Necl-1/CADM3 regulates cone synapse formation in the mouse retina.

In vertebrates, retinal neural circuitry for visual perception is organized in specific layers. The outer plexiform layer is the first synaptic region in the visual pathway, where photoreceptor synaptic terminals connect with bipolar and horizontal cell processes. However, molecular mechanisms underlying cone synapse formation to mediate OFF pathways remain unknown. This study reveals that Necl-1/CADM3 is localized at S- and S/M-opsin-containing cones and dendrites of type 4 OFF cone bipolar cells (CBCs). In Necl-1-/- mouse retina, synapses between cones and type 4 OFF CBCs were dislocated, horizontal cell distribution became abnormal, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors were dislocated. Necl-1-/- mice exhibited aberrant short-wavelength-light-elicited signal transmission from cones to OFF CBCs, which was rescued by AMPA receptor potentiator. Additionally, Necl-1-/- mice showed impaired optokinetic responses. These findings suggest that Necl-1 regulates cone synapse formation to mediate OFF cone pathways elicited by short-wavelength light in mouse retina.

Effects of tooth loss on behavioral and psychological symptoms of dementia in app knock-in mice.

OBJECTIVES: Many patients with Alzheimer's disease experience behavioral and psychological symptoms of dementia (BPSD), which significantly affect their quality of life. It is known that 5-Hydroxytryptamine (5-HT) plays a crucial role in the development of BPSD. However, the relationship between tooth loss and Alzheimer's disease symptoms, particularly aggression, has remained unexplored. Although nutritional status is known to influence the progression of dementia, the specific effect of tooth loss on peripheral symptoms, notably aggression, is not well understood. METHODS: In our study, we conducted maxillary molar extractions in aged C57BL6J and AppNL-G-F mice and observed their condition over a 3-month period. During this time, we documented significant behavioral and genetic differences between mice in the control groups and mice that underwent tooth extraction. Notably, mice that underwent tooth extraction exhibited a considerable decline in cognitive function and an increase in aggression at 3 months after tooth extraction compared with the control groups (C57BL6J or AppNL-G-Fmice). RESULTS: Our findings suggest that molar loss may lead to reduced 5-HT levels in the hippocampus, possibly mediated by the trigeminal nerve, contributing to the development of aggression and BPSD in Alzheimer's disease. CONCLUSION: This study sheds light on the intricate relationships between oral health, 5-HT, and Alzheimer's disease symptoms, offering valuable insights into potential therapeutic avenues for managing BPSD in patients with dementia.

Long-term sorbitol consumption affects the hippocampus and alters cognitive function in aged mice.

The systemic effects of the artificial sweetener sorbitol on older adult individuals have not been elucidated. We assessed the effects of sorbitol consumption on cognitive and gingival health in a mouse model. Aged mice were fed 5% sorbitol for 3 months before their behavior was assessed, and brain and gingival tissues were collected. Long-term sorbitol consumption inhibited gingival tissue aging in aged mice. However, it caused cognitive decline and decreased brain-derived neurotrophic factor (BDNF) in the hippocampus. Sorbitol consumption did not affect homeostatic function; however, it may exert effects within the brain, particularly in the hippocampus.

Neutrophil extracellular traps inhibit osteoclastogenesis.

Neutrophil extracellular traps (NETs) released by neutrophils upon inflammation or infection, act as an innate immune defense against pathogens. NETs also influence inflammatory responses and cell differentiation in host cells. Osteoclasts, which are derived from myeloid stem cells, are critical for the bone remodeling by destroying bone. In the present study, we explores the impact of NETs, induced by the inflammatory agent calcium ionophore A23187, on the differentiation and activation of osteoclasts, potentially through suppressing RANK expression. Our results collectively suggested that the inhibition of RANKL-mediated osteoclastogenesis by NETs might lead to the suppression of excessive bone resorption during inflammation.

Oral infection with Porphyromonas gingivalis augmented gingival epithelial barrier molecules alteration with aging.

OBJECTIVE: Disruption of the gingival epithelial barrier is often mediated by aging or the pathogen Porphyromonas gingivalis. This study examined the combined effects of aging and P. gingivalis exposure on gingival epithelial barrier molecules. METHODS: In vitro experiments involved treating young- and senescence-induced primary human gingival epithelial progenitor cells (HGEPp) with P. gingivalis lipopolysaccharide (LPS). Transepithelial electrical resistance (TER) and paracellular permeability were measured. In vivo, male C57BL/6J mice aged 10 (young) and 80 (old) weeks were divided into four groups: young, old, young with P. gingivalis (Pg-Young) inoculation, and old with P. gingivalis (Pg-Old) inoculation. P. gingivalis was inoculated orally thrice a week for 5 weeks. The mice were sacrificed 30 days after the last inoculation, and samples were collected for further procedures. The junctional molecules (Claudin-1, Claudin-2, E-cadherin, and Connexin) were analyzed for mRNA expression using qRT-PCR and protein production using western blotting and immunohistochemistry. The alveolar bone loss and inflammatory cytokine levels in gingival tissues were also assessed. RESULTS: LPS-treated senescent cells exhibited a pronounced reduction in TER, increased permeability to albumin protein, significant upregulation of Claudin-1 and Claudin-2, and significant downregulation of E-cadherin and Connexin. Furthermore, the Pg-Old group showed identical results with aging in addition to an increase in alveolar bone loss, significantly higher than that in the other groups. CONCLUSION: In conclusion, the host susceptibility to periodontal pathogens increases with age through changes in the gingival epithelial barrier molecules.

Correction: Furukawa et al. Long-Term Soft-Food Rearing in Young Mice Alters Brain Function and Mood-Related Behavior. Nutrients 2023, 15, 2397.

In the original publication [...].

Premature gray hair development in the interbrow region owing to the loss of maxillary first molars in young mice.

The exact sites of premature hair graying and whether tooth loss causes this condition remain unknown. In this study, we aimed to explore the effect of reduced mastication on premature hair graying. Maxillary first molars were extracted from young mice, and the mice were observed for 3 months, along with non-extraction control group mice. After 3 months, gray hair emerged in the interbrow region of mice in the tooth extraction group but not in the control group. The expression of tyrosinase-related protein-2 (TRP-2) mRNA was lower in the interbrow tissues of young mice without maxillary molars than in those with maxillary molars. Tooth loss leads to interbrow gray hair growth, possibly because of weakened trigeminal nerve input, suggesting that reduced mastication causes premature graying. Thus, prompt prosthetic treatment after molar loss is highly recommended.

Comparison of the 1-year surgical outcomes of ab interno trabeculotomy using three types of microhooks.

PURPOSE: We compared the 1-year surgical outcomes of microhook ab interno trabeculotomy (µLOT) using three types of microhooks. METHODS: We retrospectively analyzed 81 eyes that underwent µLOT, in which three microhooks, the Sinskey hook, Tanito Micro-Hook-trabeculotomy-device (TMH), and Matsushita ed. TMH, were used. We collected the data from the medical records. We analyzed the success rates and risk factors. Failure was defined as the need for additional surgery for IOP reduction, loss of light perception, and IOP ≧22 mmHg and IOP reduction <20% (definition 1), IOP ≧17 mmHg and IOP reduction <20% (definition 2), IOP ≧15 mmHg and IOP reduction <25% (definition 3), or IOP ≧12 mmHg and IOP reduction <30% (definition 4) at two consecutive follow-up visits. RESULTS: Twenty-six eyes underwent µLOT using the Sinskey microhook (group S), 21 eyes using the TMH (group T), and 34 eyes using the Matsushita ed. TMH (group M). The mean postoperative IOP and IOP-lowering medication score decreased significantly. The respective success rates among groups S, T, and M did not differ significantly (definition 1, 65.4%, 61.9%, and 55.9%; definition 2, 42.3%, 47.6%, and 32.3%; definition 3, 15.4%, 28.6%, and 23.5%; definition 4, 0%, 9.5%, and 2.9%). In group S, the hyphema-related IOP spikes decreased within 2 weeks postoperatively, and in group M, the non-hyphema-related IOP spikes decreased significantly. CONCLUSION: The 1-year surgical outcomes and complications after µLOT did not differ significantly among the three microhooks. The differences in the microhook tips might be associated with postoperative transient IOP spikes.

Cross-Sectional Analysis of Periodontal Disease and Cognitive Impairment Conducted in a Memory Clinic: The Pearl Study.

BACKGROUND: Periodontal disease (PeD) is a risk factor of Alzheimer's disease and is associated with cognitive decline in older adults. However, the relationships between subitems of neuropsychological tests and PeD have not been fully clarified. OBJECTIVE: To evaluate associations between PeD and subitems of neuropsychological tests. METHODS: We performed a cross-sectional analysis of data of 183 participants (women: 50%, mean age: 79 years) from a clinical study. We enrolled patients who visited our memory clinic and assessed demographics, dementia-related risk factors, neuropsychological tests, brain magnetic resonance images, and a dental screening check. We evaluated the relationships between cognitive function and PeD using multivariable logistic regression analyses. RESULTS: Participants with dementia were less likely to make periodical visits to the dentist, had fewer teeth, had less frequent tooth brushing habits, and were more likely to have PeD. Impaired cognitive function was significantly associated with an increasing degree of PeD. In multivariable logistic regression analyses, impaired visuospatial function and attention were associated with twice the risk of moderate or severe PeD compared with individuals with preserved visuospatial function and attention (odds ratio: 2.11, 95% confidence interval: 1.04-4.29, p = 0.037). Impaired word recall and recognition and following commands were associated with increased risk of PeD (odds ratio: 2.80, 95% confidence interval: 1.41-5.32, p = 0.003). CONCLUSIONS: Cognitive decline, such as impaired visuospatial function, attention, word recall and recognition, and inability to follow commands were independently and strongly associated with PeD. These items can be assessed easily on a daily basis.

Erythritol Can Inhibit the Expression of Senescence Molecules in Mouse Gingival Tissues and Human Gingival Fibroblasts.

Oral aging causes conditions including periodontal disease. We investigated how the sugar alcohol erythritol, which has anti-caries effects, impacts aging periodontal tissues and gingival fibroblasts in mice and humans in vivo and in vitro. Mice were classified into three groups: control groups of six-week-old (YC) and eighteen-month-old mice (AC) and a group receiving 5% w/w erythritol water for 6 months (AE). After rearing, RNA was extracted from the gingiva, and the levels of aging-related molecules were measured using PCR. Immunostaining was performed for the aging markers p21, γH2AX, and NF-κB p65. p16, p21, γH2AX, IL-1ß, and TNFα mRNA expression levels were higher in the gingiva of the AC group than in the YC group, while this enhanced expression was significantly suppressed in AE gingiva. NF-κB p65 expression was high in the AC group but was strongly suppressed in the AE group. We induced senescence in cultured human gingival fibroblasts using H2O2 and lipopolysaccharide before erythritol treatment, which reduced elevated senescence-related marker (p16, p21, SA-ß-gal, IL-1ß, and TNFα) expression levels. Knockdown of PFK or PGAM promoted p16 and p21 mRNA expression, but erythritol subsequently rescued pyruvate production. Overall, intraoral erythritol administration may prevent age-related oral mucosal diseases.

Macrophage migration inhibitory factor-mediated mast cell extracellular traps induce inflammatory responses upon Fusobacterium nucleatum infection.

Mast cell extracellular traps (MCETs) released by mast cells contribute to host defense. In this study, we investigated the effects of MCETs released from mast cells after infection with a periodontal pathogen Fusobacterium nucleatum. We found that F. nucleatum induced MCET release from mast cells, and that MCETs expressed macrophage migration inhibitory factor (MIF). Notably, MIF bound to MCETs induced proinflammatory cytokine production by monocytic cells. These findings suggest that MIF expressed on MCETs, released from mast cells upon infection with F. nucleatum, promotes inflammatory responses that may be associated with the pathogenesis of periodontal disease.

Deep-learning approach to detect childhood glaucoma based on periocular photograph.

Childhood glaucoma is one of the major causes of blindness in children, however, its diagnosis is of great challenge. The study aimed to demonstrate and evaluate the performance of a deep-learning (DL) model for detecting childhood glaucoma based on periocular photographs. Primary gaze photographs of children diagnosed with glaucoma with appearance features (corneal opacity, corneal enlargement, and/or globe enlargement) were retrospectively collected from the database of a single referral center. DL framework with the RepVGG architecture was used to automatically recognize childhood glaucoma from photographs. The average receiver operating characteristic curve (AUC) of fivefold cross-validation was 0.91. When the fivefold result was assembled, the DL model achieved an AUC of 0.95 with a sensitivity of 0.85 and specificity of 0.94. The DL model showed comparable accuracy to the pediatric ophthalmologists and glaucoma specialists in diagnosing childhood glaucoma (0.90 vs 0.81, p = 0.22, chi-square test), outperforming the average of human examiners in the detection rate of childhood glaucoma in cases without corneal opacity (72% vs. 34%, p = 0.038, chi-square test), with a bilateral corneal enlargement (100% vs. 67%, p = 0.03), and without skin lesions (87% vs. 64%, p = 0.02). Hence, this DL model is a promising tool for diagnosing missed childhood glaucoma cases.

Long-Term Capsaicin Administration Ameliorates the Dysfunction and Astrogliosis of the Brain in Aged Mice with Missing Maxillary Molars.

Tooth loss and decreased masticatory function reportedly affect cognitive function; tooth loss allegedly induces astrogliosis and aging of astrocytes in the hippocampus and hypothalamus, which is a response specific to the central nervous system owing to homeostasis in different brain regions. Capsaicin, a component of red peppers, has positive effects on brain disorders in mice. Decreased expression of transient receptor potential vanilloid 1, a receptor of capsaicin, is associated with the development of dementia. In this study, we investigated the effect of capsaicin administration in aged mice (C57BL/6N mice) with reduced masticatory function owing to the extraction of maxillary molars to investigate preventive/therapeutic methods for cognitive decline attributed to age-related masticatory function loss. The results demonstrated that mice with impaired masticatory function showed decreased motor and cognitive function at the behavioral level. At the genetic level, neuroinflammation, microglial activity, and astrogliosis, such as increased glial fibrillary acidic protein levels, were observed in the mouse brain. The mice with extracted molars fed on a diet containing capsaicin for 3 months demonstrated improved behavioral levels and astrogliosis, which suggest that capsaicin is useful in maintaining brain function in cases of poor oral function and prosthetic difficulties.

Long-Term Soft-Food Rearing in Young Mice Alters Brain Function and Mood-Related Behavior.

The relationship between caloric and nutrient intake and overall health has been extensively studied. However, little research has focused on the impact of the hardness of staple foods on health. In this study, we investigated the effects of a soft diet on brain function and behavior in mice from an early age. Mice fed a soft diet for six months exhibited increased body weight and total cholesterol levels, along with impaired cognitive and motor function, heightened nocturnal activity, and increased aggression. Interestingly, when these mice were switched back to a solid diet for three months, their weight gain ceased, total cholesterol levels stabilized, cognitive function improved, and aggression decreased, while their nocturnal activity remained high. These findings suggest that long-term consumption of a soft diet during early development can influence various behaviors associated with anxiety and mood regulation, including weight gain, cognitive decline, impaired motor coordination, increased nocturnal activity, and heightened aggression. Therefore, the hardness of food can impact brain function, mental well-being, and motor skills during the developmental stage. Early consumption of hard foods may be crucial for promoting and maintaining healthy brain function.

Intereye comparison of visual field progression in eyes with open-angle glaucoma.

PURPOSE: To investigate the intereye correlations between and differences in the rates of visual field (VF) progression in eyes with bilateral open-angle glaucoma. STUDY DESIGN: Retrospective, longitudinal, observational study. METHODS: Patients with bilateral open-angle glaucoma with 8 or more reliable 30 - 2 standard automated perimetry tests over a period of more than 2 years were enrolled. The rate of change of the MD (MD slope) was used as the indicator for the rates of VF progression. Descriptive statistics of the absolute intereye difference in the MD slope values were computed. Factors associated with a large intereye difference (> 0.42 dB/year) were explored. RESULTS: One hundred eighty-eight eyes from 94 patients (56 women) were enrolled. A significant intereye correlation of the rates of visual field progression (P = .002) was found. The mean ± standard deviation and median intereye differences of the MD slope values were 0.29 ± 0.31 and 0.18 dB/year (range: 0-1.41), respectively. The 5th, 10th, 25th, 75th, 90th, and 95th percentiles of intereye differences were 0.01, 0.02, 0.08, 0.42, 0.72, and 0.91 dB/year, respectively. Older age and slower progression were significantly associated with large intereye difference. CONCLUSION: A significant intereye correlation in the rate of VF progression was found in eyes with bilateral open-angle glaucoma. We showed the distributions and associated factors of intereye differences in VF progression. These data may be used for improving the estimation of rates of VF progression.

Long-term course with iris changes after trabeculectomy for uveitic glaucoma associated with iris mammillation: a case report.

BACKGROUND: Iris mammillation is a rare disease characterized by the distribution of multiple nodules on the iris surface. The course of uveitic glaucoma with iris mammillation has never been reported. CASE PRESENTATION: A 56-year-old woman, who presented with unilateral decreased vision, visited our hospital for treatment of uveitic glaucoma in the right eye. Multiple nodules were scattered over the iris surface in that eye. This case was diagnosed as iris mammillation on clinical findings. After excluding malignant tumors such as melanoma, trabeculectomy was performed. The resected iris had no pathologically malignant findings. The iris nodules evolved to a sand-like appearance, and the intraocular pressure remained stable without recurrent inflammation 7 years after trabeculectomy. CONCLUSIONS: In a case of unilateral uveitic glaucoma with iris mammillation, filtration surgery was performed after excluding the presence of a malignancy, and the long-term postoperative course has been stable.

Barium-induced toxic anterior segment syndrome.

Toxic anterior segment syndrome (TASS) is a rapid-onset inflammation of the eye following uneventful ocular surgery. We report a case of TASS following Baerveldt glaucoma implant (BGI) surgery. Inductively coupled plasma-mass spectrometry (ICP-MS) identified barium in the eye and in the eluate from the bleb of the BGI. We attribute TASS in our patient to the dissolution of barium from the BGI and its entry into the eye, where it causes severe inflammation.

Hericium erinaceus ethanol extract and ergosterol exert anti-inflammatory activities by neutralizing lipopolysaccharide-induced pro-inflammatory cytokine production in human monocytes.

Edible mushrooms are known to exert anti-inflammatory effects. In this study, the effects of ethanol extracts from edible mushrooms, such as Hericium erinaceus, and other edible mushrooms on inflammatory responses were investigated. Experiments were conducted using the inflammatory responses of human monocytes induced by lipopolysaccharide (LPS), a bacterial component, that provokes inflammation. Notably, we demonstrated that LPS mixed with ethanol and hot water extracts derived from edible mushrooms attenuated the production of inflammatory cytokines, such as interleukin (IL)-1ß, -6, and -8, induced by LPS in human monocytic cell cultures. Moreover, we found that the ethanol extract of H. erinaceus contained ergosterol, which attenuated IL-8 production in LPS-stimulated cells. Subsequent component analysis of the ethanol extract of H. erinaceus revealed that ergosterol binds to lipid A to attenuate LPS-induced inflammation. Together, our findings suggest that ergosterol in ethanol extracts from edible mushrooms can prevent the induction of inflammation by binding to LPS.

Analysis of senescence in gingival tissues and gingival fibroblast cultures.

OBJECTIVE: To determine senescence-associated changes in the gingival tissues of aged mice and gingival fibroblast cultures. MATERIALS AND METHODS: The production of senescence-associated ß-galactosidase (SA-ß-gal) and mRNA expression of p16, p21, interleukin (IL)-1ß, and tumor necrosis factor α (TNF-α) were evaluated in gingival tissues, gingival fibroblasts of 10- and 20-month-old C57BL/6NCrl mice, and multiple-passaged and hydrogen peroxide-stimulated human gingival fibroblasts (HGFs). Changes in molecular expression in HGF cultures due to senescent cell elimination by the senolytic drug ABT-263 (Navitoclax) were analyzed. RESULTS: Compared to 10-week-old mice, the 20-month-old mice had higher numbers of M1 macrophages. The proportion of cells expressing SA-ß-gal were also higher in 20- month-old mice than in 10-week-old-mice. Gingival fibroblasts in 20-month-old mice expressed less collagen 1a1, collagen 4a1, and collagen 4a2 mRNA than those in 10-week-old mice. Compared to control cells, H2O2 treated HGF cells expressed higher levels of SA-ß-gal and p16, p21, IL-1ß, and TNF-α. Furthermore, ABT-263 suppressed HGF cell expression of cytokines after senescence induction. CONCLUSIONS: Senescence-associated changes were observed in the gingival tissues of aged mice and HGF cultures. In addition, the potential of senolytic drugs to modify aging-related changes in the gingiva was shown.