International Journal of Molecular Sciences

Furfural and 5-hydroxymethylfurfural are considered as essential platform molecules for the chemical industry, acting as precursors and intermediates of numerous products. They are produced from pentoses and hexoses, respectively, in an acid medium. In this work, biomass from a green macroalgae, Ulva rigida, was treated under acidic conditions provided by heterogeneous catalysts in order to promote the dehydration of its monosaccharides into furfural and 5-hydroxymethylfurfural. Particularly, two functionalized mesoporous silicas, HMS and SBA-supported metal oxides (Nb₂O₅ and ZrO₂), were used as catalysts. Their textural, structural, and acid properties were deeply studied, providing excellent BET surface areas (ranging 424 to 1204 m²/g) and a high concentration of acid sites (220–460 µmol/g), which then translated into great catalytic performances (77.8% and 64.1% of furfural and HMF molar yields, respectively, using HMS-Nb) after a 4 h of reaction time at 180 and 160 °C, respectively. The catalyst showed excellent stability and recyclability as it could be reused for up to five reaction runs with only a slight decrease in performance.

Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED) are rare, autosomal dominant skeletal dysplasias characterised by disproportionate short stature, joint deformities, and early-onset osteoarthritis. These conditions result from mutations in key cartilage extracellular matrix (ECM) components, including cartilage oligomeric matrix protein (COMP), matrilin-3, and type IX collagen. Although genetically and clinically heterogeneous, PSACH and MED share convergent pathogenic mechanisms. Misfolded mutant ECM proteins are retained within the endoplasmic reticulum (ER) of growth plate chondrocytes, triggering chronic ER stress and impairing chondrocyte proliferation, differentiation, and survival. Moreover, some of the mutant protein is secreted and incorporated into the matrix, leading to altered collagen fibrillogenesis, disrupted proteoglycan distribution, and compromised biomechanical integrity. These alterations extend beyond cartilage, impacting tendons, ligaments, and muscle–tendon junctions, contributing to joint laxity, impaired force transmission, and mild myopathy. This review discusses the structural and functional consequences of ECM disorganisation in PSACH and MED, highlighting its central role in disease progression and emphasising the importance of considering ECM abnormalities when developing therapeutic strategies for rare short stature-associated skeletal disorders.

Non-alcoholic fatty liver disease (NAFLD) is increasingly recognized as a systemic condition with neuropsychiatric comorbidities, including depression. Growing evidence for the neuroprotective, antidepressant, and anxiolytic potential of Portulaca oleracea (PO) extract, provides a compelling rationale for investigating its effects in the interaction between dietary models of NAFLD and vulnerability to stress-related disorders. Fifty-four 14- to 18-week-old male and female C57BL/6N mice were distributed in two equal groups and fed either a methionine- and choline-deficient diet (MCD) or a methionine- and choline-controlled diet (MC). Subsequently, half of each group was subjected to chronic unpredictable mild stress (CUMS) and PO treatment. MCD caused significant weight loss, whereas MC promoted weight gain. Behaviorally, MCD induced anhedonia- and anxiety-like behaviors, worsened by CUMS. MC diet reduced CUMS-induced anhedonia, though anxiety-like behavior emerged only under stress. Recognition memory was impaired in stressed MCD-fed mice, while MC-fed mice showed enhanced novel object preference. At the cellular level, MCD suppressed hippocampal microglia and caused cortical astrocyte dysfunction, whereas the MC diet promoted cortical neurogenesis potentiated through PO, abolished by chronic stress. These findings underscore the impact of dietary composition on PO’s systemic effects under chronic stress and support a mechanistic link between NAFLD-related dysfunction and depression-like phenotypes.