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International Journal of Molecular Sciences

International Journal of Molecular Sciences is an international, peer-reviewed, open access journal providing an advanced forum for biochemistry, molecular and cell biology, molecular biophysics, molecular medicine, and all aspects of molecular research in chemistry, and published semimonthly online by MDPI.
The Epigenetics Society, European Chitin Society (EUCHIS), Spanish Society for Cell Biology (SEBC) and others are affiliated with IJMS and their members receive a discount on the article processing charges.
Indexed in PubMed | Quartile Ranking JCR - Q1 (Biochemistry and Molecular Biology)

All Articles (107,532)

Singlet Oxygen Generation and Signaling in Higher Plants

  • Huan Zhao,
  • Xinyue Wang and
  • Liangsheng Wang

Singlet oxygen (1O2), the excitation stage of the ground-state molecular oxygen, is a fundamental reactive oxygen species (ROS) with important functions in plant growth, development, and stress responses. In plant cells, 1O2 is mainly generated in the chloroplast due to photosensitizing activity of tetrapyrroles. Moreover, 1O2 can be generated in non-photosynthetic tissues when plants suffer environmental stresses. Although 1O2 was initially considered as a cytotoxin—causing merely photooxidative damages, more recent work suggests that 1O2 also acts as a signal that either triggers a programmed cell death response or promotes acclimation. The 1O2 signaling pathway is distinct and operates independently of other ROS signaling cascades. In Arabidopsis, EXECUTER1 (EX1) protein has been identified as a crucial signaling component that perceives and relays 1O2 signals to the nucleus, thereby initiating extensive transcriptional reprogramming. Additionally, oxidative products of carotenoids, such as β-cyclocitral, are also recognized as 1O2-derived signaling molecules. Through specific chloroplast-to-nucleus signaling and cross talk with hormone signaling networks—including jasmonic acid (JA) and salicylic acid (SA)—1O2 helps finely coordinate plant growth, defense responses, and cell fate decisions under fluctuating environmental conditions. This review aims to summarize current knowledge on 1O2 generation and signaling, 1O2-induced chloroplast changes under diverse stress conditions, and cross talk between 1O2 and phytohormone signaling.

1 February 2026

Simplified model of tetrapyrrole metabolism in chloroplasts. Tetrapyrrole biosynthesis originates from glutamic acid and shares a common biosynthetic pathway until the formation of protoporphyrin IX (Proto IX). Then, this pathway diverges to the Mg branch (leading to the formation of Chls) and Fe branch (leading to the formation of heme and the subsequent phytochromobilin or phycobilin). Mg–protoporphyrin is subsequently converted to chlorophyll a, which can be further converted to chlorophyll b by CAO. Chlorophyll degradation begins with the conversion of chlorophyll a to pheophytin a by releasing the Mg2+ ion via MgD (Mg–dechelatase), followed by cleavage by PPH and PAO to produce red chlorophyll catabolite (RCC) and subsequently fluorescent chlorophyll catabolites (FCCs), which are finally converted to non-fluorescent chlorophyll catabolites (NCCs). Heme is the precursor of phytochromoblins and phycobilins.

Cytokine Dynamics in Severe COVID-19 vs. Influenza A Elderly Patients: A Prospective Comparative Study

  • Mihai Aronel Rus,
  • Adina Huțanu and
  • Mihaela Sorina Lupșe
  • + 4 authors

COVID-19 and influenza A (FluA) cause severe respiratory infections in elderly patients, with cytokine dysregulation playing a central role. Direct comparative data in older adults remains limited. We aimed to characterize cytokine dynamics and their prognostic value in hospitalized elderly patients with COVID-19 vs. FluA. We performed a prospective cohort study including adults ≥ 60 years hospitalized with respiratory failure due to COVID-19 or FluA between March 2023 and March 2024. Serum IL-1β, IL-6, IL-10, IL-17A, IL-34, MCP-1, and CXCL10 were measured on Day 1 and Day 5 of hospitalization using Luminex®. Cytokines and associations with non-invasive ventilation (NIV) were assessed by ROC analysis and multivariate logistic regression. 83 patients were included (39 COVID-19, median age 79 years; 44 FluA, median 77 years). At Day 1, COVID-19 exhibited significantly higher IL-6, IL-10, and CXCL10; FluA showed an attenuated cytokine response. At Day 5, cytokines declined in both groups. Baseline IL-6 independently predicted NIV (adjusted OR 3.02), whereas higher MCP-1 was associated with reduced NIV requirement. Early cytokine differences between COVID-19 and FluA are evident in elderly patients, but values converged by Day 5. IL-6 remains an informative early predictor of respiratory deterioration; MCP-1 may reflect a regulated innate response.

1 February 2026

Developmental biology is focused on the study of all phenotypic traits responsible for the timely and adequate progression of all molecular genetic, biochemical, and morphogenetic processes as the norm of the corresponding biological species in an individual living organism (ontogenesis) from either fertilization during sexual reproduction or separation from the maternal organism during asexual reproduction to the end of its life [...]

1 February 2026

The neurovascular unit (NVU) is an essential, dynamic multicellular unit that maintains the homeostasis and function of the brain, with the integrity of the NVU having a tremendous impact on the pathogenic progression of ischemic stroke (IS). MicroRNAs (miRNAs) are essential regulators of gene expression and promote intercellular communication and functional unity in the NVU. This narrative review assesses the regulatory process mediated by miRNAs that help maintain homeostasis of the NVU, particularly during IS, with particular emphasis on their modulation of tight-junction (TJ) proteins, basement membrane (BM) and glial–vascular. These regulatory actions are essential for blood–brain barrier (BBB) integrity and neuronal survival. The analysis also exposes the intercommunication networks established by key miRNAs between various cells of the NVU, highlighting their complex and dynamic regulatory properties. Moreover, it investigates therapeutic strategies predicated on miRNA regulatory mechanisms, highlighting the optimistic prospects as well as the present limitations pertaining to effective IS intervention.

1 February 2026

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Advances in Research for Legume Genomics, Genetics, and Breeding
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Advances in Research for Legume Genomics, Genetics, and Breeding

Editors: Naoufal Lakhssassi, Adnane Boualem, Gunvant Patil

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Int. J. Mol. Sci. - ISSN 1422-0067