Thinning enhances forest soil C storage by shifting the soil toward an oligotrophic condition.

Forests are significant carbon reservoirs, with approximately one-third of this carbon stored in the soil. Forest thinning, a prevalent management technique, is designed to enhance timber production, preserve biodiversity, and maintain ecosystem functions. Through its influence on biotic and abiotic factors, thinning can profoundly alter soil carbon storage. Yet, the full implications of thinning on forest soil carbon reservoirs and the mechanisms underpinning these changes remain elusive. In this study, we undertook a two-year monitoring initiative, tracking changes in soil extracellular enzyme activities (EEAs), microbial communities, and other abiotic parameters across four thinning intensities within a temperate pine forest. Our results show a marked increase in soil carbon stock following thinning. However, thinning also led to decreased dissolved organic carbon (DOC) content and a reduced DOC to soil organic carbon (SOC) ratio, pointing toward a decline in soil carbon lability. Additionally, fourier transform infrared spectroscopy (FTIR) analysis revealed an augmented relative abundance of aromatic compounds after thinning. There was also a pronounced increase in absolute EEAs (per gram of dry soil) post-thinning, implying nutrient limitations for soil microbes. Concurrently, the composition of bacterial and fungal communities shifted toward oligotrophic dominance post thinning. Specific EEAs (per gram of soil organic matter) exhibit a significant reduction following thinning, indicating a deceleration in organic matter decomposition rates. In essence, our findings reveal that thinning transitions soil toward an oligotrophic state, dampening organic matter decomposition, and thus bolstering the soil carbon storage potential of forest. This study provides enhanced insights into the nuanced relationship between thinning practices and forest soil carbon dynamics, serving as a robust foundation for enlightened forest management strategies.

Calcium-enriched biochar shifts negative effects of fluoride on the properties of arid sandy soil.

This study sheds light on the influence of fluoride on the changes in the properties of alkaline sandy soils and the efficiency of calcium-enriched biochar application. The investigation involved an incubation experiment with soil contaminated with varying NaF concentrations (0, 400, 800, and 1200 mg NaF kg-1 soil) and biochar (1% w/w). The data revealed that adding NaF to the soil resulted in significant increases in soil pH and decreases in total nitrogen (TN) content. Short-term fluoride pollution did not affect the microbial abundance due to certain factors such as increased soil pH and decreased microbial metabolism promoting the survival of cells under fluoride stress. However, a shift from bacterial to fungal-dominated microbial communities was observed at the highest NaF concentration. The nitrogen functional gene amoA was found to be highly sensitive to fluoride toxicity. The decrease in the abundance of amoA gene and the increase in soil pH can explain reduced nitrogen concentration. On the other hand, our findings indicated a significant decrease in enzyme activity in soil contaminated with mild to severe levels of NaF. This reduction in enzyme activity can be attributed to increased soil pH, decreased TN content, and the inhibition of microbial metabolism due to fluoride toxicity. Furthermore, the addition of calcium-rich biochar reduced fluoride solubility and adjusted pH, mitigating the negative effects of fluoride toxicity on soil properties. The use of biochar was also found to inhibit the accumulation of soil fluoride-resistant microbial genes.

Eosinophilic Granulomatosis With Polyangiitis Following COVID-19 Vaccination: A Case Report.

The current emergence of the coronavirus disease 2019 (COVID-19) pandemic and the possible side effects of COVID-19 mRNA vaccination remain worrisome. Few cases of vaccination-related side effects, such as vasculitis, have been reported. Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss syndrome, is a type of vasculitis characterized by the histological richness of eosinophils, asthma, polyneuropathy, sinusitis, and skin or lung involvement. Here, we report the first case of new onset EGPA following COVID-19 vaccination in Korea. A 71-year old woman developed a skin rash and presented with progressive weakness of the upper and lower extremities after the BNT162b2 vaccination (Pfizer-BioNTech). She was diagnosed with EGPA and her symptoms improved after systemic steroid and immunosuppressant therapy. Although it is very rare, clinicians should be aware that EGPA may occur after COVID-19 vaccination.

Bronchial epithelial cells release inflammatory markers linked to airway inflammation and remodeling in response to TLR5 ligand flagellin.

Background/Aims: Flagellin, which is abundant in gram-negative bacteria, including Pseudomonas, is reported to influence on inflammatory responses in various lung diseases. However, its effect on airway epithelial cells in contribution to asthma pathogenesis is not elucidated yet. We aimed to investigate the effect of TLR5 ligand flagellin on the transcriptomic profile of primary human epithelial cells and to determine the markers of airway inflammation. Methods: Normal human bronchial epithelial (NHBE) cells were grown and differentiated in air-liquid interface (ALI) culture for 14-16 days. The cells were treated with flagellin in vitro at 10 and 100 ng/ml for 3 and 24 h. The conditioned media and cells were harvested to validate inflammatory markers involved in airway inflammation using ELISA, Western blot, and quantitative PCR methods. RNA-sequencing was performed to investigate the transcriptional response to flagellin in ALI-NHBE cells. Results: Altered transcriptional responses to flagellin in differentiated bronchial epithelial cells were determined, including genes encoding chemokines, matrix metalloproteinases, and antimicrobial biomolecules. Pathway analysis of the transcriptionally responsive genes revealed enrichment of signaling pathways. Flagellin induced the mRNA expressions of proinflammatory cytokines and chemokines, and secretion of GM-CSF, CXCL5, CCL5 and CXCL10. Flagellin enhanced the protein expression of MMP-13 in TGF-ß1 and TGF-ß2 pretreated cell lysates and Wnt/ß-catenin signaling. Conclusions: These findings suggest that flagellin could be a potent inducer of inflammatory markers that may contribute to airway inflammation and remodeling.

Neuromuscular blocking agent re-exposure in a retrospective cohort with neuromuscular blocking agent-associated anaphylaxis.

BACKGROUND: Neuromuscular blocking agents (NMBAs) are one of the most common causes of perioperative anaphylaxis. Although skin test positivity may help identify reactive NMBAs, it is unclear whether skin test negativity can guarantee the safety of systemically administered NMBAs. OBJECTIVE: This study aimed to evaluate the real-world safety of alternative NMBAs screened using skin tests in patients with suspected NMBA-induced anaphylaxis. METHODS: A retrospective cohort of suspected NMBA-induced anaphylaxis were recruited among patients at Seoul National University Hospital from June 2009 to May 2021, and their characteristics and outcomes were assessed. RESULTS: A total of 47 cases (0.017%) of suspected anaphylaxis occurred in 282,707 patients who received NMBAs. Cardiovascular manifestations were observed in 95.7%, whereas cutaneous findings were observed in 59.6%. Whereas 83% had a history of undergoing general anesthesia, 17% had no history of NMBA use. In skin tests, the overall positivity to any NMBA was 94.6% (81.1% to culprit NMBAs) and the cross-reactivity was 75.7%, which is related to the chemical structural similarity among NMBAs; the cross-reactivity and chemical structure similarity of rocuronium were 85.3% and 0.814, respectively, with vecuronium; this is in contrast to 50% and 0.015 with cisatracurium and 12.5% and 0.208 with succinylcholine. There were 15 patients who underwent subsequent surgery with a skin test-negative NMBA; whereas 80.0% (12/15) safely completed surgery, 20.0% (3/15) experienced hypotension. CONCLUSION: Similarities in chemical structure may contribute to the cross-reactivity of NMBAs in skin tests. Despite the high negative predictability of skin tests for suspected NMBA-induced anaphylaxis, the potential risk of recurrent anaphylaxis has not been eliminated.

Soil organic carbon is a key determinant of CH4 sink in global forest soils.

Soil organic carbon (SOC) is a primary regulator of the forest-climate feedback. However, its indicative capability for the soil CH4 sink is poorly understood due to the incomplete knowledge of the underlying mechanisms. Therefore, SOC is not explicitly included in the current model estimation of the global forest CH4 sink. Here, using in-situ observations, global meta-analysis, and process-based modeling, we provide evidence that SOC constitutes an important variable that governs the forest CH4 sink. We find that a CH4 sink is enhanced with increasing SOC content on regional and global scales. The revised model with SOC function better reproduces the field observation and estimates a 39% larger global forest CH4 sink (24.27 Tg CH4 yr-1) than the model without considering SOC effects (17.46 Tg CH4 yr-1). This study highlights the role of SOC in the forest CH4 sink, which shall be factored into future global CH4 budget quantification.

Attenuation of Methane Oxidation by Nitrogen Availability in Arctic Tundra Soils.

CH4 emission in the Arctic has large uncertainty due to the lack of mechanistic understanding of the processes. CH4 oxidation in Arctic soil plays a critical role in the process, whereby removal of up to 90% of CH4 produced in soils by methanotrophs can occur before it reaches the atmosphere. Previous studies have reported on the importance of rising temperatures in CH4 oxidation, but because the Arctic is typically an N-limited system, fewer studies on the effects of inorganic nitrogen (N) have been reported. However, climate change and an increase of available N caused by anthropogenic activities have recently been reported, which may cause a drastic change in CH4 oxidation in Arctic soils. In this study, we demonstrate that excessive levels of available N in soil cause an increase in net CH4 emissions via the reduction of CH4 oxidation in surface soil in the Arctic tundra. In vitro experiments suggested that N in the form of NO3- is responsible for the decrease in CH4 oxidation via influencing soil bacterial and methanotrophic communities. The findings of our meta-analysis suggest that CH4 oxidation in the boreal biome is more susceptible to the addition of N than in other biomes. We provide evidence that CH4 emissions in Arctic tundra can be enhanced by an increase of available N, with profound implications for modeling CH4 dynamics in Arctic regions.

Distinct Nitrification Rates and Nitrifiers in Needleleaf and Evergreen Broadleaf Forest Soils.

Research on niche specialization in the microbial communities of ammonia oxidizers is important for assessing the consequences of vegetation shift on nitrogen (N) cycling. In this study, soils were sampled from three tree stands (needleleaf, mixed, and evergreen broadleaf) from the Hannam experimental forest in South Korea in spring (May 2019), summer (August 2019), autumn (November 2019), and winter (January 2020). Quantitative polymerase chain reaction (qPCR) and high-throughput sequencing were used to measure the abundance and community structure of various nitrifiers: ammonia-oxidizing archaea and bacteria (AOA and AOB, respectively) as well as complete ammonia oxidizers (comammox). Nitrification rates and total ammonia oxidizer abundance were significantly higher in needleleaf forest soil than those in other forest stands, and they were lowest in evergreen broadleaf forest soil. Comammox clade B was most abundant in needleleaf and evergreen broadleaf forest soils, while AOA were significantly more abundant in mixed forest soil. The abundances of comammox clade B and AOA were negatively correlated with dissolved organic carbon. Phylogenetic analysis showed that NT-alpha and NS-gamma-2.3.2 were the most abundant AOA lineages in all the samples. The seasonal of AOA, AOB, and comammox varied with the sites, suggesting the need to examine the combinations of environmental factors when considering the effects of seasonal changes in the environment. Overall, the results suggest that potential vegetation shifts in forest ecosystems might affect nitrification activities by regulating the abundance and community structure of ammonia oxidizers.

Effects of vegetation shift from needleleaf to broadleaf species on forest soil CO2 emission.

Forest soil harbors diverse microbial communities with decisive roles in ecosystem processes. Vegetation shift from needleleaf to broadleaf species is occurring across the globe due to climate change and anthropogenic activities, potentially change forest soil microbial communities and C cycle. However, our knowledge on the impact of such vegetation shift on soil microbial community and activities, and its consequences on forest soil C dynamics are still not well established. Here, we examined the seasonal variation of soil CO2 emission, soil extracellular enzyme activities (EEAs), and soil bacterial, fungal communities in subtropical forest from broadleaf, needleleaf, and mixed stands. In addition, soil CO2 emission and soil EEAs were measured in temperate forest during the growing season. Soil organic matter (SOM) content significantly differs between broadleaf and needleleaf forests and primarily distinguish various soil chemical and microbial characteristics. Significantly higher EEAs and soil CO2 emission in broadleaf forest compared to needleleaf forest were observed both in subtropical and temperate forests. The relative abundance of Basidiomycota positively correlated with SOM and EEAs and indirectly increase soil CO2 emission whereas the relative abundance of Ascomycota exhibits opposite trend, suggesting that soil fungal communities play a key role in determining the different microbial activities between broadleaf and needleleaf stands. The temperature sensitivity of soil CO2 emission was significantly higher in broadleaf forest compared to needleleaf forest, further suggesting that the soil organic carbon in broadleaf forests is more vulnerable to warming.

Lipid metabolic reprogramming by hypoxia-inducible factor-1 in the hypoxic tumour microenvironment.

Cancer cells rewire metabolic processes to adapt to the nutrient- and oxygen-deprived tumour microenvironment, thereby promoting their proliferation and metastasis. Previous research has shown that modifying glucose metabolism, the Warburg effect, makes glycolytic cancer cells more invasive and aggressive. Lipid metabolism has also been receiving attention because lipids function as energy sources and signalling molecules. Because obesity is a risk factor for various cancer types, targeting lipid metabolism may be a promising cancer therapy. Here, we review the lipid metabolic reprogramming in cancer cells mediated by hypoxia-inducible factor-1 (HIF-1). HIF-1 is the master transcription factor for tumour growth and metastasis by transactivating genes related to proliferation, survival, angiogenesis, invasion, and metabolism. The glucose metabolic shift (the Warburg effect) is mediated by HIF-1. Recent research on HIF-1-related lipid metabolic reprogramming in cancer has confirmed that HIF-1 also modifies lipid accumulation, ß-oxidation, and lipolysis in cancer, triggering its progression. Therefore, targeting lipid metabolic alterations by HIF-1 has therapeutic potential for cancer. We summarize the role of the lipid metabolic shift mediated by HIF-1 in cancer and its putative applications for cancer therapy.

Temporal Variations Rather than Long-Term Warming Control Extracellular Enzyme Activities and Microbial Community Structures in the High Arctic Soil.

In Arctic soils, warming accelerates decomposition of organic matter and increases emission of greenhouse gases (GHGs), contributing to a positive feedback to climate change. Although microorganisms play a key role in the processes between decomposition of organic matter and GHGs emission, the effects of warming on temporal responses of microbial activity are still elusive. In this study, treatments of warming and precipitation were conducted from 2012 to 2018 in Cambridge Bay, Canada. Soils of organic and mineral layers were collected monthly from June to September in 2018 and analyzed for extracellular enzyme activities and bacterial community structures. The activity of hydrolases was the highest in June and decreased thereafter over summer in both organic and mineral layers. Bacterial community structures changed gradually over summer, and the responses were distinct depending on soil layers and environmental factors; water content and soil temperature affected the shift of bacterial community structures in both layers, whereas bacterial abundance, dissolved organic carbon, and inorganic nitrogen did so in the organic layer only. The activity of hydrolases and bacterial community structures did not differ significantly among treatments but among months. Our results demonstrate that temporal variations may control extracellular enzyme activities and microbial community structure rather than the small effect of warming over a long period in high Arctic soil. Although the effects of the treatments on microbial activity were minor, our study provides insight that microbial activity may increase due to an increase in carbon availability, if the growing season is prolonged in the Arctic.

Changes in Archaeal Community and Activity by the Invasion of Spartina anglica Along Soil Depth Profiles of a Coastal Wetland.

Invasion of Spartina spp. in tidal salt marshes may affect the function and characteristics of the ecosystem. Previous studies reported that the invasion alters biogeochemical and microbial processes in marsh ecosystems, yet our knowledge of changing archaeal community due to the invasion is still limited, whereas archaeal communities play a pivotal role in biogeochemical cycles within highly reduced marsh soils. In this study, we aimed to illustrate the influences of the Spartina anglica invasion on soil archaeal community and the depth profile of the influences. The relative abundance of archaeal phyla demonstrated that the invasion substantially shifted the characteristics of tidal salt marsh from marine to terrestrial soil only in surface layer, while the influences indirectly propagated to the deeper soil layer. In particular, two archaeal phyla, Asgardaeota and Diapherotrites, were strongly influenced by the invasion, indicating a shift from marine to terrestrial archaeal communities. The shifts in soil characteristics spread to the deeper soil layer that results in indirect propagation of the influences of the invasion down to the deeper soil, which was underestimated in previous studies. The changes in the concentration of dissolved organic carbon and salinity were the substantial regulating factors for that. Therefore, changes in biogeochemical and microbial characteristics in the deep soil layer, which is below the root zone of the invasive plant, should be accounted for a more accurate illustration of the consequences of the invasion.

Tumor-intrinsic FABP5 is a novel driver for colon cancer cell growth via the HIF-1 signaling pathway.

Dysfunctional lipid metabolism is a known cause of cancer development and progression, yet little is known about the underlying molecular mechanisms that contribute to cancer progression. In this study, we demonstrate that fatty acid binding protein 5 (FABP5) is elevated in colon cancer tissue and this increased expression is linked to upregulation of the hypoxia-inducible factor-1 (HIF-1) signaling pathway. Under physiologically in vivo mimicked conditions via a polydimethylsiloxane (PDMS)-based three-dimensional (3D) culture chip, FABP5-knockdown colon cancer cells exhibited attenuated cell growth throughout the culture period. FABP5 was found to regulate HIF-1α protein levels and gene expression levels within the HIF-1α signaling pathway under hypoxic conditions. Our results provide evidence that supports the use of FABP5 as a prognostic factor in colon cancer. The FABP5/HIF-1α axis is a promising target for ameliorating fatty acid-triggered cancer progression.

Contrasting early successional dynamics of bacterial and fungal communities in recently deglaciated soils of the maritime Antarctic.

Although microorganisms are the very first colonizers of recently deglaciated soils even prior to plant colonization, the drivers and patterns of microbial community succession at early-successional stages remain poorly understood. The successional dynamics and assembly processes of bacterial and fungal communities were compared on a glacier foreland in the maritime Antarctic across the ~10-year soil-age gradient from bare soil to sparsely vegetated area. Bacterial communities shifted more rapidly than fungal communities in response to glacial retreat; species turnover (primarily the transition from glacier- to soil-favouring taxa) contributed greatly to bacterial beta diversity, but this pattern was less clear in fungi. Bacterial communities underwent more predictable (more deterministic) changes along the soil-age gradient, with compositional changes paralleling the direction of changes in soil physicochemical properties following deglaciation. In contrast, the compositional shift in fungal communities was less associated with changes in deglaciation-induced changes in soil geochemistry and most fungal taxa displayed mosaic abundance distribution across the landscape, suggesting that the successional dynamics of fungal communities are largely governed by stochastic processes. A co-occurrence network analysis revealed that biotic interactions between bacteria and fungi are very weak in early succession. Taken together, these results collectively suggest that bacterial and fungal communities in recently deglaciated soils are largely decoupled from each other during succession and exert very divergent trajectories of succession and assembly under different selective forces.

Microbial decomposition of soil organic matter determined by edaphic characteristics of mangrove forests in East Asia.

Mangrove forests cover only 0.1% of the world's continental area; however, these are a substantial carbon sink owing to the high primary production and low rate of decomposition of soil organic matter (SOM). The extremely low decomposition rate of SOM in mangrove forests is believed to be caused by low oxygen and nutrient availability as well as recalcitrant biomass from mangrove. However, only a few studies have addressed the microbial mechanism that plays a key role in the decomposition of SOM. In this study, the decomposition of SOM were determined by conducting a field survey and an lab incubation experiment using soil samples from mangrove forests in three regions; Okinawa, Shenzhen, and Hong Kong. In particular, we examined the occurrence of the enzymic latch mechanism, which involves phenolic inhibition of enzymic decomposition, in mangrove forest soils that highlights the importance of phenol oxidase as a key controlling factor. The results clearly showed that enzymic latch involved in the accumulation of SOM in the mangroves of Shenzhen and Hong Kong, whereas the accumulation of SOM in Okinawa was controlled by other mechanisms, such as the iron gate mechanism, which involves stabilization of soil carbon in iron-SOM complexes. The characteristics of mangrove forests, such as iron concentration, were shown as substantial determination factors in the dynamics of SOM. We concluded that the decomposition of SOM were strongly affected by the characteristics of mangrove forests, and the occurrence of enzymic latch in mangrove forests has a potential application in geoengineering technology to enhance the carbon sequestration capacity of mangrove forests.