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DPANN archaea have characteristically small cells and unique genomes that were long overlooked in diversity surveys. Their reduced genomes often lack essential metabolic pathways, requiring symbiotic relationships with other archaeal and bacterial hosts for survival. Yet a long-standing question remains, what is the advantage of maintaining ultrasmall cells. A recent study by Zhang et al. examined genomes of DPANN archaea from marine oxygen deficient zones (ODZs) (I. H. Zhang, B. Borer, R. Zhao, S. Wilbert, et al., mBio 15:e02918-23, 2024, https://doi.org/10.1128/mbio.02918-23). Surprisingly, these genomes contain a broad array of metabolic pathways including genes predicted to be involved in nitrous oxide (N 2 O) reduction. However, N 2 O levels are likely too low in ODZs to make this metabolically feasible. Modeling co-localization of DPANN archaea (N 2 O consumers) with other larger cells (N 2 O producers) demonstrates that N 2 O uptake rates can be optimized by maximizing the producer-to-consumer size ratio and proximity of consumer cells to producers. This may explain why such a diversity of archaea maintain extremely small cell sizes., Competing Interests: The authors declare no conflict of interest.

Alkanes, single carbon methane to long-chain hydrocarbons (e.g. hexadecane and tetradecane), are important carbon sources to anaerobic microbial communities. In anoxic environments, archaea are known to utilize and produce methane via the methyl-coenzyme M reductase enzyme (MCR). Recent explorations of new environments, like deep sea sediments, that have coupled metagenomics and cultivation experiments revealed divergent MCRs, also referred to as alkyl-coenzyme M reductases (ACRs) in archaea, with similar mechanisms as the C 1 utilizing canonical MCR mechanism. These ACR enzymes have been shown to activate other alkanes such as ethane, propane and butane for subsequent degradation. The reversibility of canonical MCRs suggests that these non-methane-activating homologues (ACRs) might have similar reversibility, perhaps mediated by undiscovered lineages that produce alkanes under certain conditions. The discovery of these alternative alkane utilization pathways holds significant promise for a breadth of potential biotechnological applications in bioremediation, energy production and climate change mitigation., (© 2024 The Author(s). Microbial Biotechnology published by John Wiley & Sons Ltd.)

Hepatocyte nuclear factor 4 α (HNF4α), a transcription factor (TF) essential for embryonic development, has been recently shown to regulate the expression of inflammatory genes. To characterize HNF4a function in immunity, we measured the effect of HNF4α antagonists on immune cell responses in vitro and in vivo. HNF4α blockade reduced immune activation in vitro and disease severity in the experimental model of multiple sclerosis (MS). Network biology studies of human immune transcriptomes unraveled HNF4α together with SP1 and c-myc as master TF regulating differential expression at all MS stages. TF expression was boosted by immune cell activation, regulated by environmental MS risk factors and higher in MS immune cells compared to controls. Administration of compounds targeting TF expression or function demonstrated non-synergic, interdependent transcriptional control of CNS autoimmunity in vitro and in vivo. Collectively, we identified a coregulatory transcriptional network sustaining neuroinflammation and representing an attractive therapeutic target for MS and other inflammatory disorders., Competing Interests: Declaration of competing interest The authors declare no competing interests related to the manuscript., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Adaptation plays an important role in sensory systems as it dynamically modifies sensitivity to allow the detection of stimulus changes. The vomeronasal system controls many social behaviors in most mammals by detecting pheromones released by conspecifics. Stimuli activate a transduction cascade in vomeronasal neurons that leads to spiking activity. Whether and how these neurons adapt to stimuli is still debated and largely unknown. Here, we measured short-term adaptation performing current-clamp whole-cell recordings by using diluted urine as a stimulus, as it contains many pheromones. We measured spike frequency adaptation in response to repeated identical stimuli of 2-10 s duration that was dependent on the time interval between stimuli. Responses to paired current steps, bypassing the signal transduction cascade, also showed spike frequency adaptation. We found that voltage-gated Na + channels in VSNs undergo slow inactivation processes. Furthermore, recovery from slow inactivation of voltage-gated Na + channels occurs in several seconds, a time scale similar to that measured during paired-pulse adaptation protocols, suggesting that it partially contributes to short-term spike frequency adaptation. We conclude that vomeronasal neurons do exhibit a time-dependent short-term spike frequency adaptation to repeated natural stimuli and that slow inactivation of Na + channels contributes to this form of adaptation. These findings not only increase our knowledge about adaptation in the vomeronasal system, but also raise the question of whether slow inactivation of Na + channels may play a role in other sensory systems., (Copyright © 2022 Sarno et al.)

The mouse vomeronasal system controls several social behaviors. Pheromones and other social cues are detected by sensory neurons in the vomeronasal organ (VNO). Stimuli activate a transduction cascade that leads to membrane potential depolarization, increase in cytosolic Ca 2+ level, and increased firing. The Ca 2+ -activated chloride channels TMEM16A and TMEM16B are co-expressed within microvilli of vomeronasal neurons, but their physiological role remains elusive. Here, we investigate the contribution of each of these channels to vomeronasal neuron firing activity by comparing wild-type (WT) and knock-out (KO) mice. Performing loose-patch recordings from neurons in acute VNO slices, we show that spontaneous activity is modified by Tmem16a KO, indicating that TMEM16A, but not TMEM16B, is active under basal conditions. Upon exposure to diluted urine, a rich source of mouse pheromones, we observe significant changes in activity. Vomeronasal sensory neurons (VSNs) from Tmem16a cKO and Tmem16b KO mice show shorter interspike intervals (ISIs) compared with WT mice, indicating that both TMEM16A and TMEM16B modulate the firing pattern of pheromone-evoked activity in VSNs., (Copyright © 2021 Hernandez-Clavijo et al.)

Background: International Classification Functioning (ICF) Core Sets represent a holistic approach to functioning within rehabilitation field. Information-reporting efficacy of a rehabilitation-based Respiratory ICF set applied on a large scale throughout the ICS Maugeri network was tested., Methods: A prospective multi-center study (May-November 2018) was conducted for all respiratory inpatients consecutively admitted for rehabilitation. Doctors, physiotherapists, psychologists, nurses used an electronic Respiratory ICF set (33 items among the ICF body functions, activity and participations components) at admission and at discharge to assess the disability changes. The ICF report qualifiers, from 0 (no impairment) to 4 (maximum impairment), guided clinical, diagnostic and rehabilitation prescriptions., Results: 1886 patients (69.6±10.8 years; M=1045) were admitted (589 chronic obstructive pulmonary disease, 494 chronic respiratory failure [CRF], 21 prolonged mechanical ventilation [PMV], 496 with other respiratory diseases), of whom 15 died, and 117 were transferred to acute care. The mean length of stay was 23.1±11.8 days (range 1-122). The mean time to fill in the ICF set was 23.16±0.70 min. The rate of filled charts improved from 16% in May to 100% in November. The baseline distribution of the more severe qualifiers (>2) progressively increased from the whole sample to the PMV subgroup. After rehabilitation, in the whole sample and in the CRF and PMV subgroups, the severity qualifiers significantly decreased (P<0.0001), showing a positive effect of the intervention on patients' disability., Conclusions: Routine use of a Respiratory ICF set for chronic respiratory diseases helps to prepare a personalized rehabilitation program discriminating disability level in different respiratory diseases and assessing disability outcomes pre-post rehabilitation.

Study Objectives: There are few studies evaluating (1) exercise capacity as assessed by the 6-minute walking distance (6MWD) test in large populations with obstructive sleep apnea (OSA); and (2) correlations with patients' comorbidities., Methods: This study presents a cluster analysis performed on the data of 1,228 patients. Severity of exercise limitation was defined on the basis of 6MWD., Results: Sixty-one percent showed exercise limitation (29.2% and 31.9% mild and severe exercise limitation, respectively). About 60% and 40% of patients were included in cluster 1 (CL1) and 2 (CL2), respectively. CL1 included younger patients with high prevalence of apneas, desaturations, and hypertension with better exercise tolerance. CL2 included older patients, all with chronic obstructive pulmonary disease (COPD), high prevalence of chronic respiratory failure (CRF), fewer apneas but severe mean desaturation, daytime hypoxemia, more severe exercise limitation, and exercise-induced desaturations. Only CRF and COPD significantly (P < .001) correlated with 6MWD < 85% of predicted value. 6MWD correlated positively with apnea-hypopnea index, oxygen desaturation index, nocturnal pulse oxygen saturation (SpO₂), resting arterial oxygen tension, mean SpO₂ on exercise, and negatively with age, body mass index, time spent during night with SpO₂ < 90%, mean nocturnal desaturation, arterial carbon dioxide tension, and number of comorbidities. Patients without severe comorbidities had higher exercise capacity than those with severe comorbidities, (P < .001). Exercise limitation was significantly worse in OSA severity class I when compared to other classes (P < .001)., Conclusions: A large number of patients with OSA experience exercise limitation. Older age, comorbidities such as COPD and CRF, OSA severity class I, severe mean nocturnal desaturation, and daytime hypoxemia are associated with worse exercise tolerance., (© 2020 American Academy of Sleep Medicine.)

Recent evidence suggests that the primary progressive form of multiple sclerosis (PP-MS) may present with specific immunological alterations. In this study we focused our attention on CD161, an NK and T cell marker upregulated in relapsing-remitting MS, and investigated its transcript and protein levels in blood cells from PP-MS and healthy individuals. We demonstrated transcriptional downregulation of CD161 in PP-MS and described concomitant mRNA reduction for RORgt, CCR6, CXCR6, KLRK1/NKG2D and many other markers typical of mucosa associated invariant T (MAIT) cells. Targeted multiparametric flow cytometry on fresh blood cells from an independent cohort of case-control subjects confirmed the selective loss of circulating CD8 CD161 high T cells, which consist mainly of MAIT cells, and not of CD8 CD161 int T cells in PP-MS. These data demonstrate alterations in a specific circulating immune cell subset in MS patients with progressive onset.

Background: Lung diffusing capacity (DLCO) and lung volume distribution predict exercise performance and are altered in COPD patients. If pulmonary rehabilitation (PR) can modify DLCO parameters is unknown., Objectives: To investigate changes in DLCO and ventilation inhomogeneity following a PR program and their relation with functional outcomes in patients with COPD., Methods: This was a prospective, observational, multicentric study. Patients were evaluated before and after a standardized 3-week PR program. Functional assessment included body plethysmography, DLCO, transfer factor (KCO) and alveolar volume (VA), gas exchange, the 6-min walking test (6MWT) and exercise-related dyspnea. Patients were categorized according to the severity of airflow limitation and presence of ventilation inhomogeneity, identified by a VA/TLC <0.8., Results: Two hundred and fifty patients completed the study. Baseline forced expiratory volume in 1 s (FEV1) % predicted (mean ± SD) was 50.5 ± 20.1 (76% males); 137 patients had a severe disease. General study population showed improvements in 6MWT (38 ± 55 m; p < 0.01), DLCO (0.12 ± 0.63 mmol × min-1 kPa-1; p < 0.01), lung function and dyspnea. Comparable improvements in DLCO were observed regardless of the severity of disease and the presence of ventilation inhomogeneity. While patients with VA/TLC <0.8 improved the DLCO increasing their VA (177 ± 69 ml; p < 0.01), patients with VA/TLC >0.8 improved their KCO (8.1 ± 2.8%; p = 0.019). The latter had also better baseline lung function and higher improvements in 6MWT (14.6 ± 6.7 vs. 9.0 ± 1.8%; p = 0.015). Lower DLCO at baseline was associated with lower improvements in 6MWT, the greatest difference being between subjects with very severe and mild DLCO impairment (2.7 ± 7.4 vs. 14 ± 2%; p = 0.049)., Conclusions: In COPD patients undergoing a PR program, different pathophysiological mechanisms may drive improvements in DLCO, while ventilation inhomogeneity may limit improvements in exercise tolerance., (© 2016 S. Karger AG, Basel.)