh-Mito can specifically bind to mtDNA to cause the cytoplasmic release of mtDNA fragments to activate the cGAS-STING pathway. Moreover, Rh-Mito activates the mitochondrial retrograde signaling by disturbing the key metabolites involved in epigenetic modifications, which alters the nuclear genome methylation landscape to influence the expression of genes related to immune signaling pathways. Finally, we demonstrate that ferritin-encapsulated Rh-Mito elicits potent anticancer activities and evokes intense immune responses in vivo by intravenous injection. Overall, we report for the first time that small molecules targeting mtDNA can activate the cGAS-STING pathway, which gives insights into the development of biomacromolecule-targeted immunotherapeutic agents.

Metals and inorganic molecules in regulating protein and nucleic acid phase separation.

The realization that liquid-liquid phase separation (LLPS) underlies the formation of membraneless compartments in cells has motivated efforts to modulate the condensation process of biomolecules. Increasing evidence shows that metals and inorganic molecules abundantly distributed in cells play important roles in the regulation of biomolecular condensation. Herein, we briefly reviewed the background of biomacromolecular phase separation and summarized the recent research progress on the roles of metals and inorganic molecules in regulating protein and nucleic acid phase separation in vitro and in cells.

Pt(IV)-Deferasirox Prodrug Combats DNA Damage Repair by Regulating RNA N6-Methyladenosine Methylation.

DNA damage repair is considered to be an important mechanism of cisplatin resistance, and the roles of iron homeostasis in action mechanisms of cisplatin have not been studied yet. Herein, a Pt(IV) prodrug (DFX-Pt) integrating cisplatin and the clinical oral iron-chelating agent deferasirox (DFX) is found to be highly active toward cisplatin-insensitive triple-negative breast cancer cells both in vitro and in vivo. RNA-sequencing shows that DFX-Pt can downregulate genes related to the double-strand break (DSB) damage pathway significantly. DFX-Pt can reduce cellular free iron, regulate the expression of the RNA demethylase, and elevate the levels of RNA N6-methyladenosine (m6A), which degrades the DSB-related genes in an m6A-dependent manner. In all, we first reveal the roles of RNA modification in mechanisms of combating DNA damage repair and show that the combination of iron homeostasis intervention may bring new treatment regimens for cisplatin resistance.

Self-Amplifying Iridium(III) Photosensitizer for Ferroptosis-Mediated Immunotherapy Against Transferrin Receptor-Overexpressing Cancer.

Photoimmunotherapy is attractive for cancer treatment due to its spatial controllability and sustained responses. This work presents a ferrocene-containing Ir(III) photosensitizer (IrFc1) that can bind with transferrin and be transported into triple-negative breast cancer (TNBC) cells via a transferrin receptor-mediated pathway. When the ferrocene in IrFc1 is oxidized by reactive oxygen species, its capability to photosensitize both type I (electron transfer) and type II (energy transfer) pathways is activated through a self-amplifying process. Upon irradiation, IrFc1 induces the generation of lipid oxidation to cause ferroptosis in TNBC cells, which promotes immunogenic cell death (ICD) under both normoxia and hypoxia. In vivo, IrFc1 treatment elicits a CD8+ T-cell response, which activates ICD in TNBC resulting in enhanced anticancer immunity. In summary, this work reports a small molecule-based photosensitizer with enhanced cancer immunotherapeutic properties by eliciting ferroptosis through a self-amplifying process.

Ru(II)-modified TiO2 nanoparticles for hypoxia-adaptive photo-immunotherapy of oral squamous cell carcinoma.

The alternations in the hypoxic and immune microenvironment are closely related to the therapeutic effect and prognosis of oral squamous cell carcinoma (OSCC). Herein, a new nanocomposite, TiO2@Ru@siRNA is constructed from a ruthenium-based photosensitizer (Ru) modified-TiO2 nanoparticles (NPs) loaded with siRNA of hypoxia-inducible factor-1α (HIF-1α). Under visible light irradiation, TiO2@Ru@siRNA can elicit both Type I and Type II photodynamic effects, which causes lysosomal damage, HIF-1α gene silencing, and OSCC cell elimination efficiently. As a consequence of hypoxia relief and pyroptosis induction, TiO2@Ru@siRNA reshapes the immune microenvironment by downregulation of key immunosuppressive factors, upregulation of immune cytokines, and activation of CD4+ and CD8+ T lymphocytes. Furthermore, patient-derived xenograft (PDX) and rat oral experimental carcinogenesis models prove that TiO2@Ru@siRNA-mediated photodynamic therapy significantly inhibits the tumor growth and progression, and markedly enhances cancer immunity. In all, this study presents an effective hypoxia-adaptive photo-immunotherapeutic nanosystem with great potential for OSCC prevention and treatment.

Simultaneous Photoactivation of cGAS-STING Pathway and Pyroptosis by Platinum(II) Triphenylamine Complexes for Cancer Immunotherapy.

Activation of the cyclic GMP-AMP synthase-stimulator of the interferon gene (cGAS-STING) pathway is a potent anticancer immunotherapeutic strategy, and the induction of pyroptosis is a feasible way to stimulate the anticancer immune responses. Herein, two PtII complexes (Pt1 and Pt2) were designed as photoactivators of the cGAS-STING pathway. In response to light irradiation, Pt1 and Pt2 could damage mitochondrial/nuclear DNA and the nuclear envelope to activate the cGAS-STING pathway, and concurrently induce pyroptosis in cancer cells, which evoked an intense anticancer immune response in vitro and in vivo. Overall, we present the first photoactivator of the cGAS-STING pathway, which may provide an innovative design strategy for anticancer immunotherapy.

Real-time tracking of ER turnover during ERLAD by a rhenium complex via lifetime imaging.

Endoplasmic reticulum (ER) degradation by autophagy (ER-phagy) is a recently revealed selective autophagy pathway that plays important roles in organelle turnover and protein degradation, but the biological functions of ER-phagy are largely unknown. Here, we present an ER-targeting Re(I) tricarbonyl complex (Re-ERLAD) that can accumulate in the ER, induce ER-to-lysosome-associated degradation (ERLAD) upon visible light irradiation, and label ER buds and track their morphological alterations during ER-phagy. The emission of Re-ERLAD is sensitive to viscosity, which is a key parameter reflecting the amount of unfolded protein in the ER. Quantitative detection using two-photon fluorescence lifetime imaging microscopy shows that ER viscosity initially increases and then decreases during ERLAD, which reveals that ERLAD is a pathway for alleviating ER stress caused by unfolded proteins. In conclusion, our work presents the first specific photoinducer and tracker of ERLAD, which can be used in studying the regulatory mechanism and function of this process.

Photodegradation of carbonic anhydrase IX via a binding-enhanced ruthenium-based photosensitizer.

Carbonic anhydrase IX (CAIX) is overexpressed in many cancer types. Herein, a CAIX targeting and binding-enhanced ruthenium-based photodegrader, Ru-dppz-CAi, is constructed by conjugating the photosensitizer with the inhibiting group via a rotatable moiety. The binding of Ru-dppz-CAi and CAIX leads to significant enhancement in the emission and photosensitizing properties. Ru-dppz-CAi can photodegrade CAIX both in vitro and in living cells, which significantly inhibits its catalytic activity. The protein photodegradation method may provide new strategies for the development of tools for protein functional studies.

Validation of a Multi-Sensor-Based Kiosk in the Use of the Short Physical Performance Battery in Older Adults Attending a Fall and Balance Clinic.

BACKGROUND: The Short Physical Performance Battery (SPPB) is a well-established functional assessment tool used for the screening and assessment of frailty and sarcopenia. However, the SPPB requires trained staff experienced in conducting the standardized protocol, which may limit its widespread use in clinical settings. The automated SPPB (eSPPB) was developed to address this potential barrier; however, its validity among frail older adults remains to be established. Therefore, this exploratory study compared the eSPPB and manual SPPB in patients attending a tertiary fall clinic in relation to their construct validity, reliability, and agreement. METHODS: We studied 37 community-dwelling older adults (mean age, 78.5±6.8 years; mean FRAIL score, 1.2±1.0; 65% pre-frail) attending a tertiary falls clinic. The participants used the mSPPB and eSPPB simultaneously. We evaluated the convergent validity, discriminatory ability, reliability, and agreement using partial correlation adjusted for age and sex, an SPPB cutoff of ≤8 to denote sarcopenia, intraclass correlation coefficients (ICC), and Bland-Altman plots, respectively. RESULTS: The eSPPB showed strong correlations with the mSPPB (r=0.933, p<0.01) and Berg Balance Scale (r=0.869, p<0.01), good discriminatory ability for frailty and balance, and good to excellent reliability (ICC=0.94; 95% confidence interval, 0.88-0.97). The Bland-Altman plots indicated good agreement with the mSPPB (mean difference, -0.2; 95% confidence interval, -3.2-2.9) without evidence of systematic or proportional biases. CONCLUSION: The results of our exploratory study corroborated the construct validity, reliability, and agreement of the eSPPB with the mSPPB in a small sample of predominantly pre-frail older adults with increased fall risk. Future studies should examine the scalability and feasibility of the widespread use of the eSPPB for frailty and sarcopenia assessment.

Rising Interest in the Development of Metal Complexes in Cancer Immunotherapy.

Metal complexes have shown great potential in cancer immunotherapy. This review briefly introduces the basic concepts and strategies of cancer immunotherapy and summarizes the recent discoveries on the immune effects of traditional platinum-based anticancer compounds. In addition, we also outline the latest research progresses on metal complexes for cancer immunotherapy focusing on platinum, ruthenium, iridium, rhenium and copper complexes. Finally, the research perspectives and unsolved problems on the applications of metallo-anticancer agents in cancer immunotherapy are purposed.

A Nuclear-Targeted AIE Photosensitizer for Enzyme Inhibition and Photosensitization in Cancer Cell Ablation.

The nucleus is considered the ideal target for anti-tumor therapy because DNA and some enzymes in the nucleus are the main causes of cell canceration and malignant proliferation. However, nuclear target drugs with good biosafety and high efficiency in cancer treatment are rare. Herein, a nuclear-targeted material MeTPAE with aggregation-induced emission (AIE) characteristics was developed based on a triphenylamine structure skeleton. MeTPAE can not only interact with histone deacetylases (HDACs) to inhibit cell proliferation but also damage telomere and nucleic acids precisely through photodynamic treatment (PDT). The cocktail strategy of MeTPAE caused obvious cell cycle arrest and showed excellent PDT anti-tumor activity, which offered new opportunities for the effective treatment of malignant tumors.

Bypassing Different Parts of the Small Intestine Determines Different Metabolic Effects in Streptozotocin-Induced Diabetic Rats.

PURPOSE: Side-to-side jejunoileal bypass with proximal loop ligation (SSJIBL) has significant glucose-lowering and weight-control effects; however, no study has elucidated which segment is most effective in SSJIBL. This study investigated the effect of proximal small intestinal bypass (PSIB), middle small intestinal bypass (MSIB), and distal small intestinal bypass (DSIB) on metabolic improvement in streptozotocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: STZ-induced diabetic rats were divided into four groups: PSIB, MSIB, DSIB, and sham-operated. The primary outcome measures were body weight, food intake, fasting blood glucose (FBG) levels, oral glucose tolerance (OGTT), insulin tolerance (ITT), serum insulin, gut hormones, serum lipid profile, and liver function levels. RESULTS: Global body weight in the DSIB group was lower than that in the PSIB group. The global food intake in the PSIB group was lower than that in the MSIB group. The PSIB group had a slightly better glucose-lowering effect than the MSIB and DSIB groups. The PSIB, MSIB, and DSIB groups all had improvement in insulin sensitivity at postoperative week 6. The MSIB group exhibited the best improvement in lipid homeostasis. Serum insulin and leptin levels were higher, and serum ghrelin levels were lower in the operated groups than in the sham group. CONCLUSIONS: This study provides experimental evidence that PSIB surgery induces a better glucose-lowering effect than DSIB surgery, and MSIB induced the best improvement in lipid homeostasis, whereas DSIB was even more advantageous in terms of weight control in the STZ-induced diabetic rat model.

Ferroptosis-Enhanced Cancer Immunity by a Ferrocene-Appended Iridium(III) Diphosphine Complex.

Ferroptosis is a programmed cell death pathway discovered in recent years, and ferroptosis-inducing agents have great potential as new antitumor candidates. Here, we report a IrIII complex (Ir1) containing a ferrocene-modified diphosphine ligand that localizes in lysosomes. Under the acidic environments of lysosomes, Ir1 can effectively catalyze Fenton-like reaction, produce hydroxyl radicals, induce lipid peroxidation, down-regulate glutathione peroxidase 4, and result in ferroptosis. RNA sequencing analysis shows that Ir1 can significantly affect pathways related to ferroptosis and cancer immunity. Accordingly, Ir1 can induce immunogenic cells death and suppress tumor growth in vitro, regulate T cell activity and immune microenvironments in vivo. In conclusion, we show the potential of small molecules with ferroptosis-inducing capabilities for effective cancer immunotherapy.

Combined Impact of Positive Screen for Sarcopenia and Frailty on Physical Function, Cognition and Nutrition in the Community Dwelling Older Adult.

BACKGROUND: While sarcopenia and frailty independently contribute to functional impairment and disability, the combined impact resulting from their interplay is unclear. We investigated if functional, physical, cognitive, and nutritional measures were more adversely affected in community-dwelling older adults who were screened positive for both frailty and sarcopenia. METHODS: Using the FRAIL (≥1) and SARC-F (Strength, Assistance with walking, Rising from a chair, Climbing stairs, and Falls) (≥1) scales for screening, we categorized 200 participants (age, 67.9±7.9 years) as combined (both positive, 12.5%), intermediate (either positive, 25.5%), or robust (both negative, 62%). RESULTS: Comparisons of the three groups showed that the combined group had significantly worse functional ability (Frenchay Activities Index and Modified Barthel Index), physical performance (knee extension, gait speed, and Short Physical Performance Battery score), cognition/mood (Chinese Mini-Mental State Examination [CMMSE] score and Geriatric Depression Scale), and nutrition (Mini Nutritional Assessment [MNA] score) (p<0.05, one-way analysis of variance). Post-hoc comparisons revealed similar findings between the combined and robust groups, except for knee extension and CMMSE scores. Only MNA scores were significantly lower between the intermediate and robust groups. CONCLUSION: Functional ability, physical performance, and nutrition were more adversely affected in our study population of community-dwelling older adults who screened positive for both frailty and sarcopenia than in those who screened positive for either or neither, supporting the use of community screening for early detection and intervention for both frailty and sarcopenia as opposed to either alone.

Inhibition of Aß peptide aggregation by ruthenium(II) polypyridyl complexes through copper chelation.

Alzheimer's disease (AD) is known as a complex multifactorial syndrome and both metal chelators and amyloid ß peptide (Aß) inhibitors show promise against AD. Herein, four small hybrid compounds have been designed and synthesized utilizing 8-hydroxyquinoline, pyridine or imidazole as chelators and benzimidazole as the recognition moiety for AD treatment. These conjugates can capture Cu2+ from Aß and become dimers upon Cu2+ coordination and show high efficiency for both Cu2+ elimination and Aß assembly inhibition. Besides, these designed complexes can inhibit the production of Aß-induced reactive oxygen species (ROS), protect mitochondria from damage, and improve the survival rate of neuron cells. Our work provides a new strategy to combine hydrophobic interaction and metal ion chelation to design amyloid inhibitors.

Induction and Monitoring of DNA Phase Separation in Living Cells by a Light-Switching Ruthenium Complex.

Phase separation of DNA is involved in chromatin packing for the regulation of gene transcription. Visualization and manipulation of DNA phase separation in living cells present great challenges. Herein, we present a Ru(II) complex (Ru1) with high DNA binding affinity and DNA "light-switch" behavior that can induce and monitor DNA phase separation both in vitro and in living cells. Molecular dynamics simulations indicate that the two phen-PPh3 ligands with positively charged lipophilic triphenylphosphine substituents and flexible long alkyl chains in Ru1 play essential roles in the formation of multivalent binding forces between DNA molecules to induce DNA phase separation. Importantly, the unique environmental sensitive emission property of Ru1 enables direct visualization of the dynamic process of DNA phase separation in living cells by two-photon phosphorescent lifetime imaging. Moreover, Ru1 can change the gene expression pattern by modulating chromatin accessibility as demonstrated by integrating RNA-sequencing and transposase-accessible chromatin with high-throughput sequencing. In all, we present here the first small-molecule-based tracer and modulator of DNA phase separation in living cells and elucidate its impact on the chromatin state and transcriptome.