Recent advances in label-free imaging and quantification techniques for the study of lipid droplets in cells.

Lipid droplets (LDs), once considered mere storage depots for lipids, have gained recognition for their intricate roles in cellular processes, including metabolism, membrane trafficking, and disease states like obesity and cancer. This review explores label-free imaging techniques' applications in LD research. We discuss holotomography and vibrational spectroscopic microscopy, emphasizing their potential for studying LDs without molecular labels, and we highlight the growing integration of artificial intelligence. Clinical applications in disease diagnosis and therapy are also considered.

Irisin reduces amyloid-ß by inducing the release of neprilysin from astrocytes following downregulation of ERK-STAT3 signaling.

A pathological hallmark of Alzheimer's disease (AD) is the deposition of amyloid-ß (Aß) protein in the brain. Physical exercise has been shown to reduce Aß burden in various AD mouse models, but the underlying mechanisms have not been elucidated. Irisin, an exercise-induced hormone, is the secreted form of fibronectin type-III-domain-containing 5 (FNDC5). Here, using a three-dimensional (3D) cell culture model of AD, we show that irisin significantly reduces Aß pathology by increasing astrocytic release of the Aß-degrading enzyme neprilysin (NEP). This is mediated by downregulation of ERK-STAT3 signaling. Finally, we show that integrin αV/ß5 acts as the irisin receptor on astrocytes required for irisin-induced release of astrocytic NEP, leading to clearance of Aß. Our findings reveal for the first time a cellular and molecular mechanism by which exercise-induced irisin attenuates Aß pathology, suggesting a new target pathway for therapies aimed at the prevention and treatment of AD.

Eyebrow lifting using multidirectional absorbable thread.

BACKGROUND: Thread lifting is a common procedure in minimally invasive esthetic techniques and can also be used to raise the drooping soft tissue of the forehead by vertically inserting threads into the forehead. AIMS: This study aimed to examine the effect of forehead thread lifting on enhancing upper eyelid opening. METHODS: Fifteen patients were included in this study, all of whom underwent eyebrow thread lifting with MINT LIFT® UP. Photographs of the patients were taken before, immediately after, and 1 and 12 weeks after surgery. Changes in the position of the eyebrows and eyelids were measured. The paired t-test was used to determine the statistical significance of differences. RESULTS: At 1 week after surgery, the eyebrows were at a lower level compared with before surgery, and no significant changes in eye-opening were observed. However, at 12 weeks after surgery, the eyebrows and upper eyelids were both significantly elevated when compared to the preoperative state. CONCLUSIONS: Eyebrow lifting can be performed using multidirectional thread lifting.

Amelioration of pathologic α-synuclein-induced Parkinson's disease by irisin.

Physical activity provides clinical benefit in Parkinson's disease (PD). Irisin is an exercise-induced polypeptide secreted by skeletal muscle that crosses the blood-brain barrier and mediates certain effects of exercise. Here, we show that irisin prevents pathologic α-synuclein (α-syn)-induced neurodegeneration in the α-syn preformed fibril (PFF) mouse model of sporadic PD. Intravenous delivery of irisin via viral vectors following the stereotaxic intrastriatal injection of α-syn PFF cause a reduction in the formation of pathologic α-syn and prevented the loss of dopamine neurons and lowering of striatal dopamine. Irisin also substantially reduced the α-syn PFF-induced motor deficits as assessed behaviorally by the pole and grip strength test. Recombinant sustained irisin treatment of primary cortical neurons attenuated α-syn PFF toxicity by reducing the formation of phosphorylated serine 129 of α-syn and neuronal cell death. Tandem mass spectrometry and biochemical analysis revealed that irisin reduced pathologic α-syn by enhancing endolysosomal degradation of pathologic α-syn. Our findings highlight the potential for therapeutic disease modification of irisin in PD.

An Agonistic Monoclonal Antibody Targeting cMet Attenuates Inflammation and Up-Regulates Collagen Synthesis and Angiogenesis in Type 2 Diabetic Mice Wounds.

BACKGROUND: Diabetic wounds account for 25 to 50 percent of total diabetic health care costs annually, and present overall healing rates of less than 50 percent. Because delayed diabetic wound healing is associated with impaired fibroblast function, the authors hypothesize that tyrosine kinase Met (cMet) agonistic monoclonal antibody will promote diabetic wound healing by means of stable activation of hepatocyte growth factor/cMet signaling. METHODS: Two 6-mm dorsal wounds were created in each mouse (6-week-old, male BKS.Cg-Dock7 m +/+Lepr db /J; n = 5). After subcutaneous injections of agonist (20 mg/kg) at 0 and 72 hours, the wound sizes were measured at days 0, 1, 3, 6, and 10. Histologic and immunohistochemical analyses were performed at day 10 (cMet, α-smooth muscle actin, CD68, and transforming growth factor-ß). In vitro cytotoxicity and migration tests with diabetic fibroblasts were performed with or without agonist treatment (1 or 10 nM). cMet pathway activation of fibroblasts was confirmed through p-p44/42 mitogen-activated protein kinase, p-mTOR, p-cMet, and ROCK-1 expression. RESULTS: The cMet agonistic monoclonal antibody-treated group showed 1.60-fold lower wound area ( p = 0.027), 1.54-fold higher collagen synthesis ( p = 0.001), and 1.79-fold lower inflammatory cell infiltration ( p = 0.032) than the saline-treated control. The agonist increased cMet (1.86-fold; p = 0.029), α-smooth muscle actin (1.20-fold; p = 0.018), and vascular endothelial growth factor (1.68-fold, p = 0.029) expression but suppressed CD68 (1.25-fold; p = 0.043), transforming growth factor-ß (1.25-fold; p = 0.022), and matrix metalloproteinase-2 (2.59-fold; p = 0.029) expression. In vitro agonist treatment (10 nM) of diabetic fibroblasts increased their migration by 8.98-fold ( p = 0.029) and activated the hepatocyte growth factor/cMet pathway. CONCLUSIONS: Tyrosine kinase Met agonistic monoclonal antibody treatment improved diabetic wound healing in mice and reduced wound-site inflammatory cell infiltration. These results need to be validated in large animals before piloting human trials. CLINICAL RELEVANCE STATEMENT: Although further clinical studies are necessary to evaluate its therapeutic efficacy, our study suggested that cMet agonistic monoclonal antibody can be the alternative modality in order to improve wound healing cascade in diabetic foot patients.

Incorporation of SKI-G-801, a Novel AXL Inhibitor, With Anti-PD-1 Plus Chemotherapy Improves Anti-Tumor Activity and Survival by Enhancing T Cell Immunity.

A recently developed treatment strategy for lung cancer that combines immune checkpoint inhibitors with chemotherapy has been applied as a standard treatment for lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), and it has improved the outcomes of chemotherapy. Maintenance treatment with anti-PD-1 antibody (aPD-1) enhances the effect of immunochemical combination therapy and improves therapeutic efficacy, which contributes toward a significant improvement in patient survival rates. The AXL receptor tyrosine kinase (AXL), which is expressed in tumor cells, plays an essential role in the resistance of cancers to chemotherapy and immunotherapy, and stimulates signaling associated with epithelial-mesenchymal transition (EMT) in metastatic cancer. AXL is thus an attractive target for controlling resistance to anti-tumor therapies. In this study, we examined the effect of AXL inhibitors on immune activation and tumor growth in TC1 and C3PQ mouse tumor models, in the context of clinical immunotherapy/chemotherapy and maintenance treatment, using an aPD-1 with/without pemetrexed. To determine the optimal timing for administration of SKI-G-801, an AXL inhibitor, we investigated its anti-tumor effects based on inclusion at the immunochemotherapy and maintenance therapy stages. We also performed flow cytometry-based immune profiling of myeloid cells and lymphoid cells at different points in the treatment schedule, to investigate the immune activation and anti-tumor effects of the AXL inhibitor. The addition of SKI-G-801 to the immune checkpoint inhibitor and chemotherapy stage, as well as the maintenance therapy stage, produced the best anti-tumor results, and significant tumor growth inhibition was observed in both the TC1 and C3PQ models. Both models also exhibited increased proportion of effector memory helper T cells and increased expression of CD86+ macrophages. Especially, regulatory T cells were significantly reduced in the TC1 tumor model and there was an increase in central memory cytotoxic T cell infiltration and an increased proportion of macrophages with high CD80 expression in the C3PQ tumor model. These results suggest increased infiltration of T cells, consistent with previous studies using AXL inhibitors. It is expected that the results from this study will serve as a stepping stone for clinical research to improve the existing standard of care.

Tumor invasion in the hyponychium is associated with distant metastasis and poor prognosis in subungual melanoma: A histologic landscape of 44 cases.

BACKGROUND: Subungual melanoma (SUM) has a poor prognosis because of delayed diagnosis. Its progression, consensus on surgical treatment, and correlation with clinical outcomes remain unclear. OBJECTIVE: We aimed to identify the pattern of dermal invasion in different locations of the nail apparatus and its relationship with prognosis. METHODS: In this retrospective review of surgically treated SUM patients between January 2011 and April 2019, the nail apparatus was divided into 5 anatomic subunits: the dorsal roof of proximal nail fold, ventral floor of proximal nail fold, germinal matrix, nail bed, and hyponychium. Invasions in the subunits were categorized using 3 criteria: no tumor, in situ tumor, or invasion. RESULTS: Among 44 cases of SUM, dermal invasion occurred mostly in the distal areas, with 11, 30, 18, 7, and 4 in the hyponychium, nail bed, germinal matrix, ventral floor of proximal nail fold, and dorsal roof of proximal nail fold, respectively. The patients with hyponychial invasion showed a significantly greater Breslow depth (P = .009), a higher rate of lymph node metastasis (P = .019), distant metastasis (P = .036), and shorter disease-free survival (P = .001). CONCLUSION: Hyponychial invasion is an important prognostic predictor of SUM, given its strong association with invasion depth, metastatic progression, and disease-free survival. Patients with invasion in the hyponychium should undergo more strict workup, treatment, and surveillance.

Exercise hormone irisin is a critical regulator of cognitive function.

Identifying secreted mediators that drive the cognitive benefits of exercise holds great promise for the treatment of cognitive decline in ageing or Alzheimer's disease (AD). Here, we show that irisin, the cleaved and circulating form of the exercise-induced membrane protein FNDC5, is sufficient to confer the benefits of exercise on cognitive function. Genetic deletion of Fndc5/irisin (global Fndc5 knock-out (KO) mice; F5KO) impairs cognitive function in exercise, ageing and AD. Diminished pattern separation in F5KO mice can be rescued by delivering irisin directly into the dentate gyrus, suggesting that irisin is the active moiety. In F5KO mice, adult-born neurons in the dentate gyrus are morphologically, transcriptionally and functionally abnormal. Importantly, elevation of circulating irisin levels by peripheral delivery of irisin via adeno-associated viral overexpression in the liver results in enrichment of central irisin and is sufficient to improve both the cognitive deficit and neuropathology in AD mouse models. Irisin is a crucial regulator of the cognitive benefits of exercise and is a potential therapeutic agent for treating cognitive disorders including AD.

Clinical analysis and review of literature on pilomatrixoma in pediatric patients.

BACKGROUND: Pilomatrixoma is a benign tumor that originates from the hair follicle matrix. It usually presents as a hard, slow growing, solitary mass that can be easily misdiagnosed as other skin masses. The aim of this study was to clinically analyze a case series of pilomatrixoma in pediatric patients from Korea. METHODS: A total of 165 pediatric patients from 2011 to 2018 with a histological diagnosis of pilomatrixoma were included. A retrospective review was performed using the electronic medical records, including patient demographics, number and location of the mass, clinical and imaging presentation, and postoperative outcomes. RESULTS: There were 61 male and 104 female patients with 152 solitary and 13 multiple pilomatrixomas. Among solitary pilomatrixomas, the lesion commonly occurred in the head and neck (84.2%), followed by upper limbs (11.2%), lower limbs (3.3%), and trunk (1.3%). The pilomatrixoma lesion presented as the following types based on our clinical classification: mass (56.02%), pigmentation (25.31%), mixed (12.65%), ulceration (4.82%), and keloid-like (1.2%). Ultrasonography showed a high positive predictive value (95.56%). There were no specific complications observed except for two cases of recurrence. CONCLUSION: Pilomatrixoma has various clinical feature presentations and commonly occurs in the head and neck. Ultrasonography is a helpful diagnostic tool. Surgical removal of the lesion is the main treatment method with a low recurrence rate.

Irisin Mediates Effects on Bone and Fat via αV Integrin Receptors.

Irisin is secreted by muscle, increases with exercise, and mediates certain favorable effects of physical activity. In particular, irisin has been shown to have beneficial effects in adipose tissues, brain, and bone. However, the skeletal response to exercise is less clear, and the receptor for irisin has not been identified. Here we show that irisin binds to proteins of the αV class of integrins, and biophysical studies identify interacting surfaces between irisin and αV/ß5 integrin. Chemical inhibition of the αV integrins blocks signaling and function by irisin in osteocytes and fat cells. Irisin increases both osteocytic survival and production of sclerostin, a local modulator of bone remodeling. Genetic ablation of FNDC5 (or irisin) completely blocks osteocytic osteolysis induced by ovariectomy, preventing bone loss and supporting an important role of irisin in skeletal remodeling. Identification of the irisin receptor should greatly facilitate our understanding of irisin's function in exercise and human health.

Addressing metabolic heterogeneity in clear cell renal cell carcinoma with quantitative Dixon MRI.

BACKGROUND: Dysregulated lipid and glucose metabolism in clear cell renal cell carcinoma (ccRCC) has been implicated in disease progression, and whole tumor tissue-based assessment of these changes is challenged by the tumor heterogeneity. We studied a noninvasive quantitative MRI method that predicts metabolic alterations in the whole tumor. METHODS: We applied Dixon-based MRI for in vivo quantification of lipid accumulation (fat fraction [FF]) in targeted regions of interest of 45 primary ccRCCs and correlated these MRI measures to mass spectrometry-based lipidomics and metabolomics of anatomically colocalized tissue samples isolated from the same tumor after surgery. RESULTS: In vivo tumor FF showed statistically significant (P < 0.0001) positive correlation with histologic fat content (Spearman correlation coefficient, ρ = 0.79), spectrometric triglycerides (ρ = 0.56) and cholesterol (ρ = 0.47); it showed negative correlation with free fatty acids (ρ = -0.44) and phospholipids (ρ = -0.65). We observed both inter- and intratumoral heterogeneity in lipid accumulation within the same tumor grade, whereas most aggressive tumors (International Society of Urological Pathology [ISUP] grade 4) exhibited reduced lipid accumulation. Cellular metabolites in tumors were altered compared with adjacent renal parenchyma. CONCLUSION: Our results support the use of noninvasive quantitative Dixon-based MRI as a biomarker of reprogrammed lipid metabolism in ccRCC, which may serve as a predictor of tumor aggressiveness before surgical intervention. FUNDING: NIH R01CA154475 (YZ, MF, PK, IP), NIH P50CA196516 (IP, JB, RJD, JAC, PK), Welch Foundation I-1832 (JY), and NIH P01HL020948 (JGM).

Sural Nerve Splitting in Reverse Sural Artery Perforator Flap: Anatomical Study in 40 Cadaver Legs.

BACKGROUND: The reverse sural artery perforator flap has been widely used in reconstruction of the lower extremity. However, along with the high rate of flap necrosis, sural nerve injury is one of the most frequent complications. This cadaveric study investigated a simple sural nerve preservation technique during reverse sural artery perforator flap surgery. METHODS: Cadaver dissection was performed on 40 cadaver lower legs, to investigate the pattern of sural nerve distribution. The points where the lateral and medial sural cutaneous nerves penetrate the deep fascia were measured. The converging point of these nerves into the sural nerve was also recorded. Furthermore, the sural nerve was split until no tethering was observed, to simulate the sural nerve-sparing reverse sural artery perforator flap. RESULTS: Twenty-nine legs (72.5 percent) showed the lateral and medial sural cutaneous nerves converging to become the sural nerve (combined pattern); seven (17.5 percent) and four legs (10.0 percent) demonstrated the diminished and parallel types, respectively. The distances between the lateral malleolus and the fascia-penetrating point of the lateral and medial sural cutaneous nerves were 29.9 ± 3.3 cm and 18.8 ± 5.6 cm, respectively. In the combined type, the point of convergence was 13.6 ± 4.2 cm from the lateral malleolus. Nerve splitting was successfully performed in all combined cases, without injuring the nerve fascicles. CONCLUSIONS: The medial sural cutaneous nerve enters the deep fascia significantly more distally than does the lateral sural cutaneous nerve. Furthermore, using nerve splitting, the medial sural cutaneous nerve can be kept intact during reverse sural artery perforator flap surgery.

Dysregulation of mitophagy in carcinogenesis and tumor progression.

The mitochondrial role in carcinogenesis and cancer progression is an area of active research, with many unresolved questions. Various aspects of altered mitochondrial function have been implicated in tumorigenesis and tumor progression, including mitochondrial dysfunction, a metabolic switch to aerobic glycolysis, and dysregulation of mitophagy. Mitophagy is a highly specific quality control process which eliminates dysfunctional mitochondria and promotes mitochondrial turnover, and is involved in the adaptation to nutrient stress by controlling mitochondrial mass. The dysregulation of mitochondrial turnover has both a positive and negative role in cancer. This review will begin with a basic overview of the molecular mechanisms of mitophagy, and highlight recent trends in mitophagy from cancer studies. We will conclude this review by discussing areas of research in normal mitophagy that have yet to be explored in the context of cancer such as mitochondrial proteases, the mitochondrial unfolded protein response, and mitokine action. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux.

Rhabdomyomatous Mesenchymal Hamartoma Presenting as a Midline Mass on a Chin.

A 17-month-old boy was evaluated for a midline mass on his chin. The mass was anchored to the mentalis muscle with a stalk-like structure. The pathological diagnosis of the mass was rhabdomyomatous mesenchymal hamartoma. This is the first report of rhabdomyomatous mesenchymal hamartoma presenting as a midline chin mass in Korean pediatric patients.

Morphological and Functional Changes in the Thyroid Follicles of the Aged Murine and Humans.

BACKGROUND: Although both thyroid histology and serum concentrations of hormones are known to change with age, only a few reports exist on the relationship between the age-related structural and functional changes of the thyroid follicles in both mice and humans. Our objectives were to investigate age-related histological changes of the thyroid follicles and to determine whether these morphological changes were associated with the functional activity of the follicles. METHODS: The thyroid glands of mice at 18 weeks and at 6, 15, and 30 months of age were histologically examined, and the serum levels of thyroid hormones were measured in 11-week-old and 20-month-old mice. Samples of human thyroid tissue from 10 women over 70 years old and 10 women between 30 and 50 years of age were analyzed in conjunction with serum thyroid hormone level. RESULTS: The histological and functional changes observed in the thyroid follicles of aged mice and women were as follows: variable sizing and enlargement of the follicles; increased irregularity of follicles; Sanderson's polsters in the wall of large follicles; a large thyroglobulin (Tg) globule or numerous small fragmented Tg globules in follicular lumens; oncocytic change in follicular cells; and markedly dilated follicles empty of colloid. Serum T3 levels in 20-month-old mice and humans were unremarkable. CONCLUSIONS: Thyroid follicles of aged mice and women show characteristic morphological changes, such as cystic atrophy, empty colloid, and Tg globules.

Implications of oncocytic change in papillary thyroid cancer.

OBJECTIVE: Although the presence of oncocytic change in less than 75% of a tumour is not considered to indicate oncocytic variants of papillary thyroid carcinoma (PTC), we frequently observe partial oncocytic change, especially in obese PTC patients. Thus, we sought to investigate the relationship between the presence of oncocytic change of PTC and its prognosis. DESIGN, SETTING AND PARTICIPANTS: We retrospectively studied 142 patients with PTC who had undergone surgery between 2000 and 2005, and re-evaluated their PTC slides to record the proportion of oncocytic change in 10% increments from 0% to 100%. MAJOR OUTCOME MEASURE: We analysed the relationship between the proportion of oncocytic change and clinicopathological prognostic factors. RESULTS: Oncocytic change was found in 45·8% (65/142) of PTC patients. The proportion of patients with oncocytic change was higher in obese patients than in lean patients and showed a significant correlation with the BMI (r = 0·195, P = 0·020). The PTC patients with oncocytic change showed a higher recurrence rate than PTC patients without oncocytic change (30·8% vs 11·7%, respectively; P = 0·005). The presence of oncocytic change in PTC patients was associated with a shorter disease-free survival in a Kaplan-Meier analysis after a mean follow-up of 8·9 years. CONCLUSION: The patients with PTC with oncocytic change presented with a higher recurrence rate and were more likely to be obese. These findings suggest that presence of oncocytic change is a poor prognostic factor in PTC patients, even if the oncocytic change involves less than 75% of a tumour.

Wide Local Excision for Dermatofibrosarcoma Protuberans: A Single-Center Series of 90 Patients.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP), a rare low-grade sarcoma of fibroblast origin, tends to extend in a finger-like fashion beyond macroscopic tumor margins. Therefore, incomplete removal and subsequent recurrence are common. This study aimed to determine the efficacy of wide local excision (WLE) for controlling local recurrence of DFSP. METHODS: The medical records of 90 DFSP patients who received WLE at our hospital between June 1992 and January 2015 were retrospectively reviewed. WLE was conducted including a 3 cm (range, 1 to 5 cm) safety margin according to tumor size, location, and recurrence status. Clinical and tumor characteristics and surgical methods were evaluated for risk factor analysis and local recurrence-free survival. RESULTS: DFSP occurred most often in patients in their 30s (30%) and on the trunk (51.1%). Five patients (5.5%) experienced local recurrence during the 43.4-month follow-up period. Recurrence was found at a mean of 10.8 months after WLE. Although no factors were significantly associated with recurrence, recurrences were more frequent in head and neck. Recurrence-free survival was 87% in 6 years and 77% in 7 years. CONCLUSIONS: WLE with adequate lateral and deep margins can effectively control local recurrence rate and is a simple and effective method to treat DFSP.

Unsaturated Fatty Acids Stimulate Tumor Growth through Stabilization of ß-Catenin.

Some cancer cells exhibit elevated levels of free fatty acids (FAs) as well as high levels of ß-catenin, a transcriptional co-activator that promotes their growth. Here, we link these two phenomena by showing that unsaturated FAs inhibit degradation of ß-catenin. Unsaturated FAs bind to the UAS domain of Fas-associated factor 1 (FAF1), a protein known to bind ß-catenin, accelerating its degradation. FA binding disrupts the FAF1/ß-catenin complex, preventing proteasomal degradation of ubiquitinated ß-catenin. This mechanism for stabilization of ß-catenin differs from that of Wnt signaling, which blocks ubiquitination of ß-catenin. In clear cell renal cell carcinoma (ccRCC) cells, unsaturated FAs stimulated cell proliferation through stabilization of ß-catenin. In tissues from biopsies of human ccRCC, elevated levels of unsaturated FAs correlated with increased levels of ß-catenin. Thus, targeting FAF1 may be an effective approach to treat cancers that exhibit elevated FAs and ß-catenin.

Crystal structure of tRNA(m1G37)methyltransferase: insights into tRNA recognition.

tRNA(m(1)G37)methyltransferase (TrmD) catalyzes the transfer of a methyl group from S-adenosyl-L- methionine (AdoMet) to G(37) within a subset of bacterial tRNA species, which have a G residue at the 36th position. The modified guanosine is adjacent to and 3' of the anticodon and is essential for the maintenance of the correct reading frame during translation. Here we report four crystal structures of TrmD from Haemophilus influenzae, as binary complexes with either AdoMet or S-adenosyl-L-homocysteine (AdoHcy), as a ternary complex with AdoHcy and phosphate, and as an apo form. This first structure of TrmD indicates that it functions as a dimer. It also suggests the binding mode of G(36)G(37) in the active site of TrmD and the catalytic mechanism. The N-terminal domain has a trefoil knot, in which AdoMet or AdoHcy is bound in a novel, bent conformation. The C-terminal domain shows structural similarity to trp repressor. We propose a plausible model for the TrmD(2)-tRNA(2) complex, which provides insights into recognition of the general tRNA structure by TrmD.