Effects of 5-aminolevulinic acid and sodium ferrous citrate on fibroblasts from individuals with mitochondrial diseases

5-Aminolevulinic acid/sodium ferrous citrate improves the quality of heat-stressed bovine oocytes by reducing oxidative stress

A high temperature-humidity index during summer has deleterious effects on mitochondrial function, reducing oocyte developmental competence. 5-Aminolevulinic acid (5-ALA) and sodium ferrous citrate (SFC) are both known to support mitochondrial function and have strong anti-oxidant and anti-apoptotic activities. This study aimed to determine the mechanism of action of 5-ALA/SFC on oocyte quality. Bovine oocytes were collected from medium-sized follicles during summer (July-September, temperature-humidity index:76.6), cultured with 0, 1, 2, 4, and 8 µM 5-ALA with SFC at a molar ratio of 1:0.125, fertilized, and cultured for 10 days. The addition of 8/1 µM 5-ALA/SFC had a deleterious effect on oocyte cleavage rate in comparison with control oocytes, but did not affect the blastocyst rate, while 1/0.125 µM 5-ALA/SFC had a significantly higher increase in blastocyst rate than 8/1 µM 5-ALA/SFC. The addition of 1/0.125 and 2/0.25 µM 5-ALA/SFC improved oocyte quality by increasing the mitochondrial distribution pattern and metaphase-II oocytes, reducing reactive oxygen species and upregulating nuclear factor erythroid-2-related factor 2, heme oxygenase-1, and superoxide dismutase-1 in oocytes, and nuclear factor erythroid-2-related factor 2 and mitochondrial transcription factor A in cumulus cells. These results indicate that 1/0.125 and 2/0.25 µM 5-ALA/SFC may support oocyte quality and developmental competence and provide anti-oxidant actions in cumulus-oocyte complexes.

Sodium Ferrous Citrate and 5-Aminolevulinic Acid Exert a Therapeutic Effect on Endotoxin-Induced Uveitis in Rats

The metabolism of 5-aminolevulinic acid (ALA) is more efficient when combined with sodium ferrous citrate (SFC). Our previous study revealed that oral administration of ALA, which has anti-inflammatory properties, and SFC (ALA/SFC) immediately before lipopolysaccharide (LPS) inoculation suppressed endotoxin-induced uveitis (EIU) in rats. However, the therapeutic effect of ALA/SFC post-administration remains unexplored. Hence, this study aimed to evaluate the therapeutic efficacy of ALA/SFC on EIU in rats, which were administered with a gastric gavage of ALA/SFC (100/157 mg/kg) or prednisolone (Pred, 10 mg/kg) after 4 h of LPS inoculation. The treatment groups showed ameliorated clinical scores, inflammatory cells, protein levels in the aqueous humor (AqH), and histopathologic evaluation 24 h after LPS inoculation. Furthermore, the treatment groups had reduced tumor necrosis factor-α, nitric oxide, prostaglandin E2, and interleukin-6 levels in the AqH. ALA/SFC demonstrated an anti-inflammatory effect equivalent to that demonstrated by Pred. These findings indicate that ALA/SFC exerts a therapeutic effect on EIU in rats, indicating its clinical usefulness in uveitis treatment.

5-Aminolevulinic acid bypasses mitochondrial complex I deficiency and corrects physiological dysfunctions in Drosophila

Complex I (CI) deficiency in mitochondrial oxidative phosphorylation (OXPHOS) is the most common cause of mitochondrial diseases, and limited evidence-based treatment options exist. Although CI provides the most electrons to OXPHOS, complex II (CII) is another entry point of electrons. Enhancement of this pathway may compensate for a loss of CI; however, the effects of boosting CII activity on CI deficiency are unclear at the animal level. 5-Aminolevulinic acid (5-ALA) is a crucial precursor of heme, which is essential for CII, complex III, complex IV (CIV) and cytochrome c activities. Here, we show that feeding a combination of 5-ALA hydrochloride and sodium ferrous citrate (5-ALA-HCl + SFC) increases ATP production and suppresses defective phenotypes in Drosophila with CI deficiency. Knockdown of sicily, a Drosophila homolog of the critical CI assembly protein NDUFAF6, caused CI deficiency, accumulation of lactate and pyruvate and detrimental phenotypes such as abnormal neuromuscular junction development, locomotor dysfunctions and premature death. 5-ALA-HCl + SFC feeding increased ATP levels without recovery of CI activity. The activities of CII and CIV were upregulated, and accumulation of lactate and pyruvate was suppressed. 5-ALA-HCl + SFC feeding improved neuromuscular junction development and locomotor functions in sicily-knockdown flies. These results suggest that 5-ALA-HCl + SFC shifts metabolic programs to cope with CI deficiency. Bullet outline 5-Aminolevulinic acid (5-ALA-HCl + SFC) increases ATP production in flies with complex I deficiency.5-ALA-HCl + SFC increases the activities of complexes II and IV.5-ALA-HCl + SFC corrects metabolic abnormalities and suppresses the detrimental phenotypes caused by complex I deficiency.

5-ALA/SFC Ameliorates Endotoxin-Induced Ocular Inflammation in Rats by Inhibiting the NF-κB Signaling Pathway and Activating the HO-1/Nrf2 Signaling Pathway

Sodium ferrous citrate (SFC) is involved in the metabolism of 5-aminolevulinic acid (5-ALA) and enhances its anti-inflammatory effects. The effects of 5-ALA/SFC on inflammation in rats with endotoxin-induced uveitis (EIU) have yet to be elucidated. In this study, during lipopolysaccharide injection, 5-ALA/SFC (10 mg/kg 5-ALA plus 15.7 mg/kg SFC) or 5-ALA (10 or 100 mg/kg) was administered via gastric gavage, wherein we saw that 5-ALA/SFC ameliorated ocular inflammation in EIU rats by suppressing clinical scores; by infiltrating cell counts, aqueous humor protein, and inflammatory cytokine levels; and by improving histopathological scores to the same extent as 100 mg/kg 5-ALA. Immunohistochemistry showed that 5-ALA/SFC suppressed iNOS and COX-2 expression, NF-κB activation, IκB-α degradation, and p-IKKα/β expression, and activated HO-1 and Nrf2 expression. Therefore, this study has investigated how 5-ALA/SFC reduces inflammation and revealed the pathways involved in EIU rats. 5-ALA/SFC is shown to inhibit ocular inflammation in EIU rats by inhibiting NF-κB and activating the HO-1/Nrf2 pathways.

5-Aminolevulinic acid combined with ferrous iron ameliorates scrotal heat stress-induced spermatogenic damage by enhancing HO-1 expression

OBJECTIVE

To explore whether 5-Aminolevulinic acid combined with ferrous iron (5-ALA/Fe²⁺) could protect testicular tissues damage of mice subjected to heat stress (HS) and provide its underlying mechanisms.

METHODS

5-ALA/Fe²⁺ was administered intragastrically to mice for 10 days, then exposed to a scrotal heat stress at 43°C for 20 min on third day. Testes were harvested for morphologic and histopathological examination, oxidative stress, apoptosis, heme oxygenase-1 (HO-1) and inflammation detection. The mitogen-activated protein kinases (MAPK) signaling pathway in testis and CD4⁺FoxP3⁺regulatory T (Treg) cells in spleen were also investigated.

RESULTS

Compared to control group, the testis weight decreased and histological damage severed in HS group. Besides, HS also increased the oxidative stress, apoptosis and inflammation in testis. However, these indicators were ameliorated after 5-ALA/Fe²⁺ treatment but deteriorated after receiving ZnPPIX. The expression of HO-1 was increased both in HS group and 5-ALA/Fe²⁺ group. The protein expression levels of MAPK proteins were activated by HS and inhibited by 5-ALA/Fe²⁺. The CD4⁺FoxP3⁺ Treg generation was reduced by HS and increased by 5-ALA/Fe²⁺.

CONCLUSION

In this study, we have demonstrated that 5-ALA/Fe²⁺ ameliorated the spermatogenic damage induced by scrotal heat stress via up-regulating the expression of HO-1 and inhibiting MAPK mediated oxidative stress and apoptosis and inducing CD4⁺Foxp3⁺ Tregs to inhibit the inflammation induced by HS in mice.

Suppression of angiotensin converting enzyme 2, a host receptor for SARS-CoV-2 infection, using 5-aminolevulinic acid in vitro

Angiotensin converting enzyme 2 (ACE2), an entry receptor found on the surface of host cells, is believed to be detrimental to the infectious capability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Scientists have been working on finding a cure since its outbreak with limited success. In this study, we evaluated the potential of 5-aminolevulinic acid hydrochloride (ALA) in suppressing ACE2 expression of host cells. ACE2 expression and the production of intracellular porphyrins following ALA administration were carried out. We observed the reduction of ACE2 expression and intracellular porphyrins following ALA administration. ALA suppressed the ACE2 expression in host cells which might prevent binding of SARS-CoV-2 to host cells. Co-administration of ALA and sodium ferrous citrate (SFC) resulted in a further decrease in ACE2 expression and increase in intracellular heme level. This suggests that the suppression of ACE2 expression by ALA might occur through heme production. We found that the inhibition of heme oxygenase-1 (HO-1), which is involved in heme degradation, also resulted in decrease in ACE2 expression, suggesting a potential role of HO-1 in suppressing ACE2 as well. In conclusion, we speculate that ALA, together with SFC administration, might serve as a potential therapeutic approach in reducing SARS-CoV-2 infectivity through suppression of ACE2 expression.

Pilot Trial on the Effect of 5-Aminolevulinic Acid on Glucose Tolerance in Patients with Maternally Inherited Diabetes and Deafness

INTRODUCTION

The amino acid 5-aminolevulinic acid (5-ALA) is the first heme biosynthetic precursor. The combination of 5-ALA with sodium ferrous citrate (SFC) enhances heme production, leading to increased adenosine triphosphate (ATP) production in mitochondria. We investigated whether administering 5-ALA/SFC improves glucose tolerance with an increase in insulin secretion in patients with maternally inherited diabetes and deafness (MIDD), which is characterized by an insulin secretory disorder due to impaired mitochondrial ATP production.

METHODS

This was a single-arm, open-label, interventional study. We prospectively administered the oral glucose tolerance test (OGTT) twice in five patients with MIDD who had received intensive insulin therapy: before and 24 weeks after an administration of 5-ALA/SFC (200/232 mg per day). We measured the concentrations of glucose, insulin, C-peptide, and proinsulin at fasting, and 30, 60, and 120 min after glucose load in each OGTT. The primary endpoint was the changes in the area under the curve (AUC) of serum insulin from 0 to 120 min during OGTT from baseline to 24 weeks.

RESULTS

The serum insulin AUC (µU/mL) during the 120-min OGTT tended to increase from baseline to 24 weeks but not significantly (17.1 ± 13.7 versus 22.3 ± 13.4, p = 0.077). The plasma glucose AUC (mg/dL) during the 120-min OGTT at 24 weeks was not significantly decreased; the late phase of glucose excursion from 60 to 120 min was significantly decreased compared with baseline (357 ± 42 versus 391 ± 50, p = 0.041). The mean level of glycated hemoglobin (HbA1c) decreased from 8.3 ± 1.2% at baseline to 7.9 ± 0.3% at 24 weeks (p = 0.36) without increasing the daily dose of insulin injections.

CONCLUSION

The 24-week administration of 5-ALA/SFC did not demonstrate a significant improvement in insulin secretion in patients with MIDD. Further investigations with a larger number of patients and a placebo control group are required to clarify the potential efficacy of 5-ALA/SFC for ameliorating mitochondrial dysfunctions in MIDD.

TRIAL REGISTRATION

UMIN-CTR000040581 and jRCT071200025.

A Randomized Phase 2 Study of 5-Aminolevulinic Acid Hydrochloride and Sodium Ferrous Citrate for the Prevention of Nephrotoxicity Induced by Cisplatin-Based Chemotherapy of Lung Cancer

INTRODUCTION

Cisplatin-based chemotherapy was established in the 1980s, and it has been improved by the development of a short hydration protocol in lung cancer therapy. However, cisplatin-based chemotherapy is still associated with renal toxicity. Because 5-aminolevulinic acid (5-ALA) with sodium ferrous citrate (SFC) is known to be a mitochondrial activator and a heme oxygenase-1 (HO-1) inducer, 5-ALA with SFC is speculated to mitigate cisplatin-induced renal inflammation.

METHODS

We investigated the effects of oral administration of 5-ALA with SFC for preventing cisplatin-based nephrotoxicity in patients with lung cancer and evaluated its benefits for patients who received cisplatin-based chemotherapy. The primary endpoint was the significance of the difference between the serum creatinine (sCr) levels of the patients administered 5-ALA with SFC and those given placebo after course 1 of chemotherapy. The difference in the estimated glomerular filtration rate (eGFR) between the two groups was also evaluated as the secondary endpoint.

RESULTS

The double-blind, randomized two-arm studies were conducted at 15 medical facilities in Japan; 54 male and 20 female patients with lung cancer who received cisplatin-based chemotherapy between the ages of 42 and 75 years were included in the study. The compliance rate was greater than 94% in the primary assessment and subsequent drug administration periods. All enrolled patients completed the four cycles of cisplatin-based chemotherapy with short hydration. The average level of sCr on day 22 of course 1 was 0.707 mg/dL in the group treated with 5-ALA and SFC and 0.735 mg/dL in the placebo group, respectively, and the sCr in the test group was significantly lower than that in the placebo group (p = 0.038). In addition, the eGFR was significantly higher in the SPP-003 group than in the placebo group up to day 1 of course 3 (84.66 and 75.68 mL/min/1.73 m2, respectively, p = 0.02) and kept better even after the last administration of the study drug (82.37 and 73.49 mL/min/1.73 m2, respectively, p = 0.013).

CONCLUSIONS

The oral administration of 5-ALA with SFC is beneficial to patients undergoing cisplatin-based chemotherapy for lung cancer with short hydration.

5-aminolevulinic acid and sodium ferrous citrate decreased cell viability of gastric cancer cells by enhanced ROS generation through improving COX activity

BACKGROUND

Mitochondrial dysfunctions are related to cancer development.. 5-aminolevulinic acid (ALA) is used for photodynamic therapy (PDT). In this PDT, protoporphyrin IX (PpIX), which is converted from ALA, can generate reactive oxygen species (ROS) that kill the cancer cell. ALA is also reported to promote cytochrome c oxidase (COX) activity, which can generate ROS itself. Therefore, this study focused on the effect of ALA during PDT. In addition, in the previous study, sodium ferrous citrate (SFC) is reported to increase COX activity. So, this study also aims to improve the COX activity by the addition of SFC that can promote ROS generation, which has a cytotoxic effect.

METHODS

In this study, we used ALA and SFC, then evaluated the effects of the treatment on the human gastric cancer cell line MKN45, including the induction of cell death.

RESULTS

This study showed that treatment with ALA and SFC increases intracellular heme and heme proteins. Moreover, COX activity was promoted, resulting in the production of intracellular reactive oxygen species (ROS), which eventually reduced the cell viability in human gastric cancer cell line MKN45.

CONCLUSION

Our study can detect ROS generation with ALA and SFC. Furthermore, we found this generation of ROS has a cytotoxic effect. Therefore, this phenomenon contributes to the effect of PDT.

Impact of Levetiracetam Treatment on 5-Aminolevulinic Acid Fluorescence Expression in IDH1 Wild-Type Glioblastoma

Simple Summary

The amino acid 5-aminolevulinic acid (5-ALA) is the benchmark regarding intraoperative imaging tools for glioblastoma (GB) surgery, and is known to facilitate the extent of resection, which results in an enhanced 6 month progression-free survival rate. Recent in vitro studies suggest that antiepileptic drugs (AEDs) result in a reduction in the fluorescence quality in gliomas. To date, there is no large clinical series investigating this issue in a homogeneous cohort. Approximately 25% of all GB patients have a symptomatic epilepsy as the initial symptom at presentation. Hence, this potential dilemma is of paramount importance. We found that the preoperative intake of levetiracetam is a significant risk factor for reduced intraoperative fluorescence in IDH1 wild-type GBs. We believe that this issue must be considered in future external validations, and physicians must carefully evaluate the indication of levetiracetam and avoid a prophylactic levetiracetam treatment in terms of the suspected diagnosis of glioblastoma.

Abstract

The amino acid 5-aminolevulinic acid (5-ALA) is the most established neurosurgical fluorescent dye and facilitates the achievement of gross total resection. In vitro studies raised concerns that antiepileptic drugs (AED) reduce the quality of fluorescence. Between 2013 and 2018, 175 IDH1 wild-type glioblastoma (GB) patients underwent 5-ALA guided surgery. Patients’ data were retrospectively reviewed regarding demographics, comorbidities, medications, tumor morphology, neuropathological characteristics, and their association with intraoperative 5-ALA fluorescence. The fluorescence of 5-ALA was graded in a three point scaling system (grade 0 = no; grade 1 = weak; grade 2 = strong). Univariable analysis shows that the intake of dexamethasone or levetiracetam, and larger preoperative tumor area significantly reduce the intraoperative fluorescence activity (fluorescence grade: 0 + 1). Multivariable binary logistic regression analysis demonstrates the preoperative intake of levetiracetam (adjusted odds ratio: 12.05, 95% confidence interval: 3.91–37.16, p = 0.001) as the only independent and significant risk factor for reduced fluorescence quality. Preoperative levetiracetam intake significantly reduced intraoperative fluorescence. The indication for levetiracetam in suspected GB should be carefully reviewed and prophylactic treatment avoided for this tumor entity. Future comparative trials of neurosurgical fluorescent dyes need a special focus on the influence of levetiracetam on fluorescence intensity. Further trials must validate our findings.

Antiviral Effects of 5-Aminolevulinic Acid Phosphate against Classical Swine Fever Virus: In Vitro and In Vivo Evaluation

The inhibitory effects of 5-aminolevulinic acid phosphate (5-ALA), an important amino acid for energy production in the host, against viral infections were previously reported. Here, the antiviral effects of 5-ALA against classical swine fever virus (CSFV) belonging to the genus Pestivirus in the Flaviviridae family and its possible mechanisms were investigated. CSFV replication was suppressed in swine cells supplemented with 5-ALA or its metabolite, protoporphyrin IX (PPIX). The infectivity titer of CSFV was decreased after mixing with PPIX extracellularly. In addition, the activities of the replication cycle were decreased in the presence of PPIX based on the CSFV replicon assay. These results showed that PPIX exerted antiviral effects by inactivating virus particles and inhibiting the replication cycle. To evaluate the in vivo efficacy of 5-ALA, pigs were supplemented daily with 5-ALA for 1 week before virus inoculation and then inoculated with a virulent CSFV strain at the 10^7.0 50% tissue culture infectious dose. The clinical scores of the supplemented group were significantly lower than those of the nonsupplemented group, whereas the virus growth was not. Taken together, 5-ALA showed antiviral effects against CSFV in vitro, and PPIX played a key role by inactivating virus particles extracellularly and inhibiting the replication cycle intracellularly.

5-Aminolevulinic acid and sodium ferrous citrate ameliorate muscle aging and extend healthspan in Drosophila

Declines in mitochondrial functions are associated with aging. The combination of 5‐aminolevulinic acid (5‐ALA) and sodium ferrous citrate (SFC) improves mitochondrial functions in cultured cells. In this study, we investigated the effects of dietary supplementation with 5‐ALA and SFC (5‐ALA/SFC) on the healthspan and life span of Drosophila  melanogaster. Adult Drosophila fruit flies were fed cornmeal food containing various concentrations of 5‐ALA/SFC. Locomotor functions, life span, muscle architecture, and age‐associated changes in mitochondrial function were analyzed. We found that feeding 5‐ALA/SFC mitigated age‐associated declines in locomotor functions and extended organismal life span. Moreover, 5‐ALA/SFC preserved muscle architecture and maintained the mitochondrial membrane potential in aged animals. Since 5‐ALA phosphate/SFC is used as a human dietary supplement, our results suggest that it could be used to slow the age‐related declines in muscle functions, prevent age‐associated clinical conditions such as frailty, and extend healthspan and life span.

5-Aminolevulinic acid/sodium ferrous citrate enhanced the antitumor effects of programmed cell death-ligand 1 blockade by regulation of exhausted T cell metabolism in a melanoma model

Mitochondria are key cytoplasmic organelles. Their activation is critical for the generation of T cell proliferation and cytotoxicity. Exhausted tumor‐infiltrating T cells show a decreased mitochondrial function and mass. 5‐Aminolevulinic acid (5‐ALA), a natural amino acid that is only produced in the mitochondria, has been shown to influence metabolic functions. We hypothesized that 5‐ALA with sodium ferrous citrate (SFC) might provide metabolic support for tumor‐infiltrating T cells. In a mouse melanoma model, we found that 5‐ALA/SFC with a programmed cell death‐ligand 1 (PD‐L1) blocking Ab synergized tumor regression. After treatment with 5‐ALA/SFC and anti‐PD‐L1 Ab, tumor infiltrating lymphocytes (TILs) were not only competent for the production of cytolytic particles and cytokines (granzyme B, interleukin‐2, and γ‐interferon) but also showed enhanced Ki‐67 activity (a proliferation marker). The number of activated T cells (PD‐1⁺Tim‐3⁻) was also significantly increased. Furthermore, we found that 5‐ALA/SFC activated the mitochondrial functions, including the oxygen consumption rate, ATP level, and complex V expression. The mRNA levels of Nrf‐2, HO‐1, Sirt‐1, and PGC‐1α and the protein levels of Sirt‐1 were upregulated by treatment with 5‐ALA/SFC. Taken together, our findings revealed that 5‐ALA/SFC could be a key metabolic regulator in exhausted T cell metabolism and suggested that 5‐ALA/SFC might synergize with anti‐PD‐1/PD‐L1 therapy to boost the intratumoral efficacy of tumor‐specific T cells. Our study not only revealed a new aspect of immune metabolism, but also paved the way to develop a strategy for combined anti‐PD‐1/PD‐L1 cancer immunotherapy.

5-aminolevulinic acid improves chicken sperm motility

Objective

This study investigated the effects of 5-aminolevulinic acid (5-ALA) on the motility parameters, mitochondrial membrane depolarization, and ATP levels in chicken sperm.

Methods

The pooled semen from Barred Plymouth Rock males was used. In the first experiment, the semen was diluted 4-times with phosphate-buffered saline (PBS (-)) containing various concentrations (0, 0.01, 0.05, and 0.1 mM) of 5-ALA, and then the sperm motility parameters after incubation were evaluated by computer-assisted sperm analysis (CASA). In the second experiment, the semen was diluted 4-times with PBS (-) containing 0.05 mM 5-ALA, and then sperm mitochondrial membrane depolarization and ATP levels after 1.5 h of incubation were analyzed with the MitoPT® JC-1 Assay and ATP Assay kits, respectively. In the third experiment, the semen was removed from the seminal plasma and resuspended with the mediums of PBS (-), PBS (-) supplemented with CaCl2 and MgCl2 (PBS (+)) + 5-ALA, PBS (+) + caffeine, and PBS (+) + caffeine + 5-ALA. Then, the sperm motility parameters after incubation were evaluated by CASA. In the last experiment, the semen was treated with the mediums of PBS (-), PBS (-) + 5-ALA, 5.7% glucose, 5.7% glucose + 5-ALA after removing the seminal plasma, and then the sperm motility parameters were evaluated by CASA.

Results

The addition of 0.05 mM 5-ALA significantly increased the chicken sperm motility, progressive motility, linearity, average path velocity, curvilinear velocity, straight-line velocity, and the wobble. The sperm mitochondrial membrane depolarization was also increased by the 5-ALA treatment. The 5-ALA treatment decreased the sperm ATP levels. Both the caffeine treatment and glucose treatment decreased the sperm motility during incubation period.

Conclusion

5-ALA might increase sperm mitochondrial membrane depolarization to utilize the ATP for enhancing sperm movement.

A single-arm, open-label, intervention study to investigate the improvement of glucose tolerance after administration of the 5-aminolevulinic acid (5-ALA) in the patients with mitochondrial diabetes mellitus

BACKGROUND

Mitochondrial diabetes mellitus (MDM) is characterized by maternal inheritance, progressive neurosensory deafness, insulin secretory disorder, and progressive microvascular complications. Mitochondria are critical organelles that provide energy in the form of adenosine triphosphate (ATP). An impairment of ATP production in pancreatic β cells is regarded as the main cause of the insulin secretory disorder in patients with MDM, and these patients require insulin replacement therapy early after the diagnosis. The amino acid 5-aminolevulinic acid (5-ALA), a precursor of heme metabolites, is a non-proteinogenic δ amino acid synthesized in mitochondria. An addition of ferrous iron to 5-ALA enhances heme biosynthesis and increases ATP production through an upregulation of the respiratory complex. Several studies have reported that the administration of 5-ALA and ferrous iron to existing treatment improved the glycemic control in both patients with prediabetes and those with type 2 diabetes mellitus. The additional administration of 5-ALA and ferrous iron to MDM patients on insulin therapy may improve their insulin secretory capacity and glycemic control by improving their mitochondrial function. The findings of this study are expected to provide new treatment options for MDM and improve the patients' glycemic control and prognosis.

METHODS/DESIGN

This study is a single-arm, open-label pilot intervention study using clinical endpoints to investigate the effects of treatment with 5-ALA plus sodium ferrous citrate (SFC) to patients with MDM on their glucose tolerance. A total of 5 patients with MDM will be administered 5-ALA/SFC (200 mg/d) for 24 weeks. We will perform a 75-g oral glucose tolerance test before and at 24 weeks after the start of this 5-ALA/SFC treatment to evaluate glucose-dependent insulin responses.

DISCUSSION

To the best of our knowledge, this study will be the first assessment of the effects of 5-ALA/SFC in patients with MDM. This study will obtain an evidence regarding the effectiveness and safety of 5-ALA/SFC for patients with MDM.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Information Network (UMIN000040581) on July 1, 2020 and with the Japan Registry of Clinical Trials (jRCTs071200025) on August 3, 2020.

A case report of Leigh syndrome diagnosed by endomyocardial biopsy

BACKGROUND

Leigh syndrome is a neurodegenerative disorder caused by mitochondrial dysfunction with both phenotypic and genetic heterogeneity. Mitochondrial impairments are usually demonstrated by skeletal muscle biopsy. We report a case of Leigh syndrome diagnosed by endomyocardial biopsy (EMB), not by skeletal muscle biopsy.

CASE SUMMARY

At aged 7 months, the patient had delayed motor development. He developed metabolic acidosis triggered by an infection with elevated lactate and pyruvate values in serum and cerebrospinal fluid when he was 1 year old. T2-weighted imaging on magnetic resonance imaging of the brain revealed bilateral hyperintensity in midbrain and dorsal pons. Biopsied skeletal muscle did not show evidence of mitochondrial disease. Left ventricular hypertrophy, bilateral putamen hyperintensity in T2-weighted imaging and a lactate peak in the right basal ganglia in single voxel spectroscopy, and a convulsive seizure appeared at the age of 12, 15, and 16, respectively. When he was 17 years old, biopsied myocardium showed cytoplasmic vacuolization and a marked proliferation of mitochondria within myofibrils pathologically. Respiratory chain enzyme activity of the biopsied myocardium showed decreased activity of complex I. Genetic testing revealed an m.14453 A>G mutation on the MT-ND6 gene. He was finally diagnosed with Leigh syndrome. Administration of oral 5-aminolevulinic acid reduced the frequency of seizures.

DISCUSSION

EMB led to the diagnosis of Leigh syndrome. Efforts to find and conduct the biopsy of affected organs are important to diagnose mitochondrial disease. EMB is a useful diagnostic method when there is a difficulty in diagnosing mitochondrial disease by skeletal muscle biopsy.

Porphyric Neuropathy: Pathophysiology, Diagnosis, and Updated Management

PURPOSE OF REVIEW

To review the peripheral neurological complications of the acute hepatic porphyrias, as well as the latest advances in their pathophysiology and management.

RECENT FINDINGS

The diagnosis of porphyric neuropathy remains challenging as varying neuropathic patterns are encountered depending on disease stage, including a non-length-dependent distribution pattern. The major pathophysiologic mechanism is δ-aminolevulinic acid (ALA)-induced neurotoxicity. The less restrictive blood-nerve barrier in the autonomic ganglia and myenteric plexus may explain the frequency of dysautonomic manifestations. Recently, a prophylactic small interfering RNA (siRNA)-based therapy that reduces hepatic ALA Synthase-1 mRNA was approved for patients with recurrent neuro-visceral attacks. Neurologists should appreciate the varying patterns of porphyric neuropathy. As with most toxin-induced axonopathies, long-term outcomes depend on early diagnosis and treatment. While the short-term clinical and biochemical benefits of siRNA-based therapy are known, its long-term effects on motor recovery, chronic pain, and dysautonomic manifestations are yet to be determined.

A novel homozygous variant in MICOS13/QIL1 causes hepato-encephalopathy with mitochondrial DNA depletion syndrome

BACKGROUND

Mitochondrial DNA depletion syndrome (MTDPS) is part of a group of mitochondrial diseases characterized by a reduction in mitochondrial DNA copy number. Most MTDPS is caused by mutations in genes that disrupt deoxyribonucleotide metabolism.

METHODS

We performed the whole-exome sequencing of a hepato-encephalopathy patient with MTDPS and functional analyses to determine the clinical significance of the identified variant.

RESULTS

Here, whole-exome sequencing of a patient presenting with hepato-encephalopathy and MTDPS identified a novel homozygous frameshift variant, c.13_29del (p.Trp6Profs*71) in MICOS13. MICOS13 (also known as QIL1, MIC13, or C19orf70) is a component of the MICOS complex, which plays crucial roles in the maintenance of cristae junctions at the mitochondrial inner membrane. We found loss of MICOS13 protein and fewer cristae structures in the mitochondria of fibroblasts derived from the patient. Stable expression of a wild-type MICOS13 cDNA in the patients fibroblasts using a lentivirus system rescued mitochondrial respiratory chain complex deficiencies.

CONCLUSION

Our findings suggest that the novel c.13_29del (p.Trp6Profs*71) MICOS13 variant causes hepato-encephalopathy with MTDPS. We propose that MICOS13 is classified as the cause of MTDPS.