Search Results (176)

Melatonin is not only produced by the pineal gland but is also synthesized in extrapineal organs. It plays a key role in antioxidant defense and immune regulation during pregnancy. Two key rate-limiting enzymes are involved in the melatonin synthesis, aralkylamine N-acetyltransferase (AANAT), and acetylserotonin O-methyltransferase (ASMT). Nevertheless, it remained unclear whether pregnancy affects the expression of AANAT and ASMT in extrapineal organs. In this study, ovine maternal thymus, spleen, liver, lymph nodes, thyroid, duodenum, and endometrium were collected on day 16 of the estrous cycle (N16), and on days 13, 16, 25, and 70 (G70) of gestation (n = 6 per group). The expression of AANAT and ASMT in these extrapineal organs was analyzed using RT-qPCR, Western blot, and immunohistochemistry. The results revealed that pregnancy upregulated the expression of AANAT in the liver and ASMT in the thymus and duodenum, but downregulated AANAT expression in the lymph nodes and duodenum. Moreover, AANAT expression was elevated in the thymus and spleen but reduced in the thyroid and endometrium at G70 compared with N16. ASMT expression was increased in the lymph nodes yet decreased in the spleen, liver, and thyroid at G70 compared with N16. Notably, endometrial ASMT expression showed a pregnancy-stage-specific manner with no significant difference between N16 and G70. In summary, this paper reports, for the first time in sheep, that pregnancy modulates the expression of AANAT and ASMT in these extrapineal organs in a pregnancy-stage- and tissue-specific manner. Full article

The relationship between the morphology of pygidial glands and the chemical nature of their secretions in the tribe Chlaeniini (family Carabidae) has long been recognised. We analysed the morphological features of the pygidial glands and the chemical composition of their secretions in three taxa: Chlaenius (Chlaeniellus) tristis (Schaller, 1783), C. (Chlaenites) spoliatus spoliatus (Rossi, 1792), and C. (Chlaenius) festivus festivus (Panzer, 1796). We examined the morphology of the pygidial glands in all three taxa using bright-field microscopy (BFM) and nonlinear microscopy (NLM). We used gas chromatography–mass spectrometry (GC–MS) and nuclear magnetic resonance (NMR) to analyse the chemical composition of the secretions. We measured and photographed the glands and conducted comparative morphological analyses. We detected a total of 21 chemicals in the pygidial gland secretions of the studied Chlaeniini. We found the highest number of compounds in C. tristis (17), slightly fewer in C. festivus festivus (13), and the lowest number in C. spoliatus spoliatus (seven). Thirteen compounds were new to the tribe Chlaeniini, eight of which were also new to the entire family Carabidae. The most dominant compound in the secretions of all three taxa was 3-methylphenol. We also discussed the taxonomic value of the chemical composition of the pygidial gland secretions. Full article

The second stomach compartment (C2) of the dromedary camel (Camelus dromedarius) plays an important role in digestion. However, detailed morphological and histochemical data remain limited. This study aimed to investigate the gross anatomy, histological organization, histometric features, and histochemical distribution of muco-substances in C2. The study was conducted on twenty dromedary camels, including fetuses and adults. Gross anatomical observations were performed on eight fresh and fixed specimens, while histological, histometric, and histochemical analyses were carried out on samples from twelve adult camels using routine and special staining techniques to identify neutral and acidic mucins. C2 was the smallest gastric compartment, located on the right side of the abdominal cavity and partially continuous with C1. Its mucosa formed chambered zones supported by prominent longitudinal muscular bands. Histologically, C2 comprised glandular and non-glandular regions. The glandular mucosa contained gastric pits and branched tubular glands with mucous, chief, and parietal cells, whereas the non-glandular region was lined by keratinized stratified squamous epithelium. Submucosal lymphoid aggregations were observed near the C2–C3 junction. Histometric analysis revealed a markedly developed tunica muscularis. Strong PAS and Alcian blue reactions indicated abundant neutral and acidic mucins. These findings demonstrate that C2 is a structurally specialized compartment supporting digestion, mucosal immune defense, and adaptation to arid environments, clearly distinguishing it from the reticulum of true ruminants. Full article

The pineal gland regulates circadian physiology through the periodic production of melatonin (MLT). In addition to its established role as a chronobiotic agent, MLT regulates redox homeostasis and mitochondrial physiology. Mitochondria and redox-active molecules, particularly reactive oxygen species (ROS), play essential roles in reproduction, including gamete physiology, fertilization, and early embryonic development. Although excessive oxidative stress (OS) impairs fertility, controlled ROS signaling is necessary for normal reproductive function. This comprehensive review synthesizes current evidence regarding MLT as a key intermediary linking circadian signaling with mitochondrial physiology and redox homeostasis. We discuss molecular pathways through which MLT regulates mitochondrial function, including activation of the Nrf2 signaling pathway, modulation of mitochondrial permeability transition, regulation of electron transport chain (ETC) efficiency, and apoptotic signaling. Furthermore, this study investigates MLT’s ability to scavenge free radicals and activate antioxidant defense mechanisms. Moreover, we review novel findings regarding the effects of MLT in experimental animals and humans, assisted reproductive technologies (ART) such as in vitro fertilization (IVF), and consider the translational significance of the hormone as an enhancer of fertility. We also highlight gaps in the literature, including methodological inconsistencies, supraphysiologic doses, and insufficient data from large human cohorts. Lastly, we discuss an integrative model whereby MLT may function as an important regulator of mitochondrial redox balance, with potential implications for reproductive physiology and reproductive outcomes, and propose new avenues for investigation. Full article

This study aimed to determine whether intranasal hinokitiol modulates short-term salivary secretory IgA (SIgA) secretion dynamics and IgA antibody-forming cell (AFC) activity in the submandibular glands of aged mice, a model of age-associated mucosal immune decline. Aged BALB/c mice received intranasal hinokitiol (50 μg) once weekly for 4 weeks. Saliva was collected on days 0, 7, 14, and 21 at baseline, 0.5 h, 1.5 h, 3 h, and 6 h after each administration. SIgA levels were measured using an enzyme-linked immunosorbent assay. On day 21, IgA AFCs were enumerated using an enzyme-linked immunosorbent spot assay, and their viability and proliferative activity were assessed using the MTT assay. Salivary SIgA rose transiently after each dose, peaking at 1.5 h and returning to baseline by 6 h. By day 21, baseline SIgA secretion was significantly higher than at day 0, indicating a cumulative effect. IgA AFCs were unchanged in number, but viability and proliferation increased at 0.5 and 1.5 h, coinciding with SIgA peaks. Flow cytometry revealed significant expansion of B220⁺CD38⁺ memory B-cells; B220⁺CD138⁺ plasma cells were unaffected. Intranasal hinokitiol transiently enhances salivary SIgA secretion in aged mice, likely through short-term modulation of salivary gland immune activity. This non-invasive approach may aid mucosal defense in aging populations. These findings suggest that intranasal HNK may represent a novel non-invasive approach for enhancing mucosal immune function during aging and may provide a basis for future preventive strategies against oral and respiratory infections. Full article

Salivary aldehyde dehydrogenases (ALDHs), particularly ALDH3A1, are increasingly recognized as potential contributors to oral defense against aldehyde-associated stress at the oral–environment interface. Unlike freely secreted salivary enzymes, measurable salivary ALDH activity primarily reflects intracellular and vesicle-associated enzymes derived from salivary gland epithelial cells, oral mucosal cells, immune cells, and exfoliated cellular components. Within the oral exposome, ALDHs expressed in oral epithelial and salivary gland tissues participate in the detoxification of reactive aldehydes, while salivary ALDH activity may serve as an indicator of local aldehyde-detoxification capacity and tissue redox status. Beyond aldehyde metabolism, emerging evidence suggests that ALDH-associated pathways are linked to redox regulation, epithelial stress adaptation, inflammatory signaling, and tissue repair through NAD(P)⁺-dependent processes and stress-responsive networks such as Nrf2 and SIRT1. This review provides a saliva-focused synthesis of ALDH biology, emphasizing isoform-specific functions and the potential importance of ALDH3A1 in oral epithelial defense. Altered salivary ALDH activity has been reported in association with oral conditions including periodontitis, oral lichen planus, radiation-induced salivary dysfunction, and oral squamous cell carcinoma (OSCC). Genetic factors, particularly ALDH2 polymorphisms, together with environmental exposures and microbial dysbiosis, may further influence aldehyde burden and oral disease susceptibility. Although current evidence supports the biological relevance of salivary ALDHs, their utility as clinical biomarkers or therapeutic targets remains investigational and requires further mechanistic and clinical validation. Full article

The bean bug Riptortus pedestris is one of the principal soybean pests throughout East Asia. Males release an aggregation pheromone consisting of three compounds—(E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), (E)-2-hexenyl (E)-2-hexenoate (E2HE2H) and myristyl isobutyrate (MI)—in a ratio of 1:5:1. Although pheromone-based baits have been extensively deployed to control the pest for the past three decades, the glands responsible for producing these volatiles have remained unidentified. Our investigations revealed that the metathoracic glands (MTGs) of males synthesized the two pheromonal esters, E2HZ3H and E2HE2H, along with a suite of auxiliary compounds: (E)-2-hexenal, hexanoic acid, (E)-3-hexenoic acid, (E)-2-hexenoic acid, (E)-2-octenal, and (E)-2-hexenyl hexanoate (E2HH). Female MTGs were morphologically similar to those of males and generated the same auxiliary compounds, but lacked the capacity to produce the pheromonal esters E2HZ3H and E2HE2H. MI was released exclusively from the male abdominal sternites. Its quantity was nearly uniform across all sternal segments, implying secretion from an epidermal glandular patch (GP) that was evenly distributed over the sternites. In nymphs, dorsal abdominal glands (DAGs) emitted several volatiles—including (E)-2-hexenal, 4-oxo-(E)-2-hexenal, (E)-2-octenal, and (E)-2-octenoic acid—some of which are characteristic defensive compounds of heteropterans. Thus, our study clarifies how sex- and stage-specific glands contribute to the chemical polymorphism observed in R. pedestris. Full article

Tracheoid idioblasts in Nepenthes are anatomically specialized cells that differ distinctly from surrounding tissues in morphology, wall structure, and staining properties. Their presence has been documented in both vegetative organs, such as roots and stems, and in highly modified carnivorous leaves that form pitchers. We tested the hypothesis that if tracheoid idioblasts function to reinforce the mechanical strength of Nepenthes pitchers or to protect them from animal damage, they exhibit a secondary cell wall composition comparable to that of sclerenchyma or xylem cells, particularly with respect to its lignin and hemicellulose components. We assessed the localization of cell wall components in gland cell walls using histochemical tests, immunolabeling, and confocal microscopy. Light and scanning electron microscopy were used to reveal the tracheoid idioblast structure. Two species were examined: Nepenthes albomarginata T.Lobb ex Lindl. and Nepenthes bicalcarata Hook. f. In both species, giant tracheoid idioblasts with helical bands of secondary wall material were found throughout the pitchers. Negative phloroglucinol, fuchsin, and safranin staining test results demonstrated the absence of lignins in the tracheoid idioblast secondary cell walls. A histochemical test showed that the wall thickenings of the tracheoid idioblasts contained polysaccharides and cellulose and were rich in unsubstituted or low-substituted xylans, resembling the secondary cell walls of sclerenchyma and xylem cells. Our results suggest that tracheoid idioblasts with a helical secondary wall that is rich in xylans but not lignified most likely function as elastic reinforcing elements that increase the mechanical integrity of the organ while maintaining its flexibility and ability to undergo reversible deformation. Furthermore, tracheoid idioblasts may provide defense against herbivory. Full article

Ferroptosis is an iron-dependent form of regulated cell death characterized by lipid peroxidation and failure of cellular antioxidant defenses. Increasing evidence indicates that ferroptosis contributes to the biological effects of radiotherapy and influences both tumor radiosensitivity and normal tissue injury. Because radiotherapy is a central treatment modality for many head and neck cancers, understanding how ferroptosis interacts with radiation responses has important translational implications. Ionizing radiation can induce ferroptosis through reactive oxygen species generation, disruption of glutathione metabolism, suppression of the SLC7A11–GSH–GPX4 antioxidant axis, and remodeling of membrane lipid composition. Conversely, tumor cells frequently develop radioresistance by reinforcing ferroptosis-suppressive pathways, including enhanced cystine transport, lipid desaturation, and metabolic adaptation. In head and neck cancers such as head and neck squamous cell carcinoma, nasopharyngeal carcinoma, oral squamous cell carcinoma, and thyroid malignancies, experimental studies show that modulation of ferroptosis significantly alters radiation response. Strategies that promote ferroptosis—including inhibition of antioxidant defenses, targeting of lipid metabolism, and modulation of iron homeostasis—have demonstrated radiosensitizing effects in preclinical models. However, ferroptosis may also contribute to radiation-induced normal tissue injury, particularly in oxidative stress-sensitive organs such as the salivary glands. This review summarizes the molecular basis of ferroptosis in radiotherapy, examines its role in radiosensitivity and radioresistance in head and neck cancers, and discusses therapeutic strategies to exploit ferroptosis while minimizing normal tissue toxicity. Full article

The tomato leaf miner, Phthorimaea (Tuta) absoluta, Meyrick 1917 is recognized as a highly destructive pest, causing significant economic losses to crops in both greenhouse and open field environments across four continents: Asia, Africa, Europe, and South America. High genetic homogeneity among populations from various regions and countries indicates significant gene flow between P. absoluta populations, suggesting a lack of geographical barriers to dispersion. Furthermore, P. absoluta has developed resistance to insecticides due to target-site mutations or metabolic resistance, which enable the insect to withstand lethal doses of insecticides. To control this insect pest, the plant-mediated RNA interference (RNAi) is most promising host-induced gene silencing technique, utilized the plant’s machinery to express double-stranded (dsRNA), which triggers the RNAi pathway in P. absoluta. Due to thermal tolerance, the P. absoluta has increased its area of invasion by 600 km per year over 9 years. Female P. absoluta releases pheromones that are recognized by males with a sophisticated olfactory circuit on their antenna. Pheromone binding proteins (PBPs) play a crucial role in mate recognition and attraction, and their expression peaks during courtship, specifically around 6:00 a.m. Given its potential to significantly alter the insect genome, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) offer a revolutionary strategy to control P. absoluta. Furthermore, this pest has developed remarkable adaptations to survive on unfavorable hosts by secreting specific proteins from its salivary glands that detoxify plant defenses. Insecticide resistance is likely the cause of field control failures of P. absoluta. Biological control, sex pheromone traps, and cultural control are the most promising approaches to address insecticide resistance resulting from these failures. Therefore, the implementation of integrated control programs and appropriate resistance management strategies is necessary to keep P. absoluta infestations under economic damage thresholds. Full article

Soldier beetle larvae are characterised by numerous very small setae on their body surface, giving them a velvety appearance and hydrophobic properties, and paired gland openings on the segments of the thorax and abdomen for defensive purposes. Only recently, such a larva has been recognised in Cretaceous amber. Previously, only two specimens from Baltic amber were known from the fossil record. This provides the impression that such larvae are rare. We report 45 new larval specimens from Eocene Baltic amber and Cretaceous Kachin amber (Myanmar), demonstrating that these fossils are, in fact, more common, but simply not reported. We use the expanded dataset (with fossil and extant larvae and adults, more than 300 specimens) to explore the ontogeny of soldier beetles by quantitatively comparing morphological aspects over time. It appears that there is no major loss in the morphology of adults and larvae. On the contrary, certain larvae known in the modern fauna, so-called pre-larvae, seem absent in the fossil record. Due to the pre-larvae, some modern soldier beetles have certain characteristics of hypermetamorphosis. This type of developmental pattern is also characterised by a distinct change in the direction of the developmental trajectory. However, such a change could not be identified in soldier beetles. Full article

Bovine mastitis is a multifactorial inflammatory disease primarily characterized by inflammatory cell infiltration and the destruction of mammary alveoli. It is a major cause of reduced milk yield and quality. The imbalance between antioxidant defenses and the generation of reactive oxygen species (ROS), which occurs due to the high metabolic activity of the mammary gland during the periparturient period, increases the incidence of mastitis. During early lactation, especially in high-yielding dairy cows, the massive synthesis and secretion of milk increase the energy demand of mammary tissue, leading to excessive ROS accumulation. This results in cell membrane disruption and, ultimately, antioxidant dysfunction in the mammary tissue. This study established an in vitro oxidative stress model by treating bovine mammary epithelial cells (BMECs) with 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). The optimal concentration of 1000 μmol/L AAPH was determined using the CCK-8 assay. Model validation showed that, compared to the control group, ROS levels were significantly elevated (p < 0.001) and mitochondrial membrane potential was significantly decreased (p < 0.001) in the AAPH-treated group. Transmission electron microscopy (TEM) analysis revealed that AAPH treatment caused ultrastructural damage, including reduced microvilli, mitochondrial swelling, disappearance of cristae, and vacuolization. Mechanistic studies demonstrated that AAPH treatment significantly upregulated the mRNA and protein expression of AMPK, HMOX-1, mTOR, NOS, and SOD (p < 0.001), while significantly downregulating CYP1A1 expression (p < 0.001). Pretreatment with N-acetylcysteine (NAC) effectively alleviated the oxidative stress damage caused by AAPH. This study successfully established an in vitro AAPH-induced oxidative stress model in BMECs and revealed its molecular mechanism of cellular damage. The damage occurs through modulation of the AMPK/mTOR signaling pathway and the regulation of antioxidant-related gene expression. Full article

Pyroptosis is a pro-inflammatory form of programmed cell death mediated by inflammasomes and caspases and has been implicated in various inflammatory diseases. However, its function and regulatory role in dairy cows with clinical mastitis (CM) remain poorly understood. This study was conducted to investigate the differentially expressed proteins (DEPs) involved in biological processes (BPs) and the Kyoto Encyclopedia of Genes and Genomes pathways related to inflammasome-mediated pyroptosis based on proteomic data and to further explore their potential involvement in mastitis using in vivo and in vitro models. Histopathological analysis revealed morphological features consistent with pyroptosis in the mammary glands of CM-affected cows, including mammary epithelial cell (MEC) membrane disruption, increased reactive oxygen species production, elevated TUNEL–gasdermin D (GSDMD)-positive staining, and inflammatory cell infiltration. Proteomic profiling identified 276 DEPs and 17 BPs, among which NOD-like receptor family pyrin domain-containing 3 (NLRP3) was identified as a key candidate associated with cytokine production, immune defense, and inflammatory responses. Pathway enrichment analysis indicated that NLRP3, caspase-1 (CASP1), and GSDMD were enriched in the NOD-like receptor signaling pathway and were closely associated with mastitis. Immunohistochemical and molecular analyses demonstrated cytoplasmic localization and significant upregulation of NLRP3, CASP1, and GSDMD at both the mRNA and protein levels in CM-affected tissues. In both in vitro and in vivo models, a dose-dependent increase in the expression of pyroptosis-related targets and pro-inflammatory cytokines was observed with the progression of inflammation. Moreover, the pharmacological inhibition of CASP1 attenuated pyroptosis-associated changes and inflammatory responses in BMECs. Collectively, these findings suggest that the NLRP3–CASP1 axis is associated with inflammation-related pyroptosis in bovine mastitis and may represent a potential therapeutic target for clinical mastitis. Full article

Salivary aldehyde dehydrogenases (ALDHs), particularly ALDH3A1 and ALDH1A1, serve as frontline enzymatic defenses in the oral cavity, detoxifying reactive aldehydes generated through metabolic activity, microbial fermentation, and environmental exposures. These enzymes are essential for maintaining redox homeostasis, mucosal integrity, and immune modulation. However, under chronic metabolic stress, such as in diabetes, oral inflammation, and cancer, salivary ALDHs become vulnerable to non-enzymatic glycation by reactive carbonyl species like methylglyoxal. This modification impairs cofactor binding, catalytic activity, and structural stability, thereby compromising detoxification capacity at a time of heightened aldehyde burden. This review provides the first insights into ALDH glycation and particularly that of salivary ALDH, examining its structural mechanisms, disease-specific consequences, and emerging protective strategies. Special focus is given to natural compounds, including curcumin, thymoquinone, resveratrol, carnosine, and EGCG, that prevent glycation or restore ALDH function via carbonyl scavenging, antioxidant activation, and NAD⁺/SIRT1 pathway modulation. We also highlight critical research gaps, such as the absence of site-specific glycation maps, lack of salivary gland-based models, and limited availability of ALDH3A1-specific activators. Importantly, we propose that the glycation status of salivary ALDHs may serve as a non-invasive biomarker of oxidative stress and therapeutic response in metabolic and inflammatory disorders. By bridging biochemical insights with translational potential, this review establishes ALDH glycation as a mechanistic and clinically actionable axis in oral and systemic health. Full article

The defensive substances of ground beetles are synthesised and stored in a pair of defensive glands, commonly referred to as abdominal or pygidial glands. The chemical composition of the pygidial gland secretions and the morphology of the glands were studied in adults of four species belonging to the tribe Pterostichini: Poecilus cupreus Linnaeus, 1758, Pterostichus melanarius Illiger, 1798, P. anthracinus Illiger, 1798, and Stomis pumicatus Panzer, 1796. In addition, Tapinopterus cognatus (Dejean, 1831) was examined only with regard to the chemistry of its secretion. The pygidial gland secretions of the five species were investigated using gas chromatography-mass spectrometry (GC-MS). The combined presence of methacrylic acid and tiglic acid was observed in all taxa studied. 2-Tridecanone, which was detected in all species except P. cupreus, is reported for the first time in the defensive secretions of representatives of Pterostichini. The pygidial glands of the first four species were examined using both bright-field microscopy (BFM) and nonlinear microscopy (NLM). The examined species were similar in the general appearance of the glands, with the greatest differences observed in S. pumicatus. Full article