Type 2 diabetes mellitus is a disease which initiates with insulin resistance. Then, pancreatic β cells start to counteract this situation by increasing insulin secretion, which is known as pre-diabetic state. Amylin protein or islet amyloid polypeptide (IAPP), has multiple physiological roles such as the regulation of satiety and avoiding gastric emptying. However, amylin is able to aggregate, forming insoluble structures that affects pancreatic β cell survival. Interestingly, not all the amylin from the different species has this aggregate-prone capacity. There are species, which possesses non-amyloidogenic capacity and does not aggregate such as the rodents. However, there are versions of the protein, for instance from humans and primates, which can aggregate. Previously, we observed that small oligomers could be found in extracellular vesicles (EVs). Now, we have used a pancreatic β cell which overexpresses human amylin (hIAPP) (INS1E-hIAPP) and we have explored the capacity of amylin to be incorporated into EVs and how amylin could affect to different essential signaling pathways such as the mammalian target of rapamycin complex 1, endoplasmic-reticulum stress and senescence. Here, we report that amylin can be incorporated into EVs in an endosomal sorting complexes required for transport (ESCRT)-dependent manner. When we treated the cells with the neutral sphingomyelinase inhibitor, GW4869, one of the pathways for EV biogenesis and under high glucose conditions, there was an increased incorporation of soluble amylin into vesicles. Interestingly in this condition, when we isolated the EVs, we clearly observed that the size of the vesicles was higher, compatible with microvesicles (MVs). Resveratrol increased a pro-senescent phenotype but, it was able to revert either the high glucose or GW4869-associated senescent. In summary, these results indicate that amylin can be recruited in an ESCRT-dependent manner into EVs and, resveratrol presents an important role in inducing senescence in INS1E-hIAPP pancreatic β cells.
Diabetic nephropathy is one of the most frequent complications of diabetic patients and is the leading cause of end-stage renal disease worldwide. The complex physiopathology of this complication raises a challenge in the development of effective medical treatments. Therefore, a better understanding of this disease is necessary for producing more targeted therapies. In this work we propose human amylin as a possible mediator in the development of diabetic nephropathy. Islet amyloid polypeptide or amylin is a hormone co-secreted with insulin. The human isoform has the ability to fold and form amyloid aggregates in the pancreas of patients with type 2 diabetes mellitus, disrupting cellular homeostasis due to its ability to form pores in lipid bilayers. It has been described that hIAPP can be secreted and exported in extracellular vesicles outside the pancreas, being a plausible connecting mechanism between the β-cell and other peripheral tissues such as the kidney. Here, we demonstrate that tubular, podocytes and mesangial cells can incorporate hIAPP coming from β-cells. Then, this hIAPP can form aggregates inside these kidney cells, contributing to its failure. In order to study the consequences in vivo, we found amylin aggregates in the kidney of mice overexpressing hIAPP after feeding a high fat diet. In addition, we observed an increase in glomerulosclerosis index and inflammation. Specifically, there were significant changes in signalling pathways directly involved in the diabetic nephropathy such as an increased in mTORC1 signaling pathway, an alteration in mitochondrial dynamics and an increased in endoplasmic reticulum stress. All these results demonstrate the importance of hIAPP in the kidney and its possible contribution in the development of diabetic nephropathy.
Type 2 diabetes mellitus and Alzheimer’s disease, are two closely related pathological situations that are connected at the molecular level. In recent years, amylin, which is co-secreted with insulin, has been proposed for being a main actor in this context due to its capacity to form aggregates in a β-sheet-like structure. In a diabetic milieu, there is an increase in the production and secretion of insulin and amylin. We have analysed the role of resveratrol on aggregate formation and in the production of extracellular vesicles with amylin in its interior and in pancreatic β cells overexpressing human amylin (INS1E-hIAPP). Furthermore, we have explored the consequences of the exposition of the conditioned medium derived from INS1E-hIAPP in the hippocampal cell line HT-22 and the role of resveratrol in this cell line. Hippocampal cells were exposed to conditioned media obtained from rat insulinoma 1E overexpressing human amylin in the presence or in the absence of resveratrol. When we exposed HT-22 cells to the conditioned media of INS1E-hIAPP we observed amylin-aggregates inside HT-22 cells. Resveratrol was able to alleviate this effect not only in HT-22 but also in pancreatic β cells. Furthermore, resveratrol decreased the average exosome size produced by the INS1E-hIAPP stimulated with high glucose, diminishing the toxic effect of these exosomes in HT-22 cells. We have uncovered that resveratrol inhibits the aggregation capacity of amylin and it can diminish the deleterious spreading of the toxic protein, to other cell types such as the hippocampal neuron cells, HT-22.
Se presenta el caso de un paciente joven de raza caucásica, con una enfermedad renal de causa no clara, con un diagnóstico final establecido por biopsia renal de nefroangioesclerosis benigna evolucionada. Debido a la posibilidad de haber tenido hipertensión arterial en edad pediátrica (sin estudio ni tratamiento), con los hallazgos de biopsia renal, el estudio genético de hipertensión mostró polimorfismos de riesgo en los genes APOL1 y MYH9 y, además, un diagnóstico inesperado de una deleción completa del gen NPHP1 en homocigosis, asociada al desarrollo de nefronoptisis. En conclusión, este caso ilustra la importancia de hacer estudio genético, sobre todo en pacientes jóvenes con enfermedad renal de causa no clara, incluso teniendo un diagnóstico histológico de nefroangioesclerosis.
Nephroangiosclerosis or kidney disease that accompanies chronic essential arterial hypertension has been known for more than a hundred years. The definitive diagnosis is established by renal biopsy, which is reserved for doubtful cases or atypical presentation, being in most cases a presumptive clinical diagnosis. The objective of this review is to analyse the main controversies that currently exist related to nephroangiosclerosis: inaccuracy in epidemiological aspects (prevalence and incidence unknown), diagnostic difficulties and lack of correlation studies between clinical data and histopathology, progression factors in Caucasians. Currently, with advances in genetic studies in hypertension, not using or redefining the term hypertensive kidney disease for another condition such as nephropathy related to the present genetic alteration is being considered.
Hutchinson-Gilford Progeria Syndrome is an ultrarare disease which is characterized by an accelerated senescence phenotype with deleterious consequences to people suffering this pathology. The production of an abnormal protein derived from lamin A, called progerin, presents a farnesylated domain, which is not eliminated by the causal mutation of the disease, and accumulates in the interior of the nucleus, provoking a disruption of nuclear membrane, chromatin organization and an altered gene expression. The mutation in these patients occurs in a single nucleotide change, which creates a de novo splicing site, producing a shorter version of the protein. Apart from this mutation, an alteration in the metalloproteinase Zmpste24, involved in the maturation of lamin A, causing a similar alteration than in progeria. However, in this case, patients accumulate a protein, called prelamin A, which generates similar alterations in the nucleus than progerin. The reduction of prelamin A protein levels facilitates the recovery of the phenotype in different mice models of the disease, reducing the aging process. Different strategies have been studied for eliminating this toxic protein. Here, we report that immortalization of primary cells derived from the Zmpste24 KO mice, facilitates prelamin A degradation by different mechanisms, being essential, the enhancing proliferative capacity that the immortalized cells present. Then, these data suggest that using different treatments for increasing proliferative capacity of these cells, potentially could have a beneficial effect, facilitating prelamin A toxicity.
Nanotechnology changed the concept of treatment for a variety of diseases, producing a huge impact regarding drug and gene delivery. Among the different targeted diseases, osteoporosis has devastating clinical and economic consequences. Since current osteoporosis treatments present several side effects, new treatment approaches are needed. Recently, the application of small interfering RNA (siRNA) has become a promising alternative. Wnt/β-catenin signaling pathway controls bone development and formation. This pathway is negatively regulated by sclerostin, which knock-down through siRNA application would potentially promote bone formation. However, the major bottleneck for siRNA-based treatments is the necessity of a delivery vector, bringing nanotechnology as a potential solution. Among the available nanocarriers, mesoporous silica nanoparticles (MSNs) have attracted great attention for intracellular delivery of siRNAs. The mesoporous structure of MSNs permits the delivery of siRNAs together with another biomolecule, achieving a combination therapy. Here, the effectiveness of a new potential osteoporosis treatment based on MSNs is evaluated. The proposed system is effective in delivering SOST siRNA and osteostatin through systemic injection to bone tissue. The nanoparticle administration produced an increase expression of osteogenic related genes improving the bone microarchitecture. The treated osteoporotic mice recovered values of a healthy situation approaching to osteoporosis remission.
espanolLa hipertension arterial y la fragilidad son patologias comunes asociadas al envejecimiento. Su enfoque al considerar el tratamiento antihipertensivo podra tener implicaciones en el pronostico vital del paciente. El grado de control de presion arterial a alcanzar en el anciano fragil deberia individualizarse, para lo cual se hace necesario implementar una correcta evaluacion de fragilidad y de la situacion clinica en los protocolos y guias de hipertension arterial. EnglishHypertension and frailty are common pathologies associated with aging. Your approach in considering antihypertensive treatment may have prognostic implications patient´s. The degree of blood pressure to be achieved in the frail elderly should be individualized, for which it is necessary to implement a correct assessment of frailty and of the clinical situation in the protocols and guidelines for hypertension.
Type 2 diabetes mellitus is a progressive disease that is characterized by the appearance of insulin resistance. The term insulin resistance is very wide and could affect different proteins involved in insulin signaling, as well as other mechanisms. In this review, we have analyzed the main molecular mechanisms that could be involved in the connection between type 2 diabetes and neurodegeneration, in general, and more specifically with the appearance of Alzheimer's disease. We have studied, in more detail, the different processes involved, such as inflammation, endoplasmic reticulum stress, autophagy, and mitochondrial dysfunction.
Pancreatic β cells are essential in the maintenance of glucose homeostasis during the progression to type 2 Diabetes Mellitus (T2DM), generating compensatory hyperinsulinemia to counteract insulin resistance. It is well known, that throughout the process there is an increased mTORC1 signaling pathway, with an impairment in different quality control systems including ubiquitin-proteasome system and autophagy. In addition, under this situation, pancreatic β cells start to accumulate amylin protein (IAPP) in aggregates, and this accumulation contributes to the failure of autophagy, damaging different organelles such as plasma membrane, endoplasmic reticulum, mitochondria, and others. Here, we report that IAPP can be incorporated to multivesicular bodies (MVB) and secreted into exosomes, a mechanism responsible for the exportation of these toxic aggregates as vehicles of cell to cell communication. On this regard, we have demonstrated that the exosomes bearing toxic hIAPP released from pancreatic β cells are capable to induce hyperactivation of mTORC1 signaling, a failure in the autophagic cellular quality control, and favor pro-fission status of the mitochondrial dynamics in hippocampal cells. In summary, our results show that harmful accumulation of hIAPP in pancreatic β cells may be detoxified by the release of exosomes, which may be captured by endocytosis mechanism damaging neuronal hippocampal cells, which suggest an underlying molecular mechanism to the link between type 2 diabetes and neurodegenerative diseases.
Sirtuins are a group of enzymes involved in a great variety of important cellular processes such as autophagy, cell growth, metabolism, aging, and many others. However, under certain circumstances, which are not completely understood, there is an alteration in those functions controlled by the sirtuins. These changes affect the formation and/or the progression of conditions including cancer, neurodegeneration, metabolic disturbances, and many others. These enzymes are key protective factors for the appearance of several disorders and the maintenance of cellular homeostasis. In this chapter we have analyzed the role of the different sirtuins in the appearance and development of different diseases.
Background: Cardiovascular dysfunction is linked to insulin-resistant states. In this paper, we analyzed whether the severe hepatic insulin resistance of an inducible liver-specific insulin receptor knockout (iLIRKO) might generate vascular insulin resistance and dysfunction, and whether insulin receptor (IR) isoforms gene therapy might revert it. Methods: We studied in vivo insulin signaling in aorta artery and heart from iLIRKO. Vascular reactivity and the mRNA levels of genes involved in vascular dysfunction were analyzed in thoracic aorta rings by qRT-PCR. Finally, iLIRKO mice were treated with hepatic-specific gene therapy to analyze vascular dysfunction improvement. Results: Our results suggest that severe hepatic insulin resistance was expanded to cardiovascular tissues. This vascular insulin resistance observed in aorta artery from iLIRKO mice correlated with a reduction in both PI3K/AKT/eNOS and p42/44 MAPK pathways, and it might be implicated in their vascular alterations characterized by endothelial dysfunction, hypercontractility and eNOS/iNOS levels’ imbalance. Finally, regarding long-term hepatic expression of IR isoforms, IRA was more efficient than IRB in the improvement of vascular dysfunction observed in iLIRKO mice. Conclusion: Severe hepatic insulin resistance is sufficient to produce cardiovascular insulin resistance and dysfunction. Long-term hepatic expression of IRA restored the vascular damage observed in iLIRKO mice.
Sambucus nigra flowers (elderflower) have been widely used in traditional medicine for the relief of early symptoms of common cold. Its chemical composition mainly consists of polyphenolic compounds such as flavonoids, hydroxycinnamic acids, and triterpenes. Although the antioxidant properties of polyphenols are well known, the aim of this study is to assess the antioxidant and protective potentials of Sambucus nigra flowers in the human neuroblastoma (SH-SY5Y) cell line using different in vitro approaches. The antioxidant capacity is first evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Cell viability is assessed by the crystal violet method; furthermore, the intracellular ROS formation (DCFH-DA method) is determined, together with the effect on the cell antioxidant defenses: reduced glutathione (GSH) and antioxidant enzyme activities (GPx, GR). On the other hand, mTORC1 hyperactivation and autophagy blockage have been associated with an increase in the formation of protein aggregates, this promoting the transference and expansion of neurodegenerative diseases. Then, the ability of Sambucus nigra flowers in the regulation of mTORC1 signaling activity and the reduction in oxidative stress through the activation of autophagy/mitophagy flux is also examined. In this regard, search for different molecules with a potential inhibitory effect on mTORC1 activation could have multiple positive effects either in the molecular pathogenic events and/or in the progression of several diseases including neurodegenerative ones.
Polyphenols represent a group of secondary metabolites of plants which have been analyzed as potent regulators of multiple biological processes, including cell proliferation, apoptosis, and autophagy, among others. These natural compounds exhibit beneficial effects and protection against inflammation, oxidative stress, and related injuries including metabolic diseases, such as cardiovascular damage, obesity and diabetes, and neurodegeneration. This review aims to summarize the mechanisms of action of polyphenols in relation to the activation of autophagy, stimulation of mitochondrial function and antioxidant defenses, attenuation of oxidative stress, and reduction in cell apoptosis, which may be responsible of the health promoting properties of these compounds.
Herausgeber und Verlag der Zeitschrift "Biological Cybernetics" gedenken Karl Kiipfmtillers, dem Mitbegrtinder dieser Zeitschrift, zu deren Entstehen er entscheidend beigetragen und deren Entwicklung er maBgeblich gef6rdert hat. Das erste Heft der "Biological Cybernetics" (seinerzeit ,,Kybernetik" benannt) erschien im Januar 1961. Es wurde mit einem Beitrag yon K. Kiipfmtiller und F. Jenik zum Thema ,,Uber die Nachrichtenverarbeitung in der Nervenzelle" er6ffnet. Karl Kiipfmtiller hat als einer der ersten, ausgehend yon der allgemeinen Nachrichtentechnik, grundlegende Arbeiten zur Simulation biologischer Vorg~inge durchgeftihrt und damit eine Forschungsrichtung begrtindet, die unter dem von Norbert Wiener gepr~igten Begriff Kybernetik zusammengefal3t wurde. Aus Anlag seines 80. Geburtstages, am 6. Oktober 1977, wurde Karl Kiipfmiiller in dieser Zeitschrift geehrt, sein Lebensweg nachgezeichnet und seine grol3en Verdienste als Hochschullehrer und Forscher gewtirdigt. Er war einer der grof3en Pioniere der Nachrichtentechnik und hat mit seinen Arbeiten weltweit hohes Ansehen erworben. Wir verlieren mit Karl Kiipfmiiller einen F6rderer, Gelehrten und Menschen yon besonderem Rang. Die Stgtte seiner akademischen Wirksamkeit war sowohl die groge Vorlesung als auch die reine Forschungsarbeit, deren Ergebnisse in vielen grundlegenden Ver6ffentlichungen ihren Niederschlag gefunden haben. Der groge Kreis seiner Schiiler und Kollegen ist ihm fiber die Zeiten hinweg dankbar verbunden geblieben. Seine besondere F~ihigkeit im Auffinden von L6sungen und Vermittlungsm6glichkeiten hat seinem Wort und seiner Empfehlung ein hohes Gewicht zukommen lassen. Um so gr6ger ist die Liicke, die sein Tod hervorgerufen hat. Wir gedenken in Trauer und Dankbarkeit der Pers6nlichkeit Karl Kiipfmiillers.
espanolIntroduccion: La hiperpotasemia es un trastorno electrolitico potencialmente letal cuya causa mas frecuente es iatrogenica en pacientes con insuficiencia renal preexistente. Caso clinico: Presentamos un paciente con diabetes mellitus tipo 1 que fue sometido a un trasplante de pancreas-rinon y que desarrolla hiperpotasemia leve en el postoperatorio inmediato tras haber iniciado el tratamiento con trimetoprima. Conclusiones: Comunicamos el primer caso de hiperpotasemia secundaria al tratamiento con trimetoprima en el trasplante simultaneo renal y pancreatico. Este caso enfatiza la importancia de monitorizar los niveles de kaliemia en este tipo de pacientes. EnglishBackground: Hyperkalaemia is a potentially lethal electrolytic disorder which the most common cause is iatrogenic in patients with pre-existing renal insufficiency. Case description: We report a patient with diabetes mellitus type 1 who was transplanted a pancreas and a kidney and developed mild hyperkalaemia in the immediate postoperative period after initiating trimethoprim. Conclusions: We communicate the first case of hyperkalaemia secondary to trimethoprim treatment in a simultaneous pancreas-kidney transplanted patient. We emphasize the importance of potassium levels monitoring in these patients.