University of Porto

TUESDAY, Dec. 17, 2024 -- There’s fungus among us, and it might be making allergies and asthma worse. People with allergy sniffles and asthma have different fungal colonies in their noses than folks who don’t suffer respiratory allergies, researchers report Dec. 16 in the journal Frontiers in Microbiology . “We showed that allergic rhinitis samples displayed a significantly higher fungal diversity and a different fungal community structure compared to those of healthy controls,” said researcher Dr. Luís Delgado with the University of Porto in Portugal. For the study, researchers took nasal swabs from 214 children and young adults being treated at an immunology and asthma clinic in Porto. Researchers sequenced the fungal DNA they found, and compared it to samples taken from 125 healthy people. They detected common fungi that are known to promote allergies or disease in humans. “This suggests that the nasal cavity is a major reservoir for fungi that could be involved in allergic rhinitis and asthma,” Delgado said in a journal news release. What’s more, patients with respiratory diseases had more diverse and richer fungal colonies in their nose, particularly those with allergies and asthma combined. This could indicate that the fungi are affecting the immune environment in the nose. “However, we could not control all patient-specific variables, such as disease severity and related treatment levels, and patients were sampled at a single time,” Delgado cautioned. Follow-up studies will focus on those variables, he said. Future research could also see if lowering fungal levels in the nose might improve allergy or asthma symptoms. Whatever your topic of interest, subscribe to our newsletters to get the best of Drugs.com in your inbox.

小胶质细胞以其在中枢神经系统中的免疫和保护作用而闻名。这些功能需要小胶质感觉体的协调响应，其中细胞表面的模式识别受体(PRRs)识别病原体相关分子模式(PAMPs)和组织损伤相关分子模式(DAMPs) 小胶质细胞以其在中枢神经系统中的免疫和保护作用而闻名。这些功能需要小胶质感觉体的协调响应，其中细胞表面的模式识别受体(PRRs)识别病原体相关分子模式(PAMPs)和组织损伤相关分子模式(DAMPs)是最关键的参与者。PAMPs，如nod样受体(NLRs)和toll样受体(TLRs)，通常识别存在于各种病原体中的结构保守分子。受损细胞释放的DAMPs(如ATP、谷氨酸、DNA、RNA)通常与将小胶质细胞吸引到受损部位有关。 图片来源：https://doi-org.libproxy1.nus.edu.sg/10.1038/s41419-023-06217-w 近日，来自波尔图大学的研究者们在Cell Death Dis.杂志上发表了题为“RhoA balances microglial reactivity and survival during neuroinflammation”的文章，该研究表明在神经炎症期间，最低水平的RhoA活性是连接小胶质细胞炎症反应和存活所必需的。 小胶质细胞是大脑中最大的髓系细胞群。在损伤、疾病或炎症期间，小胶质细胞采取不同的功能状态，主要参与恢复大脑稳态。然而，持续或加剧的小胶质细胞炎症反应可导致脑损伤。动态细胞骨架重组与外部信号驱动的小胶质细胞反应性改变相关，而控制细胞骨架重组的蛋白质，如Rho GTPase RhoA，在损伤、疾病或炎症期间可以很好地改善或调节小胶质细胞的功能状态。 在这里，研究者使用基于多生物传感器的活细胞成像方法和小鼠组织特异性条件基因消融来了解RhoA在小胶质细胞对炎症反应中的作用。研究者发现RhoA活性的降低是小胶质细胞代谢重编程和炎症反应性的绝对要求。然而，如果没有RhoA，炎症会破坏Ca2+和pH稳态，抑制线粒体功能，恶化小胶质细胞坏死，并引发小胶质细胞凋亡。 小胶质细胞对神经炎症的反应需要严格控制RhoA活性 图片来源：https://doi-org.libproxy1.nus.edu.sg/10.1038/s41419-023-06217-w 综上所述，降低RhoA活性(在一定程度上)是实现足够的小胶质细胞炎症能力所必需的。然而，维持最低水平的RhoA活性对于炎症期间小胶质细胞的存活至关重要。因此，微调RhoA信号以平衡小胶质细胞的反应性可能有利于在涉及神经炎症的脑疾病中保持神经元的可塑性。(生物谷 Bioon.com） 参考文献 Renato Socodato et al. Cell Death Dis. RhoA balances microglial reactivity and survival during neuroinflammation. 2023 Oct 20;14(10):690. doi: 10.1038/s41419-023-06217-w.

Using ancestry decomposition techniques an international research team has revealed a deeply divergent ancestry among admixed populations from the Angolan Namib desert. This unique genetic heritage brings the researchers closer to understanding the distribution of genetic variation in the broader region of southern Africa before the spread of food production. Using ancestry decomposition techniques an international research team has revealed a deeply divergent ancestry among admixed populations from the Angolan Namib desert. This unique genetic heritage brings the researchers closer to understanding the distribution of genetic variation in the broader region of southern Africa before the spread of food production. Africa is the birthplace of modern humans and the continent with the highest level of genetic diversity. While ancient DNA studies are revealing some aspects of the genetic structure of Africa before the spread of food production, issues concerning DNA preservation have limited the insights from ancient DNA. Hoping to find clues in modern populations, researchers from a Portuguese-Angolan TwinLab ventured into the Angolan Namib desert -- a remote, multi-ethnic region where different traditions met. "We were able to locate groups which were thought to have disappeared more than 50 years ago," states Jorge Rocha, a population geneticist from Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO, University of Porto) who led the fieldwork, together with Angolan anthropologists Samuel and Teresa Aço from the Centro de Estudos do Deserto (CEDO). Among the communities the team encountered are the Kwepe, a pastoral group who used to speak a language known as Kwadi. "Kwadi was a click-language that shared a common ancestor with the Khoe languages spoken by foragers and herders across southern Africa," explains Anne-Maria Fehn, a linguist from CIBIO who participated in the fieldwork and was able to interview what may well be the last two speakers of Kwadi. "Khoe-Kwadi languages have been linked to a prehistoric migration of eastern African pastoralists," adds Rocha, whose research focuses on southern African population history. In addition, the team contacted Bantu-speaking groups that are part of the dominant pastoral tradition of southwest Africa, as well as marginalized groups whose origins have been associated with a foraging tradition, distinct from that of the neighboring Kalahari peoples, and whose original language was supposedly lost. Modern DNA research can complement ancient DNA studies The team's new study shows that the inhabitants of the Angolan Namib are quite divergent from other modern populations but also highly structured among themselves. "In agreement with our previous studies on the maternally-inherited DNA, most genome-wide diversity segregates according to socio-economic status. A lot of our efforts were placed in understanding how much of this local variation and global excentricity was caused by genetic drift -- a random process that disproportionally affects small populations -- and by admixture from vanished populations," says Sandra Oliveira, a researcher at the University of Bern in Switzerland who worked with these populations during her PhD and post-doc studies with Rocha and Mark Stoneking at CIBIO and the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig, Germany. The team demonstrated that besides the high impact of genetic drift, which contributed to differences among neighboring groups of different socio-economic status, the descendants of Kwadi speakers and the marginalized communities of the Namib Desert retain a unique Pre-Bantu ancestry that is only found in populations from the Namib desert. Mark Stoneking, who contributed to the earliest genome-wide studies on southern African foragers and participated in this study, says: "Previous studies revealed that foragers from the Kalahari desert descend from an ancestral population who was the first to split from all other extant humans. Our results consistently place the newly identified ancestry within the same ancestral lineage but suggest that the Namib-related ancestry diverged from all other southern African ancestries, followed by a split of northern and southern Kalahari ancestries." With this new information, the researchers could reconstruct the fine-scale histories of contact emerging from the migration of Khoe-Kwadi-speaking pastoralists and Bantu-speaking farmers into southern Africa. Moreover, the study demonstrates that modern DNA research targeting understudied regions of high ethnolinguistic diversity can complement ancient DNA studies in probing the deep genetic structure of the African continent.