Biology subjects

Morabito, A.

Publications and source records attributed to Morabito, A..

8 recordsLinked to original sources

bioRxiv2026

Differential serum binding patterns predicting healthy subjects and cancer patients

A viral exposure signature (VES) has been previously described predicting the development of Hepatocellular carcinoma (HCC) in at-risk patients. This has been achieved by a serological profiling of the viral infection history using a synthetic human virome including >100k epitopes (VirScan). In the present study we applied the same VirScan strategy to identify a differential serum binding pattern (DSBP) for classifying patients of different cancer types from healthy individuals. In particular, the healthy group included both age-matched (ADULTS) as well as elderly (ELDERS) individuals, the latter counting also nonagenarians and centenarians. The class comparison performed with serological data show DSBPs supporting class predictions, as confirmed by the receiver operating characteristic (ROC) curve analysis. Antibody responses supporting the class predictions are specific to peptides from persistent herpesviruses, acute-infecting viruses and, consistently in all comparisons, human respiratory syncytial virus (HRSV). Strikingly, the DSB of the ELDERS vs. CANCER comparison is characterized by higher titers in the healthy subjects; on the contrary, the DSB of the ADULTS vs. CANCER comparison is characterized by lower titers in the healthy subjects. Overall, the results show a differential serological binding pattern predicting healthy individuals (ADULTS or ELDERS) from patients with different types of cancer. Such results provide the first evidence suggesting a close link between anti-microbial immunity and cancer development. They may be of the highest relevance in terms of predictive, diagnostic and/or prognostic impact in oncology.

immunology↗

bioRxiv2024

WNT signaling coordinately controls mouse limb bud outgrowth and establishment of the digit-interdigit pattern

Self-organization, such as the emergence of a pattern from a homogenous state, is a fascinating property of biological systems. Early limb bud outgrowth and patterning in mice are controlled by a robust and self-regulatory signaling system, and initiation of the periodic digit-interdigit pattern appears under control of a self-regulatory Turing system. Previous studies established the requirement of WNT and BMP signaling for both early limb bud and digit-interdigit morphogenesis, but the molecular changes underlying the transition from early limb bud signaling to the digit-interdigit patterning system remained unknown. Here, we use small molecule inhibitors to rapidly but transiently block WNT signaling to identify the early transcriptional targets that are altered during disruption and recovery of limb bud and digit development. Together, this study highlights the overarching role of WNT signaling in controlling early limb bud outgrowth and patterning, and establishment of the periodic digit-interdigit pattern. Finally, the transient WNT signaling disruption approach reveals the plasticity and robustness of these self-organizing limb bud and digit patterning systems.

developmental biology↗

bioRxiv2024

A dendritic substrate for temporal diversity of cortical inhibition

In the mammalian neocortex, GABAergic interneurons (INs) inhibit cortical networks in profoundly different ways. The extent to which this depends on how different INs process excitatory signals along their dendrites is poorly understood. Here, we reveal that the functional specialization of two major populations of cortical INs is determined by the unique association of different dendritic integration modes with distinct synaptic organization motifs. We found that somatostatin (SST)-INs exhibit NMDAR-dependent dendritic integration and uniform synapse density along the dendritic tree. In contrast, dendrites of parvalbumin (PV)-INs exhibit passive synaptic integration coupled with proximally enriched synaptic distributions. Theoretical analysis shows that these two dendritic configurations result in different strategies to optimize synaptic efficacy in thin dendritic structures. Yet, the two configurations lead to distinct temporal engagement of each IN during network activity. We confirmed these predictions with in vivo recordings of IN activity in the visual cortex of awake mice, revealing a rapid and linear recruitment of PV-INs as opposed to a long-lasting integrative activation of SST-INs. Our work reveals the existence of distinct dendritic strategies that confer distinct temporal representations for the two major classes of neocortical INs and thus dynamics of inhibition.

neuroscience↗

bioRxiv2024

Single-cell profiling of penta- and tetradactyl mouse limb buds identifies mesenchymal progenitors controlling digit numbers and identities

The cellular mechanisms controlling digit numbers and identities have remained elusive. Profiling of wild-type (pentadactyl) and Grem1 tetradactyl mouse limb buds identifies cellular changes affecting two limb bud mesenchymal progenitor (LMP) populations. In mutant limb buds, the anteriorly biased distribution of peripheral LMPs (pLMPs) is lost and the population expanded, while the distal-posterior LMP (dLMP) population is reduced from early stages onward. Analysis of LMP signature genes in wildtype and mutant mouse limb buds with digit loss or gain establishes that pLMPs are positively regulated by BMP signaling, while dLMPs require GREM1-mediated BMP antagonism. dLMPs encompass digit progenitors and altering their population size prefigures changes in digit numbers. The anteriorly biased pLMP distribution is linked to digit asymmetry as loss of this bias in tetradactyl mouse and pig limb buds underlies middle digit symmetry and identity loss. This study indicates that variable spatial Grem1 expression in mutant and evolutionary diversified limb buds tunes BMP activity, impacting both LMP populations in a complementary manner.

developmental biology↗

bioRxiv2024

Feedforward circuits enable modality-specific control of cortical inhibition during behavioral state transitions.

Local inhibitory neurons (INs), specifically those involved in disinhibitory circuits like somatostatin (SST) and vasoactive intestinal peptide (VIP)-positive INs, are essential for regulating cortical function during behavior. However, it is unclear the mechanisms by which these INs are recruited during active states and whether their activity is consistent across different sensory cortices. We now reveal that in mice, locomotor activity strongly recruits SST-INs in primary somatosensory (S1) but not visual (V1) cortex. This diverse engagement of SST-INs could not be explained by differences in VIP-IN function but was absent in the presence of visual sensory drive suggesting involvement of feedforward sensory pathways. In agreement, inactivating the somatosensory thalamus, but not decreasing VIP-INs activity, significantly reduces the recruitment of SST-INs in S1 by locomotion. Finally, model simulations suggest differences in SST-INs activity can be explained by varying ratios of VIP-driven inhibition and thalamus-driven cortical excitation. Our work suggests that by integrating feedforward activity with neuromodulation, SST-INs play a central role in adapting sensory processing to behavioral states.

neuroscience↗

bioRxiv2022

A spatio-temporally constrained gene regulatory network directed by PBX1/2 acquires limb patterning specificity via HAND2

During development cell fates are specified by tightly controlled gene expression programs. PBX TALE transcription factors control gene regulatory networks (GRN) that direct vertebrate tissue patterning and organ morphogenesis. How PBX1/2 proteins acquire context-specific functions, despite widespread embryonic expression of Pbx1/2, remains elusive. In mouse limb buds, mesenchymal-specific loss of PBX1/2 or of the transcriptional regulator HAND2 results in similar phenotypes, suggesting that PBX1/2- and HAND2-dependent programs converge to control limb development. To investigate this scenario, we combined tissue-specific and temporally-controlled mutagenesis with multi-omics approaches using the murine hindlimb bud as a model. We reconstructed a GRN collaboratively directed by PBX1/2 and HAND2, demonstrating that Pbx1-Hand2 genetically interact in vivo during hindlimb patterning, with PBX1 concomitantly acting as an upstream regulator of Hand2. At organismal-level resolution the GRN is active within restricted subsets of posterior-proximal hindlimb mesenchymal cells, wherein Pbx1/2 and Hand2 are co-expressed with their target genes. Genome-wide profiling of PBX1 binding across multiple tissues further revealed that HAND2 selects a subset of PBX-bound regions to impart limb patterning functionality. This research elucidates mechanisms underlying limb bud-specific functions by PBX1/2, while informing general principles by which promiscuous transcription factors cooperate with select cofactors to instruct distinct developmental programs.

developmental biology↗

bioRxiv2021

Activity-dependent modulation of NMDA receptors by endogenous zinc shapes dendritic function in cortical neurons.

Activation of NMDA receptors (NMDARs) has been proposed to be a key component of single neuron computations in vivo. However is unknown if specific mechanisms control the function of such receptors and modulate input-output transformations performed by cortical neurons under in vivo-like conditions. Here we found that in layer 2/3 pyramidal neurons (L2/3 PNs), repeated synaptic stimulation results in an activity-dependent decrease in NMDARs activity by vesicular zinc. Such a mechanism shifted the threshold for dendritic non-linearities and strongly reduced LTP induction. Modulation of NMDARs was cell- and pathway-specific, being present selectively in L2/3-L2/3 connections but absent in ascending bottom-up inputs originating from L4 neurons. Numerical simulations highlighted that activity-dependent modulation of NMDARs has an important influence in dendritic computations endowing L2/3 PN dendrites with the ability to sustain dendritic non-linear integrations constant across different regimes of synaptic activity like those found in vivo. The present results therefore provide a new perspective on the action of vesicular zinc in cortical circuits by highlighting the role of this endogenous ion in normalizing dendritic integration of PNs during a constantly changing synaptic input pattern.

neuroscience↗

bioRxiv2020

The effect of acute sleep deprivation on skeletal muscle protein synthesis and the hormonal environment

Chronic sleep loss is a potent catabolic stressor, increasing the risk of metabolic dysfunction and loss of muscle mass and function. To provide mechanistic insight into these clinical outcomes, we sought to determine if acute sleep deprivation blunts skeletal muscle protein synthesis and promotes a catabolic environment. Healthy young adults (N=13; 7 male, 6 female) were subjected to one night of total sleep deprivation (DEP) and normal sleep (CON) in a randomized cross-over design. Anabolic and catabolic hormonal profiles, skeletal muscle fractional synthesis rate and markers of muscle protein degradation were assessed across the following day. Acute sleep deprivation reduced muscle protein synthesis by 18% (CON: 0.072 {+/-} 0.015 vs. DEP: 0.059 {+/-} 0.014 %*h-1, p=0.040). In addition, it increased plasma cortisol by 21% (p=0.030) and decreased plasma testosterone, but not IGF-1, by 22% (p=0.029). A single night of total sleep deprivation is sufficient to induce anabolic resistance and a pro-catabolic environment. These acute changes may represent mechanistic precursors driving the metabolic dysfunction and body composition changes associated with chronic sleep deprivation.

physiology↗