Breast milk stem cells: four questions looking for an answer

The finding of stem/progenitor cells in the maternal milk and the discovery of their multilineage potential, associated with some evidence regarding the ability of maternal cells to cross the gastrointestinal barrier and integrate into the organs of the breastfed neonate, has opened an intriguing debate, regarding the strict relationship between mother and son in the postnatal period. In particular, thanks to the discovery of the presence in high quantities of mammary stem cells, a new vision of maternal milk is emerging, in which breastfeeding appears as an unique occasion for reinforcing the physiological development of the newborn, putting all the formulas at a different level of relevance for the neonate. In this contribution the authors try to give an answer to the following 4 questions: 1. is there heterogeneity and a hierarchy among breast milk stem cells? 2. can stem cells present in breast milk enter into the newborn organism? 3. can breast milk stem cells integrate in the neonatal organs and differentiate toward different tissues, including neurons and neuroglia? 4. could metabolomics be useful for the study of stem cells in the human milk

Evolution of satellite DNA sequences in two tribes of Bovidae: a cautionary tale

Two clones, Bt1 from Bos taurus and Om1 from Ovis orientalis musimon, were used as probes for hybridization on genomic DNA and on metaphase chromosomes in members of Bovini and Caprini tribes. Bt1 and Om1 are sequences respectively belonging to the 1.715 and 1.714 DNA satellite I families. Southern blots and fluorescence in situ hybridization experiments showed completely coherent results: the Bovini probe Bt1 hybridized only to members of the Bovini tribe and not to members of Caprini. Likewise, the Caprini probe Om1 hybridized only to members of the Caprini tribe and not to members of Bovini. Hybridization signals were detected in the heterochromatic regions of every acrocentric autosome, except for two pairs of autosomes from Capra hircus that did not show hybridization to probe Om1. No signal was detected on X and Y chromosomes or on bi-armed autosomes. Remarkably, probe Om1 showed almost 100% homology with a bacterial sequence reported in Helicobacter pylor

Multipotent stem cells of mother's milk

In recent years the presence of stem cells (hBSCs: human breastmilkderived stem cells) and epithelial progenitors has been demonstrated in mother’s milk (MM). Stem cells present in samples of fresh MM exhibit a high degree of vitality and this makes possible the performance of cell cultures and to evaluate the differentiation capacity of the hBSCs. The most important datum that expresses the enormous potential of the use of MM stem cells is the presence of a cell population capable of differentiating into the three mesoderm, endoderm and ectoderm lines. The small number of studies and MM samples analyzed and the different sampling methods applied suggest standardization in the collection, analysis and culture of MM in future studies, in consideration of the well-known extreme variability of MM composition, also from the standpoint of cells. The analysis of literature data confirms the uniqueness of MM and its enormous potential

Undercover Toxic Ménage à Trois of Amylin, Copper (II) and Metformin in Human Embryonic Kidney Cells

In recent decades, type 2 diabetes complications have been correlated with amylin aggregation, copper homeostasis and metformin side effects. However, each factor was analyzed separately, and only in some rare cases copper/amylin or copper/metformin complexes were considered. We demonstrate for the first time that binary metformin/amylin and tertiary copper (II)/amylin/metformin complexes of high cellular toxicity are formed and lead to the formation of aggregated multi-level lamellar structures on the cell membrane. Considering the increased concentration of amylin, copper (II) and metformin in kidneys of T2DM patients, our findings on the toxicity of amylin and its adducts may be correlated with diabetic nephropathy development

Living with the enemy: from protein-misfolding pathologies we know, to those we want to know

Conformational diseases are caused by the aggregation of misfolded proteins. The risk for such pathologies develops years before clinical symptoms appear, and is higher in people with alpha-1 antitrypsin (AAT) polymorphisms. Thousands of people with alpha-1 antitrypsin deficiency (AATD) are underdiagnosed. Enemyaggregating proteins may reside in these underdiagnosed AATD patients for many years before a pathology for AATD fully develops. In this perspective review, we hypothesize that the AAT protein could exert a new and previously unconsidered biological effect as an endogenous metal ion chelator that plays a significant role in essential metal ion homeostasis. In this respect, AAT polymorphism may cause an imbalance of metal ions, which could be correlated with the aggregation of amylin, tau, amyloid beta, and alpha synuclein proteins in type 2 diabetes mellitus (T2DM), Alzheimer’s and Parkinson’s diseases, respectively

Para -Aminosalicylic acid in the treatment of manganese toxicity. Complexation of Mn2+ with 4-amino-2-hydroxybenzoic acid and its N -acetylated metabolite

Manganese excess can induce in humans a neurological disorder known as manganism. A possible remedy should be chelation therapy, even though a chelation schedule for manganism has not been currently established. para-Aminosalicylic acid (PAS) has demonstrated effectiveness in reducing manganism symptoms. In this work, a study of the protonation equilibria of para-aminosalicylic acid and of its N-acetylated metabolite (Ac-PAS) and of their complexation reactions with Mn2+ is presented, and also extended to the main essential metal ions Cu2+ and Fe3+. A number of complementary techniques (potentiometry, spectrophotometry, fluorimetry, EPR) have been used for a thorough comprehension of the protonation and complex formation equilibria, with the addition of DFT calculations, which provide insights into the relative stabilities and electronic properties of the formed species. Both PAS and Ac-PAS form 1 : 1 and 1 : 2 metal : ligand complexes with the target Mn2+ ion; surprisingly the N-acetylated metabolite forms stronger complexes, whose implications in chelation therapy have been pointed out by a speciation study. It is presumed that the relatively small metabolite can penetrate across the blood-brain-barrier and exert its Mn-mobilizing action intracellularly in vulnerable neurons

“Physiological” renal regenerating medicine in VLBW preterm infants: could a dream come true?

An emerging hypothesis from the recent literature explain how specific adverse factors related with growth retardation as well as of low birth weight (LBW) might influence renal development during fetal life and then the insurgence of hypertension and renal disease in adulthood. In this article, after introducing a brief overview of human nephrogenesis, the most important factors influencing nephron number at birth will be reviewed, focusing on the "in utero" experiences that lead to an increased risk of developing hypertension and/or kidney disease in adult. Since nephrogenesis in preterm human newborns does not stop at birth, but it continues for 4-6 weeks postnatally, a better knowledge of the mechanisms able to accelerate nephrogenesis in the perinatal period, could represent a powerful tool in the hands of neonatologists. We suggest to define this approach to a possible therapy of a deficient nephrogenesis at birth "physiological renal regenerating medicine". Our goal in preterm infants, especially VLBW, could be to prolong the nephrogenesis not only for 6 weeks after birth but until 36 weeks of post conceptual age, allowing newborn kidneys to restore their nephron endowment, escaping susceptibility to hypertension and to renal disease later in life

Mitochondria morphology and DNA content upon sublethal exposure to beta-amyloid(1-42) peptide

Brains affected by Alzheimer's disease (AD) show a large spectrum of mitochondrial alterations at both morphological and genetic level. The causal link between amyloid beta peptides (AP) and mitochondrial dysfunction has been established in cellular models of AD using Abeta concentrations capable of triggering massive neuronal death. However, mitochondrial changes related to sublethal exposure to Abeta are less known. Here we show that subtoxic, 1 microM Abeta(1-42) exposure does not change the mitochondrial shape of living cells, as visualized upon the uptake of the non-potentiometric fluorescent probe Mitotracker Green and enhanced yellow fluorescent protein (EYFP)-tagged cytochrome c oxidase expression. Immunolocalization of oxidative adducts 8-hydroxy-2'-deoxyguanosine, 8-hydroxyguanine and 8-hydroxyguanosine demonstrates that one-micromolar concentration of Abeta(1-42) is also not sufficient to elicit dramatic qualitative changes in the RNA/DNA oxidative products. However, in comparison with controls, semi-quantitative analysis of the overall mitochondrial mass by integrated fluorescence intensity reveals an ongoing down-regulation in mitochondrial biosynthesis or, conversely, an enhanced autophagic demise of Abeta treated cells. Furthermore, a significant increase of the full-length mitochondrial DNA (mtDNA) from Abeta-treated versus control cells is found, as measured by long range polymerase chain reaction (PCR). Such up-regulation is accompanied by extensive fragmentation of the unamplified mtDNA, probably due to the detrimental effect of Abeta. We interpret these results as a sequence of compensatory responses induced by mtDNA damage, which are devoted to repression of oxidative burst. In conclusion, our findings suggest that early therapeutic interventions aimed at prevention of mitochondrial oxidative damage may delay AD progression and help in treating AD patients

Carenza congenita di alfa 1 antitripsina. Una malattia rara o raramente diagnosticata?

II test di laboratorio stanno assumendo un’importanza sempre maggiore nella pratica clinica poiché sono spesso determinanti per orientare il percorso diagnostico e per scegliere e monitorare una corretta terapia. La possibilità di poter utilizzare test molecolari ha inoltre dato un nuovo risalto a test routinari di laboratorio che erano stati in parte sottovalutati. L’esempio che riportiamo in questa nota riguarda la diagnosi di una malattia metabolica, considerata rara, che è associata a diversi tipi di patologie soprattutto polmonari ed epatiche: la carenza congenita di alfa 1 antitripsina. L’Alfa-1-AntiTripsina (AAT) è una glicoproteina serica del peso di 52 KD, la cui concentrazione va normalmente dai 100 ai 130 mg/dl e costituisce più del 90% della banda delle alfa-1-globuline in un normale protidogramma elettroforetico. È una proteina della fase acuta appartenente alla famiglia delle Serpine («Serine Protease Inihbitors »), ovvero proteine che inibiscono le serino proteasi. L’azione antiproteasica dell’A1AT è rivolta prevalentemente contro l’elastasi neutrofila (EN), proteasi coinvolta nel rimaneggiamento delle fibre elastiche che compongono la matrice connettivale. L’AAT viene prodotta normalmente nel fegato, nei monociti, nei macrofagi alveolari e nel pancreas esocrino(1) ma, solo gli epatociti hanno capacità secretiva Giornalmente vengono rilasciati in circolo circa 2 g di AAT e la molecola possiede una emivita di circa 4-5 giorni. La sua sintesi aumenta in risposta a vari stimoli, quali stati infiammatori, neoplasie, estrogeni, interventi chirurgici, interleuchina 6 e oncostatina-M (l’AAT aumenta in certe neoplasie). Una volta secreta, la proteina diffonde in numerosi organi dove protegge le strutture extra-cellulari dall’attacco dell’elastasi rilasciata dai neutrofili attivati o senescenti. (1). La patogenesi dell’enfisema polmonare nel deficit di AAT (DAAT) è legata ai ridotti valori plasmatici della proteina che, quindi, non è in grado di modulare l’azione dell’elastasi rilasciata dai neutofili negli alveoli polmonari, con conseguente distruzione dei setti interalveolari. Un importante cofattore nella patogenesi dell’enfisema polmonare nei pazienti affetti da DAAT è rappresentato dal fumo di sigaretta che determina l’inattivazione dell’AAT presente negli alveoli attraverso un processo di ossidazione. Poiché il danno polmonare nei pazienti affetti da DAAT è legato ai bassi valori sierici della glicoproteina, la terapia sostitutiva con somministrazione endovenosa di AAT umana parzialmente purificata è in grado di contrastare l’insorgenza dell’enfisema polmonare (2). A differenza di ciò che avviene a livello polmonare, il danno epatico è legato all’azione tossica esercitata dall’AAT mutata che si accumula nelle cisterne del reticolo endoplasmatico rugoso (RER) degli epatociti, principale sito di sintesi della proteina. La proteina mutata presenta, rispetto alla proteina normale, una configurazione tridimensionale alterata. Ciò favorisce la sua polimerizzazione all’interno del RER, determinando un ritardo nella successiva tappa di rilascio e secrezione della proteina e il suo accumulo all’interno del RER (3)