Coenzyme A precursors flow from mother to zygote and from microbiome to host.

Coenzyme A (CoA) is essential for metabolism and protein acetylation. Current knowledge holds that each cell obtains CoA exclusively through biosynthesis via the canonical five-step pathway, starting with pantothenate uptake. However, recent studies have suggested the presence of additional CoA-generating mechanisms, indicating a more complex system for CoA homeostasis. Here, we uncovered pathways for CoA generation through inter-organismal flows of CoA precursors. Using traceable compounds and fruit flies with a genetic block in CoA biosynthesis, we demonstrate that progeny survive embryonal and early larval development by obtaining CoA precursors from maternal sources. Later in life, the microbiome can provide the essential CoA building blocks to the host, enabling continuation of normal development. A flow of stable, long-lasting CoA precursors between living organisms is revealed. This indicates the presence of complex strategies to maintain CoA homeostasis.

Vps13 is required for timely removal of nurse cell corpses.

Programmed cell death and consecutive removal of cellular remnants is essential for development. During late stages of Drosophila melanogaster oogenesis, the small somatic follicle cells that surround the large nurse cells promote non-apoptotic nurse cell death, subsequently engulf them, and contribute to the timely removal of nurse cell corpses. Here, we identify a role for Vps13 in the timely removal of nurse cell corpses downstream of developmental programmed cell death. Vps13 is an evolutionarily conserved peripheral membrane protein associated with membrane contact sites and lipid transfer. It is expressed in late nurse cells, and persistent nurse cell remnants are observed when Vps13 is depleted from nurse cells but not from follicle cells. Microscopic analysis revealed enrichment of Vps13 in close proximity to the plasma membrane and the endoplasmic reticulum in nurse cells undergoing degradation. Ultrastructural analysis uncovered the presence of an underlying Vps13-dependent membranous structure in close association with the plasma membrane. The newly identified structure and function suggests the presence of a Vps13-dependent process required for complete degradation of bulky remnants of dying cells.

Barrington's nucleus in the guinea pig (Cavia porcellus): location in relation to noradrenergic cell groups and connections to the lumbosacral spinal cord.

Micturition is largely controlled by Barrington's nucleus in the dorsolateral tegmentum of the pons. This nucleus coordinates simultaneous bladder contraction and external urethral sphincter relaxation, by means of a specific pattern of projections to the lumbosacral spinal cord. The most widely used small animal model in neurourological research is the rat. However, urodynamic studies suggest that, in sharp comparison to rat, guinea pig micturition is very similar to human micturition. Therefore, the present study, using retrograde and anterograde tracing and double immunofluorescence, was designed to investigate the location of Barrington's nucleus in the guinea pig, to identify Barrington's nucleus projections to the spinal cord and to clarify the relationship of Barrington's nucleus to pontine noradrenergic cell groups. Results show that Barrington's nucleus is located in the dorsolateral pons, projects to the intermediolateral and intermediomedial cell groups of the lumbosacral spinal cord and is clearly distinct from the pontine noradrenergic cell groups. These results show that the neuroanatomical circuitry in the spinal cord and brainstem that controls micturition in the guinea pig is similar to that in rat. This means that the differences between rat and guinea pig micturition on a behavioral level are not the result of different neuroanatomical connections in these parts of the central nervous system. These results provide a neuroanatomical basis for further neurourological studies in guinea pig.

Hypoxia enhances migration and invasion in glioblastoma by promoting a mesenchymal shift mediated by the HIF1α-ZEB1 axis.

Glioblastoma (GBM) is the most common brain tumor in adults and the mesenchymal GBM subtype was reported to be the most malignant, presenting severe hypoxia and necrosis. Here, we investigated the possible role of a hypoxic microenvironment for inducing a mesenchymal and invasive phenotype. The exposure of non-mesenchymal SNB75 and U87 cells to hypoxia induced a strong change in cell morphology that was accompanied by enhanced invasive capacity and the acquisition of mesenchymal marker expression. Further analyses showed the induction of HIF1α and HIF2α by hypoxia and exposure to digoxin, a cardiac glycoside known to inhibit HIF1/2 expression, was able to prevent hypoxia-induced mesenchymal transition. ShRNA-mediated knockdown of HIF1α, and not HIF2α, prevented this transition, as well as the knockdown of the EMT transcription factor ZEB1. We provide further evidence for a hypoxia-induced mesenchymal shift in GBM primary material by showing co-localization of GLUT1, ZEB1 and the mesenchymal marker YKL40 in hypoxic regions of the tumor. Collectively, our results identify a HIF1α-ZEB1 signaling axis that promotes hypoxia induced mesenchymal shift and invasion in GBM in a cell line dependent fashion.

Serum-Induced Differentiation of Glioblastoma Neurospheres Leads to Enhanced Migration/Invasion Capacity That Is Associated with Increased MMP9.

Glioblastoma (GBM) is a highly infiltrative brain tumor in which cells with properties of stem cells, called glioblastoma stem cells (GSCs), have been identified. In general, the dominant view is that GSCs are responsible for the initiation, progression, invasion and recurrence of this tumor. In this study, we addressed the question whether the differentiation status of GBM cells is associated with their invasive capacity. For this, several primary GBM cell lines were used, cultured either as neurospheres known to enrich for GSCs or in medium supplemented with 10% FCS that promotes differentiation. The differentiation state of the cells was confirmed by determining the expression of stem cell and differentiation markers. The migration/invasion potential of these cells was tested using in vitro assays and intracranial mouse models. Interestingly, we found that serum-induced differentiation enhanced the invasive potential of GBM cells, which was associated with enhanced MMP9 expression. Chemical inhibition of MMP9 significantly reduced the invasive potential of differentiated cells in vitro. Furthermore, the serum-differentiated cells could revert back to an undifferentiated/stem cell state that were able to form neurospheres, although with a reduced efficiency as compared to non-differentiated counterparts. We propose a model in which activation of the differentiation program in GBM cells enhances their infiltrative potential and that depending on microenvironmental cues a significant portion of these cells are able to revert back to an undifferentiated state with enhanced tumorigenic potential. Thus, effective therapy should target both GSCs and differentiated offspring and targeting of differentiation-associated pathways may offer therapeutic opportunities to reduce invasive growth of GBM.

A discrete dopaminergic projection from the incertohypothalamic A13 cell group to the dorsolateral periaqueductal gray in rat.

Several findings have indicated an involvement of dopamine in panic and defensive behaviors. The dorsolateral column of the periaqueductal gray (dlPAG) is crucially involved in the expression of panic attacks in humans and defensive behaviors, also referred to as panic-like behaviors, in animals. Although the dlPAG is known to receive a specific innervation of dopaminergic fibers and abundantly expresses dopamine receptors, the origin of this dopaminergic input is largely unknown. This study aimed at mapping the dopaminergic projections to the dlPAG in order to provide further insight into the panic-like related behavior circuitry of the dlPAG. For this purpose, the retrograde tracer cholera toxin subunit b (CTb) was injected into the dlPAG of male Wistar rats and double immunofluorescence for CTb and tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of dopamine, was performed. Neurons labeled for both CTb and TH were counted in different dopaminergic cell groups. The findings indicate that the dopaminergic nerve terminals present in the dlPAG originate from multiple dopamine-containing cell groups in the hypothalamus and mesencephalon. Interestingly, the A13 cell group is the main source of dopaminergic afferents to the dlPAG and contains at least 45% of the total number of CTb/TH-positive neurons. Anterograde tracing with biotinylated dextran amine (BDA) combined with double immunofluorescence for BDA and TH confirmed the projections from the A13 cell group to the dlPAG. The remainder of the dopamine-positive terminals present in the dlPAG was found to originate from the extended A10 cell group and the A11 group. The A13 cell group is known to send dopaminergic efferents to several other brain regions implicated in defensive behavior, including the central amygdala and ventromedial hypothalamus. Therefore, although direct behavioral evidence is lacking, our finding that the A13 cell group is also the main source of dopaminergic input to the dlPAG suggests that dopamine might contribute to the regulation of dlPAG-mediated defensive behaviors.

Involvement of the insular cortex in regulating glucocorticoid effects on memory consolidation of inhibitory avoidance training.

Glucocorticoids are known to enhance the consolidation of memory of emotionally arousing experiences by acting upon a network of interconnected brain regions. Although animal studies typically do not consider the insular cortex (IC) to be part of this network, the present findings indicate that the IC is importantly involved in regulating glucocorticoid effects on memory consolidation of emotionally arousing inhibitory avoidance training. The specific glucocorticoid receptor (GR) agonist RU 28362 (3 or 10 ng in 0.5 µl) infused bilaterally into the IC of male Sprague-Dawley rats immediately after one-trial inhibitory avoidance training dose-dependently enhanced 48 h retention performance. Moreover, training on the inhibitory avoidance task increased neuronal activity of the IC, as assessed by an increased number of cells expressing immunoreactivity for phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2). However, systemic administration of a memory-enhancing dose of corticosterone (1 mg/kg) after inhibitory avoidance training rapidly reduced the number of pERK1/2-positive cells in the IC, suggesting that glucocorticoid administration reduces overall neuronal activity of the IC. To investigate which components of the inhibitory avoidance training experience were influenced by the intra-IC glucocorticoid administration, in the last experiment rats were trained on a modified inhibitory avoidance task in which context exposure and footshock training occur on two sequential days. RU 28362 administration into the IC enhanced later retention when infused immediately after either the context or footshock training. Thus, these findings indicate that the IC mediates glucocorticoid effects on the consolidation of memory of different components of inhibitory avoidance training and suggest that the IC might be an important element of the rodent brain network involved in emotional regulation of learning and memory.

The ventrolateral upper cervical cell group in cat projects to all rostrocaudal levels of the periaqueductal gray matter.

The lateral ventral horn of the upper cervical (C(1-3vl)) cord in rat, cat and monkey contains many cells that project to the periaqueductal gray matter (PAG). Until now it was assumed that these cells only project to the ventrolateral part of the caudal PAG. Because the ventrolateral caudal PAG is involved in quiescence and hypotension, it was hypothesized that the C(1-3vl)-PAG projecting cells play a role in immobility behavior, possibly activated by neck muscle afferents. However, in the present anterograde and retrograde study in cat we showed that C(1-3vl) cells do not only target the caudal PAG, but terminate even more abundantly in the intermediate and rostral parts of the PAG. There, projections target the ventrolateral column, like in the caudal PAG, but also terminate in the lateral and dorsomedial columns. This finding, combined with the current, albeit limited, physiological data on C(1-3vl)-PAG and C(1-3vl)-thalamic projecting cells, sheds a new light on the possible functions of C(1-3vl) cells. It might be that the C(1-3vl) cells with complex response properties and large receptive fields have a relay function similar to cells in the dorsal column nuclei, lateral cervical or central cervical nucleus. Other C(1-3vl) cells might receive somatic or visceral input that was never tested before, or perhaps other input, like vestibular information. It might also be that these cells project to the more caudal cord to modulate visceral input, with ascending collaterals to more rostrally located structures, including mesencephalon and thalamus.

No disease in the brain of a 115-year-old woman.

Are there limits to the duration of high quality of life? Are there limits to healthy life for a human brain? We have had the opportunity to evaluate the performance of a 112-113-year-old woman and perform full pathological examination of her body immediately after death at the age of 115. The psychological tests revealed that her general performance was above average of healthy adults of 60-75 years. The pathological observations revealed almost no atherosclerotic changes throughout the body. In the brain almost no beta-amyloid plaques or vascular changes were found and only slight accumulation of hyperphosphorylated tau protein with a Braak-stage 2. Counts of the number of locus coeruleus neurons corresponded with the number of neurons found in the brains of healthy people of 60-80 years old. Our observations indicate that the limits of human cognitive function extends far beyond the range that is currently enjoyed by most individuals and that brain disease, even in supercentanarians, is not inevitable.