Facial Skin Rejuvenation Using Poly-dl-Lactic Acid Injected With a Laser-Generated Needle-Free Microjet Injector.

BACKGROUND: A laser-induced needle-free microjet injector was developed for rapid, high-speed drug delivery of microliters into the skin. OBJECTIVE: This study evaluated the clinical rejuvenation effect of repeated dermal injections of the collagen simulator poly-dl-lactic acid (PDLA) using a laser-induced needle-free microjet injector. METHODS: Five PDLA injection sessions using a laser-induced needle-free microjet injector were conducted in patients concerned about aging skin. Facial uplifting, darkness, redness, roughness, pore size, subjective satisfaction, and side effects were evaluated before each session and 4 weeks after treatment completion. Histological evaluation was also performed with immunohistochemical staining of collagen and elastic fibers. RESULTS: The clinical results of 27 female patients were evaluated. The treatment resulted in a noticeable skin surface uplifting (0.711 ± 0.42 mm) and significant improvements in darkness (p = .013), redness (p = .009), and roughness (p = .036), with no significant difference in the pore size (p = .770). Patients were reported being satisfied with the overall therapeutic effects, despite mild and tolerable adverse effects. Histological findings revealed growth and thickening of collagen and elastic fibers, with marked increase in collagen I and III levels. CONCLUSION: Repeated dermal injections of PDLA using a laser-induced microjet injector offer excellent drug delivery, achieving high efficacy in skin rejuvenation, patient satisfaction, and safety.

Effects of Limosilactobacillus reuteri ID-D01 Probiotic Supplementation on Exercise Performance and Gut Microbiota in Sprague-Dawley Rats.

The gut microbiota composition in animals and humans has recently been found to be influenced by exercise. Although Limosilactobacillus reuteri strains have notable probiotic properties that promote human health, understanding of its effects in combination with exercise and physical activity is limited. Therefore, this study examined the effects of L. reuteri ID-D01, a human-derived probiotic, on exercise performance and fatigue in Sprague-Dawley rats. Organ weight, maximal running distance, serum biochemistry, muscle performance, microbial community composition, and short-chain fatty acid (SCFA) levels were assessed. Results indicated that ID-D01 supplementation significantly improved endurance performance. Rats in the probiotic group demonstrated a significant increase in maximal running distance compared with that in the control group (p < 0.05). Additionally, levels of fatigue markers, such as lactate and creatine phosphokinase, were significantly reduced in the ID-D01-administered groups, suggesting its potential to alleviate exercise-induced fatigue. Microbiome analysis revealed a distinct shift in gut microbiota composition in response to ID-D01 administration. The group that received ID-D01 probiotics exhibited a significant increase in the abundance of SCFA-producing bacteria, particularly Akkermansia spp., compared with that in the control groups. Furthermore, they showed elevated production of SCFAs, such as acetate and butyrate. In conclusion, this study demonstrated that ID-D01 can enhance exercise performance and reduce fatigue. Herein, we highlighted that human-derived probiotics could improve physical performance, as observed by changes in gut microbiota composition and SCFA production.

Synergistic Anti-Cancer Effects of ERB-041 and Genistein through Estrogen Receptor Suppression-Mediated PI3K/AKT Pathway Downregulation in Canine Mammary Gland Tumor Cells.

Canine-mammary-gland tumors (CMTs) are prevalent in female dogs, with approximately 50% of them being malignant and often presenting as inoperable owing to their size or metastasis. Owing to poor outcomes, effective alternatives to conventional chemotherapy for humans are necessary. Two estrogen receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERß), which act in opposition to each other, are involved, and CMT growth involves ERα through the phosphoinositide 3-kinases (PI3K)/AKT pathway. In this study, we aimed to identify the synergistic anti-cancer effects of ERB-041, an ERß agonist, and genistein, an isoflavonoid from soybeans known to have ERß-specific pseudo-estrogenic actions, on CMT-U27 and CF41.Mg CMT cell lines. ERB-041 and genistein synergistically inhibited cell proliferation and increased the number of annexin V-positive cells in both cell lines. Furthermore, we observed a synergistic increase in the Bax/Bcl-2 ratio and cleaved caspase-3 expression. Additionally, cell-cycle arrest occurred through the synergistic regulation of cyclin D1 and cyclin-dependent kinase 4 (CDK4). We also found a synergistic decrease in the expression of ERα, and the expression of proteins involved in the PI3K/AKT pathway, including p-PI3K, phosphatase and tensin homolog (PTEN), AKT, and mechanistic target of rapamycin (mTOR). In conclusion, ERB-041 and genistein exhibited a synergistic anticancer effect on CMTs, suggesting that cotreatment with ERB-041 and genistein is a promising treatment for CMTs.

Evaluation of purine-nucleoside degrading ability and in vivo uric acid lowering of Streptococcus thermophilus IDCC 2201, a novel antiuricemia strain.

This study evaluated 15 lactic acid bacteria with a focus on their ability to degrade inosine and hypo-xanthine-which are the intermediates in purine metabolism-for the management of hyperuricemia and gout. After a preliminary screening based on HPLC, Lactiplantibacillus plantarum CR1 and Lactiplantibacillus pentosus GZ1 were found to have the highest nucleoside degrading rates, and they were therefore selected for further characterization. S. thermophilus IDCC 2201, which possessed the hpt gene encoding hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and exhibited purine degradation, was also selected for further characterization. These three selected strains were examined in terms of their probiotic effect on lowering serum uric acid in a Sprague-Dawley (SD) rat model of potassium oxonate (PO)-induced hyperuricemia. Among these three strains, the level of serum uric acid was most reduced by S. thermophilus IDCC 2201 (p < 0.05). Further, analysis of the microbiome showed that administration of S. thermophlilus IDCC 2201 led to a significant difference in gut microbiota composition compared to that in the group administered with PO-induced hyperuricemia. Moreover, intestinal short-chain fatty acids (SCFAs) were found to be significantly increased. Altogether, the results of this work indicate that S. thermophilus IDCC 2201 lowers uric acid levels by degrading purine-nucleosides and also restores intestinal flora and SCFAs, ultimately suggesting that S. thermophilus IDCC 2201 is a promising candidate for use as an adjuvant treatment in patients with hyperuricemia.

Blending Three Probiotics Alleviates Loperamide-Induced Constipation in Sprague-Dawley (SD)-Rats.

BIOVITA 3 bacterial species (BIOVITA 3), a probiotic blend powder containing Clostridium butyricum IDCC 1301, Weizmannia coagulans IDCC 1201 and Bacillus subtilis IDCC 1101, has been used as a food ingredient for gut health. However, its efficacy in improving constipation has not been reported. Therefore, we aimed to investigate the functional effects of oral administration of BIOVITA 3 as well as its component strains alone (at 1.0×109 CFU/day) in Sprague-Dawley (SD) rats with loperamide-induced constipation. The study included fecal analysis, gastrointestinal transit ratio, histopathological analysis, short chain fatty acids (SCFAs), and metagenome analysis. As results, the BIOVITA 3 group showed significant improvements in fecal number, water content, gastrointestinal transit ratio, and thickening of the mucosal layer. In the SCFAs analysis, all probiotic-treated groups showed an increase in total SCFAs compared to the loperamide-constipated group. Changes in microbial abundance and the diversity index of three groups (normal, constipated, and BIOVITA 3) were also defined. Of these, the BIOVITA 3 showed a significant improvement in loperamide-constipated SD-rats. This study suggests the possibility that BIOVITA 3 can be applied as an ingredient in functional foods to relieve constipation.

Immunohistochemical differentiation of keratins and involucrin between palmar psoriasis, chronic hand eczema and hyperkeratotic hand eczema.

BACKGROUND: Common hyperkeratotic palmar skin lesions include chronic hand eczema (CHE), hyperkeratotic hand eczema (HHE), palmar psoriasis (PP). However, clinically differentiating these disorders is often challenging. OBJECTIVES: To compare the expressions of keratin (K) 5, K9, K14 and involucrin in palmar hyperkeratotic lesions (HHE, CHE and PP). MATERIALS AND METHODS: Immunohistochemical staining was performed on skin biopsy specimens obtained from the palms of patients clinically diagnosed with CHE, HHE and PP (n = 21, 24 and 18, respectively). RESULTS: K5 and K14 expression levels were higher in the spinous and granular layers of PP and HHE compared to CHE. Involucrin was expressed in the basal layer of PP and HHE but not in CHE. K9 expression was decreased in PP and HHE compared to CHE. CONCLUSION: Keratin and involucrin expression in the epidermis are markers of keratinocyte differentiation. Expression levels of keratin and involucrin were similar between the HHE and PP groups, suggesting that HHE shares pathogenesis with PP rather than CHE.

Anti-cancer effect of palmatine through inhibition of the PI3K/AKT pathway in canine mammary gland tumor CMT-U27 cells.

Canine mammary gland tumors (CMTs) are the most common and lethal cancers in female dogs. Dysregulated phosphoinositide 3-kinases (PI3K)/AKT pathway reportedly was involved in the growth and metastasis of CMTs. However, there are few studies on therapeutic strategies for targeting the PI3K pathway in CMTs. In this study, we aimed to determine whether palmatine, a natural isoquinoline alkaloid with anti-cancer properties, could inhibit the growth of CMTs and whether the inhibitory effect was mediated through the PI3K/AKT pathway. Our in vitro experiments on CMT-U27, a CMT cell line, showed that palmatine reduced cell proliferation and induced cell death. Western blotting results revealed that palmatine decreased the protein expression of PI3K, PTEN, AKT, and mechanistic target of rapamycin in the PI3K/AKT pathway, which was supported by the results of immunocytochemistry. Additionally, palmatine suppressed the migration and tube formation of canine aortic endothelial cells as well as the migration of CMT U27 cells. Our in vivo results showed that palmatine inhibited tumor growth in a CMT-U27 mouse xenograft model. We observed a decreased expression of proteins in the PI3K/AKT pathway in tumor tissues, similar to the in vitro results. Furthermore, palmatine significantly disrupted the tumor vasculature and inhibited metastasis to adjacent lymph nodes. In conclusion, our findings demonstrate that palmatine exerts anti-cancer effects against CMTs by inhibiting PI3K/AKT signaling pathway, suggesting that palmatine has potential as a canine-specific PI3K inhibitor for the treatment of CMTs.

Development and clinical evaluation of a quantitative fluorescent immunoassay for detecting canine CRP.

Canine C-reactive protein (cCRP) is one of the major positive acute phase proteins in dogs and is commonly measured to detect and monitor systemic inflammation as well as the efficacy of treatment. Traditional methods for testing cCPR, including enzyme-linked immunosorbent assay (ELISA), have some drawbacks, such as a long time for diagnosis and the requirement of well-equipped laboratories. Therefore, there is a need for a rapid and precise diagnostic test for cCRP at point-of-care. This study assessed the accuracy, precision, and validated clinical effectiveness of a diagnostic test based on fluorescent lateral flow immunoassay to detect cCRP. For the standard cCRP concentration ranging from 0 to 200 µg/mL, the cCRP diagnostic test showed strong linearity with R2 of 0.9977 (p < 0.001), and both inter- and intra-assay CVs were <14%. The limit of detection and limit of quantitation were found to be 4.0 µg/mL and 5.0 µg/mL, respectively. The cCRP serum concentration was evaluated in 21 client-owned dogs and the results were compared to a previously validated ELISA. The Pearson Correlation Coefficient between the diagnostic test kit and ELISA was 0.942 [95% confidence interval: 0.859 to 0.976, p < 0.001], and the Bland-Altman plot indicated a bias of 26.82% [95% limits of agreement: -56.03 to 109.67], indicating a significant correlation and the agreement between the data from the cCRP diagnostic test and ELISA. In conclusion, the fluorescent immunoassay based diagnostic test is a suitable option for rapidly and precisely detecting cCRP in dogs, providing a convenient alternative to traditional methods for diagnosing acute inflammation.

High Mean Platelet Volume Is Associated with Cerebral White Matter Hyperintensities in Non-Stroke Individuals.

PURPOSE: The mean platelet volume (MPV) is regarded as a marker for thrombosis, atherosclerosis, and inflammation in various vascular diseases. However, it still remains unclear whether plasma MPV is associated with cerebral white matter hyperintensities (WMH) and cerebral microvascular pathology in the elderly population. MATERIALS AND METHODS: We examined whether MPV level is associated with the presence of cerebral WMH on brain magnetic resonance imaging from 870 non-stroke outpatient subjects. The subjects were divided into three groups according to the consecutive level of MPV (low T1, middle T2, and high T3 MPV tertile groups). To determine the association of MPV levels with the WMH, logistic regression and receiver operating characteristic curve analyses were conducted. RESULTS: Subjects with higher MPV level were older and more likely to have hypertension, diabetes mellitus, and low renal function. Cerebral WMH were more prevalent in subjects with higher MPV level. After adjusting for confounding factors, moderate to severe cerebral WMH were significantly associated with high MPV tertile level. This association remained significant after adjusting for other cerebral vascular pathologies. T2 [odds ratio (OR): 1.49, 95% confidence interval (CI): 1.03-2.15] and T3 MPV tertile groups (OR: 1.51, 95%CI: 1.04-2.20) had more cerebral WMH lesions compared to T1 MPV tertile group. In addition, the subjects with higher Fazekas scores showed higher MPV level (p=0.020). CONCLUSION: We found that high MPV level is independently associated with cerebral WMH. This result suggests that platelet activation plays a role in the development of cerebral WMH.

Dysphagia with Unilateral Vocal Cord Paralysis in Herpes Zoster: A Case Report.

Herpes zoster is caused by the varicella-zoster virus, which becomes latent in ganglia after primary infection. When the varicella-zoster virus reactivates on the cranial nerve, the patient can suffer from cranial nerve palsy, pain, and skin lesions on the head and neck area. A 57-year-old immunocompetent male presented with dysphagia lasting 10 days. Computed tomography and other neurological findings were normal. However, laryngoscopy showed right vocal cord paralysis, which might be the reason for dysphagia in this patient. There was a grouped crusted lesion on the right posterior auricular area that appeared 5 days after the dysphagia. After famciclovir and prednisolone combination therapy, the patient was cured with no sequelae. This is a rare case of herpes zoster in an immunocompetent patient who presented with dysphagia. In addition, it was difficult to make an accurate diagnosis because his skin lesion appeared several days after dysphagia.

The Potential of Bovine Colostrum-Derived Exosomes to Repair Aged and Damaged Skin Cells.

In this study, we examined the potentially beneficial effects of bovine colostrum-derived exosomes on UV-induced aging and damage in three major resident skin cells including keratinocytes, melanocytes, and fibroblasts. The treatment with colostrum exosomes prevented the UV-induced generation of intracellular reactive oxygen species in epidermal keratinocytes. In UV-stimulated melanocytes, colostrum exosomes could also significantly reduce the production of the protective skin-darkening pigment melanin, which may help to reduce the risk of excessive melanin formation causing skin hyperpigmentation disorders. In the human dermal fibroblasts treated with colostrum exosomes, the expression of matrix metalloproteinases was suppressed, whereas increased cell proliferation was accompanied by enhanced production of collagen, a major extracellular matrix component of skin. Taken together, our findings indicate that bovine colostrum-derived exosomes having excellent structural and functional stability offer great potential as natural therapeutic agents to repair UV-irradiated skin aging and damage.

Safety Evaluation of Weissella cibaria JW15 by Phenotypic and Genotypic Property Analysis.

Weissella cibaria is one of the bacteria in charge of the initial fermentation of kimchi and has beneficial effects such as immune-modulating, antagonistic, and antioxidant activities. In our study, we aimed to estimate the safety of W. cibaria JW15 for the use of probiotics according to international standards based on phenotypic (antibiotic resistance, hemolysis, and toxic metabolite production) and genotypic analysis (virulence genes including antibiotic resistance genes). The results of the safety assessment on W. cibaria JW15 were as follows; (1) antibiotic resistance genes (ARGs) (kanamycin and vancomycin etc.) were intrinsic characteristics; (2) There were no acquired virulence genes including Cytolysin (cylA), aggregation substance (asa1), Hyaluronidase (hyl), and Gelatinase (gelE); (3) this strain also lacked ß-hemolysis and the production of toxic metabolites (D-lactate and bile salt deconjugation). Consequently, W. cibaria JW15 is expected to be applied as a functional food ingredient in the food market.

A Rare Case of Transient Friction Melanosis of the Finger: A Case Report.

Friction melanosis (FM) is an acquired pigmented disease that is caused by recurrent mechanical stress. There is no previous report explaining the presence of tiny brown-colored particles confined to the corneal layer. We describe a case of a rare form of FM of the finger that showed a relatively transient clinical course. A 17-year-old Korean female presented with a 5-month history of an asymptomatic localized hyperpigmented patch on the tip of the right index finger. The dermoscopic examination revealed homogenous globular pattern, which favored pigmentation over hemorrhage. Histopathologically, hyperkeratosis and acanthosis with lymphohistiocytic infiltration of the superficial dermis were noted on hematoxylin and eosin staining; however, there was neither a definite increase in melanophages in the upper dermis nor melanocytic proliferation in the basal layer. Per high-power field, multiple brown-colored tiny particles were scattered in the corneal layer. The particles were not dyed by Fontana-Masson stain, iron stain, and S-100. We questioned the patient about the presence of irritation and found that she had bought new shoes at the time of the onset. She was habituated to placing her fingers in her shoes while wearing them because they were slightly tight. The lesion disappeared spontaneously a week after the cause of friction was eliminated. Altogether, we encountered a rare form of FM that occurred in a rare location with a transient clinical course. Further cases on pigmentation restricted to finger tips might reveal the origin of the particles.

Immunohistochemical Analysis of Differences of Toll-Like Receptor 2, Mast Cells, and Neurofilaments between Granulomatous Rosacea and Non-Granulomatous Rosacea.

BACKGROUND: Granulomatous rosacea is a distinct variant of rosacea because of its unique histopatholiogic findings. However, the pathogenesis of granulomatous rosacea has not yet been clearly demonstrated. AIMS AND OBJECTIVES: The aim of this study was to investigate the expression of toll-like receptor 2, mast cells, and neurofilaments in the granulomatous rosacea compared with the non-granulomatous rosacea. MATERIALS AND METHODS: Biopsy specimens were obtained from 12 patients with erythematotelangiectatic rosacea, 11 patients with granulomatous rosacea, and 11 control patients. Biopsy tissue blocks were subjected to immunohistochemical staining using antibodies against toll-like receptor 2, mast cells, and neurofilaments. RESULTS: In granulomatous rosacea, the expression of mast cells increased significantly, compared to the erythematotelangiectatic rosacea and the control group (P-value = 0.001 and 0.013, respectively). Additionally, the expression of toll-like receptor 2 in the granulomatous rosacea group was higher than that in the control group (P-value = 0.04). CONCLUSION: The results of this study suggest that the increased expression of mast cells may be a sign of chronic, later stage of granulomatous rosacea compared to the erythematotelangiectatic rosacea. The increased expression of toll-like receptor 2 suggests that cathelicidin-induced neuroimmune pathogenesis also contributes to the pathophysiology of granulomatous rosacea.

A Rare Case of Cutaneous T-Cell Lymphoma Accompanied by Acute Monoblastic Leukemia and Diffuse Large B-Cell Lymphoma.

A 70-year-old female was referred for brown-to-gray colored papules and nodules on her lower legs. She had been diagnosed with diffuse large B-cell lymphoma (DLBCL) in her stomach, and myelodysplastic syndrome (MDS) by bone marrow biopsy. Three years after complete remission of DLBCL, she experienced DLBCL recurrence in her small bowel and was hospitalized. MDS had been stationary, but during the treatment of DLBCL, her laboratory findings suggested signs of leukemia. Bone marrow biopsy was done, and acute monoblastic leukemia (AMoL) was diagnosed. After 1 cycle of chemotherapy for AMoL, skin lesions developed, and her skin biopsy showed cutaneous T-cell lymphoma (CTCL). Terminal deoxynucleotidyl transferase staining and CD123 staining were negative, and bone marrow re-biopsy conducted after the skin lesion developed still showed monoblastic proliferation. Whether the CTCL represented with an AMoL lineage switch could not be completely proved due to the absence of molecular or clonal marker evaluations, but the possibility of coexistence of three different malignancies was higher. During treatment, a neutropenic fever developed, and the patient died due to sepsis. We herein report a rare case of CTCL accompanied by AmoL and DLBCL.

A Case of Herpes Zoster Granulomatous Dermatitis: Report of Wolf's Isotopic Response.

Wolf's isotopic response refers to the occurrence of a novel skin disease at the site of a preceding treated or untreated skin disease. Although the most common preceding skin disease was found to be herpes zoster (HZ), HZ-related dermatological phenomena are not well known in the literature. We report a case of HZ granulomatous dermatitis in a 77-year-old female with a previous history of hypertension, diabetes mellitus, chronic kidney disease, and HZ. She presented with a 3-month history of a pruritic skin lesion on her right thigh. The location of the lesion was consistent with a previous HZ site. Histopathological examination revealed lympho- histiocytic infiltration in the superficial dermis, forming a granulomatous structure. Based on clinical and histopathological findings, we made a diagnosis of granulomatous dermatitis at a previous HZ site. We assumed that the lesion arose from an isotopic response of Wolf. The patient was treated with topical steroids for 3 months and showed clearance of the lesion and symptom. We suggest that treatment should be based on the individual disease, which in our case was topical steroid.

Electric Stimulation Elicits Heterogeneous Responses in ON but Not OFF Retinal Ganglion Cells to Transmit Rich Neural Information.

Retinal implants electrically stimulate surviving retinal neurons to restore vision in people blinded by outer retinal degeneration. Although the healthy retina is known to transmit a vast amount of visual information to the brain, it has not been studied whether prosthetic vision contains a similar amount of information. Here, we assessed the neural information transmitted by population responses arising in brisk transient (BT) and brisk sustained (BS) subtypes of ON and OFF retinal ganglion cells (RGCs) in the rabbit retina. To correlate the response heterogeneity and the information transmission, we first quantified the cell-to-cell heterogeneity by calculating the spike time tiling coefficient (STTC) across spiking patterns of RGCs in each type. Then, we computed the neural information encoded by the RGC population in a given type. In responses to light stimulation, spiking activities were more heterogeneous in OFF than ON RGCs (STTCAVG = 0.36, 0.45, 0.77 and 0.55 for OFF BT, OFF BS, ON BT, and ON BS, respectively). Interestingly, however, in responses to electric stimulation, both BT and BS subtypes of OFF RGCs showed remarkably homogeneous spiking patterns across cells (STTCAVG = 0.93 and 0.82 for BT and BS, respectively), whereas the two subtypes of ON RGCs showed slightly increased populational heterogeneity compared to light-evoked responses (STTCAVG = 0.71 and 0.63 for BT and BS, respectively). Consequently, the neural information encoded by the electrically-evoked responses of a population of 15 RGCs was substantially lower in the OFF than the ON pathway: OFF BT and BS cells transmit only ~23% and ~53% of the neural information transmitted by their ON counterparts. Together with previously-reported natural spiking activities in ON RGCs, the higher neural information may make ON responses more recognizable, eliciting the biased percepts of bright phosphenes.

Comparative Evaluation of Quality and Metabolite Profiles in Meju Using Starter Cultures of Bacillus velezensis and Aspergillus oryzae.

The production of good Meju soybean paste primarily depends on the selection of raw materials and fermenting microorganisms, which together influence its characteristic metabolites, taste, and aroma. In this study, we analyzed the relationship between properties and metabolites in Meju samples fermented by Aspergillus oryzae alone or with Bacillus velezensis. We developed fast-stable processing techniques to obtain Meju from A. oryzae and B. velezensis using the inoculation method, thereby ensuring safety in the production of soybean paste. The amino-type nitrogen content increased from an initial 180-228 mg% to a final 226-776 mg% during fermentation and was higher in Meju inoculated separately with the fungi and bacteria (C group) than in Meju co-inoculated with both the starters concurrently (D group). The levels of metabolites such as glucose, myo-inositol, glycerol, and fatty acids (palmitic, stearic, oleic, and linoleic acids) in Meju fermented by A. oryzae with B. velezensis were higher than those in Meju fermented by A. oryzae alone. Fungal growth was affected by the inoculated bacteria, which often occurs during the fermentation of co-inoculated Meju.

Screening of endogenous strong promoters of Leuconostoc citreum EFEL2700 based on transcriptome analysis and its application for food-grade production of ß-galactosidase.

Leuconostoc citreum is a heterofermentative lactic acid bacterium frequently found in the various fermented foods. L. citreum EFEL2700 isolated from Korean kimchi has been used as a host strain for biotechnological applications. For the use as a food-grade host to over-produce food ingredients or enzymes, strong endogenous promoters guarantying high expression levels of target genes are necessary. In this study, transcriptomic analysis of L. citreum EFEL2700 was performed using RNA-Seq and three promoters of the most highly expressed genes were selected: glyceraldehyde 3-phosphate dehydrogenase (G3PD), 6-phosphogluconate dehydrogenase (6PGD), and phosphoketolase (PPK). Thereafter, they were used as promoters to express ß-galactosidase gene from Lactobacillus plantarum WCFS1 in L. citreum EFEL2700 and the levels were compared with the control promoter P710 from L. mesenteroides ATCC 8293. As results, the ß-galactosidase activities of the transformants were 2.73, 0.27, 37.43, and 9.25 units/mg under the P710, G3PD, 6PGD, and PPK promoters, respectively. The expression level of endogenous promoter 6PGD was superior to the heterologous P710 promoter previously used in a Leuconostoc-Escherichia coli shuttle vector. The 6PGD developed in this study can be used as the most suitable promoter for ß-galactosidase expression in L. citreum EFEL2700.

Retinal Degeneration Reduces Consistency of Network-Mediated Responses Arising in Ganglion Cells to Electric Stimulation.

Retinal prostheses use periodic repetition of electrical stimuli to form artificial vision. To enhance the reliability of evoked visual percepts, repeating stimuli need to evoke consistent spiking activity in individual retinal ganglion cells (RGCs). However, it is not well known whether outer retinal degeneration alters the consistency of RGC responses. Hence, here we systematically investigated the trial-to-trial variability in network-mediated responses as a function of the degeneration level. We patch-clamp recorded spikes in ON and OFF types of alpha RGCs from r d10 mice at four different postnatal days (P15, P19, P31, and P60), representing distinct stages of degeneration. To assess the consistency of responses, we analyzed variances in spike count and timing across repeats of the same stimulus delivered multiple times. We found the trial-to-trial variability of network-mediated responses increased considerably as the disease progressed. Compared to responses taken before degeneration onset, those of degenerate retinas showed up to ~70% higher variability (Fano Factor) in spike counts (p < 0.001) and ~95% lower correlation level in spike timing (p < 0.001). These results indicate consistency weakens significantly in electrically-evoked network-mediated responses and therefore raise concerns about the ability of microelectronic retinal implants to elicit consistent visual percepts at advanced stages of retinal degeneration.