Metformin inhibits age-related centrosome amplification in Drosophila midgut stem cells through AKT/TOR pathway

Age- and oxidative stress-induced centrosome amplification and renal stones in Drosophila Malpighian tubules

Renal diseases, including cancer, are rapidly increasing worldwide, driven by rising temperatures and changing diets, especially among younger people. Renal stones, a major risk for chronic renal disease, are increasingly common due to various health issues. Research on the underlying mechanisms, drug discovery, and the effects of aging and stress is limited. We used Drosophila, due to its similarity to the human renal system and ease of use, to identify cancer hallmarks and renal stone formation related to aging and oxidative stress. Our results indicate that centrosome amplification and stone formation increase with age and oxidative stress, and high sucrose feeding also heightens stone formation in the renal system. Our results show a close relationship between these diseases and aging, reactive oxygen species (ROS) stress, and chronic diseases. We suggest that the Drosophila renal model could be a powerful tool to study the relationship between age and age-related diseases and to discovering new agents for nephropathy.

Advancing Longevity: Exploring Antiaging Pharmaceuticals in Contemporary Clinical Trials Amid Aging Dynamics

Aging is an inevitable biological process that significantly impacts human health, leading to a decline in cellular function and an increase in cellular damage. This study elucidates the burgeoning potential of antiaging pharmaceuticals in mitigating the thriving burden of chronic conditions linked to advancing age. It underscores the pivotal role of these pharmacotherapeutic agents in fostering longevity free from debilitating age-related afflictions, notably cardiovascular disorders, neoplastic processes, and neurodegenerative pathologies. While commendable strides have been made evident in preclinical models, it is crucial to thoroughly investigate their effectiveness and safety in human groups. In addition, ethical concerns about fair access, societal impacts, and careful resource distribution are significant in discussions about developing and using antiaging medications. By approaching the development and utilization of antiaging medications with diligence and foresight, we can strive toward a future where individuals can enjoy extended lifespans free from the debilitating effects of age-related ailments.

The anti-aging effect of vitamin D and vitamin D receptor in Drosophila midgut

Adult stem cells are pivotal for maintaining tissue homeostasis, and their functional decline is linked to aging and its associated diseases, influenced by the niche cells' environment. Age- and cancer-related reduction of vitamin D and its receptor levels are well documented in human clinical studies. However, the mechanisms through which the vitamin D/vitamin D receptor pathway contributes to anti-aging and extends life expectancy are not well understood. In this study, we aimed to determine the protective role of the vitamin D/vitamin D receptor pathway in differentiated enterocytes (ECs) during intestinal stem cell (ISC) aging. By utilizing a well- established Drosophila midgut model for stem cell aging biology, we revealed that vitamin D receptor knockdown in ECs induced ISC proliferation, EC death, ISC aging, and enteroendocrine cell differentiation. Additionally, age- and oxidative stress-induced increases in ISC proliferation and centrosome amplification were reduced by vitamin D treatment. Our findings suggest a direct evidence of the anti-aging role of the vitamin D/vitamin D receptor pathway and provides insights into the molecular mechanisms underlying healthy aging in Drosophila.

The development and benefits of metformin in various diseases

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.

Metformin promotes female germline stem cell proliferation by upregulating Gata-binding protein 2 with histone β-hydroxybutyrylation

BACKGROUND

Metformin as a first-line clinical anti-diabetic agent prolongs the lifespan of model animals and promotes cell proliferation. However, the molecular mechanisms underlying the proliferative phenotype, especially in epigenetics, have rarely been reported. The aim of this study was to investigate the physiological effects of metformin on female germline stem cells (FGSCs) in vivo and in vitro, uncover β-hydroxybutyrylation epigenetic modification roles of metformin and identify the mechanism of histone H2B Lys5 β-hydroxybutyrylation (H2BK5bhb) in Gata-binding protein 2 (Gata2)-mediated proliferation promotion of FGSCs.

METHODS

The physiological effects of metformin were evaluated by intraperitoneal injection and histomorphology. The phenotype and mechanism studies were explored by cell counting, cell viability, cell proliferation assay and protein modification omics, transcriptomics, chromatin immunoprecipitation sequencing in FGSCs in vitro.

RESULTS

We found that metformin treatment increased the number of FGSCs, promoted follicular development in mouse ovaries and enhanced the proliferative activity of FGSCs in vitro. Quantitative omics analysis of protein modifications revealed that H2BK5bhb was increased after metformin treatment of FGSCs. In combination with H2BK5bhb chromatin immunoprecipitation and transcriptome sequencing, we found that Gata2 might be a target gene for metformin to regulate FGSC development. Subsequent experiments showed that Gata2 promoted FGSC proliferation.

CONCLUSION

Our results provide novel mechanistic understanding of metformin in FGSCs by combining histone epigenetics and phenotypic analyses, which highlight the role of the metformin-H2BK5bhb-Gata2 pathway in cell fate determination and regulation.

A familial natural short sleep mutation promotes healthy aging and extends lifespan in Drosophila

Sleep loss typically imposes negative effects on animal health. However, humans with a rare genetic mutation in the dec2 gene ( dec2 P384R ) present an exception; these individuals sleep less without the usual effects associated with sleep deprivation. Thus, it has been suggested that the dec2 P384R mutation activates compensatory mechanisms that allows these individuals to thrive with less sleep. To test this directly, we used a Drosophila model to study the effects of the dec2 P384R mutation on animal health. Expression of human dec2 P384R in fly sleep neurons was sufficient to mimic the short sleep phenotype and, remarkably, dec2 P384R mutants lived significantly longer with improved health despite sleeping less. The improved physiological effects were enabled, in part, by enhanced mitochondrial fitness and upregulation of multiple stress response pathways. Moreover, we provide evidence that upregulation of pro-health pathways also contributes to the short sleep phenotype, and this phenomenon may extend to other pro-longevity models.

Cellular rejuvenation: molecular mechanisms and potential therapeutic interventions for diseases

The ageing process is a systemic decline from cellular dysfunction to organ degeneration, with more predisposition to deteriorated disorders. Rejuvenation refers to giving aged cells or organisms more youthful characteristics through various techniques, such as cellular reprogramming and epigenetic regulation. The great leaps in cellular rejuvenation prove that ageing is not a one-way street, and many rejuvenative interventions have emerged to delay and even reverse the ageing process. Defining the mechanism by which roadblocks and signaling inputs influence complex ageing programs is essential for understanding and developing rejuvenative strategies. Here, we discuss the intrinsic and extrinsic factors that counteract cell rejuvenation, and the targeted cells and core mechanisms involved in this process. Then, we critically summarize the latest advances in state-of-art strategies of cellular rejuvenation. Various rejuvenation methods also provide insights for treating specific ageing-related diseases, including cellular reprogramming, the removal of senescence cells (SCs) and suppression of senescence-associated secretory phenotype (SASP), metabolic manipulation, stem cells-associated therapy, dietary restriction, immune rejuvenation and heterochronic transplantation, etc. The potential applications of rejuvenation therapy also extend to cancer treatment. Finally, we analyze in detail the therapeutic opportunities and challenges of rejuvenation technology. Deciphering rejuvenation interventions will provide further insights into anti-ageing and ageing-related disease treatment in clinical settings.

Chronic exposure to zearalenone induces intestinal inflammation and oxidative injury in adult Drosophila melanogaster midgut

In the past decade, mycotoxin zearalenone (ZEN)-induced gastrointestinal adverse effects have been increasingly attracting worldwide attention. This study aimed to determine the gastrointestinal adverse effects of ZEN in Drosophila melanogaster (D. melanogaster) and reveal possible mechanisms of action of ZEN in insects. Here, chronic exposure of D. melanogaster to ZEN killed flies in a dose-dependent manner (2-20 µM). ZEN (20 µM) decreased the survival rates and climbing ability of flies, and activated immune deficiency-mediated intestinal immunity in midgut, leading to the production of antimicrobial peptides. Meanwhile, ZEN exposure induced morphological alteration of adult midgut. Further study suggested that high levels of oxidative stress was observed in ZEN-treated midgut due to the imbalance between the production of reactive oxygen species and the expression and activities of cellular antioxidant enzyme, including superoxide dismutase and catalase. ZEN-induced oxidative stress then caused cell death, impaired gut barrier function and increased gut permeability, leading to oxidative injury in midgut. Subsequently, ZEN-induce midgut injury further disrupted intestinal stem cell (ISC) homeostasis, stimulating ISC proliferation and tissue regeneration, but did not alter cell fate specification of ISC. Additionally, activation of Jun N-terminal kinase pathway was involved in ZEN-induced oxidative injury and tissue regeneration in midgut. Antioxidant vitamin E alleviated ZEN-induced oxidative injury to midgut epithelium. Collectively, this study provided additional evidences for ZEN-induced gastrointestinal adverse effects from an invertebrate model, extended our understanding of the mechanisms mediating mycotoxin toxicity in organisms.

Gender-specific effects of pro-longevity interventions in Drosophila

Sex differences in lifespan are well recognized in the majority of animal species. For example, in male versus female Drosophila melanogaster there are significant differences in behavior and physiology. However, little is known about the underlying mechanisms of gender differences in responses to pro-longevity interventions in this model organism. Here we summarize the existing data on the effects of nutritional and pharmacological anti-aging interventions such as nutrition regimens, diet and dietary supplementation on the lifespan of male and female Drosophila. We demonstrate that males and females have different sensitivities to interventions and that the effects are highly dependent on genetic background, mating, dose and exposure duration. Our work highlights the importance of understanding the mechanisms that underlie the gender-specific effect of anti-aging manipulations. This will provide insight into how these benefits may be valuable for elucidating the primary physiological and molecular targets involved in aging and lifespan determination.

Metformin Repurposing for Parkinson Disease Therapy: Opportunities and Challenges

Parkinson disease (PD) is a severe neurodegenerative disorder that affects around 2% of the population over 65 years old. It is characterized by the progressive loss of nigrostriatal dopaminergic neurons, resulting in motor disabilities of the patients. At present, only symptomatic cures are available, without suppressing disease progression. In this frame, the anti-diabetic drug metformin has been investigated as a potential disease modifier for PD, being a low-cost and generally well-tolerated medication, which has been successfully used for decades in the treatment of type 2 diabetes mellitus. Despite the precise mechanisms of action of metformin being not fully elucidated, the drug has been known to influence many cellular pathways that are associated with PD pathology. In this review, we present the evidence in the literature supporting the neuroprotective role of metformin, i.e., autophagy upregulation, degradation of pathological α-synuclein species, and regulation of mitochondrial functions. The epidemiological studies conducted in diabetic patients under metformin therapy aimed at evaluating the correlation between long-term metformin consumption and the risk of developing PD are also discussed. Finally, we provide an interpretation for the controversial results obtained both in experimental models and in clinical studies, thus providing a possible rationale for future investigations for the repositioning of metformin for PD therapy.

The Aged Intestine: Performance and Rejuvenation

Owing to the growing elderly population, age-related problems are gaining increasing attention from the scientific community. With senescence, the intestine undergoes a spectrum of changes and infirmities that are likely the causes of overall aging. Therefore, identification of the aged intestine and the search for novel strategies to rescue it, are required. Although progress has been made in research on some components of the aged intestine, such as intestinal stem cells, the comprehensive understanding of intestinal aging is still limited, and this restricts the in-depth search for efficient strategies. In this concise review, we discuss several aspects of intestinal aging. More emphasis is placed on the appraisal of current and potential strategies to alleviate intestinal aging, as well as future targets to rejuvenate the aged intestine.

Multiscale analysis reveals that diet-dependent midgut plasticity emerges from alterations in both stem cell niche coupling and enterocyte size

The gut is the primary interface between an animal and food, but how it adapts to qualitative dietary variation is poorly defined. We find that the Drosophila midgut plastically resizes following changes in dietary composition. A panel of nutrients collectively promote gut growth, which sugar opposes. Diet influences absolute and relative levels of enterocyte loss and stem cell proliferation, which together determine cell numbers. Diet also influences enterocyte size. A high sugar diet inhibits translation and uncouples intestinal stem cell proliferation from expression of niche-derived signals, but, surprisingly, rescuing these effects genetically was not sufficient to modify diet’s impact on midgut size. However, when stem cell proliferation was deficient, diet’s impact on enterocyte size was enhanced, and reducing enterocyte-autonomous TOR signaling was sufficient to attenuate diet-dependent midgut resizing. These data clarify the complex relationships between nutrition, epithelial dynamics, and cell size, and reveal a new mode of plastic, diet-dependent organ resizing.

Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure

The heart has a reduced capacity to generate sufficient energy when failing, resulting in an energy-starved condition with diminished functions. Studies have identified numerous changes in metabolic pathways in the failing heart that result in reduced oxidation of both glucose and fatty acid substrates, defects in mitochondrial functions and oxidative phosphorylation, and inefficient substrate utilization for the ATP that is produced. Recent early-phase clinical studies indicate that inhibitors of fatty acid oxidation and antioxidants that target the mitochondria may improve heart function during failure by increasing compensatory glucose oxidation. Adrenergic receptors (α1 and β) are a key sympathetic nervous system regulator that controls cardiac function. β-AR blockers are an established treatment for heart failure and α1A-AR agonists have potential therapeutic benefit. Besides regulating inotropy and chronotropy, α1- and β-adrenergic receptors also regulate metabolic functions in the heart that underlie many cardiac benefits. This review will highlight recent studies that describe how adrenergic receptor-mediated metabolic pathways may be able to restore cardiac energetics to non-failing levels that may offer promising therapeutic strategies.

Anti-Aging Effect of Metformin: A Molecular and Therapeutical Perspective

Aging is a time-dependent inevitable process, in which cellular homeostasis is affected, which has an impact on tissue function. This represents a risk factor for the development of numerous non-transmissible diseases. In consequence, the scientific community continues to search for therapeutic measures capable of improving quality of life and delaying cellular aging. At the center of this research is metformin, a widely used drug in Type 2 Diabetes Mellitus treatment that has a reduced adverse effects profile. Furthermore, there is evidence that this drug has beneficial health effects that go beyond its anti-hyperglycemic properties. Among these effects, its geronto-protection capability stands out. There is growing evidence that points out to an increased life expectancy as well as the quality of life in model organisms treated with metformin. Therefore, there is an abundance of research centered on elucidating the mechanism through which metformin has its anti-aging effects. Among these, the AMPK, mTORC1, SIRT1, FOXO, NF.kB, and DICER1 pathways can be mentioned. Furthermore, studies have highlighted the possibility of a role for the gut microbiome in these processes. The next step is the design of clinical essays that have as a goal evaluating the efficacy and safety of metformin as an anti-aging drug in humans to create a paradigm in the medical horizon. The question being if metformin is, in fact, the new antiaging therapy in humans?

Melatonin: Multi-Target Mechanism Against Diminished Ovarian Reserve Based on Network Pharmacology

BACKGROUND

Diminished ovarian reserve (DOR) significantly increases the risk of female infertility and contributes to reproductive technology failure. Recently, the role of melatonin in improving ovarian reserve (OR) has attracted widespread attention. However, details on the pharmacological targets and mechanisms of melatonin-improved OR remain unclear.

OBJECTIVE

A systems pharmacology strategy was proposed to elucidate the potential therapeutic mechanism of melatonin on DOR at the molecular, pathway, and network levels.

METHODS

The systems pharmacological approach consisted of target identification, data integration, network construction, bioinformatics analysis, and molecular docking.

RESULTS

From the molecular perspective, 26 potential therapeutic targets were identified. They participate in biological processes related to DOR development, such as reproductive structure development, epithelial cell proliferation, extrinsic apoptotic signaling pathway, PI3K signaling, among others. Eight hub targets (MAPK1, AKT1, EGFR, HRAS, SRC, ESR1, AR, and ALB) were identified. From the pathway level, 17 significant pathways, including the PI3K-Akt signaling pathway and the estrogen signaling pathway, were identified. In addition, the 17 signaling pathways interacted with the 26 potential therapeutic targets to form 4 functional modules. From the network point of view, by regulating five target subnetworks (aging, cell growth and death, development and regeneration, endocrine and immune systems), melatonin could exhibit anti-aging, anti-apoptosis, endocrine, and immune system regulation effects. The molecular docking results showed that melatonin bound well to all hub targets.

CONCLUSION

This study systematically and intuitively illustrated the possible pharmacological mechanisms of OR improvement by melatonin through anti-aging, anti-apoptosis, endocrine, and immune system regulation effects.

Effect of metformin on stem cells: Molecular mechanism and clinical prospect

Metformin is a first-line medication for type II diabetes. Numerous studies have shown that metformin not only has hypoglycemic effects, but also modulates many physiological and pathological processes ranging from aging and cancer to fracture healing. During these different physiological activities and pathological changes, stem cells usually play a core role. Thus, many studies have investigated the effects of metformin on stem cells. Metformin affects cell differentiation and has promising applications in stem cell medicine. It exerts anti-aging effects and can be applied to gerontology and regenerative medicine. The potential anti-cancer stem cell effect of metformin indicates that it can be an adjuvant therapy for cancers. Furthermore, metformin has beneficial effects against many other diseases including cardiovascular and autoimmune diseases. In this review, we summarize the effects of metformin on stem cells and provide an overview of its molecular mechanisms and clinical prospects.

Centrosomes in asymmetric cell division

Asymmetric cell division (ACD) is a strategy for achieving cell diversity. Research carried out over the last two decades has shown that in some cell types that divide asymmetrically, mother and daughter centrosomes are noticeably different from one another in structure, behaviour, and fate, and that robust ACD depends upon centrosome function. Here, I review the latest advances in this field with special emphasis on the complex structure-function relationship of centrosomes with regards to ACD and on mechanistic insight derived from cell types that divide symmetrically but is likely to be relevant in ACD. I also include a comment arguing for the need to investigate the centrosome cycle in other cell types that divide asymmetrically.

Restoring aged stem cell functionality: Current progress and future directions

Stem cell dysfunction is a hallmark of aging, associated with the decline of physical and cognitive abilities of humans and other mammals [Cell 2013;153:1194]. Therefore, it has become an active area of research within the aging and stem cell fields, and various techniques have been employed to mitigate the decline of stem cell function both in vitro and in vivo. While some techniques developed in model organisms are not directly translatable to humans, others show promise in becoming clinically relevant to delay or even mitigate negative phenotypes associated with aging. This review focuses on diet, treatment, and small molecule interventions that provide evidence of functional improvement in at least one type of aged adult stem cell.

Benefits of Metformin in Attenuating the Hallmarks of Aging

Biological aging involves an interplay of conserved and targetable molecular mechanisms, summarized as the hallmarks of aging. Metformin, a biguanide that combats age-related disorders and improves health span, is the first drug to be tested for its age-targeting effects in the large clinical trial-TAME (targeting aging by metformin). This review focuses on metformin's mechanisms in attenuating hallmarks of aging and their interconnectivity, by improving nutrient sensing, enhancing autophagy and intercellular communication, protecting against macromolecular damage, delaying stem cell aging, modulating mitochondrial function, regulating transcription, and lowering telomere attrition and senescence. These characteristics make metformin an attractive gerotherapeutic to translate to human trials.

Anti-Aging Effect of the Ketone Metabolite β-Hydroxybutyrate in Drosophila Intestinal Stem Cells

Age-related changes in tissue-resident adult stem cells may be closely linked to tissue aging and age-related diseases, such as cancer. β-Hydroxybutyrate is emerging as an important molecule for exhibiting the anti-aging effects of caloric restriction and fasting, which are generally considered to be beneficial for stem cell maintenance and tissue regeneration. The effects of β-hydroxybutyrate on adult stem cells remain largely unknown. Therefore, this study was undertaken to investigate whether β-hydroxybutyrate supplementation exerts beneficial effects on age-related changes in intestinal stem cells that were derived from the Drosophila midgut. Our results indicate that β-hydroxybutyrate inhibits age- and oxidative stress-induced changes in midgut intestinal stem cells, including centrosome amplification (a hallmark of cancers), hyperproliferation, and DNA damage accumulation. Additionally, β-hydroxybutyrate inhibits age- and oxidative stress-induced heterochromatin instability in enterocytes, an intestinal stem cells niche cells. Our results suggest that β-hydroxybutyrate exerts both intrinsic as well as extrinsic influence in order to maintain stem cell homeostasis.

TOR as a Regulatory Target in Rhipicephalus microplus Embryogenesis

Embryogenesis is a metabolically intensive process carried out under tightly controlled conditions. The insulin signaling pathway regulates glucose homeostasis and is essential for reproduction in metazoan model species. Three key targets are part of this signaling pathway: protein kinase B (PKB, or AKT), glycogen synthase kinase 3 (GSK-3), and target of rapamycin (TOR). While the role of AKT and GSK-3 has been investigated during tick embryonic development, the role of TOR remains unknown. In this study, TOR and two other downstream effectors, namely S6 kinase (S6K) and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), were investigated in in vitro studies using the tick embryonic cell line BME26. First, we show that exogenous insulin can stimulate TOR transcription. Second, TOR chemical inhibition led to a decrease in BME26 cell viability, loss of membrane integrity, and downregulation of S6K and 4E-BP1 transcription. Conversely, treating BME26 cells with chemical inhibitors of AKT or GSK-3 did not affect S6K and 4E-BP1 transcription, showing that TOR is specifically required to activate its downstream targets. To address the role of TOR in tick reproduction, in vivo studies were performed. Analysis of relative transcription during different stages of tick embryonic development showed different levels of transcription for TOR, and a maternal deposition of S6K and 4E-BP1 transcripts. Injection of TOR double-stranded RNA (dsRNA) into partially fed females led to a slight delay in oviposition, an atypical egg external morphology, decreased vitellin content in eggs, and decreased larval hatching. Taken together, our data show that the TOR signaling pathway is important for tick reproduction, that TOR acts as a regulatory target in Rhipicephalus microplus embryogenesis and represents a promising target for the development of compounds for tick control.

Age-related AMP-activated protein kinase alterations: From cellular energetics to longevity

5' adenosine monophosphate-activated protein kinase (AMPK) is a key regulator of energy in the cell, which allows the cell/organism to survive with deficit of ATP. Since AMPK is involved in the adaptation to caloric restriction, the role of age-related changes in AMPK activity in both the aging organism and the aging cell is actively investigated in gerontology. Studies on yeast, worms, flies, rodents, and primates have demonstrated an important effect of this regulator on key signalling pathways involved in the aging process. In some cases, researchers conclude that AMPK promotes aging. However, in our opinion, in such cases, we observe a disturbance in the adaptive ability because of the prolonged cell/organism presence in stressful conditions because the functional capacity of any adaptation system is limited. Interestingly, AMPK can regulate metabolic processes in noncell-autonomous manner. The main effects of AMPK activation in the cell are realized in restriction of proliferation and launching autophagy. In tissues of an aging organism, the ability of AMPK to respond to energy deficit decreases; this fact is especially critical for organs that contain postmitotic cells. In this review, we have tried to consider the involvement of AMPK in age-related changes in the cell and in the organism.

Pan-cancer association of a centrosome amplification gene expression signature with genomic alterations and clinical outcome

Centrosome amplification (CA) is a common feature of human tumours and a promising target for cancer therapy. However, CA's pan-cancer prevalence, molecular role in tumourigenesis and therapeutic value in the clinical setting are still largely unexplored. Here, we used a transcriptomic signature (CA20) to characterise the landscape of CA-associated gene expression in 9,721 tumours from The Cancer Genome Atlas (TCGA). CA20 is upregulated in cancer and associated with distinct clinical and molecular features of breast cancer, consistently with our experimental CA quantification in patient samples. Moreover, we show that CA20 upregulation is positively associated with genomic instability, alteration of specific chromosomal arms and C>T mutations, and we propose novel molecular players associated with CA in cancer. Finally, high CA20 is associated with poor prognosis and, by integrating drug sensitivity with drug perturbation profiles in cell lines, we identify candidate compounds for selectively targeting cancer cells exhibiting transcriptomic evidence for CA.

Inhalational supplementation of metformin butyrate: A strategy for prevention and cure of various pulmonary disorders

The management of chronic lung diseases such as cancer, asthma, COPD and pulmonary hypertension remains unsatisfactory till date, and several strategies are being tried to control the same. Metformin, a popular anti-diabetic drug has shown promising effects in pre-clinical studies and has been subject to several trials in patients with debilitating pulmonary diseases. However, the clinical evidence for the use of metformin in these conditions is disappointing. Recent observations suggest that metformin use in diabetic patients is associated with an increase in butyrate-producing bacteria in the gut microbiome. Butyrate, similar to metformin, shows beneficial effects in pathological conditions found in pulmonary diseases. Further, the pharmacokinetic data of metformin suggests that metformin is predominantly concentrated in the gut, even after absorption. Butyrate, on the other hand, has a short half-life and thus oral supplementation of butyrate and metformin is unlikely to result in high concentrations of these drugs in the lung. In this paper, we review the pre-clinical studies of metformin and butyrate pertaining to pathologies commonly encountered in chronic lung diseases and underscore the need to administer these drugs directly to the lung via the inhalational route.

Deficiency in DNA damage response of enterocytes accelerates intestinal stem cell aging in Drosophila

Stem cell dysfunction is closely linked to tissue and organismal aging and age-related diseases, and heavily influenced by the niche cells' environment. The DNA damage response (DDR) is a key pathway for tissue degeneration and organismal aging; however, the precise protective role of DDR in stem cell/niche aging is unclear. The Drosophila midgut is an excellent model to study the biology of stem cell/niche aging because of its easy genetic manipulation and its short lifespan. Here, we showed that deficiency of DDR in Drosophila enterocytes (ECs) accelerates intestinal stem cell (ISC) aging. We generated flies with knockdown of Mre11, Rad50, Nbs1, ATM, ATR, Chk1, and Chk2, which decrease the DDR system in ECs. EC-specific DDR depletion induced EC death, accelerated the aging of ISCs, as evidenced by ISC hyperproliferation, DNA damage accumulation, and increased centrosome amplification, and affected the adult fly's survival. Our data indicated a distinct effect of DDR depletion in stem or niche cells on tissue-resident stem cell proliferation. Our findings provide evidence of the essential role of DDR in protecting EC against ISC aging, thus providing a better understanding of the molecular mechanisms of stem cell/niche aging.

Deficiency of Atg6 impairs beneficial effect of metformin on intestinal stem cell aging in Drosophila

Age-related changes of adult stem cell are crucial for tissue aging and age-related diseases. Thus, clarifying mechanisms to prevent adult stem cell aging is indispensable for healthy aging. Metformin, a drug for type 2 diabetes, has been highlighted for its anti-aging and anti-cancer effect. In Drosophila intestinal stem cell (ISC), we previously reported the inhibitory effect of metformin on age-related phenotypes of ISC. Here, we showed that knockdown of Atg6, a crucial autophagy-related factor, in ISC induces age-related phenotypes of ISC such as hyperproliferation, centrosome amplification, and DNA damage accumulation. Then, we revealed that metformin inhibits ISC aging phenotypes in Atg6-dependent manner. Taken together, our study suggests that Atg6 is required for the inhibitory effect of metformin on ISC aging, providing an intervention mechanism of metformin on adult stem cell aging.

Exacerbated cardiac fibrosis induced by β-adrenergic activation in old mice due to decreased AMPK activity

Senescent hearts exhibit defective responses to β-adrenergic receptor (β-AR) over-activation upon stress, leading to more severe pathological cardiac remodelling. However, the underlying mechanisms remain unclear. Here, we investigated the role of adenosine monophosphate-activated protein kinase (AMPK) in protecting against ageing-associated cardiac remodelling in mice upon β-AR over-activation. 10-week-old (young) and 18-month-old (old) mice were subcutaneously injected with the β-AR agonist isoproterenol (ISO; 5 mg/kg). More extensive cardiac fibrosis was found in old mice upon ISO exposure than in young mice. Meanwhile, ISO treatment decreased AMPK activity and increased β-arrestin 1, but not β-arrestin 2, expression, and the effects of ISO on AMPK and β-arrestin 1 were greater in old mice than in young mice. Similarly, young AMPKα2-knockout (KO) mice showed more extensive cardiac fibrosis upon ISO exposure than that was observed in age-matched wild-type (WT) littermates. The extent of cardiac fibrosis in WT old mice was similar to that in young KO mice. Additionally, AMPK activities were decreased and β-arrestin 1 expression increased in KO mice. In contrast, the AMPK activator metformin decreased β-arrestin 1 expression and attenuated cardiac fibrosis in both young and old mice upon ISO exposure. In conclusion, more severe cardiac fibrosis is induced by ISO in old mice than in young mice. A decrease in AMPK activity, which further increases β-arrestin 1 expression, is the central mechanism underlying the ageing-related cardiac fibrosis induced by ISO. The AMPK activator metformin is a promising therapeutic agent for treating ageing-related cardiac remodelling upon β-AR over-activation.

Targeting mTOR signaling by polyphenols: A new therapeutic target for ageing

Current ageing research is aimed not only at the promotion of longevity, but also at improving ‎health span‎ through the‎ discovery and development‎ of new therapeutic strategies‎‏‎ by investigating ‎molecular and ‎cellular ‎pathways involved in cellular senescence.‎ Understanding the mechanism of action ‎of ‎polyphenolic compounds targeting mTOR (mechanistic target of rapamycin) and related pathways opens up new directions ‎‎to revolutionize ways to slow down the ‎onset and development of age-dependent degeneration. Herein, we will ‎discuss the mechanisms by which polyphenols can delay the‎ molecular ‎pathogenesis of ageing via manipulation or more specifically inhibition of mTOR-signaling pathways. We will also discuss the implications of polyphenols in targeting mTOR and its related ‎pathways‎‎ on ‎health life span extension and longevity.‎.

Nutrients and ageing: what can we learn about ageing interactions from animal biology?

PURPOSE OF REVIEW

Many prevalent clinical conditions, such as chronic kidney disease, diabetes mellitus, chronic obstructive pulmonary, and cardiovascular disease associate with features of premature ageing, such as muscle wasting, hypogonadism, osteoporosis, and arteriosclerosis. Studies on various animal models have shown that caloric restriction prolongs lifespan. Studies of animals with unusual long or short life for their body size may also contribute to better understanding of ageing processes. The aim of the present article is to review what we can learn about nutritional modulations and ageing interactions from animal biology.

RECENT FINDINGS

Caloric restriction is a powerful intervention that increases longevity in animals ranging from short-lived species, such as worms and flies, to primates. As long-term studies on caloric restriction are not feasible to conduct in humans, much interest has focused on the impact of caloric restriction mimetics, such as resveratrol, on ageing processes. Recent data from studies on the long-lived naked mole rat have provided important novel information on metabolic alterations and antioxidative defense mechanisms that characterize longevity.

SUMMARY

Better understanding of the biology of exceptionally long-lived animals will contribute to better understanding of ageing processes and novel interventions to extend lifespan also in humans.

AMPK activation can delay aging

AMPK controls the regulation of cellular homeostasis, metabolism, resistance to stress, cell survival and growth, cell death, autophagy, which are some of the most critical determinants of aging and lifespan. Specific AMPK activation was recently shown to delay aging and prolong lifespan in Drosophila melanogaster. Indirect AMPK activators, such as resveratrol, metformin and exercise, are currently in clinical trials for studying their impact on human aging-related characteristics, tissue homeostasis and metabolic dysfunctions. In this minireview, I am briefly discussing the recent advances on AMP involvement in aging and lifespan elongation.